CAP1126
6 Channel Capacitive Touch Sensor with 2 LED Drivers
General Description
Features
®
The CAP1126, which incorporates RightTouch technology, is a multiple channel Capacitive Touch sensor
with multiple power LED drivers. It contains six (6) individual capacitive touch sensor inputs with programmable sensitivity for use in touch sensor applications.
Each sensor input automatically recalibrates to compensate for gradual environmental changes.
The CAP1126 also contains two (2) LED drivers that
offer full-on / off, variable rate blinking, dimness controls, and breathing. Each of the LED drivers may be
linked to one of the sensor inputs to be actuated when
a touch is detected. As well, each LED driver may be
individually controlled via a host controller.
The CAP1126 includes Multiple Pattern Touch recognition that allows the user to select a specific set of buttons to be touched simultaneously. If this pattern is
detected, then a status bit is set and an interrupt generated.
Additionally, the CAP1126 includes circuitry and support for enhanced sensor proximity detection.
The CAP1126 offers multiple power states operating at
low quiescent currents. In the Standby state of operation, one or more capacitive touch sensor inputs are
active and all LEDs may be used. If a touch is detected,
it will wake the system using the WAKE/SPI_MOSI pin.
Deep Sleep is the lowest power state available, drawing 5uA (typical) of current. In this state, no sensor
inputs are active. Driving the WAKE/SPI_MOSI pin or
communications will wake the device.
Applications
•
•
•
•
Desktop and Notebook PCs
LCD Monitors
Consumer Electronics
Appliances
2015 Microchip Technology Inc.
• Six (6) Capacitive Touch Sensor Inputs
- Programmable sensitivity
- Automatic recalibration
- Individual thresholds for each button
• Proximity Detection
• Multiple Button Pattern Detection
• Calibrates for Parasitic Capacitance
• Analog Filtering for System Noise Sources
• Press and Hold feature for Volume-like Applications
• Multiple Communication Interfaces
- SMBus / I2C compliant interface
- SPI communications
- Pin selectable communications protocol and
multiple slave addresses (SMBus / I2C only)
• Low Power Operation
- 5uA quiescent current in Deep Sleep
- 50uA quiescent current in Standby (1 sensor
input monitored)
- Samples one or more channels in Standby
• Two (2) LED Driver Outputs
- Open Drain or Push-Pull
- Programmable blink, breathe, and dimness
controls
- Can be linked to Capacitive Touch Sensor
inputs
• Dedicated Wake output flags touches in low
power state
• System RESET pin
• Available in 16-pin 4mm x 4mm RoHS compliant
QFN package
DS00001623B-page 1
CAP1126
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The last character of the literature number is the version number, (e.g., DS30000000A is version A of document DS30000000).
Errata
An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the
revision of silicon and revision of document to which it applies.
To determine if an errata sheet exists for a particular device, please check with one of the following:
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DS00001623B-page 2
2015 Microchip Technology Inc.
CAP1126
Table of Contents
1.0 Block Diagram ................................................................................................................................................................................. 4
2.0 Pin Description ................................................................................................................................................................................ 5
3.0 Electrical Specifications .................................................................................................................................................................. 9
4.0 Communications ........................................................................................................................................................................... 12
5.0 General Description ...................................................................................................................................................................... 23
6.0 Register Description ...................................................................................................................................................................... 29
7.0 Package Information ..................................................................................................................................................................... 67
Appendix A: Device Delta ................................................................................................................................................................... 72
Appendix B: Data Sheet Revision History ........................................................................................................................................... 74
The Microchip Web Site ...................................................................................................................................................................... 76
Customer Change Notification Service ............................................................................................................................................... 76
Customer Support ............................................................................................................................................................................... 76
Product Identification System ............................................................................................................................................................. 77
2015 Microchip Technology Inc.
DS00001623B-page 3
CAP1126
1.0
BLOCK DIAGRAM
LED1
LED2
RESET
VDD
GND
WAKE / SPI_MOSI
SPI_CS#
LED Driver, Breathe, and
Dimness control
SMBus /
BC-Link /
SPI Slave
Protocol
Capacitive Touch Sensing Algorithm
SMCLK BC_CLK /
SPI_CLK
SMDATA BC_DATA / SPI_MSIO /
SPI_MISO
ALERT# / BC_IRQ#
ADDR_COMM
CS1
DS00001623B-page 4
CS2
CS3
CS4
CS5
CS6
2015 Microchip Technology Inc.
CAP1126
PIN DESCRIPTION
TABLE 2-1:
SMCLK / BC_CLK /
SPI_CLK
4
VDD
CS1
CS2
CS3
15
14
13
8
3
ALERT# / BC_IRQ#
SMDATA / BC_DATA / SPI_MSIO /
SPI_MISO
CAP1126
16 pin QFN
7
2
RESET
WAKE / SPI_MOSI
6
1
LED2
SPI_CS#
16
CAP1126 Pin Diagram (16-Pin QFN)
5
FIGURE 2-1:
LED1
2.0
12
CS4
11
CS5
10
CS6
9
ADDR_COMM
GND
PIN DESCRIPTION FOR CAP1126
Pin
Number
Pin Name
Pin Function
Pin Type
Unused
Connection
1
SPI_CS#
Active low chip-select for SPI bus
DI (5V)
Connect to
Ground
WAKE - Active high wake / interrupt output
Standby power state - requires pull-down resistor
DO
2
Pull-down
Resistor
WAKE - Active high wake input - requires pull-down
resistor
Deep Sleep power state
DI
SPI_MOSI - SPI Master-Out-Slave-In port when used in
normal mode
DI (5V)
WAKE / SPI_MOSI
2015 Microchip Technology Inc.
Connect to
Ground
DS00001623B-page 5
CAP1126
TABLE 2-1:
Pin
Number
3
4
5
6
7
PIN DESCRIPTION FOR CAP1126 (CONTINUED)
Pin Name
SMDATA /
SPI_MSIO /
SPI_MISO
SMCLK / SPI_CLK
Pin Type
SMDATA - Bi-directional, open-drain SMBus data requires pull-up resistor
DIOD (5V)
SPI_MSIO - SPI Master-Slave-In-Out bidirectional port
when used in bi-directional mode
DIO
SPI_MISO - SPI Master-In-Slave-Out port when used in
normal mode
DO
SMCLK - SMBus clock input - requires pull-up resistor
DI (5V)
SPI_CLK - SPI clock input
DI (5V)
n/a
Open drain LED 1 driver (default)
OD (5V)
Connect to
Ground
Push-pull LED 1 driver
DO
leave open or
connect to
Ground
Open drain LED 2 driver (default)
OD (5V)
Connect to
Ground
Push-pull LED 2 driver
DO
leave open or
connect to
Ground
Active high soft reset for system - resets all registers to
default values. If not used, connect to ground.
DI (5V)
Connect to
Ground
ALERT# - Active low alert / interrupt output for SMBus
alert or SPI interrupt
OD (5V)
Connect to
Ground
ALERT# - Active high push-pull alert / interrupt output for
SMBus alert or SPI interrupt
DO
leave open
n/a
LED1
LED2
RESET
Unused
Connection
Pin Function
8
ALERT#
9
ADDR_COMM
Address / communications select pin - pull-down resistor
determines address / communications mechanism
AI
n/a
10
CS6
Capacitive Touch Sensor Input 6
AIO
Connect to
Ground
11
CS5
Capacitive Touch Sensor Input 5
AIO
Connect to
Ground
12
CS4
Capacitive Touch Sensor Input 4
AIO
Connect to
Ground
13
CS3
Capacitive Touch Sensor Input 3
AIO
Connect to
Ground
14
CS2
Capacitive Touch Sensor Input 2
AIO
Connect to
Ground
15
CS1
Capacitive Touch Sensor Input 1
AIO
Connect to
Ground
16
VDD
Positive Power supply
Power
n/a
DS00001623B-page 6
2015 Microchip Technology Inc.
CAP1126
TABLE 2-1:
PIN DESCRIPTION FOR CAP1126 (CONTINUED)
Pin
Number
Pin Name
Pin Function
Pin Type
Unused
Connection
Bottom
Pad
GND
Ground
Power
n/a
APPLICATION NOTE: When the ALERT# pinis configured as an active low output, it will be open drain. When it is
configured as an active high output, it will be push-pull.
APPLICATION NOTE: For the 5V tolerant pins that have a pull-up resistor, the pull-up voltage must not exceed 3.6V
when the CAP1126 is unpowered.
APPLICATION NOTE: The SPI_CS# pin should be grounded when SMBus, or I2C,communications are used.
The pin types are described in Table 2-2. All pins labeled with (5V) are 5V tolerant.
TABLE 2-2:
PIN TYPES
Pin Type
Power
DI
AIO
Description
This pin is used to supply power or ground to the device.
Digital Input - This pin is used as a digital input. This pin is 5V tolerant.
Analog Input / Output -This pin is used as an I/O for analog signals.
DIOD
Digital Input / Open Drain Output - This pin is used as a digital I/O. When it is used as an output, it is open drain and requires a pull-up resistor. This pin is 5V tolerant.
OD
Open Drain Digital Output - This pin is used as a digital output. It is open drain and requires a
pull-up resistor. This pin is 5V tolerant.
DO
Push-pull Digital Output - This pin is used as a digital output and can sink and source current.
DIO
Push-pull Digital Input / Output - This pin is used as an I/O for digital signals.
2015 Microchip Technology Inc.
DS00001623B-page 7
CAP1126
3.0
ELECTRICAL SPECIFICATIONS
TABLE 3-1:
ABSOLUTE MAXIMUM RATINGS
Voltage on 5V tolerant pins (V5VT_PIN)
-0.3 to 5.5
Voltage on 5V tolerant pins (|V5VT_PIN - VDD|) Note 3-2
0 to 3.6
V
V
Voltage on VDD pin
-0.3 to 4
V
Voltage on any other pin to GND
-0.3 to VDD + 0.3
V
Package Power Dissipation up to TA = 85°C for 16 pin QFN
(see Note 3-3)
0.9
W
Junction to Ambient (θJA) (see Note 3-4)
58
°C/W
Operating Ambient Temperature Range
-40 to 125
°C
Storage Temperature Range
-55 to 150
°C
ESD Rating, All Pins, HBM
8000
V
Note 3-1
Stresses above those listed could cause permanent damage to the device. This is a stress rating
only and functional operation of the device at any other condition above those indicated in the
operation sections of this specification is not implied.
Note 3-2
For the 5V tolerant pins that have a pull-up resistor, the voltage difference between V5VT_PIN and VDD
must never exceed 3.6V.
Note 3-3
The Package Power Dissipation specification assumes a recommended thermal via design consisting
of a 3x3 matrix of 0.3mm (12mil) vias at 1.0mm pitch connected to the ground plane with a 2.1mm
x 2.1mm thermal landing.
Note 3-4
Junction to Ambient (θJA) is dependent on the design of the thermal vias. Without thermal vias and
a thermal landing, the θJA is approximately 60°C/W including localized PCB temperature increase.
DS00001623B-page 8
2015 Microchip Technology Inc.
CAP1126
TABLE 3-2:
ELECTRICAL SPECIFICATIONS
VDD = 3V to 3.6V, TA = 0°C to 85°C, all typical values at TA = 27°C unless otherwise noted.
Characteristic
Symbol
Min
Typ
Max
Unit
Conditions
DC Power
Supply Voltage
VDD
3.0
ISTBY
3.3
120
3.6
V
170
50
ISTBY
uA
Standby state active
1 sensor input monitored
No LEDs active
Default conditions (8 avg, 70ms
cycle time)
uA
Standby state active
1 sensor input monitored
No LEDs active
1 avg, 140ms cycle time,
Supply Current
IDSLEEP
5
15
uA
Deep Sleep state active
LEDs at 100% or 0% Duty Cycle
No communications
TA < 40°C
3.135 < VDD < 3.465V
IDD
500
600
uA
Capacitive Sensing Active
No LEDs active
pF
Pad untouched
fF
Pad touched - default conditions (1
avg, 35ms cycle time, 1x sensitivity)
pF
Pad touched - Not tested
counts /
V
Untouched Current Counts
Base Capacitance 5pF - 50pF
Maximum sensitivity
Negative Delta Counts disabled
All other parameters default
Capacitive Touch Sensor Inputs
Maximum Base
Capacitance
CBASE
Minimum Detectable
Capacitive Shift
ΔCTOUCH
20
Recommended Cap
Shift
ΔCTOUCH
0.1
Power Supply Rejection
PSR
RESET Pin Delay
tRST_DLY
Time to communications ready
tCOMM_DLY
Time to first conversion ready
tCONV_DLY
Duty Cycle
DUTYLED
50
2
±3
±10
Timing
10
ms
170
15
ms
200
ms
LED Drivers
0
100
2
%
Programmable
Drive Frequency
fLED
Sinking Current
ISINK
24
kHz
mA
VOL = 0.4
Sourcing Current
ISOURCE
24
mA
VOH = VDD - 0.4
Leakage Current
ILEAK
±5
uA
powered or unpowered
TA < 85°C
pull-up voltage < 3.6V if unpowered
Output Low Voltage
VOL
0.4
V
ISINK_IO = 8mA
Output High Voltage
VOH
V
ISOURCE_IO = 8mA
I/O Pins
2015 Microchip Technology Inc.
VDD - 0.4
DS00001623B-page 9
CAP1126
TABLE 3-2:
ELECTRICAL SPECIFICATIONS (CONTINUED)
VDD = 3V to 3.6V, TA = 0°C to 85°C, all typical values at TA = 27°C unless otherwise noted.
Characteristic
Symbol
Min
Typ
Max
Unit
Input High Voltage
VIH
2.0
Input Low Voltage
VIL
0.8
V
Leakage Current
ILEAK
±5
uA
RESET Pin Release
to conversion ready
tRESET
200
ms
Conditions
V
170
powered or unpowered
TA < 85°C
pull-up voltage < 3.6V if unpowered
SMBus Timing
5
pF
Input Capacitance
CIN
Clock Frequency
fSMB
Spike Suppression
tSP
Bus Free Time Stop to
Start
tBUF
1.3
us
Start Setup Time
tSU:STA
0.6
us
Start Hold Time
tHD:STA
0.6
us
Stop Setup Time
tSU:STO
0.6
us
10
400
kHz
50
ns
Data Hold Time
tHD:DAT
0
us
When transmitting to the master
Data Hold Time
tHD:DAT
0.3
us
When receiving from the master
Data Setup Time
tSU:DAT
0.6
us
Clock Low Period
tLOW
1.3
us
0.6
Clock High Period
tHIGH
Clock / Data Fall Time
tFALL
300
ns
us
Min = 20+0.1CLOAD ns
Clock / Data Rise
Time
tRISE
300
ns
Min = 20+0.1CLOAD ns
Capacitive Load
CLOAD
400
pF
per bus line
SPI Timing
Clock Period
tP
250
Clock Low Period
tLOW
0.4 x tP
0.6 x tP
ns
Clock High Period
tHIGH
0.4 x tP
0.6 x tP
ns
Clock Rise / Fall time
tRISE / tFALL
0.1 x tP
ns
Data Output Delay
tD:CLK
10
ns
Data Setup Time
tSU:DAT
20
ns
ns
Data Hold Time
tHD:DAT
20
ns
SPI_CS# to SPI_CLK
setup time
tSU:CS
0
ns
Wake Time
tWAKE
10
20
us
SPI_CS# asserted to CLK assert
Note 3-5
The ALERT pin will not glitch high or low at power up if connected to VDD or another voltage.
Note 3-6
The SMCLK and SMDATA pins will not glitch low at power up if connected to VDD or another voltage.
DS00001623B-page 10
2015 Microchip Technology Inc.
CAP1126
4.0
COMMUNICATIONS
4.1
Communications
The CAP1126communicates using the 2-wire SMBus or I2C bus, the 2-wire proprietary BC-Link, or the SPI bus. If the
proprietary BC-Link protocol is required for your application, please contact your Microchip representative for ordering
instructions. Regardless of communication mechanism, the device functionality remains unchanged. The communications mechanism as well as the SMBus (or I2C) slave address is determined by the resistor connected between the
ADDR_COMM pin and ground as shown in Table 4-1.
TABLE 4-1:
4.1.1
ADDR_COMM PIN DECODE
Pull-Down Resistor (+/- 5%)
Protocol Used
SMBus Address
GND
SPI Communications using Normal
4-wire Protocol Used
n/a
56k
SPI Communications using BiDirectional 3-wire Protocol Used
n/a
68k
Reserved
n/a
I2 C
82k
SMBus /
100k
SMBus / I2C
0101_011(r/w)
120k
SMBus / I2C
0101_010(r/w)
150k
SMBus / I2C
0101_001(r/w)
VDD
SMBus / I2C
0101_000(r/w)
0101_100(r/w)
SMBUS (I2C) COMMUNICATIONS
When configured to communicate via the SMBus, the CAP1126 supports the following protocols: Send Byte, Receive
Byte, Read Byte, Write Byte, Read Block, and Write Block. In addition, the device supports I2C formatting for block read
and block write protocols.
APPLICATION NOTE: For SMBus/I2C communications, the SPI_CS# pin is not used and should be grounded; any
data presented to this pin will be ignored.
See Section 4.2 and Section 4.3 for more information on the SMBus bus and protocols respectively.
4.1.2
SPI COMMUNICATIONS
When configured to communicate via the SPI bus, the CAP1126supports both bi-directional 3-wire and normal 4-wire
protocols and uses the SPI_CS# pin to enable communications.
APPLICATION NOTE: See Section 4.5 and Section 4.6 for more information on the SPI bus and protocols
respectively.Upon power up, the CAP1126 will not respond to any communications for up to
15ms. After this time, full functionality is available.
4.2
System Management Bus
The CAP1126 communicates with a host controller, such as an SIO, through the SMBus. The SMBus is a two-wire serial
communication protocol between a computer host and its peripheral devices. A detailed timing diagram is shown in
Figure 4-1. Stretching of the SMCLK signal is supported; however, the CAP1126 will not stretch the clock signal.
2015 Microchip Technology Inc.
DS00001623B-page 11
CAP1126
FIGURE 4-1:
SMBus Timing Diagram
TLOW
THIGH
THD:STA
TSU:STO
TRISE
SMCLK
THD:STA
THD:DAT
TFALL
TSU:STA
TSU:DAT
SMDATA
TBUF
P
4.2.1
S
S - Start Condition
S
P - Stop Condition P
SMBUS START BIT
The SMBus Start bit is defined as a transition of the SMBus Data line from a logic ‘1’ state to a logic ‘0’ state while the
SMBus Clock line is in a logic ‘1’ state.
4.2.2
SMBUS ADDRESS AND RD / WR BIT
The SMBus Address Byte consists of the 7-bit slave address followed by the RD / WR indicator bit. If this RD / WR bit
is a logic ‘0’, then the SMBus Host is writing data to the slave device. If this RD / WR bit is a logic ‘1’, then the SMBus
Host is reading data from the slave device.
See Table 4-1 for available SMBus addresses.
4.2.3
SMBUS DATA BYTES
All SMBus Data bytes are sent most significant bit first and composed of 8-bits of information.
4.2.4
SMBUS ACK AND NACK BITS
The SMBus slave will acknowledge all data bytes that it receives. This is done by the slave device pulling the SMBus
Data line low after the 8th bit of each byte that is transmitted. This applies to both the Write Byte and Block Write protocols.
The Host will NACK (not acknowledge) the last data byte to be received from the slave by holding the SMBus data line
high after the 8th data bit has been sent. For the Block Read protocol, the Host will ACK each data byte that it receives
except the last data byte.
4.2.5
SMBUS STOP BIT
The SMBus Stop bit is defined as a transition of the SMBus Data line from a logic ‘0’ state to a logic ‘1’ state while the
SMBus clock line is in a logic ‘1’ state. When the CAP1126 detects an SMBus Stop bit and it has been communicating
with the SMBus protocol, it will reset its slave interface and prepare to receive further communications.
4.2.6
SMBUS TIMEOUT
The CAP1126 includes an SMBus timeout feature. Following a 30ms period of inactivity on the SMBus where the
SMCLK pin is held low, the device will timeout and reset the SMBus interface.
The timeout function defaults to disabled. It can be enabled by setting the TIMEOUT bit in the Configuration register
(see Section 6.6, "Configuration Registers").
4.2.7
SMBUS AND I2C COMPATIBILITY
The major differences between SMBus and I2C devices are highlighted here. For more information, refer to the SMBus
2.0 and I2C specifications. For information on using the CAP1126 in an I2C system, refer to AN 14.0 Dedicated Slave
Devices in I2C Systems.
DS00001623B-page 12
2015 Microchip Technology Inc.
CAP1126
CAP1126 supports I2C fast mode at 400kHz. This covers the SMBus max time of 100kHz.
Minimum frequency for SMBus communications is 10kHz.
The SMBus slave protocol will reset if the clock is held at a logic ‘0’ for longer than 30ms. This timeout functionality is disabled by default in the CAP1126 and can be enabled by writing to the TIMEOUT bit. I2C does not have
a timeout.
The SMBus slave protocol will reset if both the clock and data lines are held at a logic ‘1’ for longer than 200µs
(idle condition). This function is disabled by default in the CAP1126 and can be enabled by writing to the TIMEOUT bit. I2C does not have an idle condition.
I2C devices do not support the Alert Response Address functionality (which is optional for SMBus).
I2C devices support block read and write differently. I2C protocol allows for unlimited number of bytes to be sent
in either direction. The SMBus protocol requires that an additional data byte indicating number of bytes to read /
write is transmitted. The CAP1126 supports I2C formatting only.
1.
2.
3.
4.
5.
6.
4.3
SMBus Protocols
The CAP1126 is SMBus 2.0 compatible and supports Write Byte, Read Byte, Send Byte, and Receive Byte as valid
protocols as shown below.
All of the below protocols use the convention in Table 4-2.
TABLE 4-2:
PROTOCOL FORMAT
Data Sent to
Device
Data sent
4.3.1
Data Sent to the
HOst
Data sent
SMBUS WRITE BYTE
The Write Byte is used to write one byte of data to a specific register as shown in Table 4-3.
TABLE 4-3:
WRITE BYTE PROTOCOL
Start
Slave
Address
WR
ACK
Register
Address
ACK
Register Data
ACK
Stop
1 ->0
YYYY_YYY
0
0
XXh
0
XXh
0
0 -> 1
4.3.2
SMBUS READ BYTE
The Read Byte protocol is used to read one byte of data from the registers as shown in Table 4-4.
TABLE 4-4:
READ BYTE PROTOCOL
Start
Slave
Address
WR
ACK
Register
Address
ACK
Start
Slave
Address
RD
ACK
Register
Data
NACK
Stop
1->0
YYYY_YYY
0
0
XXh
0
1 ->0
YYYY_YYY
1
0
XXh
1
0 -> 1
4.3.3
SMBUS SEND BYTE
The Send Byte protocol is used to set the internal address register pointer to the correct address location. No data is
transferred during the Send Byte protocol as shown in Table 4-5.
APPLICATION NOTE: The Send Byte protocol is not functional in Deep Sleep (i.e., DSLEEP bit is set).
TABLE 4-5:
SEND BYTE PROTOCOL
Start
Slave Address
WR
ACK
Register Address
ACK
Stop
1 -> 0
YYYY_YYY
0
0
XXh
0
0 -> 1
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DS00001623B-page 13
CAP1126
4.3.4
SMBUS RECEIVE BYTE
The Receive Byte protocol is used to read data from a register when the internal register address pointer is known to
be at the right location (e.g., set via Send Byte). This is used for consecutive reads of the same register as shown in
Table 4-6.
APPLICATION NOTE: The Receive Byte protocol is not functional in Deep Sleep (i.e., DSLEEP bit is set).
TABLE 4-6:
RECEIVE BYTE PROTOCOL
Start
Slave Address
RD
ACK
Register Data
NACK
Stop
1 -> 0
YYYY_YYY
1
0
XXh
1
0 -> 1
I2C Protocols
4.4
The CAP1126 supports I2C Block Write and Block Read.
The protocols listed below use the convention in Table 4-2.
4.4.1
BLOCK WRITE
The Block Write is used to write multiple data bytes to a group of contiguous registers as shown in Table 4-7.
APPLICATION NOTE: When using the Block Write protocol, the internal address pointer will be automatically
incremented after every data byte is received. It will wrap from FFh to 00h.
TABLE 4-7:
BLOCK WRITE PROTOCOL
Start
Slave
Address
WR
ACK
Register
Address
ACK
Register Data
ACK
1 ->0
YYYY_YYY
0
0
XXh
0
XXh
0
Register Data
ACK
Register
Data
ACK
...
Register
Data
ACK
Stop
XXh
0
XXh
0
...
XXh
0
0 -> 1
4.4.2
BLOCK READ
The Block Read is used to read multiple data bytes from a group of contiguous registers as shown in Table 4-8.
APPLICATION NOTE: When using the Block Read protocol, the internal address pointer will be automatically
incremented after every data byte is received. It will wrap from FFh to 00h.
TABLE 4-8:
BLOCK READ PROTOCOL
Start
Slave
Address
WR
ACK
Register
Address
ACK
Start
Slave
Address
RD
ACK
Register
Data
1->0
YYYY_YYY
0
0
XXh
0
1 ->0
YYYY_YYY
1
0
XXh
ACK
Register
Data
ACK
Register
Data
ACK
Register
Data
ACK
...
Register
Data
NACK
Stop
0
XXh
0
XXh
0
XXh
0
...
XXh
1
0 -> 1
4.5
SPI Interface
The SMBus has a predefined packet structure, the SPI does not. The SPI Bus can operate in two modes of operation,
normal 4-wire mode and bi-directional 3-wire mode. All SPI commands consist of 8-bit packets sent to a specific slave
device (identified by the CS pin).
The SPI bus will latch data on the rising edge of the clock and the clock and data both idle high.
All commands are supported via both operating modes. The supported commands are: Reset Serial interface, set
address pointer, write command and read command. Note that all other codes received during the command phase are
ignored and have no effect on the operation of the device.
DS00001623B-page 14
2015 Microchip Technology Inc.
CAP1126
FIGURE 4-2:
SPI Timing
tP
tHIGH
tLOW
SPI_CLK
tFALL
tRISE
tSU:DAT
SPI_MSIO or
SPI_MOSI or
SPI_MISO
4.5.1
tD:CLK
tHD:DAT
SPI NORMAL MODE
The SPI Bus can operate in two modes of operation, normal and bi-directional mode. In the normal mode of operation,
there are dedicated input and output data lines. The host communicates by sending a command along the CAP1126
SPI_MOSI data line and reading data on the SPI_MISO data line. Both communications occur simultaneously which
allows for larger throughput of data transactions.
All basic transfers consist of two 8 bit transactions from the Master device while the slave device is simultaneously sending data at the current address pointer value.
Data writes consist of two or more 8-bit transactions. The host sends a specific write command followed by the data to
write the address pointer. Data reads consist of one or more 8-bit transactions. The host sends the specific read data
command and continues clocking for as many data bytes as it wishes to receive.
4.5.2
SPI BI-DIRECTIONAL MODE
In the bi-directional mode of operation, the SPI data signals are combined into the SPI_MSIO line, which is shared for
data received by the device and transmitted by the device. The protocol uses a simple handshake and turn around
sequence for data communications based on the number of clocks transmitted during each phase.
All basic transfers consist of two 8 bit transactions. The first is an 8 bit command phase driven by the Master device.
The second is by an 8 bit data phase driven by the Master for writes, and by the CAP1126 for read operations.
The auto increment feature of the address pointer allows for successive reads or writes. The address pointer will return
to 00h after reaching FFh.
4.5.3
SPI_CS# PIN
The SPI Bus is a single master, multiple slave serial bus. Each slave has a dedicated CS pin (chip select) that the master
asserts low to identify that the slave is being addressed. There are no formal addressing options.
4.5.4
ADDRESS POINTER
All data writes and reads are accessed from the current address pointer. In both Bi-directional mode and Full Duplex
mode, the Address pointer is automatically incremented following every read command or every write command.
The address pointer will return to 00h after reaching FFh.
4.5.5
SPI TIMEOUT
The CAP1126 does not detect any timeout conditions on the SPI bus.
2015 Microchip Technology Inc.
DS00001623B-page 15
Normal SPI Protocols
When operating in normal mode, the SPI bus internal address pointer is incremented depending upon which command has been transmitted. Multiple commands may
be transmitted sequentually so long as the SPI_CS# pin is asserted low. Figure 4-3 shows an example of this operation.
FIGURE 4-3:
Example SPI Bus Communication - Normal Mode
SPI_CS#
SPI_MOSI
7Ah
7Ah
7Dh
41h
7Eh
66h
7Dh
41h
7Fh
7Fh
7Fh
7Fh
7Fh
7Fh
7Dh
40h
7Fh
7Fh
SPI_MISO
XXh
(invalid)
XXh
(invalid)
YYh
(invalid)
YYh
(invalid)
XXh
(invalid)
45h
AAh
(invalid)
AAh
(invalid)
55h
(invalid)
66h
AAh
AAh
55h
80h
43h
78h
XXh
(invalid)
56h
SPI Address Pointer
SPI Data output buffer
Register Address /
Data
41h
45h
00h
XXh
40h / 56h
41h / 45h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
46h / 78h
42h
AAh
41h
55h
41h
66h
42h
AAh
43h
55h
44h
80h
45h
43h
46h
78h
40h
80h
40h
56h
40h / 56h
41h / 45h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
46h / 78h
46h / 78h
46h / 78h
46h / 78h
46h / 78h
46h /78h
46h /78h
46h / 78h
46h /78h
Indicates SPI Address pointer incremented
4.6.1
RESET INTERFACE
Resets the Serial interface whenever two successive 7Ah codes are received. Regardless of the current phase of the transaction - command or data, the receipt of the
successive reset commands resets the Serial communication interface only. All other functions are not affected by the reset operation.
CAP1126
2015 Microchip Technology Inc.
4.6
DS00001623B-page 16
CAP1126
FIGURE 4-4:
SPI Reset Interface Command - Normal Mode
SPI_CS#
SPI_CLK
Master SPDOUT
SPI_MOSI
‘0’
‘1’
‘1’
‘1’
‘1’
‘0’
‘1’
‘0’
‘0’
Reset - 7Ah
‘1’
‘1’
‘1’
‘0’
‘1’
‘0’
Reset - 7Ah
Invalid register data
SPI_MISO
00h – Internal Data buffer empty
Master Drives
4.6.2
‘1’
Slave Drives
SET ADDRESS POINTER
The Set Address Pointer command sets the Address pointer for subsequent reads and writes of data. The pointer is set
on the rising edge of the final data bit. At the same time, the data that is to be read is fetched and loaded into the internal
output buffer but is not transmitted.
FIGURE 4-5:
SPI Set Address Pointer Command - Normal Mode
SPI_CS#
SPI_CLK
Master SPDOUT
SPI_MOSI
‘0’
‘1’
‘1’
‘1’
‘1’
‘1’
‘0’
Register Address
‘1’
Set Address Pointer – 7Dh
SPI_MISO
Master Drives
4.6.3
Unknown, Invalid Data
Unknown, Invalid Data
Slave Drives
Address pointer set
WRITE DATA
The Write Data protocol updates the contents of the register referenced by the address pointer. As the command is processed, the data to be read is fetched and loaded into the internal output buffer but not transmitted. Then, the register
is updated with the data to be written. Finally, the address pointer is incremented.
2015 Microchip Technology Inc.
DS00001623B-page 17
CAP1126
FIGURE 4-6:
SPI Write Command - Normal Mode
SPI_CS#
SPI_CLK
Master SPDOUT
SPI_MOSI
Write Command – 7Eh
SPI_MISO
Unknown, Invalid Data
Data to Write
Old Data at Current Address Pointer
Master Drives
Slave Drives
1. Data written at current
address pointer
2. Address pointer incremented
4.6.4
READ DATA
The Read Data protocol is used to read data from the device. During the normal mode of operation, while the device is
receiving data, the CAP1126 is simultaneously transmitting data to the host. For the Set Address commands and the
Write Data commands, this data may be invalid and it is recommended that the Read Data command is used.
FIGURE 4-7:
SPI Read Command - Normal Mode
SPI_CS#
SPI_CLK
Master SPDOUT
SPI_MOSI
‘0’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
First Read Command – 7Fh
SPI_MISO
Invalid, Unknown Data *
Master Drives
‘1’
‘0’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
Subsequent Read
Commands – 7F
Data at Current Address Pointer
Address Pointer
Incremented **
Slave Drives
* The first read command after any other command will return invalid data for the first
byte. Subsequent read commands will return the data at the Current Address Pointer
** The Address Pointer is incremented 8 clocks after the Read Command has been
received. Therefore continually sending Read Commands will result in each command
reporting new data. Once Read Commands have been finished, the last data byte will be
read during the next 8 clocks for any command
DS00001623B-page 18
2015 Microchip Technology Inc.
CAP1126
FIGURE 4-8:
SPI Read Command - Normal Mode - Full
1. Register Read Address
updated to Current SPI Read
Address pointer.
2. Register Read Address
incremented = current address
pointer +1 – end result =
register address pointer doesn’t
change
1. Register Read Address
incremented = current address
pointer + 1
1. Register Read Address
updated to Current SPI Read
Address pointer
SPI_CS#
SPI_MISO
‘0’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
‘0’
XXh
Read Command – 7Fh
Master SPDOUT
SPI_MOSI
Data at previously set register address = current
SPI_CLK
address pointer
Data at previously set register address = current
address pointer (SPI)
Master Drives
1. Output buffer transmitted =
data at previous address
1. Register data loaded into
pointer + 1 = current address
output buffer = data at current
pointer
address pointer
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
Data at previously set register address = current
address pointer (SPI)
Slave Drives
Register Data loaded into
1. Register data loaded into
Output buffer = data at current
output buffer = data at current
address pointer + 1
address pointer
1. SPI Read Address
Incremented = new current
1. Output buffer transmitted =
address pointer
data at current address pointer
2. Register Read Address
+1
Incremented = current address 1. Output buffer transmitted =
2. Flag set to increment SPI
data at previous register
pointer +1
Read Address at end of next 8
address pointer + 1 = current
clocks
address pointer
1. Output buffer transmitted =
data at current address pointer
+1
2. Flag set to increment SPI
Read Address at end of next 8
clocks
4.7
‘1’
Subsequent Read Commands – 7Fh
Bi-Directional SPI Protocols
4.7.1
RESET INTERFACE
Resets the Serial interface whenever two successive 7Ah codes are received. Regardless of the current phase of the
transaction - command or data, the receipt of the successive reset commands resets the Serial communication interface
only. All other functions are not affected by the reset operation.
FIGURE 4-9:
SPI Reset Interface Command - Bi-directional Mode
SPI_CS#
SPI_CLK
Master SPDOUT
SPI_MSIO
‘0’
‘1’
‘1’
‘1’
‘1’
‘0’
Reset - 7Ah
4.7.2
‘1’
‘0’
‘0’
‘1’
‘1’
‘1’
‘1’
‘0’
‘1’
‘0’
Reset - 7Ah
SET ADDRESS POINTER
Sets the address pointer to the register to be accessed by a read or write command. This command overrides the autoincrementing of the address pointer.
2015 Microchip Technology Inc.
DS00001623B-page 19
CAP1126
FIGURE 4-10:
SPI Set Address Pointer Command - Bi-directional Mode
SPI_CS#
SPI_CLK
Master SPDOUT
SPI_MSIO
‘0’
‘1’
‘1’
‘1’
‘1’
‘1’
‘0’
Register Address
‘1’
Set Address Pointer – 7Dh
4.7.3
WRITE DATA
Writes data value to the register address stored in the address pointer. Performs auto increment of address pointer after
the data is loaded into the register.
FIGURE 4-11:
SPI Write Data Command - Bi-directional Mode
SPI_CS#
SPI_CLK
Master SPDOUT
SPI_MSIO
‘0’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
‘0’
Register Write Data
Write Command – 7Eh
4.7.4
READ DATA
Reads data referenced by the address pointer. Performs auto increment of address pointer after the data is transferred
to the Master.
FIGURE 4-12:
SPI Read Data Command - Bi-directional Mode
SPI_CS#
SPI_CLK
Master SPDOUT
SPI_MSIO
‘0’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
Register Read Data
‘1’
Read Command – 7Fh
Master Drives
DS00001623B-page 20
Slave Drives
Indeterminate
2015 Microchip Technology Inc.
CAP1126
4.8
BC-Link Interface
The BC-Link is a proprietary bus developed to allow communication between a host controller device to a companion
device. This device uses this serial bus to read and write registers and for interrupt processing. The interface uses a
data port concept, where the base interface has an address register, data register and a control register, defined in the
8051’s SFR space.
Refer to documentation for the BC-Link compatible host controller for details on how to access the CAP1126 via the BCLink Interface.
2015 Microchip Technology Inc.
DS00001623B-page 21
CAP1126
5.0
GENERAL DESCRIPTION
The CAP1126 is a multiple channel Capacitive Touch sensor with multiple power LED drivers. It contains six (6) individual capacitive touch sensor inputs with programmable sensitivity for use in touch sensor applications. Each sensor input
automatically recalibrates to compensate for gradual environmental changes.
The CAP1126 also contains two (2) low side (or push-pull) LED drivers that offer full-on / off, variable rate blinking, dimness controls, and breathing. Each of the LED drivers may be linked to one of the sensor inputs to be actuated when a
touch is detected. As well, each LED driver may be individually controlled via a host controller.
Finally, the device contains a dedicated RESET pin to act as a soft reset by the system.
The CAP1126 offers multiple power states. It operates at the lowest quiescent current during its Deep Sleep state. In
the low power Standby state, it can monitor one or more channels and respond to communications normally. The device
contains a wake pin (WAKE/SPI_MOSI) output to wake the system when a touch is detected in Standby and to wake
the device from Deep Sleep.
The device communicates with a host controller using the SPI bus, or via SMBus / I2C. The host controller may poll the
device for updated information at any time or it may configure the device to flag an interrupt whenever a touch is
detected on any sensor pad.
A typical system diagram is shown in Figure 5-1.
DS00001623B-page 22
2015 Microchip Technology Inc.
CAP1126
System Diagram for CAP1126
SPI_CS#
RESET
WAKE / SPI_MOSI
SMCLK / BC_CLK / SPI_CLK
3.3V – 5V
ALERT# / BC_IRQ#
Embedded Controller
VDD
SMDATA / BC_DATA / SPI_MSIO / SPI_MISO
FIGURE 5-1:
ADDR_COMM
3.3V – 5V
CAP1126
5.1
LED1
LED2
Touch
Button
CS1
CS2
Touch
Button
Touch
Button
CS3
CS4
Touch
Button
Touch
Button
CS5
CS6
Touch
Button
Power States
The CAP1126 has three operating states depending on the status of the STBY and DSLEEP bits. When the device transitions between power states, previously detected touches (for inactive channels) are cleared and the status bits reset.
1.
2.
Fully Active - The device is fully active. It is monitoring all active capacitive sensor inputs and driving all LED channels as defined.
Standby - The device is in a lower power state. It will measure a programmable number of channels using the
Standby Configuration controls (see Section 6.20 through Section 6.22). Interrupts will still be generated based
on the active channels. The device will still respond to communications normally and can be returned to the Fully
Active state of operation by clearing the STBY bit.
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DS00001623B-page 23
CAP1126
3.
Deep Sleep - The device is in its lowest power state. It is not monitoring any capacitive sensor inputs and not
driving any LEDs. All LEDs will be driven to their programmed non-actuated state and no PWM operations will
be done. While in Deep Sleep, the device can be awakened by SMBus or SPI communications targeting the
device. This will not cause the DSLEEP to be cleared so the device will return to Deep Sleep once all communications have stopped.
If the device is not communicating via the 4-wire SPI bus, then during this state of operation, if the WAKE/SPI_MOSI
pin is driven high by an external source, the device will clear the DSLEEP bit and return to Fully Active.
APPLICATION NOTE: In the Deep Sleep state, the LED output will be either high or low and will not be PWM’d at
the min or max duty cycle.
5.2
RESET Pin
The RESET pin is an active high reset that is driven from an external source. While it is asserted high, all the internal
blocks will be held in reset including the communications protocol used. No capacitive touch sensor inputs will be sampled and the LEDs will not be driven. All configuration settings will be reset to default states and all readings will be
cleared.
The device will be held in Deep Sleep that can only be removed by driving the RESET pin low. This will cause the
RESET status bit to be set to a logic ‘1’ and generate an interrupt.
5.3
WAKE/SPI_MOSI Pin Operation
The WAKE / SPI_MOSI pin is a multi-function pin depending on device operation. When the device is configured to communicate using the 4-wire SPI bus, this pin is an input.
However, when the CAP1126 is placed in Standby and is not communicating using the 4-wire SPI protocol, the WAKE
pin is an active high output. In this condition, the device will assert the WAKE/SPI_MOSI pin when a touch is detected
on one of its sampled sensor inputs. The pin will remain asserted until the INT bit has been cleared and then it will be
de-asserted.
When the CAP1126 is placed in Deep Sleep and it is not communicating using the 4-wire SPI protocol, the WAKE/SPI_MOSI pin is monitored by the device as an input. If the WAKE/SPI_MOSI pin is driven high by an external source, the
CAP1126will clear the DSLEEP bit causing the device to return to Fully Active.
When the device is placed in Deep Sleep, this pin is a High-Z input and must have a pull-down resistor to GND for proper
operation.
5.4
LED Drivers
The CAP1126 contains two (2) LED drivers. Each LED driver can be linked to its respective capacitive touch sensor
input or it can be controlled by the host. Each LED driver can be configured to operate in one of the following modes
with either push-pull or open drain drive.
1.
2.
3.
4.
Direct - The LED is configured to be on or off when the corresponding input stimulus is on or off (or inverted). The
brightness of the LED can be programmed from full off to full on (default). Additionally, the LED contains controls
to individually configure ramping on, off, and turn-off delay.
Pulse 1 - The LED is configured to “Pulse” (transition ON-OFF-ON) a programmable number of times with programmable rate and min / max brightness. This behavior may be actuated when a press is detected or when a
release is detected.
Pulse 2 - The LED is configured to “Pulse” while actuated and then “Pulse” a programmable number of times with
programmable rate and min / max brightness when the sensor pad is released.
Breathe - The LED is configured to transition continuously ON-OFF-ON (i.e. to “Breathe”) with a programmable
rate and min / max brightness.
When an LED is not linked to a sensor and is actuated by the host, there’s an option to assert the ALERT# pin when
the initiated LED behavior has completed.
5.4.1
LINKING LEDS TO CAPACITIVE TOUCH SENSOR INPUTS
All LEDs can be linked to the corresponding capacitive touch sensor input so that when the sensor input detects a touch,
the corresponding LED will be actuated at one of the programmed responses.
DS00001623B-page 24
2015 Microchip Technology Inc.
CAP1126
5.5
Capacitive Touch Sensing
The CAP1126 contains six (6) independent capacitive touch sensor inputs. Each sensor input has dynamic range to
detect a change of capacitance due to a touch. Additionally, each sensor input can be configured to be automatically
and routinely re-calibrated.
5.5.1
SENSING CYCLE
Each capacitive touch sensor input has controls to be activated and included in the sensing cycle. When the device is
active, it automatically initiates a sensing cycle and repeats the cycle every time it finishes. The cycle polls through each
active sensor input starting with CS1 and extending through CS6. As each capacitive touch sensor input is polled, its
measurement is compared against a baseline “Not Touched” measurement. If the delta measurement is large enough,
a touch is detected and an interrupt is generated.
The sensing cycle time is programmable (see Section 6.10, "Averaging and Sampling Configuration Register").
5.5.2
RECALIBRATING SENSOR INPUTS
There are various options for recalibrating the capacitive touch sensor inputs. Recalibration re-sets the Base Count Registers (Section 6.24, "Sensor Input Base Count Registers") which contain the “not touched” values used for touch detection comparisons.
APPLICATION NOTE: The device will recalibrate all sensor inputs that were disabled when it transitions from
Standby. Likewise, the device will recalibrate all sensor inputs when waking out of Deep
Sleep.
5.5.2.1
Manual Recalibration
The Calibration Activate Registers (Section 6.11, "Calibration Activate Register") force recalibration of selected sensor
inputs. When a bit is set, the corresponding capacitive touch sensor input will be recalibrated (both analog and digital).
The bit is automatically cleared once the recalibration routine has finished.
Note:
5.5.2.2
During this recalibration routine, the sensor inputs will not detect a press for up to 200ms and the Sensor
Base Count Register values will be invalid. In addition, any press on the corresponding sensor pads will
invalidate the recalibration.
Automatic Recalibration
Each sensor input is regularly recalibrated at a programmable rate (see Section 6.17, "Recalibration Configuration Register"). By default, the recalibration routine stores the average 64 previous measurements and periodically updates the
base “not touched” setting for the capacitive touch sensor input.
Note:
5.5.2.3
Automatic recalibration only works when the delta count is below the active sensor input threshold. It is disabled when a touch is detected.
Negative Delta Count Recalibration
It is possible that the device loses sensitivity to a touch. This may happen as a result of a noisy environment, an accidental recalibration during a touch, or other environmental changes. When this occurs, the base untouched sensor input
may generate negative delta count values. The NEG_DELTA_CNT bits (see Section 6.17, "Recalibration Configuration
Register") can be set to force a recalibration after a specified number of consecutive negative delta readings.
Note:
5.5.2.4
During this recalibration, the device will not respond to touches.
Delayed Recalibration
It is possible that a “stuck button” occurs when something is placed on a button which causes a touch to be detected
for a long period. By setting the MAX_DUR_EN bit (see Section 6.6, "Configuration Registers"), a recalibration can be
forced when a touch is held on a button for longer than the duration specified in the MAX_DUR bits (see Section 6.8,
"Sensor Input Configuration Register").
2015 Microchip Technology Inc.
DS00001623B-page 25
CAP1126
Note:
5.5.3
Delayed recalibration only works when the delta count is above the active sensor input threshold. If
enabled, it is invoked when a sensor pad touch is held longer than the MAX_DUR bit setting.
PROXIMITY DETECTION
Each sensor input can be configured to detect changes in capacitance due to proximity of a touch. This circuitry detects
the change of capacitance that is generated as an object approaches, but does not physically touch, the enabled sensor
pad(s). When a sensor input is selected to perform proximity detection, it will be sampled from 1x to 128x per sampling
cycle. The larger the number of samples that are taken, the greater the range of proximity detection is available at the
cost of an increased overall sampling time.
5.5.4
MULTIPLE TOUCH PATTERN DETECTION
The multiple touch pattern (MTP) detection circuitry can be used to detect lid closure or other similar events. An event
can be flagged based on either a minimum number of sensor inputs or on specific sensor inputs simultaneously exceeding an MTP threshold or having their Noise Flag Status Register bits set. An interrupt can also be generated. During an
MTP event, all touches are blocked (see Section 6.15, "Multiple Touch Pattern Configuration Register").
5.5.5
LOW FREQUENCY NOISE DETECTION
Each sensor input has an EMI noise detector that will sense if low frequency noise is injected onto the input with sufficient power to corrupt the readings. If this occurs, the device will reject the corrupted sample and set the corresponding
bit in the Noise Status register to a logic ‘1’.
5.5.6
RF NOISE DETECTION
Each sensor input contains an integrated RF noise detector. This block will detect injected RF noise on the CS pin. The
detector threshold is dependent upon the noise frequency. If RF noise is detected on a CS line, that sample is removed
and not compared against the threshold.
5.6
ALERT# Pin
The ALERT# pin is an active low (or active high when configured) output that is driven when an interrupt event is
detected.
Whenever an interrupt is generated, the INT bit (see Section 6.1, "Main Control Register") is set. The ALERT# pin is
cleared when the INT bit is cleared by the user. Additionally, when the INT bit is cleared by the user, status bits are only
cleared if no touch is detected.
5.6.1
SENSOR INTERRUPT BEHAVIOR
The sensor interrupts are generated in one of two ways:
1.
2.
An interrupt is generated when a touch is detected and, as a user selectable option, when a release is detected
(by default - see Section 6.6). See Figure 5-3.
If the repeat rate is enabled then, so long as the touch is held, another interrupt will be generated based on the
programmed repeat rate (see Figure 5-2).
When the repeat rate is enabled, the device uses an additional control called MPRESS that determines whether a touch
is flagged as a simple “touch” or a “press and hold”. The MPRESS[3:0] bits set a minimum press timer. When the button
is touched, the timer begins. If the sensor pad is released before the minimum press timer expires, it is flagged as a
touch and an interrupt is generated upon release. If the sensor input detects a touch for longer than this timer value, it
is flagged as a “press and hold” event. So long as the touch is held, interrupts will be generated at the programmed
repeat rate and upon release (if enabled).
APPLICATION NOTE: Figure 5-2 and Figure 5-3 show default operation which is to generate an interrupt upon
sensor pad release and an active-low ALERT# pin.
APPLICATION NOTE: The host may need to poll the device twice to determine that a release has been detected.
DS00001623B-page 26
2015 Microchip Technology Inc.
CAP1126
FIGURE 5-2:
Interrupt on
Touch
Sensor Interrupt Behavior - Repeat Rate Enabled
Polling Cycle
(35ms)
Min Press Setting
(280ms)
Touch Detected
Button Repeat Rate
(175ms)
Interrupt on
Release
(optional)
Button Repeat Rate
(175ms)
INT bit
ALERT# pin
(active low)
Button Status
Write to INT bit
FIGURE 5-3:
Interrupt on
Touch
Sensor Interrupt Behavior - No Repeat Rate Enabled
Polling Cycle
(35ms)
Touch Detected
Interrupt on
Release
(optional)
INT bit
ALERT# pin
(active low)
Button Status
Write to INT bit
2015 Microchip Technology Inc.
DS00001623B-page 27
CAP1126
6.0
REGISTER DESCRIPTION
The registers shown in Table 6-1 are accessible through the communications protocol. An entry of ‘-’ indicates that the
bit is not used and will always read ‘0’.
TABLE 6-1:
REGISTER SET IN HEXADECIMAL ORDER
Register
Address
R/W
Register Name
Function
Default Value
Page
00h
R/W
Main Control
Controls general power states and
power dissipation
00h
Page 31
02h
R
General Status
Stores general status bits
00h
Page 32
00h
Page 32
03h
R
Sensor Input Status
Returns the state of the sampled
capacitive touch sensor inputs
04h
R
LED Status
Stores status bits for LEDs
00h
Page 32
0Ah
R
Noise Flag Status
Stores the noise flags for sensor inputs
00h
Page 33
10h
R
Sensor Input 1 Delta
Count
Stores the delta count for CS1
00h
Page 33
11h
R
Sensor Input 2 Delta
Count
Stores the delta count for CS2
00h
Page 33
12h
R
Sensor Input 3 Delta
Count
Stores the delta count for CS3
00h
Page 33
13h
R
Sensor Input 4 Delta
Count
Stores the delta count for CS4
00h
Page 33
14h
R
Sensor Input 5 Delta
Count
Stores the delta count for CS5
00h
Page 33
15h
R
Sensor Input 6 Delta
Count
Stores the delta count for CS6
00h
Page 33
1Fh
R/W
Sensitivity Control
Controls the sensitivity of the threshold
and delta counts and data scaling of
the base counts
2Fh
Page 33
20h
R/W
Configuration
Controls general functionality
20h
Page 35
Sensor Input Enable
Controls whether the capacitive touch
sensor inputs are sampled
3Fh
Page 36
21h
R/W
22h
R/W
Controls max duration and auto-repeat
Sensor Input Configuradelay for sensor inputs operating in the
tion
full power state
A4h
Page 36
23h
R/W
Sensor Input Configuration 2
Controls the MPRESS controls for all
sensor inputs
07h
Page 38
24h
R/W
Averaging and Sampling Config
Controls averaging and sampling window
39h
Page 38
26h
R/W
Calibration Activate
Forces re-calibration for capacitive
touch sensor inputs
00h
Page 39
27h
R/W
Interrupt Enable
Enables Interrupts associated with
capacitive touch sensor inputs
3Fh
Page 40
28h
R/W
Repeat Rate Enable
Enables repeat rate for all sensor
inputs
3Fh
Page 40
2Ah
R/W
Multiple Touch Configuration
Determines the number of simultaneous touches to flag a multiple touch
condition
80h
Page 41
2Bh
R/W
Multiple Touch Pattern
Configuration
Determines the multiple touch pattern
(MTP) configuration
00h
Page 41
DS00001623B-page 28
2015 Microchip Technology Inc.
CAP1126
TABLE 6-1:
REGISTER SET IN HEXADECIMAL ORDER (CONTINUED)
Register
Address
R/W
Register Name
Function
Default Value
Page
2Dh
R/W
Multiple Touch Pattern
Determines the pattern or number of
sensor inputs used by the MTP circuitry
3Fh
Page 42
2Fh
R/W
Recalibration Configuration
Determines re-calibration timing and
sampling window
8Ah
Page 43
30h
R/W
Sensor Input 1 Threshold
Stores the delta count threshold to
determine a touch for Capacitive
Touch Sensor Input 1
40h
Page 44
31h
R/W
Sensor Input 2 Threshold
Stores the delta count threshold to
determine a touch for Capacitive
Touch Sensor Input 2
40h
Page 44
32h
R/W
Sensor Input 3 Threshold
Stores the delta count threshold to
determine a touch for Capacitive
Touch Sensor Input 3
40h
Page 44
33h
R/W
Sensor Input 4 Threshold
Stores the delta count threshold to
determine a touch for Capacitive
Touch Sensor Input 4
40h
Page 44
34h
R/W
Sensor Input 5 Threshold
Stores the delta count threshold to
determine a touch for Capacitive
Touch Sensor Input 5
40h
Page 44
35h
R/W
Sensor Input 6 Threshold
Stores the delta count threshold to
determine a touch for Capacitive
Touch Sensor Input 6
40h
Page 44
38h
R/W
Sensor Input Noise
Threshold
Stores controls for selecting the noise
threshold for all sensor inputs
01h
Page 44
Standby Configuration Registers
40h
R/W
Standby Channel
Controls which sensor inputs are
enabled while in standby
00h
Page 45
41h
R/W
Standby Configuration
Controls averaging and cycle time
while in standby
39h
Page 45
42h
R/W
Standby Sensitivity
Controls sensitivity settings used while
in standby
02h
Page 47
43h
R/W
Standby Threshold
Stores the touch detection threshold
for active sensor inputs in standby
40h
Page 47
44h
R/W
Configuration 2
Stores additional configuration controls for the device
40h
Page 35
Base Count Registers
50h
R
Sensor Input 1 Base
Count
Stores the reference count value for
sensor input 1
C8h
Page 47
51h
R
Sensor Input 2 Base
Count
Stores the reference count value for
sensor input 2
C8h
Page 47
52h
R
Sensor Input 3 Base
Count
Stores the reference count value for
sensor input 3
C8h
Page 47
53h
R
Sensor Input 4 Base
Count
Stores the reference count value for
sensor input 4
C8h
Page 47
54h
R
Sensor Input 5 Base
Count
Stores the reference count value for
sensor input 5
C8h
Page 47
55h
R
Sensor Input 6 Base
Count
Stores the reference count value for
sensor input 6
C8h
Page 47
2015 Microchip Technology Inc.
DS00001623B-page 29
CAP1126
TABLE 6-1:
Register
Address
REGISTER SET IN HEXADECIMAL ORDER (CONTINUED)
R/W
Register Name
Function
Default Value
Page
00h
Page 48
00h
Page 48
LED Controls
71h
R/W
LED Output Type
Controls the output type for the LED
outputs
72h
R/W
Sensor Input LED Linking
Controls linking of sensor inputs to
LED channels
73h
R/W
LED Polarity
Controls the output polarity of LEDs
00h
Page 49
74h
R/W
LED Output Control
Controls the output state of the LEDs
00h
Page 50
77h
R/W
Linked LED
Transition Control
Controls the transition when LEDs are
linked to CS channels
00h
Page 51
79h
R/W
LED Mirror Control
Controls the mirroring of duty cycles
for the LEDs
00h
Page 51
81h
R/W
LED Behavior 1
Controls the behavior and response of
LEDs 1 - 2
00h
Page 51
84h
R/W
LED Pulse 1 Period
Controls the period of each breathe
during a pulse
20h
Page 53
85h
R/W
LED Pulse 2 Period
Controls the period of the breathing
during breathe and pulse operation
14h
Page 55
86h
R/W
LED Breathe Period
Controls the period of an LED breathe
operation
5Dh
Page 56
88h
R/W
LED Config
Controls LED configuration
04h
Page 56
F0h
Page 57
90h
R/W
LED Pulse 1 Duty Cycle
Determines the min and max duty
cycle for the pulse operation
91h
R/W
LED Pulse 2 Duty Cycle
Determines the min and max duty
cycle for breathe and pulse operation
F0h
Page 57
92h
R/W
LED Breathe Duty Cycle
Determines the min and max duty
cycle for the breathe operation
F0h
Page 57
93h
R/W
LED Direct Duty Cycle
Determines the min and max duty
cycle for Direct mode LED operation
F0h
Page 57
94h
R/W
LED Direct Ramp Rates
Determines the rising and falling edge
ramp rates of the LEDs
00h
Page 58
95h
R/W
LED Off Delay
Determines the off delay for all LED
behaviors
00h
Page 58
B1h
B2h
B3h
B4h
B5h
B6h
B9h
BAh
R
Sensor Input 1 Calibra- Stores the upper 8-bit calibration value
tion
for sensor input 1
00h
Page 61
R
Sensor Input 2 Calibra- Stores the upper 8-bit calibration value
tion
for sensor input 2
00h
Page 61
R
Sensor Input 3 Calibra- Stores the upper 8-bit calibration value
for sensor input 3
tion
00h
Page 61
R
Sensor Input 4 Calibra- Stores the upper 8-bit calibration value
tion
for sensor input 4
00h
Page 61
R
Sensor Input 5 Calibra- Stores the upper 8-bit calibration value
tion
for sensor input 5
00h
Page 61
R
Sensor Input 6 Calibra- Stores the upper 8-bit calibration value
tion
for sensor input 6
00h
Page 61
R
Sensor Input Calibration LSB 1
Stores the 2 LSBs of the calibration
value for sensor inputs 1 - 4
00h
Page 61
R
Sensor Input Calibration LSB 2
Stores the 2 LSBs of the calibration
value for sensor inputs 5 - 6
00h
Page 61
DS00001623B-page 30
2015 Microchip Technology Inc.
CAP1126
TABLE 6-1:
REGISTER SET IN HEXADECIMAL ORDER (CONTINUED)
Register
Address
R/W
Register Name
Function
Default Value
Page
FDh
R
Product ID
Stores a fixed value that identifies
each product
53h
Page 62
FEh
R
Manufacturer ID
Stores a fixed value that identifies
Microchip
5Dh
Page 62
FFh
R
Revision
Stores a fixed value that represents
the revision number
83h
Page 62
During Power-On-Reset (POR), the default values are stored in the registers. A POR is initiated when power is first
applied to the part and the voltage on the VDD supply surpasses the POR level as specified in the electrical characteristics. Any reads to undefined registers will return 00h. Writes to undefined registers will not have an effect.
When a bit is “set”, this means that the user writes a logic ‘1’ to it. When a bit is “cleared”, this means that the user writes
a logic ‘0’ to it.
6.1
TABLE 6-2:
Main Control Register
MAIN CONTROL REGISTER
ADDR
R/W
Register
00h
R/W
Main Control
B7
B6
GAIN[1:0]
B5
B4
B3
B2
B1
B0
Default
STBY
DSLEEP
-
-
-
INT
00h
The Main Control register controls the primary power state of the device.
Bits 7 - 6 - GAIN[1:0] - Controls the gain used by the capacitive touch sensing circuitry. As the gain is increased, the
effective sensitivity is likewise increased as a smaller delta capacitance is required to generate the same delta count
values. The sensitivity settings may need to be adjusted along with the gain settings such that data overflow does not
occur.
APPLICATION NOTE: The gain settings apply to both Standby and Active states.
TABLE 6-3:
GAIN BIT DECODE
GAIN[1:0]
Capacitive Touch Sensor Gain
1
0
0
0
1
0
1
2
1
0
4
1
1
8
Bit 5 - STBY - Enables Standby.
• ‘0’ (default) - Sensor input scanning is active and LEDs are functional.
• ‘1’ - Capacitive touch sensor input scanning is limited to the sensor inputs set in the Standby Channel register (see
Section 6.20). The status registers will not be cleared until read. LEDs that are linked to capacitive touch sensor
inputs will remain linked and active. Sensor inputs that are no longer sampled will flag a release and then remain
in a non-touched state. LEDs that are manually controlled will be unaffected.
• Bit 4 - DSLEEP - Enables Deep Sleep by deactivating all functions. This bit will be cleared when the WAKE pin is
driven high. ‘0’ (default) - Sensor input scanning is active and LEDs are functional.
• ‘1’ - All sensor input scanning is disabled. All LEDs are driven to their programmed non-actuated state and no
PWM operations will be done. The status registers are automatically cleared and the INT bit is cleared.
Bit 0 - INT - Indicates that there is an interrupt. When this bit is set, it asserts the ALERT# pin. If a channel detects a
touch and its associated interrupt enable bit is not set to a logic ‘1’, no action is taken.
2015 Microchip Technology Inc.
DS00001623B-page 31
CAP1126
This bit is cleared by writing a logic ‘0’ to it. When this bit is cleared, the ALERT# pin will be deasserted and all status
registers will be cleared if the condition has been removed. If the WAKE/SPI_MOSI pin is asserted as a result of a touch
detected while in Standby, it will likewise be deasserted when this bit is cleared.
Note that the WAKE / SPI_MOSI pin is not driven when communicating via the 4-wire SPI protocol.
• ‘0’ - No interrupt pending.
• ‘1’ - A touch has been detected on one or more channels and the interrupt has been asserted.
6.2
Status Registers
TABLE 6-4:
STATUS REGISTERS
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
02h
R
General Status
-
-
-
LED
RESET
MULT
MTP
TOUCH
00h
03h
R
Sensor Input Status
-
-
CS6
CS5
CS4
CS3
CS2
CS1
00h
04h
R
LED Status
-
-
-
-
-
-
LED2_
DN
LED1_
DN
00h
All status bits are cleared when the device enters the Deep Sleep (DSLEEP = ‘1’ - see Section 6.1).
6.2.1
GENERAL STATUS - 02H
Bit 4 - LED - Indicates that one or more LEDs have finished their programmed activity. This bit is set if any bit in the LED
Status register is set.
Bit 3 - RESET - Indicates that the device has come out of reset. This bit is set when the device exits a POR state or
when the RESET pin has been deasserted and qualified via the RESET pin filter (see Section 5.2). This bit will cause
the INT bit to be set and is cleared when the INT bit is cleared.
Bit 2 - MULT - Indicates that the device is blocking detected touches due to the Multiple Touch detection circuitry (see
Section 6.14). This bit will not cause the INT bit to be set and hence will not cause an interrupt.
Bit 1 - MTP - Indicates that the device has detected a number of sensor inputs that exceed the MTP threshold either via
the pattern recognition or via the number of sensor inputs (see Section 6.15). This bit will cause the INT bit to be set if
the MTP_ALERT bit is also set. This bit will not be cleared until the condition that caused it to be set has been removed.
Bit 0 - TOUCH - Indicates that a touch was detected. This bit is set if any bit in the Sensor Input Status register is set.
6.2.2
SENSOR INPUT STATUS - 03H
The Sensor Input Status Register stores status bits that indicate a touch has been detected. A value of ‘0’ in any bit
indicates that no touch has been detected. A value of ‘1’ in any bit indicates that a touch has been detected.
All bits are cleared when the INT bit is cleared and if a touch on the respective capacitive touch sensor input is no longer
present. If a touch is still detected, the bits will not be cleared (but this will not cause the interrupt to be asserted - see
Section 6.6).
Bit 5 - CS6 - Indicates that a touch was detected on Sensor Input 6.
Bit 4 - CS5 - Indicates that a touch was detected on Sensor Input 5.
Bit 3 - CS4 - Indicates that a touch was detected on Sensor Input 4.
Bit 2 - CS3 - Indicates that a touch was detected on Sensor Input 3.
Bit 1 - CS2 - Indicates that a touch was detected on Sensor Input 2. This sensor input can be linked to LED2.
Bit 0 - CS1 - Indicates that a touch was detected on Sensor Input 1. This sensor input can be linked to LED1.
6.2.3
LED STATUS - 04H
The LED Status Registers indicate when an LED has completed its configured behavior (see Section 6.31, "LED Behavior Register") after being actuated by the host (see Section 6.28, "LED Output Control Register"). These bits are ignored
when the LED is linked to a capacitive sensor input. All LED Status bits are cleared when the INT bit is cleared.
Bit 1 - LED2_DN - Indicates that LED2 has finished its behavior after being actuated by the host.
Bit 0 - LED1_DN - Indicates that LED1 has finished its behavior after being actuated by the host.
DS00001623B-page 32
2015 Microchip Technology Inc.
CAP1126
6.3
Noise Flag Status Registers
TABLE 6-5:
NOISE FLAG STATUS REGISTERS
ADDR
R/W
Register
0Ah
R
Noise Flag Status
B7
B6
B5
B4
B3
B2
B1
B0
Default
-
-
CS6_
NOISE
CS5_
NOISE
CS4_
NOISE
CS3_
NOISE
CS2_
NOISE
CS1_
NOISE
00h
The Noise Flag Status registers store status bits that are generated from the analog block if the detected noise is above
the operating region of the analog detector or the RF noise detector. These bits indicate that the most recently received
data from the sensor input is invalid and should not be used for touch detection. So long as the bit is set for a particular
channel, the delta count value is reset to 00h and thus no touch is detected.
These bits are not sticky and will be cleared automatically if the analog block does not report a noise error.
APPLICATION NOTE: If the MTP detection circuitry is enabled, these bits count as sensor inputs above the MTP
threshold (see Section 5.5.4, "Multiple Touch Pattern Detection") even if the corresponding
delta count is not. If the corresponding delta count also exceeds the MTP threshold, it is not
counted twice.
APPLICATION NOTE: Regardless of the state of the Noise Status bits, if low frequency noise is detected on a
sensor input, that sample will be discarded unless the DIS_ANA_NOISE bit is set. As well,
if RF noise is detected on a sensor input, that sample will be discarded unless the
DIS_RF_NOISE bit is set.
6.4
Sensor Input Delta Count Registers
TABLE 6-6:
SENSOR INPUT DELTA COUNT REGISTERS
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
10h
R
Sensor Input 1
Delta Count
Sign
64
32
16
8
4
2
1
00h
11h
R
Sensor Input 2
Delta Count
Sign
64
32
16
8
4
2
1
00h
12h
R
Sensor Input 3
Delta Count
Sign
64
32
16
8
4
2
1
00h
13h
R
Sensor Input 4
Delta Count
Sign
64
32
16
8
4
2
1
00h
14h
R
Sensor Input 5
Delta Count
Sign
64
32
16
8
4
2
1
00h
15h
R
Sensor Input 6
Delta Count
Sign
64
32
16
8
4
2
1
00h
The Sensor Input Delta Count registers store the delta count that is compared against the threshold used to determine
if a touch has been detected. The count value represents a change in input due to the capacitance associated with a
touch on one of the sensor inputs and is referenced to a calibrated base “Not Touched” count value. The delta is an
instantaneous change and is updated once per sensor input per sensing cycle (see Section 5.5.1, "Sensing Cycle").
The value presented is a standard 2’s complement number. In addition, the value is capped at a value of 7Fh. A reading
of 7Fh indicates that the sensitivity settings are too high and should be adjusted accordingly (see Section 6.5).
The value is also capped at a negative value of 80h for negative delta counts which may result upon a release.
6.5
TABLE 6-7:
Sensitivity Control Register
SENSITIVITY CONTROL REGISTER
ADDR
R/W
Register
B7
1Fh
R/W
Sensitivity Control
-
2015 Microchip Technology Inc.
B6
B5
B4
DELTA_SENSE[2:0]
B3
B2
B1
B0
Default
BASE_SHIFT[3:0]
DS00001623B-page 33
2Fh
CAP1126
The Sensitivity Control register controls the sensitivity of a touch detection.
Bits 6-4 DELTA_SENSE[2:0] - Controls the sensitivity of a touch detection. The sensitivity settings act to scale the relative delta count value higher or lower based on the system parameters. A setting of 000b is the most sensitive while a
setting of 111b is the least sensitive. At the more sensitive settings, touches are detected for a smaller delta capacitance
corresponding to a “lighter” touch. These settings are more sensitive to noise, however, and a noisy environment may
flag more false touches with higher sensitivity levels.
APPLICATION NOTE: A value of 128x is the most sensitive setting available. At the most sensitivity settings, the
MSB of the Delta Count register represents 64 out of ~25,000 which corresponds to a touch
of approximately 0.25% of the base capacitance (or a ΔC of 25fF from a 10pF base
capacitance). Conversely, a value of 1x is the least sensitive setting available. At these
settings, the MSB of the Delta Count register corresponds to a delta count of 8192 counts
out of ~25,000 which corresponds to a touch of approximately 33% of the base capacitance
(or a ΔC of 3.33pF from a 10pF base capacitance).
TABLE 6-8:
DELTA_SENSE BIT DECODE
DELTA_SENSE[2:0]
Sensitivity Multiplier
2
1
0
0
0
0
128x (most sensitive)
0
0
1
64x
0
1
0
32x (default)
0
1
1
16x
1
0
0
8x
1
0
1
4x
1
1
0
2x
1
1
1
1x - (least sensitive)
Bits 3 - 0 - BASE_SHIFT[3:0] - Controls the scaling and data presentation of the Base Count registers. The higher the
value of these bits, the larger the range and the lower the resolution of the data presented. The scale factor represents
the multiplier to the bit-weighting presented in these register descriptions.
APPLICATION NOTE: The BASE_SHIFT[3:0] bits normally do not need to be updated. These settings will not affect
touch detection or sensitivity. These bits are sometimes helpful in analyzing the Cap Sensing
board performance and stability.
TABLE 6-9:
BASE_SHIFT BIT DECODE
BASE_SHIFT[3:0]
Data Scaling Factor
3
2
1
0
0
0
0
0
1x
0
0
0
1
2x
0
0
1
0
4x
0
0
1
1
8x
0
1
0
0
16x
0
1
0
1
32x
0
1
1
0
64x
0
1
1
1
128x
1
0
0
0
256x
All others
DS00001623B-page 34
256x
(default = 1111b)
2015 Microchip Technology Inc.
CAP1126
6.6
TABLE 6-10:
ADDR
R/W
Configuration Registers
CONFIGURATION REGISTERS
Register
B7
B6
B5
B4
B3
DIS_ DIG_
NOISE
DIS_ ANA_
NOISE
MAX_
DUR_EN
-
BLK_PWR_
CTRL
BLK_POL_
MIR
SHOW_
RF_
NOISE
DIS_
RF_
NOISE
20h
R/W
Configuration
TIMEOUT
WAKE_
CFG
44h
R/W
Configuration 2
INV_LINK_
TRAN
ALT_
POL
B2
B1
B0
Default
-
-
A0h
(Rev B)
20h
(rev C)
-
INT_
REL_n
40h
The Configuration registers control general global functionality that affects the entire device.
6.6.1
CONFIGURATION - 20H
Bit 7 - TIMEOUT - Enables the timeout and idle functionality of the SMBus protocol.
• ‘0’ (default for Functional Revision C) - The SMBus timeout and idle functionality are disabled. The SMBus interface will not time out if the clock line is held low. Likewise, it will not reset if both the data and clock lines are held
high for longer than 200us. This is used for I2C compliance.
• ‘1’ (default for Functional Revision B) - The SMBus timeout and idle functionality are enabled. The SMBus interface will time out if the clock line is held low for longer than 30ms. Likewise, it will reset if both the data and clock
lines are held high for longer than 200us.
Bit 6 - WAKE_CFG - Configures the operation of the WAKE pin.
• ‘0’ (default) - The WAKE pin is not asserted when a touch is detected while the device is in Standby. It will still be
used to wake the device from Deep Sleep when driven high.
• ‘1’ - The WAKE pin will be asserted high when a touch is detected while the device is in Standby. It will also be
used to wake the device from Deep Sleep when driven high.
Bit 5 - DIS_DIG_NOISE - Determines whether the digital noise threshold (see Section 6.19, "Sensor Input Noise Threshold Register") is used by the device. Setting this bit disables the feature.
• ‘0’ - The digital noise threshold is used. If a delta count value exceeds the noise threshold but does not exceed the
touch threshold, the sample is discarded and not used for the automatic re-calibration routine.
• ‘1’ (default) - The noise threshold is disabled. Any delta count that is less than the touch threshold is used for the
automatic re-calibration routine.
Bit 4 - DIS_ANA_NOISE - Determines whether the analog noise filter is enabled. Setting this bit disables the feature.
• ‘0’ (default) - If low frequency noise is detected by the analog block, the delta count on the corresponding channel
is set to 0. Note that this does not require that Noise Status bits be set.
• ‘1’ - A touch is not blocked even if low frequency noise is detected.
Bit 3 - MAX_DUR_EN - Determines whether the maximum duration recalibration is enabled.
• ‘0’ (default) - The maximum duration recalibration functionality is disabled. A touch may be held indefinitely and no
re-calibration will be performed on any sensor input.
• ‘1’ - The maximum duration recalibration functionality is enabled. If a touch is held for longer than the MAX_DUR
bit settings, then the re-calibration routine will be restarted (see Section 6.8).
6.6.2
CONFIGURATION 2 - 44H
Bit 7 - INV_LINK_TRAN - Determines the behavior of the Linked LED Transition controls (see Section 6.29).
• ‘0’ (default) - The Linked LED Transition controls set the min duty cycle equal to the max duty cycle.
• ‘1’ - The Linked LED Transition controls will invert the touch signal. For example, a touch signal will be inverted to
a non-touched signal.
Bit 6 - ALT_POL - Determines the ALERT# pin polarity and behavior.
• ‘0’ - The ALERT# pin is active high and push-pull.
• ‘1’ (default) - The ALERT# pin is active low and open drain.
2015 Microchip Technology Inc.
DS00001623B-page 35
CAP1126
Bit 5 - BLK_PWR_CTRL - Determines whether the device will reduce power consumption while waiting between conversion time completion and the end of the polling cycle.
• ‘0’ (default) - The device will always power down as much as possible during the time between the end of the last
conversion and the end of the polling cycle.
• ‘1’ - The device will not power down the Cap Sensor during the time between the end of the last conversion and
the end of the polling cycle.
Bit 4 - BLK_POL_MIR - Determines whether the LED Mirror Control register bits are linked to the LED Polarity bits. Setting this bit blocks the normal behavior which is to automatically set and clear the LED Mirror Control bits when the LED
Polarity bits are set or cleared.
• ‘0’ (default) - When the LED Polarity controls are set, the corresponding LED Mirror control is automatically set.
Likewise, when the LED Polarity controls are cleared, the corresponding LED Mirror control is also cleared.
• ‘1’ - When the LED Polarity controls are set, the corresponding LED Mirror control is not automatically set.
Bit 3 - SHOW_RF_NOISE - Determines whether the Noise Status bits will show RF Noise as the only input source.
• ‘0’ (default) - The Noise Status registers will show both RF noise and low frequency EMI noise if either is detected
on a capacitive touch sensor input.
• ‘1’ - The Noise Status registers will only show RF noise if it is detected on a capacitive touch sensor input. EMI
noise will still be detected and touches will be blocked normally; however, the status bits will not be updated.
Bit 2 - DIS_RF_NOISE - Determines whether the RF noise filter is enabled. Setting this bit disables the feature.
• ‘0’ (default) - If RF noise is detected by the analog block, the delta count on the corresponding channel is set to 0.
Note that this does not require that Noise Status bits be set.
• ‘1’ - A touch is not blocked even if RF noise is detected.
Bit 0 - INT_REL_n - Controls the interrupt behavior when a release is detected on a button.
• ‘0’ (default) - An interrupt is generated when a press is detected and again when a release is detected and at the
repeat rate (if enabled - see Section 6.13).
• ‘1’ - An interrupt is generated when a press is detected and at the repeat rate but not when a release is detected.
6.7
TABLE 6-11:
Sensor Input Enable Registers
SENSOR INPUT ENABLE REGISTERS
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
21h
R/W
Sensor Input
Enable
-
-
CS6_EN
CS5_EN
CS4_EN
CS3_EN
CS2_EN
CS1_EN
3Fh
The Sensor Input Enable registers determine whether a capacitive touch sensor input is included in the sampling cycle.
The length of the sampling cycle is not affected by the number of sensor inputs measured.
Bit 5 - CS6_EN - Enables the CS6 input to be included during the sampling cycle.
• ‘0’ - The CS6 input is not included in the sampling cycle.
• ‘1’ (default) - The CS6 input is included in the sampling cycle.
Bit 4 - CS5_EN - Enables the CS5 input to be included during the sampling cycle.
Bit 3 - CS4_EN - Enables the CS4 input to be included during the sampling cycle.
Bit 2 - CS3_EN - Enables the CS3 input to be included during the sampling cycle.
Bit 1 - CS2_EN - Enables the CS2 input to be included during the sampling cycle.
Bit 0 - CS1_EN - Enables the CS1 input to be included during the sampling cycle.
6.8
Sensor Input Configuration Register
TABLE 6-12:
SENSOR INPUT CONFIGURATION REGISTER
ADDR
R/W
Register
22h
R/W
Sensor Input
Configuration
DS00001623B-page 36
B7
B6
B5
MAX_DUR[3:0]
B4
B3
B2
B1
RPT_RATE[3:0]
B0
Default
A4h
2015 Microchip Technology Inc.
CAP1126
The Sensor Input Configuration Register controls timings associated with the Capacitive sensor inputs 1 - 6.
Bits 7 - 4 - MAX_DUR[3:0] - (default 1010b) - Determines the maximum time that a sensor pad is allowed to be touched
until the capacitive touch sensor input is recalibrated, as shown in Table 6-13.
TABLE 6-13:
MAX_DUR BIT DECODE
MAX_DUR[3:0]
Time Before Recalibration
3
2
1
0
0
0
0
0
560ms
0
0
0
1
840ms
0
0
1
0
1120ms
0
0
1
1
1400ms
0
1
0
0
1680ms
0
1
0
1
2240ms
0
1
1
0
2800ms
1
1
1
3360ms
1
0
0
0
3920ms
1
0
0
1
4480ms
1
0
1
0
5600ms (default)
1
0
1
1
6720ms
1
1
0
0
7840ms
1
1
0
1
8906ms
1
1
1
0
10080ms
1
1
1
1
11200ms
Bits 3 - 0 - RPT_RATE[3:0] - (default 0100b) Determines the time duration between interrupt assertions when auto
repeat is enabled. The resolution is 35ms the range is from 35ms to 560ms as shown in Table 6-14.
TABLE 6-14:
RPT_RATE BIT DECODE
RPT_RATE[3:0]
Interrupt Repeat RATE
3
2
1
0
0
0
0
0
35ms
0
0
0
1
70ms
0
0
1
0
105ms
0
0
1
1
140ms
0
1
0
0
175ms (default)
0
1
0
1
210ms
0
1
1
0
245ms
0
1
1
1
280ms
1
0
0
0
315ms
1
0
0
1
350ms
1
0
1
0
385ms
1
0
1
1
420ms
1
1
0
0
455ms
1
1
0
1
490ms
1
1
1
0
525ms
1
1
1
1
560ms
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6.9
Sensor Input Configuration 2 Register
TABLE 6-15:
SENSOR INPUT CONFIGURATION 2 REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
23h
R/W
Sensor Input
Configuration 2
-
-
-
-
B3
B2
B1
B0
M_PRESS[3:0]
Default
07h
Bits 3 - 0 - M_PRESS[3:0] - (default 0111b) - Determines the minimum amount of time that sensor inputs configured to
use auto repeat must detect a sensor pad touch to detect a “press and hold” event. If the sensor input detects a touch
for longer than the M_PRESS[3:0] settings, a “press and hold” event is detected. If a sensor input detects a touch for
less than or equal to the M_PRESS[3:0] settings, a touch event is detected.
The resolution is 35ms the range is from 35ms to 560ms as shown in Table 6-16.
TABLE 6-16:
M_PRESS BIT DECODE
M_PRESS[3:0]
M_PRESS SETTINGS
6.10
3
2
1
0
0
0
0
0
35ms
0
0
0
1
70ms
0
0
1
0
105ms
0
0
1
1
140ms
0
1
0
0
175ms
0
1
0
1
210ms
0
1
1
0
245ms
0
1
1
1
280ms (default)
1
0
0
0
315ms
1
0
0
1
350ms
1
0
1
0
385ms
1
0
1
1
420ms
1
1
0
0
455ms
1
1
0
1
490ms
1
1
1
0
525ms
1
1
1
1
560ms
Averaging and Sampling Configuration Register
TABLE 6-17:
ADDR
24h
AVERAGING AND SAMPLING CONFIGURATION REGISTER
R/W
Register
R/W
Averaging and
Sampling Config
B7
B6
B5
AVG[2:0]
B4
B3
B2
SAMP_TIME[1:0]
B1
B0
CYCLE_TIME
[1:0]
Default
39h
The Averaging and Sampling Configuration register controls the number of samples taken and the total sensor input
cycle time for all active sensor inputs while the device is functioning in Active state.
Bits 6 - 4 - AVG[2:0] - Determines the number of samples that are taken for all active channels during the sensor cycle
as shown in Table 6-18. All samples are taken consecutively on the same channel before the next channel is sampled
and the result is averaged over the number of samples measured before updating the measured results.
For example, if CS1, CS2, and CS3 are sampled during the sensor cycle, and the AVG[2:0] bits are set to take 4 samples
per channel, then the full sensor cycle will be: CS1, CS1, CS1, CS1, CS2, CS2, CS2, CS2, CS3, CS3, CS3, CS3.
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CAP1126
TABLE 6-18:
AVG BIT DECODE
AVG[2:0]
2
1
0
Number of Samples Taken per
Measurement
0
0
0
1
0
0
1
2
0
1
0
4
0
1
1
8 (default)
1
0
0
16
1
0
1
32
1
1
0
64
1
1
1
128
Bits 3 - 2 - SAMP_TIME[1:0] - Determines the time to take a single sample as shown in Table 6-19.
TABLE 6-19:
SAMP_TIME BIT DECODE
SAMP_TIME[1:0]
Sample Time
1
0
0
0
0
1
640us
1
0
1.28ms (default)
1
1
2.56ms
320us
Bits 1 - 0 - CYCLE_TIME[1:0] - Determines the overall cycle time for all measured channels during normal operation as
shown in Table 6-20. All measured channels are sampled at the beginning of the cycle time. If additional time is remaining, then the device is placed into a lower power state for the remaining duration of the cycle.
TABLE 6-20:
CYCLE_TIME BIT DECODE
CYCLE_TIME[1:0]
Overall Cycle Time
1
0
0
0
35ms
0
1
70ms (default)
1
0
105ms
1
1
140ms
APPLICATION NOTE: The programmed cycle time is only maintained if the total averaging time for all samples is
less than the programmed cycle. The AVG[2:0] bits will take priority so that if more samples
are required than would normally be allowed during the cycle time, the cycle time will be
extended as necessary to accommodate the number of samples to be measured.
6.11
Calibration Activate Register
TABLE 6-21:
CALIBRATION ACTIVATE REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
26h
R/W
Calibration
Activate
-
-
CS6_
CAL
CS5_
CAL
CS4_
CAL
CS3_
CAL
CS2_
CAL
CS1_
CAL
00h
The Calibration Activate register forces the respective sensor inputs to be re-calibrated affecting both the analog and
digital blocks. During the re-calibration routine, the sensor inputs will not detect a press for up to 600ms and the Sensor
Input Base Count register values will be invalid. During this time, any press on the corresponding sensor pads will invalidate the re-calibration. When finished, the CALX[9:0] bits will be updated (see Section 6.39).
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When the corresponding bit is set, the device will perform the calibration and the bit will be automatically cleared once
the re-calibration routine has finished.
Bit 5 - CS6_CAL - When set, the CS6 input is re-calibrated. This bit is automatically cleared once the sensor input has
been re-calibrated successfully.
Bit 4 - CS5_CAL - When set, the CS5 input is re-calibrated. This bit is automatically cleared once the sensor input has
been re-calibrated successfully.
Bit 3 - CS4_CAL - When set, the CS4 input is re-calibrated. This bit is automatically cleared once the sensor input has
been re-calibrated successfully.
Bit 2 - CS3_CAL - When set, the CS3 input is re-calibrated. This bit is automatically cleared once the sensor input has
been re-calibrated successfully.
Bit 1 - CS2_CAL - When set, the CS2 input is re-calibrated. This bit is automatically cleared once the sensor input has
been re-calibrated successfully.
Bit 0 - CS1_CAL - When set, the CS1 input is re-calibrated. This bit is automatically cleared once the sensor input has
been re-calibrated successfully.
6.12
TABLE 6-22:
Interrupt Enable Register
INTERRUPT ENABLE REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
27h
R/W
Interrupt
Enable
-
-
CS6_
INT_EN
CS5_
INT_EN
CS4_
INT_EN
CS3_
INT_EN
CS2_
INT_EN
CS1_
INT_EN
3Fh
The Interrupt Enable register determines whether a sensor pad touch or release (if enabled) causes the interrupt pin to
be asserted.
Bit 5 - CS6_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS6 (associated with the CS6
status bit).
• ‘0’ - The interrupt pin will not be asserted if a touch is detected on CS6 (associated with the CS6 status bit).
• ‘1’ (default) - The interrupt pin will be asserted if a touch is detected on CS6 (associated with the CS6 status bit).
Bit 4 - CS5_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS5 (associated with the CS5
status bit).
Bit 3 - CS4_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS4 (associated with the CS4
status bit).
Bit 2 - CS3_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS3 (associated with the CS3
status bit).
Bit 1 - CS2_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS2 (associated with the CS2
status bit).
Bit 0 - CS1_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS1 (associated with the CS1
status bit).
6.13
TABLE 6-23:
Repeat Rate Enable Register
REPEAT RATE ENABLE REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
28h
R/W
Repeat Rate
Enable
-
-
CS6_
RPT_EN
CS5_
RPT_EN
CS4_
RPT_EN
CS3_
RPT_EN
CS2_
RPT_EN
CS1_
RPT_EN
3Fh
The Repeat Rate Enable register enables the repeat rate of the sensor inputs as described in Section 5.6.1.
Bit 5 - CS6_RPT_EN - Enables the repeat rate for capacitive touch sensor input 6.
• ‘0’ - The repeat rate for CS6 is disabled. It will only generate an interrupt when a touch is detected and when a
release is detected no matter how long the touch is held for.
• ‘1’ (default) - The repeat rate for CS6 is enabled. In the case of a “touch” event, it will generate an interrupt when a
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CAP1126
touch is detected and a release is detected (as determined by the INT_REL_n bit - see Section 6.6). In the case of
a “press and hold” event, it will generate an interrupt when a touch is detected and at the repeat rate so long as
the touch is held.
Bit 4 - CS5_RPT_EN - Enables the repeat rate for capacitive touch sensor input 5.
Bit 3 - CS4_RPT_EN - Enables the repeat rate for capacitive touch sensor input 4.
Bit 2 - CS3_RPT_EN - Enables the repeat rate for capacitive touch sensor input 3.
Bit 1 - CS2_RPT_EN - Enables the repeat rate for capacitive touch sensor input 2.
Bit 0 - CS1_RPT_EN - Enables the repeat rate for capacitive touch sensor input 1.
6.14
Multiple Touch Configuration Register
TABLE 6-24:
MULTIPLE TOUCH CONFIGURATION
ADDR
R/W
Register
B7
B6
B5
B4
2Ah
R/W
Multiple Touch
Config
MULT_
BLK_
EN
-
-
-
B3
B2
B_MULT_T[1:0]
B1
B0
Default
-
-
80h
The Multiple Touch Configuration register controls the settings for the multiple touch detection circuitry. These settings
determine the number of simultaneous buttons that may be pressed before additional buttons are blocked and the MULT
status bit is set.
Bit 7 - MULT_BLK_EN - Enables the multiple button blocking circuitry.
• ‘0’ - The multiple touch circuitry is disabled. The device will not block multiple touches.
• ‘1’ (default) - The multiple touch circuitry is enabled. The device will flag the number of touches equal to programmed multiple touch threshold and block all others. It will remember which sensor inputs are valid and block all
others until that sensor pad has been released. Once a sensor pad has been released, the N detected touches
(determined via the cycle order of CS1 - CS6) will be flagged and all others blocked.
Bits 3 - 2 - B_MULT_T[1:0] - Determines the number of simultaneous touches on all sensor pads before a Multiple Touch
Event is detected and sensor inputs are blocked. The bit decode is given by Table 6-25.
TABLE 6-25:
B_MULT_T BIT DECODE
B_MULT_T[1:0]
Number of Simultaneous Touches
6.15
TABLE 6-26:
ADDR
2Bh
1
0
0
0
1 (default)
0
1
2
1
0
3
1
1
4
Multiple Touch Pattern Configuration Register
MULTIPLE TOUCH PATTERN CONFIGURATION
R/W
Register
R/W
Multiple Touch
Pattern Config
B7
MTP_ EN
B6
-
B5
-
B4
B3
B2
MTP_TH[1:0]
B1
B0
Default
COMP_
PTRN
MTP_
ALERT
00h
The Multiple Touch Pattern Configuration register controls the settings for the multiple touch pattern detection circuitry.
This circuitry works like the multiple touch detection circuitry with the following differences:
1.
2.
The detection threshold is a percentage of the touch detection threshold as defined by the MTP_TH[1:0] bits
whereas the multiple touch circuitry uses the touch detection threshold.
The MTP detection circuitry either will detect a specific pattern of sensor inputs as determined by the Multiple
Touch Pattern register settings or it will use the Multiple Touch Pattern register settings to determine a minimum
number of sensor inputs that will cause the MTP circuitry to flag an event. When using pattern recognition mode,
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3.
4.
if all of the sensor inputs set by the Multiple Touch Pattern register have a delta count greater than the MTP
threshold or have their corresponding Noise Flag Status bits set, the MTP bit will be set. When using the absolute
number mode, if the number of sensor inputs with thresholds above the MTP threshold or with Noise Flag Status
bits set is equal to or greater than this number, the MTP bit will be set.
When an MTP event occurs, all touches are blocked and an interrupt is generated.
All sensor inputs will remain blocked so long as the requisite number of sensor inputs are above the MTP threshold or have Noise Flag Status bits set. Once this condition is removed, touch detection will be restored. Note that
the MTP status bit is only cleared by writing a ‘0’ to the INT bit once the condition has been removed.
Bit 7 - MTP_EN - Enables the multiple touch pattern detection circuitry.
• ‘0’ (default) - The MTP detection circuitry is disabled.
• ‘1’ - The MTP detection circuitry is enabled.
Bits 3-2 - MTP_TH[1:0] - Determine the MTP threshold, as shown in Table 6-27. This threshold is a percentage of sensor
input threshold (see Section 6.18, "Sensor Input Threshold Registers") when the device is in the Fully Active state or of
the standby threshold (see Section 6.23, "Standby Threshold Register") when the device is in the Standby state.
TABLE 6-27:
MTP_TH BIT DECODE
MTP_TH[1:0]
Threshold Divide Setting
1
0
0
0
12.5% (default)
0
1
25%
1
0
37.5%
1
1
100%
Bit 1 - COMP_PTRN - Determines whether the MTP detection circuitry will use the Multiple Touch Pattern register as a
specific pattern of sensor inputs or as an absolute number of sensor inputs.
• ‘0’ (default) - The MTP detection circuitry will use the Multiple Touch Pattern register bit settings as an absolute
minimum number of sensor inputs that must be above the threshold or have Noise Flag Status bits set. The number will be equal to the number of bits set in the register.
• ‘1’ - The MTP detection circuitry will use pattern recognition. Each bit set in the Multiple Touch Pattern register
indicates a specific sensor input that must have a delta count greater than the MTP threshold or have a Noise Flag
Status bit set. If the criteria are met, the MTP status bit will be set.
Bit 0 - MTP_ALERT - Enables an interrupt if an MTP event occurs. In either condition, the MTP status bit will be set.
• ‘0’ (default) - If an MTP event occurs, the ALERT# pin is not asserted.
• ‘1’ - If an MTP event occurs, the ALERT# pin will be asserted.
6.16
Multiple Touch Pattern Register
TABLE 6-28:
MULTIPLE TOUCH PATTERN REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
2Dh
R/W
Multiple
Touch Pattern
-
-
CS6_
PTRN
CS5_
PTRN
CS4_
PTRN
CS3_
PTRN
CS2_
PTRN
CS1_
PTRN
3Fh
The Multiple Touch Pattern register acts as a pattern to identify an expected sensor input profile for diagnostics or other
significant events. There are two methods for how the Multiple Touch Pattern register is used: as specific sensor inputs
or number of sensor input that must exceed the MTP threshold or have Noise Flag Status bits set. Which method is used
is based on the COMP_PTRN bit (see Section 6.15). The methods are described below.
1.
2.
Specific Sensor Inputs: If, during a single polling cycle, the specific sensor inputs above the MTP threshold or
with Noise Flag Status bits set match those bits set in the Multiple Touch Pattern register, an MTP event is
flagged.
Number of Sensor Inputs: If, during a single polling cycle, the number of sensor inputs with a delta count above
the MTP threshold or with Noise Flag Status bits set is equal to or greater than the number of pattern bits set, an
MTP event is flagged.
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Bit 5 - CS6_PTRN - Determines whether CS6 is considered as part of the Multiple Touch Pattern.
• ‘0’ - CS6 is not considered a part of the pattern.
• ‘1’ - CS6 is considered a part of the pattern or the absolute number of sensor inputs that must have a delta count
greater than the MTP threshold or have the Noise Flag Status bit set is increased by 1.
Bit 4 - CS5_PTRN - Determines whether CS5 is considered as part of the Multiple Touch Pattern.
Bit 3 - CS4_PTRN - Determines whether CS4 is considered as part of the Multiple Touch Pattern.
Bit 2 - CS3_PTRN - Determines whether CS3 is considered as part of the Multiple Touch Pattern.
Bit 1 - CS2_PTRN - Determines whether CS2 is considered as part of the Multiple Touch Pattern.
Bit 0 - CS1_PTRN - Determines whether CS1 is considered as part of the Multiple Touch Pattern.
6.17
Recalibration Configuration Register
TABLE 6-29:
RECALIBRATION CONFIGURATION REGISTERS
ADDR
R/W
Register
B7
B6
B5
B4
2Fh
R/W
Recalibration
Configuration
BUT_
LD_TH
NO_
CLR_
INTD
NO_
CLR_
NEG
B3
B2
NEG_DELTA_
CNT[1:0]
B1
B0
Default
CAL_CFG[2:0]
8Ah
The Recalibration Configuration register controls the automatic re-calibration routine settings as well as advanced controls to program the Sensor Input Threshold register settings.
Bit 7 - BUT_LD_TH - Enables setting all Sensor Input Threshold registers by writing to the Sensor Input 1 Threshold
register.
• ‘0’ - Each Sensor Input X Threshold register is updated individually.
• ‘1’ (default) - Writing the Sensor Input 1 Threshold register will automatically overwrite the Sensor Input Threshold
registers for all sensor inputs (Sensor Input Threshold 1 through Sensor Input Threshold 6). The individual Sensor
Input X Threshold registers (Sensor Input 2 Threshold through Sensor Input 6 Threshold) can be individually
updated at any time.
Bit 6 - NO_CLR_INTD - Controls whether the accumulation of intermediate data is cleared if the noise status bit is set.
• ‘0’ (default) - The accumulation of intermediate data is cleared if the noise status bit is set.
• ‘1’ - The accumulation of intermediate data is not cleared if the noise status bit is set.
APPLICATION NOTE: Bits 5 and 6 should both be set to the same value. Either both should be set to ‘0’ or both
should be set to ‘1’.
Bit 5 - NO_CLR_NEG - Controls whether the consecutive negative delta counts counter is cleared if the noise status bit
is set.
• ‘0’ (default) - The consecutive negative delta counts counter is cleared if the noise status bit is set.
• ‘1’ - The consecutive negative delta counts counter is not cleared if the noise status bit is set.
Bits 4 - 3 - NEG_DELTA_CNT[1:0] - Determines the number of negative delta counts necessary to trigger a digital recalibration as shown in Table 6-30.
TABLE 6-30:
NEG_DELTA_CNT BIT DECODE
NEG_DELTA_CNT[1:0]
Number of Consecutive Negative Delta Count Values
1
0
0
0
8
0
1
16 (default)
1
0
32
1
1
None (disabled)
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Bits 2 - 0 - CAL_CFG[2:0] - Determines the update time and number of samples of the automatic re-calibration routine.
The settings apply to all sensor inputs universally (though individual sensor inputs can be configured to support re-calibration - see Section 6.11).
TABLE 6-31:
CAL_CFG BIT DECODE
CAL_CFG[2:0]
2
1
0
Recalibration Samples
(see Note 6-1)
Update Time (see
Note 6-2)
0
0
0
16
16
0
0
1
32
32
0
1
0
64
64 (default)
0
1
1
128
128
1
0
0
256
256
1
0
1
256
1024
1
1
0
256
2048
1
1
1
256
4096
Note 6-1
Recalibration Samples refers to the number of samples that are measured and averaged before the
Base Count is updated however does not control the base count update period.
Note 6-2
Update Time refers to the amount of time (in polling cycle periods) that elapses before the Base
Count is updated. The time will depend upon the number of channels active, the averaging setting,
and the programmed cycle time.
6.18
Sensor Input Threshold Registers
TABLE 6-32:
SENSOR INPUT THRESHOLD REGISTERS
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
30h
R/W
Sensor Input 1
Threshold
-
64
32
16
8
4
2
1
40h
31h
R/W
Sensor Input 2
Threshold
-
64
32
16
8
4
2
1
40h
32h
R/W
Sensor Input 3
Threshold
-
64
32
16
8
4
2
1
40h
33h
R/W
Sensor Input 4
Threshold
-
64
32
16
8
4
2
1
40h
34h
R/W
Sensor Input 5
Threshold
-
64
32
16
8
4
2
1
40h
35h
R/W
Sensor Input 6
Threshold
-
64
32
16
8
4
2
1
40h
The Sensor Input Threshold registers store the delta threshold that is used to determine if a touch has been detected.
When a touch occurs, the input signal of the corresponding sensor pad changes due to the capacitance associated with
a touch. If the sensor input change exceeds the threshold settings, a touch is detected.
When the BUT_LD_TH bit is set (see Section 6.17 - bit 7), writing data to the Sensor Input 1 Threshold register will
update all of the sensor input threshold registers (31h - 35h inclusive).
6.19
Sensor Input Noise Threshold Register
TABLE 6-33:
SENSOR INPUT NOISE THRESHOLD REGISTER
ADDR
R/W
Register
38h
R/W
Sensor Input
Noise Threshold
DS00001623B-page 44
B7
B6
B5
B4
B3
B2
B1
B0
CS_BN_TH [1:0]
Default
01h
2015 Microchip Technology Inc.
CAP1126
The Sensor Input Noise Threshold register controls the value of a secondary internal threshold to detect noise and
improve the automatic recalibration routine. If a capacitive touch sensor input exceeds the Sensor Input Noise Threshold
but does not exceed the sensor input threshold, it is determined to be caused by a noise spike. That sample is not used
by the automatic re-calibration routine. This feature can be disabled by setting the DIS_DIG_NOISE bit.
Bits 1-0 - CS1_BN_TH[1:0] - Controls the noise threshold for all capacitive touch sensor inputs, as shown in Table 6-34.
The threshold is proportional to the threshold setting.
TABLE 6-34:
CSX_BN_TH BIT DECODE
CS_BN_TH[1:0]
Percent Threshold Setting
6.20
1
0
0
0
25%
0
1
37.5% (default)
1
0
50%
1
1
62.5%
Standby Channel Register
TABLE 6-35:
STANDBY CHANNEL REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
40h
R/W
Standby Channel
-
-
CS6_
STBY
CS5_
STBY
CS4_
STBY
CS3_
STBY
CS2_
STBY
CS1_
STBY
00h
The Standby Channel register controls which (if any) capacitive touch sensor inputs are active during Standby.
Bit 5 - CS6_STBY - Controls whether the CS6 channel is active in Standby.
• ‘0’ (default) - The CS6 channel not be sampled during Standby mode.
• ‘1’ - The CS6 channel will be sampled during Standby Mode. It will use the Standby threshold setting, and the
standby averaging and sensitivity settings.
Bit 4 - CS5_STBY - Controls whether the CS5 channel is active in Standby.
Bit 3 - CS4_STBY - Controls whether the CS4 channel is active in Standby.
Bit 2 - CS3_STBY - Controls whether the CS3 channel is active in Standby.
Bit 1 - CS2_STBY - Controls whether the CS2 channel is active in Standby.
Bit 0 - CS1_STBY - Controls whether the CS1 channel is active in Standby.
6.21
Standby Configuration Register
TABLE 6-36:
STANDBY CONFIGURATION REGISTER
ADDR
R/W
Register
B7
41h
R/W
Standby Configuration
AVG_
SUM
B6
B5
STBY_AVG[2:0]
B4
B3
B2
STBY_SAMP_
TIME[1:0]
B1
B0
STBY_CY_TIME
[1:0]
Default
39h
The Standby Configuration register controls averaging and cycle time for those sensor inputs that are active in Standby.
This register is useful for detecting proximity on a small number of sensor inputs as it allows the user to change averaging and sample times on a limited number of sensor inputs and still maintain normal functionality in the fully active
state.
Bit 7 - AVG_SUM - Determines whether the active sensor inputs will average the programmed number of samples or
whether they will accumulate for the programmed number of samples.
• ‘0’ - (default) - The active sensor input delta count values will be based on the average of the programmed number
of samples when compared against the threshold.
• ‘1’ - The active sensor input delta count values will be based on the summation of the programmed number of
samples when compared against the threshold. This bit should only be set when performing proximity detection as
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CAP1126
a physical touch will overflow the delta count registers and may result in false readings.
Bits 6 - 4 - STBY_AVG[2:0] - Determines the number of samples that are taken for all active channels during the sensor
cycle as shown in Table 6-37. All samples are taken consecutively on the same channel before the next channel is sampled and the result is averaged over the number of samples measured before updating the measured results.
TABLE 6-37:
STBY_AVG BIT DECODE
STBY_AVG[2:0]
2
1
0
Number of Samples Taken per
Measurement
0
0
0
1
0
0
1
2
0
1
0
4
0
1
1
8 (default)
1
0
0
16
1
0
1
32
1
1
0
64
1
1
1
128
Bit 3-2 - STBY SAMP_TIME[1:0] - Determines the time to take a single sample when the device is in Standby as shown
in Table 6-38.
TABLE 6-38:
STBY_SAMP_TIME BIT DECODE
STBY_SAMP_TIME[1:0]
Sampling Time
1
0
0
0
0
1
640us
1
0
1.28ms (default)
1
1
2.56ms
320us
Bits 1 - 0 - STBY_CY_TIME[2:0] - Determines the overall cycle time for all measured channels during standby operation
as shown in Table 6-39. All measured channels are sampled at the beginning of the cycle time. If additional time is
remaining, the device is placed into a lower power state for the remaining duration of the cycle.
TABLE 6-39:
STBY_CY_TIME BIT DECODE
STBY_CY_TIME[1:0]
Overall Cycle Time
1
0
0
0
35ms
0
1
70ms (default)
1
0
105ms
1
1
140ms
APPLICATION NOTE: The programmed cycle time is only maintained if the total averaging time for all samples is
less than the programmed cycle. The STBY_AVG[2:0] bits will take priority so that if more
samples are required than would normally be allowed during the cycle time, the cycle time
will be extended as necessary to accommodate the number of samples to be measured.
DS00001623B-page 46
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CAP1126
6.22
Standby Sensitivity Register
TABLE 6-40:
STANDBY SENSITIVITY REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
42h
R/W
Standby Sensitivity
-
-
-
-
-
B2
B1
B0
STBY_SENSE[2:0]
Default
02h
The Standby Sensitivity register controls the sensitivity for sensor inputs that are active in Standby.
Bits 2 - 0 - STBY_SENSE[2:0] - Controls the sensitivity for sensor inputs that are active in Standby. The sensitivity settings act to scale the relative delta count value higher or lower based on the system parameters. A setting of 000b is the
most sensitive while a setting of 111b is the least sensitive. At the more sensitive settings, touches are detected for a
smaller delta C corresponding to a “lighter” touch. These settings are more sensitive to noise however and a noisy environment may flag more false touches than higher sensitivity levels.
APPLICATION NOTE: A value of 128x is the most sensitive setting available. At the most sensitivity settings, the
MSB of the Delta Count register represents 64 out of ~25,000 which corresponds to a touch
of approximately 0.25% of the base capacitance (or a ΔC of 25fF from a 10pF base
capacitance). Conversely a value of 1x is the least sensitive setting available. At these
settings, the MSB of the Delta Count register corresponds to a delta count of 8192 counts
out of ~25,000 which corresponds to a touch of approximately 33% of the base capacitance
(or a ΔC of 3.33pF from a 10pF base capacitance).
TABLE 6-41:
STBY_SENSE BIT DECODE
STBY_SENSE[2:0]
Sensitivity Multiplier
6.23
2
1
0
0
0
0
128x (most sensitive)
0
0
1
64x
0
1
0
32x (default)
0
1
1
16x
1
0
0
8x
1
0
1
4x
1
1
0
2x
1
1
1
1x - (least sensitive)
Standby Threshold Register
TABLE 6-42:
STANDBY THRESHOLD REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
43h
R/W
Standby Threshold
-
64
32
16
8
4
2
1
40h
The Standby Threshold register stores the delta threshold that is used to determine if a touch has been detected. When
a touch occurs, the input signal of the corresponding sensor pad changes due to the capacitance associated with a
touch. If the sensor input change exceeds the threshold settings, a touch is detected.
6.24
Sensor Input Base Count Registers
TABLE 6-43:
SENSOR INPUT BASE COUNT REGISTERS
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
50h
R
Sensor Input 1
Base Count
128
64
32
16
8
4
2
1
C8h
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CAP1126
TABLE 6-43:
SENSOR INPUT BASE COUNT REGISTERS (CONTINUED)
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
51h
R
Sensor Input 2
Base Count
128
64
32
16
8
4
2
1
C8h
52h
R
Sensor Input 3
Base Count
128
64
32
16
8
4
2
1
C8h
53h
R
Sensor Input 4
Base Count
128
64
32
16
8
4
2
1
C8h
54h
R
Sensor Input 5
Base Count
128
64
32
16
8
4
2
1
C8h
55h
R
Sensor Input 6
Base Count
128
64
32
16
8
4
2
1
C8h
The Sensor Input Base Count registers store the calibrated “Not Touched” input value from the capacitive touch sensor
inputs. These registers are periodically updated by the re-calibration routine.
The routine uses an internal adder to add the current count value for each reading to the sum of the previous readings
until sample size has been reached. At this point, the upper 16 bits are taken and used as the Sensor Input Base Count.
The internal adder is then reset and the re-calibration routine continues.
The data presented is determined by the BASE_SHIFT[3:0] bits (see Section 6.5).
6.25
LED Output Type Register
TABLE 6-44:
LED OUTPUT TYPE REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
71h
R/W
LED Output
Type
-
-
-
-
-
-
LED2_
OT
LED1_
OT
00h
The LED Output Type register controls the type of output for the LED pins. Each pin is controlled by a single bit. Refer
to application note 21.4 CAP1126Family LED Configuration Options for more information about implementing LEDs.
Bit 1 - LED2_OT - Determines the output type of the LED2 pin.
• ‘0’ (default) - The LED2 pin is an open-drain output with an external pull-up resistor. When the appropriate pin is
set to the “active” state (logic ‘1’), the pin will be driven low. Conversely, when the pin is set to the “inactive” state
(logic ‘0’), then the pin will be left in a High Z state and pulled high via an external pull-up resistor.
• ‘1’ - The LED2 pin is a push-pull output. When driving a logic ‘1’, the pin is driven high. When driving a logic ‘0’, the
pin is driven low.
Bit 0 - LED1_OT - Determines the output type of the LED1 pin.
6.26
Sensor Input LED Linking Register
TABLE 6-45:
SENSOR INPUT LED LINKING REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
72h
R/W
Sensor Input
LED Linking
-
-
-
-
-
-
CS2_
LED2
CS1_
LED1
00h
The Sensor Input LED Linking register controls whether a capacitive touch sensor input is linked to an LED output. If
the corresponding bit is set, then the appropriate LED output will change states defined by the LED Behavior controls
(see Section 6.31) in response to the capacitive touch sensor input.
Bit 1 - CS2_LED2 - Links the LED2 output to a detected touch on the CS2 sensor input. When a touch is detected, the
LED is actuated and will behave as determined by the LED Behavior controls.
• ‘0’ (default) - The LED 2 output is not associated with the CS2 input. If a touch is detected on the CS2 input, the
LED will not automatically be actuated. The LED is enabled and controlled via the LED Output Control register
(see Section 6.28) and the LED Behavior registers (see Section 6.31).
DS00001623B-page 48
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CAP1126
• ‘1’ - The LED 2 output is associated with the CS2 input. If a touch is detected on the CS2 input, the LED will be
actuated and behave as defined in Table 6-52.
Bit 0 - CS1_LED1 - Links the LED1 output to a detected touch on the CS1 sensor input. When a touch is detected, the
LED is actuated and will behave as determined by the LED Behavior controls.
6.27
TABLE 6-46:
LED Polarity Register
LED POLARITY REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
73h
R/W
LED Polarity
-
-
-
-
-
-
LED2_
POL
LED1_
POL
00h
The LED Polarity register controls the logical polarity of the LED outputs. When these bits are set or cleared, the corresponding LED Mirror controls are also set or cleared (unless the BLK_POL_MIR bit is set - see Section 6.6, "Configuration Registers"). Table 6-48, "LED Polarity Behavior" shows the interaction between the polarity controls, output
controls, and relative brightness.
APPLICATION NOTE: The polarity controls determine the final LED pin drive. A touch on a linked capacitive touch
sensor input is treated in the same way as the LED Output Control bit being set to a logic ‘1’.
APPLICATION NOTE: The LED drive assumes that the LEDs are configured such that if the LED pin is driven to
a logic ‘0’ then the LED will be on and that the CAP1126 LED pin is sinking the LED current.
Conversely, if the LED pin is driven to a logic ‘1’, the LED will be off and there is no current
flow. See Figure 5-1, "System Diagram for CAP1126".
APPLICATION NOTE: This application note applies when the LED polarity is inverted (LEDx_POL = ‘0’). For LED
operation, the duty cycle settings determine the % of time that the LED pin will be driven to
a logic ‘0’ state in. The Max Duty Cycle settings define the maximum % of time that the LED
pin will be driven low (i.e. maximum % of time that the LED is on) while the Min Duty Cycle
settings determine the minimum % of time that the LED pin will be driven low (i.e. minimum
% of time that the LED is on). When there is no touch detected or the LED Output Control
register bit is at a logic ‘0’, the LED output will be driven at the minimum duty cycle setting.
Breathe operations will ramp the duty cycle from the minimum duty cycle to the maximum
duty cycle.
APPLICATION NOTE: This application note applies when the LED polarity is non-inverted (LEDx_POL = ‘1’). For
LED operation, the duty cycle settings determine the % of time that the LED pin will be driven
to a logic ‘1’ state. The Max Duty Cycle settings define the maximum % of time that the LED
pin will be driven high (i.e. maximum % of time that the LED is off) while the Min Duty Cycle
settings determine the minimum % of time that the LED pin will be driven high (i.e. minimum
% of time that the LED is off). When there is no touch detected or the LED Output Control
register bit is at a logic ‘0’, the LED output will be driven at 100 minus the minimum duty
cycle setting. Breathe operations will ramp the duty cycle from 100 minus the minimum duty
cycle to 100 minus the maximum duty cycle.
APPLICATION NOTE: The LED Mirror controls (see Section 6.30, "LED Mirror Control Register") work with the
polarity controls with respect to LED brightness but will not have a direct effect on the output
pin drive.
Bit 1 - LED2_POL - Determines the polarity of the LED2 output.
• ‘0’ (default) - The LED2 output is inverted. For example, a setting of ‘1’ in the LED Output Control register will
cause the LED pin output to be driven to a logic ‘0’.
• ‘1’ - The LED2 output is non-inverted. For example, a setting of ‘1’ in the LED Output Control register will cause
the LED pin output to be driven to a logic ‘1’ or left in the high-z state as determined by its output type.
Bit 0 - LED1_POL - Determines the polarity of the LED1 output.
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DS00001623B-page 49
CAP1126
6.28
LED Output Control Register
TABLE 6-47:
LED OUTPUT CONTROL REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
74h
R/W
LED Output
Control
-
-
-
-
-
-
LED2_
DR
LED1_
DR
00h
The LED Output Control Register controls the output state of the LED pins that are not linked to sensor inputs.
Note:
If an LED is linked to a sensor input in the Sensor Input LED Linking Register (Section 6.26, "Sensor Input
LED Linking Register"), the corresponding bit in the LED Output Control Register is ignored (i.e. a linked
LED cannot be host controlled).
The LED Polarity Control Register will determine the non actuated state of the LED pins. The actuated LED behavior is
determined by the LED behavior controls (see Section 6.31, "LED Behavior Register").
Table 6-48 shows the interaction between the polarity controls, output controls, and relative brightness.
Bit 1 - LED2_DR - Determines whether LED2 output is driven high or low.
• ‘0’ (default) - The LED2 output is driven at the minimum duty cycle or not actuated.
• ‘1’ - The LED2 output is High Z or driven at the maximum duty cycle or actuated.
Bit 0 - LED1_DR - Determines whether LED1 output is driven high or low.
TABLE 6-48:
LED POLARITY BEHAVIOR
LED Output
Control
Register or
Touch
Polarity
Max Duty
0
inverted (‘0’)
not used
1
maximum % of time
inverted (‘0’) that the LED is on
(logic 0)
minimum % of time
that the LED is on
(logic 0)
0
non-inverted
(‘1’)
not used
minimum % of time maximum brightness at
that the LED is off
100 minus min duty
(logic 1)
cycle.
on at 100 - min
duty cycle
maximum % of time
that the LED is off
(logic 1)
For Direct behavior,
maximum brightness is
100 minus max duty
cycle. When breathminimum % of time
ing, max brightness is
that the LED is off
100 minus min duty
(logic 1)
cycle. Brightness
ramps from 100 - min
duty cycle to 100 - max
duty cycle.
according to LED
behavior
1
non-inverted
(‘1’)
DS00001623B-page 50
Min Duty
Brightness
minimum % of time
maximum brightness at
that the LED is on
min duty cycle
(logic 0)
LED Appearance
on at min duty
cycle
maximum brightness at
max duty cycle. Brightaccording to LED
ness ramps from min
behavior
duty cycle to max duty
cycle
2015 Microchip Technology Inc.
CAP1126
6.29
TABLE 6-49:
Linked LED Transition Control Register
LINKED LED TRANSITION CONTROL REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
77h
R/W
Linked LED Transition Control
-
-
-
-
-
-
LED2_
LTRAN
LED1_
LTRAN
00h
The Linked LED Transition Control register controls the LED drive when the LED is linked to a capacitive touch sensor
input. These controls work in conjunction with the INV_LINK_TRAN bit (see Section 6.6.2, "Configuration 2 - 44h") to
create smooth transitions from host control to linked LEDs.
Bit 1 - LED2_LTRAN - Determines the transition effect when LED2 is linked to CS2.
• ‘0’ (default) - When the LED output control bit for LED2 is ‘1’, and then LED2 is linked to CS2 and no touch is
detected, the LED will change states.
• ‘1’ - If the INV_LINK_TRAN bit is ‘1’, when the LED output control bit for CS2 is ‘1’, and then CS2 is linked to LED2
and no touch is detected, the LED will not change states. In addition, the LED state will change when the sensor
pad is touched. If the INV_LINK_TRAN bit is ‘0’, when the LED output control bit for CS2 is ‘1’, and then CS2 is
linked to LED2 and no touch is detected, the LED will not change states. However, the LED state will not change
when the sensor pad is touched.
APPLICATION NOTE: If the LED behavior is not “Direct” and the INV_LINK_TRAN bit it ‘0’, the LED will not perform
as expected when the LED2_LTRAN bit is set to ‘1’. Therefore, if breathe and pulse
behaviors are used, set the INV_LINK_TRAN bit to ‘1’.
Bit 0 - LED1_LTRAN - Determines the transition effect when LED1 is linked to CS1.
6.30
TABLE 6-50:
LED Mirror Control Register
LED MIRROR CONTROL REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
79h
R/W
LED Mirror Control
-
-
-
-
-
-
LED2_
MIR _
EN
LED1_
MIR _
EN
00h
The LED Mirror Control Registers determine the meaning of duty cycle settings when polarity is non-inverted for each
LED channel. When the polarity bit is set to ‘1’ (non-inverted), to obtain correct steps for LED ramping, pulse, and
breathe behaviors, the min and max duty cycles need to be relative to 100%, rather than the default, which is relative
to 0%.
APPLICATION NOTE: The LED drive assumes that the LEDs are configured such that if the LED pin is driven to
a logic ‘0’, the LED will be on and the CAP1126 LED pin is sinking the LED current. When
the polarity bit is set to ‘1’, it is considered non-inverted. For systems using the opposite LED
configuration, mirror controls would apply when the polarity bit is ‘0’.
These bits are changed automatically if the corresponding LED Polarity bit is changed (unless the BLK_POL_MIR bit is
set - see Section 6.6).
Bit 1 - LED2_MIR_EN - Determines whether the duty cycle settings are “biased” relative to 0% or 100% duty cycle.
• ‘0’ (default) - The duty cycle settings are determined relative to 0% and are determined directly with the settings.
• ‘1’ - The duty cycle settings are determined relative to 100%.
Bit 0 - LED1_MIR_EN - Determines whether the duty cycle settings are “biased” relative to 0% or 100% duty cycle.
6.31
LED Behavior Register
TABLE 6-51:
LED BEHAVIOR REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
81h
R/W
LED Behavior 1
-
-
-
-
2015 Microchip Technology Inc.
B3
B2
LED2_CTL[1:0]
B1
B0
LED1_CTL[1:0]
Default
00h
DS00001623B-page 51
CAP1126
The LED Behavior register controls the operation of LEDs. Each LED pin is controlled by a 2-bit field and the behavior
is determined by whether the LED is linked to a capacitive touch sensor input or not.
If the corresponding LED output is linked to a capacitive touch sensor input, the appropriate behavior will be enabled /
disabled based on touches and releases.
If the LED output is not associated with a capacitive touch sensor input, the appropriate behavior will be enabled / disabled by the LED Output Control register. If the respective LEDx_DR bit is set to a logic ‘1’, this will be associated as a
“touch”, and if the LEDx_DR bit is set to a logic ‘0’, this will be associated as a “release”.
Table 6-52, "LEDx_CTL Bit Decode" shows the behavior triggers. The defined behavior will activate when the Start Trigger is met and will stop when the Stop Trigger is met. Note the behavior of the Breathe Hold and Pulse Release option.
The LED Polarity Control register will determine the non actuated state of the LED outputs (see Section 6.27, "LED
Polarity Register").
APPLICATION NOTE: If an LED is not linked to a capacitive touch sensor input and is breathing (via the Breathe
or Pulse behaviors), it must be unactuated and then re-actuated before changes to behavior
are processed. For example, if the LED output is breathing and the Maximum duty cycle is
changed, this change will not take effect until the LED output control register is set to ‘0’ and
then re-set to ‘1’.
APPLICATION NOTE: If an LED is not linked to the capacitive touch sensor input and configured to operate using
Pulse 1 Behavior, then the circuitry will only be actuated when the corresponding output
control bit is set. It will not check the bit condition until the Pulse 1 behavior is finished. The
device will not remember if the bit was cleared and reset while it was actuated.
APPLICATION NOTE: If an LED is actuated and not linked and the desired LED behavior is changed, this new
behavior will take effect immediately; however, the first instance of the changed behavior
may act incorrectly (e.g. if changed from Direct to Pulse 1, the LED output may ‘breathe’ 4
times and then end at minimum duty cycle). LED Behaviors will operate normally once the
LED has been un-actuated and then re-actuated.
APPLICATION NOTE: If an LED is actuated and it is switched from linked to a capacitive touch sensor input to
unlinked (or vice versa), the LED will respond to the new command source immediately if
the behavior was Direct or Breathe. For Pulse behaviors, it will complete the behavior
already in progress. For example, if a linked LED was actuated by a touch and the control
is changed so that it is unlinked, it will check the status of the corresponding LED Output
Control bit. If that bit is ‘0’, then the LED will behave as if a release was detected. Likewise,
if an unlinked LED was actuated by the LED Output Control register and the control is
changed so that it is linked and no touch is detected, then the LED will behave as if a release
was detected.
Bits 3 - 2 - LED2_CTL[1:0] - Determines the behavior of LED2 as shown in Table 6-52.
Bits 1 - 0 - LED1_CTL[1:0] - Determines the behavior of LED1 as shown in Table 6-52.
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CAP1126
TABLE 6-52:
LEDx_CTL
[1:0]
1
LEDX_CTL BIT DECODE
Operation
Description
Start TRigger
Stop Trigger
The LED is driven to the programmed state
(active or inactive). See Figure 6-7
Touch Detected or
LED Output Control bit set
Release
Detected or
LED Output
Control bit
cleared
0
0
0
0
1
1
0
1
1
Direct
Pulse 1
The LED will “Pulse” a programmed number
Touch or Release
of times. During each “Pulse” the LED will
Detected or LED
breathe up to the maximum brightness and
Output Control bit
back down to the minimum brightness so that
set or cleared
the total “Pulse” period matches the pro(see Section 6.32)
grammed value.
n/a
Pulse 2
The LED will “Pulse” when the start trigger is
Touch Detected or
detected. When the stop trigger is detected, it
LED Output Conwill “Pulse” a programmable number of times
trol bit set
then return to its minimum brightness.
Release
Detected or
LED Output
Control bit
cleared
Breathe
The LED will breathe. It will be driven with a
duty cycle that ramps up from the programmed minimum duty cycle (default 0%) to
the programmed maximum duty cycle duty Touch Detected or
cycle (default 100%) and then back down.
LED Output ConEach ramp takes up 50% of the programmed
trol bit set
period. The total period of each “breath” is
determined by the LED Breathe Period controls - see Section 6.34.
Release
Detected or
LED Output
Control bit
cleared
APPLICATION NOTE: The PWM frequency is determined based on the selected LED behavior, the programmed
breathe period, and the programmed min and max duty cycles. For the Direct behavior
mode, the PWM frequency is calculated based on the programmed Rise and Fall times. If
these are set at 0, then the maximum PWM frequency will be used based on the
programmed duty cycle settings.
6.32
TABLE 6-53:
LED Pulse 1 Period Register
LED PULSE 1 PERIOD REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
84h
R/W
LED Pulse 1
Period
ST_
TRIG
P1_
PER6
P1_
PER5
P1_
PER4
P1_
PER3
P1_
PER2
P1_
PER1
P1_
PER0
20h
The LED Pulse Period 1 register determines the overall period of a pulse operation as determined by the LED_CTL
registers (see Table 6-52 - setting 01b). The LSB represents 32ms so that a setting of 18h (24d) would represent a
period of 768ms (24 x 32ms = 768ms). The total range is from 32ms to 4.064 seconds as shown in Table 6-54 with the
default being 1024ms.
APPLICATION NOTE: Due to constraints on the LED Drive PWM operation, any Breathe Period less than 160ms
(05h) may not be achievable. The device will breathe at the minimum period possible as
determined by the period and min / max duty cycle settings.
Bit 7 - ST_TRIG - Determines the start trigger for the LED Pulse behavior.
• ‘0’ (default) - The LED will Pulse when a touch is detected or the drive bit is set.
• ‘1’ - The LED will Pulse when a release is detected or the drive bit is cleared.
2015 Microchip Technology Inc.
DS00001623B-page 53
CAP1126
The Pulse 1 operation is shown in Figure 6-1 when the LED output is configured for non-inverted polarity (LEDx_POL
= 1) and in Figure 6-2 for inverted polarity (LEDx_POL = 0).
.
FIGURE 6-1:
Pulse 1 Behavior with Non-Inverted Polarity
Touch Detected or
Release Detected
X pulses after touch or after release
Normal – untouched
operation
Normal – untouched
operation
(100% - Pulse 1 Min Duty Cycle) * Brightness
LED
Brightness
(100% - Pulse 1 Max Duty Cycle) * Brightness
Pulse 1 Period
(P1_PER)
FIGURE 6-2:
Pulse 1 Behavior with Inverted Polarity
Touch Detected or
Release Detected
X pulses after touch or after release
Pulse 1 Max Duty Cycle * Brightness
LED
Brightness
Normal – untouched
operation
Normal – untouched
operation
Pulse 1 Min Duty Cycle * Brightness
Pulse Period
(P1_PER)
TABLE 6-54:
LED PULSE / BREATHE PERIOD EXAMPLE
Setting (HEX)
Setting (Decimal)
Total Breathe / Pulse Period (MS)
00h
0
32
01h
1
32
02h
2
64
03h
3
96
...
...
...
7Dh
125
4000
DS00001623B-page 54
2015 Microchip Technology Inc.
CAP1126
TABLE 6-54:
6.33
LED PULSE / BREATHE PERIOD EXAMPLE (CONTINUED)
Setting (HEX)
Setting (Decimal)
Total Breathe / Pulse Period (MS)
7Eh
126
4032
7Fh
127
4064
LED Pulse 2 Period Register
TABLE 6-55:
LED PULSE 2 PERIOD REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
85h
R/W
LED Pulse 2
Period
-
P2_
PER6
P2_
PER5
P2_
PER4
P2_
PER3
P2_
PER2
P2_
PER1
P2_
PER0
14h
The LED Pulse 2 Period register determines the overall period of a pulse operation as determined by the LED_CTL
registers (see Table 6-52 - setting 10b). The LSB represents 32ms so that a setting of 18h (24d) would represent a
period of 768ms. The total range is from 32ms to 4.064 seconds (see Table 6-54) with a default of 640ms.
APPLICATION NOTE: Due to constraints on the LED Drive PWM operation, any Breathe Period less than 160ms
(05h) may not be achievable. The device will breathe at the minimum period possible as
determined by the period and min / max duty cycle settings.
The Pulse 2 Behavior is shown in Figure 6-3 for non-inverted polarity (LEDx_POL = 1) and in Figure 6-4 for inverted
polarity (LEDx_POL = 0).
FIGURE 6-3:
Normal – untouched
operation
Pulse 2 Behavior with Non-Inverted Polarity
Release Detected
Touch Detected
X additional pulses after release
Normal – untouched
operation
(100% - Pulse 2 Min Duty Cycle) *
Brightness
LED
Brightness
...
Pulse
Period
(P2_PER)
2015 Microchip Technology Inc.
(100% - Pulse 2 Max Duty Cycle) * Brightness
DS00001623B-page 55
CAP1126
FIGURE 6-4:
Pulse 2 Behavior with Inverted Polarity
Normal – untouched
operation
Release Detected
Touch Detected
Normal – untouched
operation
X additional pulses after release
Pulse 2 Max Duty Cycle * Brightness
LED
Brightness
...
Pulse 2 Min Duty Cycle * Brightness
Pulse
Period
(P2_PER)
6.34
LED Breathe Period Register
TABLE 6-56:
LED BREATHE PERIOD REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
86h
R/W
LED Breathe
Period
-
BR_
PER6
BR_
PER5
BR_
PER4
BR_
PER3
BR_
PER2
BR_
PER1
BR_
PER0
5Dh
The LED Breathe Period register determines the overall period of a breathe operation as determined by the LED_CTL
registers (see Table 6-52 - setting 11b). The LSB represents 32ms so that a setting of 18h (24d) would represent a
period of 768ms. The total range is from 32ms to 4.064 seconds (see Table 6-54) with a default of 2976ms.
APPLICATION NOTE: Due to constraints on the LED Drive PWM operation, any Breathe Period less than 160ms
(05h) may not be achievable. The device will breathe at the minimum period possible as
determined by the period and min / max duty cycle settings.
6.35
TABLE 6-57:
LED Configuration Register
LED CONFIGURATION REGISTER
ADDR
R/W
Register
B7
B6
88h
R/W
LED Config
-
RAMP_
ALERT
B5
B4
B3
PULSE2_CNT[2:0]
B2
B1
B0
PULSE1_CNT[2:0]
The LED Configuration register controls general LED behavior as well as the number of pulses that are sent for the
PULSE LED output behavior.
Bit 6 - RAMP_ALERT - Determines whether the device will assert the ALERT# pin when LEDs actuated by the LED
Output Control register bits have finished their respective behaviors. Interrupts will only be generated if the LED activity
is generated by writing the LED Output Control registers. Any LED activity associated with touch detection will not cause
an interrupt to be generated when the LED behavior has been finished.
• ‘0’ (default) - The ALERT# pin will not be asserted when LEDs actuated by the LED Output Control register have
finished their programmed behaviors.
• ‘1’ - The ALERT# pin will be asserted whenever any LED that is actuated by the LED Output Control register has
finished its programmed behavior.
Bits 5 - 3 - PULSE2_CNT[2:0] - Determines the number of pulses used for the Pulse 2 behavior as shown in Table 6-58.
Bits 2 - 0 - PULSE1_CNT[2:0] - Determines the number of pulses used for the Pulse 1 behavior as shown in Table 6-58.
DS00001623B-page 56
2015 Microchip Technology Inc.
Default
04h
CAP1126
TABLE 6-58:
PULSEX_CNT DECODE
PULSEX_CNT[2:0]
Number of Breaths
2
6.36
1
0
0
0
0
1 (default - Pulse 2)
0
0
1
2
0
1
0
3
0
1
1
4
1
0
0
5 (default - Pulse 1)
1
0
1
6
1
1
0
7
1
1
1
8
LED Duty Cycle Registers
TABLE 6-59:
LED DUTY CYCLE REGISTERS
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
90h
R/W
LED Pulse 1 Duty
Cycle
P1_MAX_DUTY[3:0]
P1_MIN_DUTY[3:0]
F0h
91h
R/W
LED Pulse 2 Duty
Cycle
P2_MAX_DUTY[3:0]
P2_MIN_DUTY[3:0]
F0h
92h
R/W
LED Breathe
Duty Cycle
BR_MAX_DUTY[3:0]
BR_MIN_DUTY[3:0]
F0h
93h
R/W
Direct Duty Cycle
DR_MAX_DUTY[3:0]
DR_MIN_DUTY[3:0]
F0h
The LED Duty Cycle registers determine the minimum and maximum duty cycle settings used for the LED for each LED
behavior. These settings affect the brightness of the LED when it is fully off and fully on.
The LED driver duty cycle will ramp up from the minimum duty cycle to the maximum duty cycle and back down again.
APPLICATION NOTE: When operating in Direct behavior mode, changes to the Duty Cycle settings will be applied
immediately. When operating in Breathe, Pulse 1, or Pulse 2 modes, the LED must be
unactuated and then re-actuated before changes to behavior are processed.
Bits 7 - 4 - X_MAX_DUTY[3:0] - Determines the maximum PWM duty cycle for the LED drivers as shown in Table 6-60.
Bits 3 - 0 - X_MIN_DUTY[3:0] - Determines the minimum PWM duty cycle for the LED drivers as shown in Table 6-60.
TABLE 6-60:
LED DUTY CYCLE DECODE
x_MAX/MIN_Duty [3:0]
Maximum Duty Cycle
Minimum Duty Cycle
7%
0%
3
2
1
0
0
0
0
0
0
0
0
1
9%
7%
0
0
1
0
11%
9%
0
0
1
1
14%
11%
0
1
0
0
17%
14%
0
1
0
1
20%
17%
0
1
1
0
23%
20%
0
1
1
1
26%
23%
1
0
0
0
30%
26%
1
0
0
1
35%
30%
1
0
1
0
40%
35%
2015 Microchip Technology Inc.
DS00001623B-page 57
CAP1126
TABLE 6-60:
LED DUTY CYCLE DECODE (CONTINUED)
x_MAX/MIN_Duty [3:0]
Maximum Duty Cycle
Minimum Duty Cycle
1
46%
40%
0
53%
46%
0
1
63%
53%
1
0
77%
63%
1
1
100%
77%
3
2
1
0
1
0
1
1
1
0
1
1
1
1
1
1
6.37
LED Direct Ramp Rates Register
TABLE 6-61:
LED DIRECT RAMP RATES REGISTER
ADDR
R/W
Register
B7
B6
94h
R/W
LED Direct Ramp
Rates
-
-
B5
B4
B3
RISE_RATE[2:0]
B2
B1
B0
FALL_RATE[2:0]
Default
00h
The LED Direct Ramp Rates register control the rising and falling edge time of an LED that is configured to operate in
Direct behavior mode. The rising edge time corresponds to the amount of time the LED takes to transition from its minimum duty cycle to its maximum duty cycle. Conversely, the falling edge time corresponds to the amount of time that
the LED takes to transition from its maximum duty cycle to its minimum duty cycle.
Bits 5 - 3 - RISE_RATE[2:0] - Determines the rising edge time of an LED when it transitions from its minimum drive state
to its maximum drive state as shown in Table 6-62.
Bits 2 - 0 - FALL_RATE[2:0] - Determines the falling edge time of an LED when it transitions from its maximum drive
state to its minimum drive state as shown in Table 6-62.
TABLE 6-62:
RISE / FALL RATE DECODE
RISE_RATE/ FALL_RATE/ Bit Decode
6.38
Rise / Fall Time (TRISE / TFALL)
2
1
0
0
0
0
0
0
0
1
250ms
0
1
0
500ms
0
1
1
750ms
1
0
0
1s
1
0
1
1.25s
1
1
0
1.5s
1
1
1
2s
LED Off Delay Register
TABLE 6-63:
LED OFF DELAY REGISTER
ADDR
R/W
Register
B7
95h
R/W
LED Off Delay
Register
-
B6
B5
B4
BR_OFF_DLY[2:0]
B3
B2
B1
DIR_OFF_DLY[3:0]
B0
Default
00h
The LED Off Delay register determines the amount of time that an LED remains at its maximum duty cycle (or minimum
as determined by the polarity controls) before it starts to ramp down. If the LED is operating in Breathe mode, this delay
is applied at the top of each “breath”. If the LED is operating in the Direct mode, this delay is applied when the LED is
unactuated.
DS00001623B-page 58
2015 Microchip Technology Inc.
CAP1126
Bits 6 - 4 - BR_OFF_DLY[2:0] - Determines the Breathe behavior mode off delay, which is the amount of time an LED
in Breathe behavior mode remains inactive after it finishes a breathe pulse (ramp on and ramp off), as shown in Figure 65 (non-inverted polarity LEDx_POL = 1) and Figure 6-6 (inverted polarity LEDx_POL = 0). Available settings are shown
in Table 6-64.
FIGURE 6-5:
Breathe Behavior with Non-Inverted Polarity
LED Actuated
LED Unactuated
100% - Breathe Max Min Cycle * Brightness
LED
Brightness
Breathe
Period
(BR_PER)
FIGURE 6-6:
Breathe Off
Delay
(BR_OFF_DLY)
100% - Breathe Min Duty Cycle *
Brightness
Breathe Behavior with Inverted Polarity
LED Actuated
LED Unactuated
Breathe Max Duty Cycle * Brightness
LED
Brightness
Breathe Min Duty Cycle * Brightness
Breathe
Period
(BR_PER)
2015 Microchip Technology Inc.
Breathe Off
Delay
(BR_OFF_DLY)
DS00001623B-page 59
CAP1126
TABLE 6-64:
BREATHE OFF DELAY SETTINGS
BR_OFF_DLY [2:0]
OFF Delay
2
1
0
0
0
0
0 (default)
0
0
1
0.25s
0
1
0
0.5s
0
1
1
0.75s
1
0
0
1.0s
1
0
1
1.25s
1
1
0
1.5s
1
1
1
2.0s
Bits 3 - 0 - DIR_OFF_DLY[3:0] - Determines the turn-off delay, as shown in Table 6-65, for all LEDs that are configured
to operate in Direct behavior mode.
The Direct behavior operation is determined by the combination of programmed Rise Time, Fall Time, Min and Max Duty
cycles, Off Delay, and polarity. Figure 6-7 shows the behavior for non-inverted polarity (LEDx_POL = 1) while Figure 68 shows the behavior for inverted polarity (LEDx_POL = 0).
FIGURE 6-7:
N orm al –
untouched
operation
LE D
B rightness
Direct Behavior for Non-Inverted Polarity
N orm al –
untouched
operation
(100% - M in D uty C ycle) *
B rightness
R IS E _R A TE
S etting (t R IS E )
FIGURE 6-8:
R elease
D etected
Touch
D etected
(100% - M ax D uty
C ycle) * B rightness
O ff D elay
(t O FF _D LY )
FA LL_R A TE
S etting (t FA LL )
Direct Behavior for Inverted Polarity
Release
Detected
Touch
Detected
M ax Duty Cycle * Brightness
LED
Brightness
Norm al –
untouched
operation
DS00001623B-page 60
Norm al –
untouched
operation
M in Duty Cycle * Brightness
RISE_RATE
Setting (t R ISE )
O ff Delay
(t OFF_DLY )
FALL_RATE
Setting (t FALL )
2015 Microchip Technology Inc.
CAP1126
TABLE 6-65:
OFF DELAY DECODE
OFF Delay[3:0] Bit Decode
OFF Delay (tOFF_DLY)
3
2
1
0
0
0
0
0
0
0
0
0
1
250ms
0
0
1
0
500ms
0
0
1
1
750ms
0
1
0
0
1s
0
1
0
1
1.25s
0
1
1
0
1.5s
0
1
1
1
2s
1
0
0
0
2.5s
1
0
0
1
3.0s
1
0
1
0
3.5s
1
0
1
1
4.0s
1
1
0
0
4.5s
All others
6.39
TABLE 6-66:
5.0s
Sensor Input Calibration Registers
SENSOR INPUT CALIBRATION REGISTERS
ADDR
Register
R/W
B7
B6
B5
B4
B3
B2
B1
B0
Default
B1h
Sensor Input 1
Calibration
R
CAL1_9
CAL1_8
CAL1_7
CAL1_6
CAL1_5
CAL1_4
CAL1_3
CAL1_2
00h
B2h
Sensor Input 2
Calibration
R
CAL2_9
CAL2_8
CAL2_7
CAL2_6
CAL2_5
CAL2_4
CAL2_3
CAL2_2
00h
B3h
Sensor Input 3
Calibration
R
CAL3_9
CAL3_8
CAL3_7
CAL3_6
CAL3_5
CAL3_4
CAL3_3
CAL3_2
00h
B4h
Sensor Input 4
Calibration
R
CAL4_9
CAL4_8
CAL4_7
CAL4_6
CAL4_5
CAL4_4
CAL4_3
CAL4_2
00h
B5h
Sensor Input 5
Calibration
R
CAL5_9
CAL5_8
CAL5_7
CAL5_6
CAL5_5
CAL5_4
CAL5_3
CAL5_2
00h
B6h
Sensor Input 6
Calibration
R
CAL6_9
CAL6_8
CAL6_7
CAL6_6
CAL6_5
CAL6_4
CAL6_3
CAL6_2
00h
B9h
Sensor Input
Calibration LSB
1
R
CAL4_1
CAL4_0
CAL3_1
CAL3_0
CAL2_1
CAL2_0
CAL1_1
CAL1_0
00h
BAh
Sensor Input
Calibration LSB
2
R
-
-
-
-
CAL6_1
CAL6_0
CAL5_1
CAL5_0
00h
The Sensor Input Calibration registers hold the 10-bit value that represents the last calibration value.
2015 Microchip Technology Inc.
DS00001623B-page 61
CAP1126
6.40
Product ID Register
TABLE 6-67:
PRODUCT ID REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
FDh
R
Product ID
0
1
0
1
0
0
1
1
53h
The Product ID register stores a unique 8-bit value that identifies the device.
6.41
Manufacturer ID Register
TABLE 6-68:
VENDOR ID REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
FEh
R
Manufacturer ID
0
1
0
1
1
1
0
1
5Dh
The Vendor ID register stores an 8-bit value that represents Microchip.
6.42
Revision Register
TABLE 6-69:
REVISION REGISTER
ADDR
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
FFh
R
Revision
1
0
0
0
0
0
1
1
83h
The Revision register stores an 8-bit value that represents the part revision.
DS00001623B-page 62
2015 Microchip Technology Inc.
CAP1126
7.0
Note:
7.1
PACKAGE INFORMATION
For the most current package drawings, see the Microchip Packaging Specification at:
http://www.microchip.com/packaging.
CAP1126 Package Drawings
FIGURE 7-1:
16-Pin QFN 4mm x 4mm Package Drawing
2015 Microchip Technology Inc.
DS00001623B-page 63
CAP1126
FIGURE 7-2:
16-Pin QFN 4mm x 4mm Package Dimensions
FIGURE 7-3:
16-Pin QFN 4mm x 4mm PCB Footprint
DS00001623B-page 64
2015 Microchip Technology Inc.
CAP1126
7.2
Package Marking
FIGURE 7-4:
CAP1126 Package Markings
TOP
0.41
Line 1 – SMSC Logo without circled R symbol
Line 2 – Device ID, Version
Line 3 – Year, Week, Alphanumeric Traceability Code
Line 4 – Revision, Country Code
C 1 1 2 6 - 1
Y WW N N N A
R C C
3x 0.56
e3
PIN 1
PB-FREE/GREEN SYMBOL
(Matte Sn)
Lines 1-3: Center Horizontal Alignment
Line 4: Left Horizontal Alignment
BOTTOM
Bottom marking not allowed
2015 Microchip Technology Inc.
DS00001623B-page 65
CAP1126
APPENDIX A:
A.1
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
DEVICE DELTA
Delta from CAP1026 to CAP1126
Updated circuitry to improve power supply rejection.
Updated LED driver duty cycle decode values to have more distribution at lower values - closer to a logarithmic
curve. See Table 6-60, "LED Duty Cycle Decode".
Updated bug that breathe periods were not correct above 2.6s. This includes rise / fall time decodes above 1.5s.
Added filtering on RESET pin to prevent errant resets.
Updated controls so that the RESET pin assertion places the device into the lowest power state available and
causes an interrupt when released. See Section 5.2, "RESET Pin".
Added 1 bit to the LED Off Delay register (see Section 6.38, "LED Off Delay Register") to extend times from 2s
to 5s in 0.5s intervals.
Breathe behavior modified. A breathe off delay control was added to the LED Off Delay Register (see Section
6.38, "LED Off Delay Register") so the LEDs can be configured to remain inactive between breathes.
Added controls for the LED transition effects when linking LEDs to capacitive sensor inputs. See Section 6.29,
"Linked LED Transition Control Register".
Added controls to “mirror” the LED duty cycle outputs so that when polarity changes, the LED brightness levels
look right. These bits are automatically set when polarity is set. Added control to break this auto-set behavior.
See Section 6.30, "LED Mirror Control Register".
Added Multiple Touch Pattern detection circuitry. See Section 6.15, "Multiple Touch Pattern Configuration Register".
Added General Status register to flag Multiple touches, Multiple Touch Pattern issues and general touch detections. See Section 6.2, "Status Registers".
Added bits 6 and 5 to the Recalibration Configuration register (2Fh - see Section 6.17, "Recalibration Configuration Register"). These bits control whether the accumulation of intermediate data and the consecutive negative
delta counts counter are cleared when the noise status bit is set.
Added Configuration 2 register for LED linking controls, noise detection controls, and control to interrupt on press
but not on release. Added control to change alert pin polarity. See Section 6.6, "Configuration Registers".
Updated Deep Sleep behavior so that device does not clear DSLEEP bit on received communications but will
wake to communicate.
Changed PWM frequency for LED drivers. The PWM frequency was derived from the programmed breathe
period and duty cycle settings and it ranged from ~4Hz to ~8000 Hz. The PWM frequency has been updated to
be a fixed value of ~2000Hz.
Register delta:
Table A.1 Register Delta From CAP1026 to CAP1126
Address
Register Delta
Delta
Default
00h
Page 31
Changed - Main Status /
Control
added bits 7-6 to control gain
00h
02h
Page 32
New - General Status
new register to store MTP, MULT, LED,
RESET, and general TOUCH bits
00h
44h
Page 35
New - Configuration 2
new register to control alert polarity, LED
touch linking behavior, LED output behavior, and noise detection, and interrupt on
release
40h
24h
Page 38
Changed - Averaging
Control
updated register bits - moved
SAMP_AVG[2:0] bits and added SAMP_TIME bit 1. Default changed
39h
2Bh
Page 41
New - Multiple Touch
Pattern Configuration
new register for Multiple Touch Pattern
configuration - enable and threshold settings
80h
DS00001623B-page 66
2015 Microchip Technology Inc.
CAP1126
Table A.1 Register Delta From CAP1026 to CAP1126 (continued)
Address
Register Delta
Delta
Default
2Dh
Page 42
New - Multiple Touch
Pattern Register
new register for Multiple Touch Pattern
detection circuitry - pattern or number of
sensor inputs
3Fh
2Fh
Page 43
Changed - Recalibration
Configuration
updated register - updated CAL_CFG bit
decode to add a 128 averages setting and
removed highest time setting. Default
changed. Added bit 6 NO_CLR_INTD and
bit 5 NO_CLR_NEG.
8Ah
38h
Page 44
Changed - Sensor Input
Noise Threshold
updated register bits - removed bits 7 - 3
and consolidated all controls into bits 1 - 0.
These bits will set the noise threshold for
all channels. Default changed
01h
39h
Removed - Noise
Threshold Register 2
removed register
n/a
41h
Page 45
Changed - Standby Configuration
updated register bits - moved
STBY_AVG[2:0] bits and added STBY_TIME bit 1. Default changed
39h
77h
Page 51
New - Linked LED Transition Control
new register to control transition effect
when LED linked to sensor inputs
00h
79h
Page 51
New - LED Mirror Control
new register to control LED output mirroring for brightness control when polarity
changed
00h
90h
Page 57
Changed - LED Pulse 1
Duty Cycle
changed bit decode to be more logarithmic
F0h
91h
Page 57
Changed - LED Pulse 2
Duty Cycle
changed bit decode to be more logarithmic
F0h
92h
Page 57
Changed - LED Breathe
Duty Cycle
changed bit decode to be more logarithmic
F0h
93h
Page 57
Changed - LED Direct
Duty Cycle
changed bit decode to be more logarithmic
F0h
95h
Added controls - LED Off
Delay
Added bits 6-4 BR_OFF_DLY[2:0]
Added bit 3 DIR_OFF_DLY[3]
00h
FDh
Page 62
Changed - Product ID
Changed bit decode for CAP1126
53h
2015 Microchip Technology Inc.
DS00001623B-page 67
CAP1126
APPENDIX B:
DATA SHEET REVISION HISTORY
Revision
DS00001623B (02-09-15)
Section/Figure/Entry
Correction
Features, Table 2-1, Table 22, "Pin Types", Section 5.0,
"General Description"
References to BC-Link Interface, BC_DATA, BC_CLK, BC-IRQ#, BC-Link bus have been removed
Application Note under Table
2-6
[BC-Link] hidden in data sheet
Table 3-2, "Electrical Specifications"
BC-Link Timing Section hidden in data sheet
Table 4-1
Protocol Used for 68K Pull Down Resistor changed
from “BC-Link Communications” to “Reserved”
Section 4.2.2, "SMBus
Address and RD / WR Bit"
Replaced “client address” with “slave address” in this
section.
Section 4.2.4, SMBus ACK
Replaced “client” with “slave” in these sections.
and NACK Bits, Section 4.2.5,
SMBus Stop Bit,Section 4.2.7,
SMBus and I2C Compatibility
REV A
Rev. 1.32 (01-05-12)
Table 4-4, "Read Byte Protocol"
Heading changed from “Client Address” to “Slave
Address”
Table 6-1
Register Name for Register Address 77h changed
from “LED Linked Transition Control” to “Linked LED
Transition Control”
Section 6.30
changed CS2 to LED2
Section 7.7 Package Marking
Updated package drawing
Appendix A: Device Delta
changed 2Dh to 2Fh in item #12
Product Identification System
Removed BC-Link references
REV A replaces previous SMSC version Rev. 1.32 (01-05-12)
Table 3-2, "Electrical Specifications"
Added conditions for tHD:DAT.
Section 4.2.7, "SMBus and
I2C Compatibility"
Renamed from “SMBus and I2C Compliance.”
First paragraph, added last sentence: “For information on using the CAP1188 in an I2C system, refer to
SMSC AN 14.0 SMSC Dedicated Slave Devices in
I2C Systems.”
Added: CAP1188 supports I2C fast mode at 400kHz.
This covers the SMBus max time of 100kHz.
Section 6.4, "Sensor Input
Delta Count Registers"
Changed negative value cap from FFh to 80h.
Section 4.3.3, "SMBus Send
Byte"
Added an application note: The Send Byte protocol
is not functional in Deep Sleep (i.e., DSLEEP bit is
set).
Section 4.3.4, "SMBus
Receive Byte"
Added an application note: The Receive Byte protocol is not functional in Deep Sleep (i.e., DSLEEP bit
is set).
Rev. 1.3 (05-18-11)
Section 6.42, "Revision Register"
Updated revision ID from 82h to 83h.
Rev. 1.2 (02-10-11)
Section A.8, "Delta from Rev
B (Mask B0) to Rev C (Mask
B1)"
Added.
Cover
Corrected block diagram. ALERT#/BC_IRQ# is an
output, not an input.
Rev. 1.31 (08-18-11)
DS00001623B-page 68
2015 Microchip Technology Inc.
CAP1126
Revision
Section/Figure/Entry
Correction
Table 2-1, "Pin Description for Changed value in “Unused Connection” column for
CAP1126"
the ADDR_COMM pin from “Connect to Ground” to
“n/a“.
Rev. 1.1 (11-17-10)
Table 3-2, "Electrical Specifications"
PSR improvements made in functional revision B.
Changed PSR spec from ±100 typ and ±200 max
counts / V to ±3 and ±10 counts / V. Conditions
updated.
Section 5.5.2, "Recalibrating
Sensor Inputs"
Added more detail with subheadings for each type of
recalibration.
Section 6.6, "Configuration
Registers"
Added bit 5 BLK_PWR_CTRL to the Configuration 2
Register 44h.
The TIMEOUT bit is set to ‘1’ by default for functional
revision B and is set to ‘0’ by default for functional
revision C.
Section 6.42, "Revision Register"
Updated revision ID in register FFh from 81h to 82h.
Document
Updated for functional revision B. See Section A.7,
"Delta from Rev A (Mask A0) to Rev B (Mask B0)".
Cover
Added to General Description: “includes circuitry and
support for enhanced sensor proximity detection.”
Added the following Features:
Calibrates for Parasitic Capacitance
Analog Filtering for System Noise Sources
Press and Hold feature for Volume-like Applications
Table 3-2, "Electrical Specifications"
Conditions for Power Supply Rejection modified adding the following:
Sampling time = 2.56ms
Averaging = 1
Negative Delta Counts = Disabled
All other parameters default
Section 6.11, "Calibration Acti- Updated register description to indicate which re-calvate Register"
ibration routine is used.
Rev. 1.0 (06-14-10)
2015 Microchip Technology Inc.
Section 6.14, "Multiple Touch
Configuration Register"
Updated register description to indicate what will
happen.
Table 6-34, "CSx_BN_TH Bit
Decode"
Table heading changed from “Threshold Divide Setting” to “Percent Threshold Setting”.
Initial release
DS00001623B-page 69
CAP1126
THE MICROCHIP WEB SITE
Microchip provides online support via our WWW site at www.microchip.com. This web site is used as a means to make
files and information easily available to customers. Accessible by using your favorite Internet browser, the web site contains the following information:
• Product Support – Data sheets and errata, application notes and sample programs, design resources, user’s
guides and hardware support documents, latest software releases and archived software
• General Technical Support – Frequently Asked Questions (FAQ), technical support requests, online discussion
groups, Microchip consultant program member listing
• Business of Microchip – Product selector and ordering guides, latest Microchip press releases, listing of seminars and events, listings of Microchip sales offices, distributors and factory representatives
CUSTOMER CHANGE NOTIFICATION SERVICE
Microchip’s customer notification service helps keep customers current on Microchip products. Subscribers will receive
e-mail notification whenever there are changes, updates, revisions or errata related to a specified product family or
development tool of interest.
To register, access the Microchip web site at www.microchip.com. Under “Support”, click on “Customer Change Notification” and follow the registration instructions.
CUSTOMER SUPPORT
Users of Microchip products can receive assistance through several channels:
•
•
•
•
Distributor or Representative
Local Sales Office
Field Application Engineer (FAE)
Technical Support
Customers should contact their distributor, representative or field application engineer (FAE) for support. Local sales
offices are also available to help customers. A listing of sales offices and locations is included in the back of this document.
Technical support is available through the web site at: http://www.microchip.com/support
DS00001623B-page 70
2015 Microchip Technology Inc.
CAP1126
PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
PART NO.
[X]
l
l
Device Temperature
Range
Device:
CAP1126
Temperature
Range:
Blank
Package:
AP = QFN
Tape and
Reel Option:
TR
=
1
0°C to
-
XXX
[X](1)
l
l
Package
Tape and Reel
Option
+85°C
(Extended Commercial)
= Tape and Reel(1)
Example:
CAP1126-1-AP-TR
16-pin QFN 4mm x 4mm (RoHS compliant)
Six capacitive touch sensor inputs, Two
LED drivers, Dedicated Wake, Reset,
SMBus / BC-Link / SPI interfaces
Reel size is 4,000 pieces
Note 1:
Tape and Reel identifier only appears in the catalog part number description. This identifier is used for ordering
purposes and is not printed on the device package. Check with your Microchip Sales Office for package availability
with the Tape and Reel option.
2015 Microchip Technology Inc.
DS00001623B-page 71
CAP1126
Note the following details of the code protection feature on Microchip devices:
•
Microchip products meet the specification contained in their particular Microchip Data Sheet.
•
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
•
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
•
Microchip is willing to work with the customer who is concerned about the integrity of their code.
•
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Information contained in this publication regarding device applications and the like is provided only for your convenience and may be
superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO
REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR
OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE,
MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of
Microchip devices in life support and/or safety applications is entirely at the buyer’s risk, and the buyer agrees to defend, indemnify and
hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights.
Trademarks
The Microchip name and logo, the Microchip logo, dsPIC, FlashFlex, flexPWR, JukeBlox, KEELOQ, KEELOQ logo, Kleer, LANCheck,
MediaLB, MOST, MOST logo, MPLAB, OptoLyzer, PIC, PICSTART, PIC32 logo, RightTouch, SpyNIC, SST, SST Logo, SuperFlash and
UNI/O are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.
The Embedded Control Solutions Company and mTouch are registered trademarks of Microchip Technology Incorporated in the U.S.A.
Analog-for-the-Digital Age, BodyCom, chipKIT, chipKIT logo, CodeGuard, dsPICDEM, dsPICDEM.net, ECAN, In-Circuit Serial
Programming, ICSP, Inter-Chip Connectivity, KleerNet, KleerNet logo, MiWi, MPASM, MPF, MPLAB Certified logo, MPLIB, MPLINK,
MultiTRAK, NetDetach, Omniscient Code Generation, PICDEM, PICDEM.net, PICkit, PICtail, RightTouch logo, REAL ICE, SQI, Serial
Quad I/O, Total Endurance, TSHARC, USBCheck, VariSense, ViewSpan, WiperLock, Wireless DNA, and ZENA are trademarks of
Microchip Technology Incorporated in the U.S.A. and other countries.
SQTP is a service mark of Microchip Technology Incorporated in the U.S.A.
Silicon Storage Technology is a registered trademark of Microchip Technology Inc. in other countries.
GestIC is a registered trademarks of Microchip Technology Germany II GmbH & Co. KG, a subsidiary of Microchip Technology Inc., in
other countries.
All other trademarks mentioned herein are property of their respective companies.
© 2015, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved.
ISBN: 9781632770332
QUALITY MANAGEMENT SYSTEM
CERTIFIED BY DNV
== ISO/TS 16949 ==
DS00001623B-page 72
Microchip received ISO/TS-16949:2009 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona; Gresham, Oregon and design centers in California
and India. The Company’s quality system processes and procedures
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping
devices, Serial EEPROMs, microperipherals, nonvolatile memory and
analog products. In addition, Microchip’s quality system for the design
and manufacture of development systems is ISO 9001:2000 certified.
2015 Microchip Technology Inc.
Worldwide Sales and Service
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01/27/15
2015 Microchip Technology Inc.
DS00001623B-page 73