mXT228UD-MAU002 2.0
maXTouch 228-node Touchscreen Controller
maXTouch® Adaptive Sensing Technology
Touch Performance
• Up to 14 X (transmit) lines and 24 Y (receive) lines for
use by a touchscreen and/or key array (see
Section 4.3 “Permitted Configurations”)
• A maximum of 228 nodes can be allocated to the
touch sensor
• Touchscreen size of 5.75 inches (3:2 aspect ratio),
assuming a sensor electrode pitch of 6.5 mm. Other
sizes are possible with different electrode pitches and
appropriate sensor material
• Multiple touch support with up to 10 concurrent
touches tracked in real time
• Moisture/Water Compensation
- No false touch with condensation or water drop
up to 22 mm diameter
- One-finger tracking with condensation or water
drop up to 22 mm diameter
• Mutual capacitance and self capacitance
measurements supported for robust touch detection
• P2P mutual capacitance measurements supported for
extra sensitive multi-touch sensing
• Noise suppression technology to combat ambient and
power-line noise
- Up to 240 VPP between 1 Hz and 1 kHz sinusoidal
waveform (no touches)
- IEC 61000-4-6, 7 Vrms, Class A (normal touch
operation) conducted noise immunity
Keys
• Up to 16 nodes can be allocated as mutual
capacitance sensor keys in addition to the
touchscreen, defined as 1 key array (subject to
availability of X and Y lines and other configurations)
• Adjacent Key Suppression (AKS) technology is
supported for false key touch prevention
Touch Sensor Technology
• Discrete/out-cell support including glass and PET filmbased sensors
• On-cell/touch-on display support including TFT, LCD
(ITPS, IPS) and OLED
• Synchronization with display refresh timing capability
• Support for standard (for example, Diamond) and
proprietary sensor patterns (review of designs by
Microchip or a Microchip-qualified touch sensor
module partner is recommended)
Front Panel Material
• Works with PET or glass, including curved profiles
(configuration and stack-up to be approved by
Microchip or a Microchip-qualified touch sensor
module partner)
• 10 mm glass (or 5 mm PMMA) with bare finger
(dependent on sensor size, touch size, configuration
and stack-up)
• 6 mm glass (or 3 mm PMMA) with multi-finger 5 mm
glove (2.7 mm PMMA equivalent) (dependent on
sensor size, touch size, configuration and stack-up)
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• Stylus Support
- Supports passive stylus with 1.5 mm contact
diameter, subject to configuration, stack-up, and
sensor design
• Scan Speed
- Typical report rate for 10 touches 90 Hz (subject
to configuration)
- Initial touch latency 90 ns
Vdd
VddIO
(VddIO)
RESET
> 90 ns
Note: When using external RESET at power-up,
VddIO must not be enabled after Vdd
It is recommended that customer designs include the capability for the host to control all the maXTouch power supplies
and pull the RESET line low.
After power-up, the device typically takes 48 ms to 70 ms before it is ready to start communications, depending on the
configuration.
NOTE
Device initialization will not complete until after all the power supplies are present. If any power supply is
not present, internal initialization stalls and the device will not communicate with the host.
If the RESET line is released before the AVdd supply has reached its nominal voltage (see Figure 5-2), then some
additional operations need to be carried out by the host. There are two options open to the host controller:
• Start the part in Deep Sleep mode and then send the command sequence to set the cycle time to wake the part
and allow it to run normally. Note that in this case a calibration command is also needed.
• Send a RESET command.
DS40002409A-page 16
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
FIGURE 5-2:
POWER SEQUENCING ON THE MXT228UD-MAU002 – LATE RISE ON AVDD
RESET deasserted before AVdd at
nominal level
(Nom)
AVdd
Vdd
(Nom)
VddIO
(Nom)
(VddIO)
RESET
5.2
Hardware Reset
The RESET pin can be used to reset the device whenever necessary. The RESET pin must be asserted low for at least
90 ns to cause a reset. After the host has released the RESET pin, the device typically takes 47 ms to 70 ms before it
is ready to start communications, depending on the configuration. It is recommended to connect the RESET pin to a
host controller to allow the host to initiate a full hardware reset without requiring the mXT228UD-MAU002 to be powered
down.
WARNING
The device should be reset only by using the RESET line. If an attempt is made to reset by removing
the power from the device without also sending the signal lines low, power will be drawn from the
communication and I/O lines and the device will not reset correctly.
Make sure that any lines connected to the device are below or equal to Vdd during power-up and power-down. For
example, if RESET is supplied from a different power domain to the VDDIO pin, make sure that it is held low when Vdd
is off. If this is not done, the RESET signal could parasitically couple power via the RESET pin into the Vdd supply.
NOTE
5.3
The voltage level on the RESET pin of the device must never exceed VddIO (digital supply voltage).
Software Reset
A software RESET command (using the Command Processor T6 object) can be used to reset the chip. A software reset
typically takes 69 ms to 90 ms before it is ready to start communications, depending on the configuration.
The reset flag is set in the Command Processor T6 object message data to indicate to the host that it has just completed
a reset cycle. This bit can be used by the host to detect any unexpected brownout events. This allows the host to take
any necessary corrective actions, such as reconfiguration.
5.4
CHG Line
After the device has reset, it asserts the CHG line to signal to the host that a message is available.
NOTE
The CHG line is briefly set (~100 ms) as an input during power-up or reset. It is therefore particularly
important that the line should be allowed to float high via the CHG line pull-up resistor during this period: it
should never be driven by the host (see Section 11.5.3 “Reset Timings”).
At power-on, the device can be configured to perform self tests (using the Self Test Control T10 object) to check for
faults in the device.
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 17
mXT228UD-MAU002 2.0
5.5
Power-up and Reset Sequence – VddIO Enabled after Vdd
The power-up sequence that can be used in applications where VddIO must be powered up after Vdd, is shown in
Figure 5-3.
In this case the communication interface to the maXTouch device is not driven by the host system. The RESET and
CHG lines are connected to VddIO using suitable pull-up resistors. Vdd is powered up, followed by VddIO, no more than
10 ms after Vdd. Due to the pull-up resistors, RESET and CHG lines will rise with VddIO. The internal POR system
ensures reliable boot up of the device and the CHG line will go low approximately 48 ms to 70 ms (depending on the
configuration) after Vdd to notify the host that the device is ready to start communication.
FIGURE 5-3:
POWER-UP SEQUENCE
< 10 ms
Vdd
VddIO
RESET
RESET
No
No External
External drive.
drive. Pull-up
Pull-up resistor
resistor to
to VddIO
VddIO on
on RESET
RESET and
and CHG.
CHG
When
VddIO rises,
rises, RESET
RESET and
and CHG
CHG rise
when VddIO
rise with
with VddIO.
VddIO
CHG
CHG
~48 ms
to 70
> 90
msms (1)
Note 1:
DS40002409A-page 18
Depends on configuration
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mXT228UD-MAU002 2.0
6.0
DETAILED OPERATION
6.1
Touch Detection
The mXT228UD-MAU002 allows for both mutual and self capacitance measurements, with the self capacitance
measurements being used to augment the mutual capacitance measurements to produce reliable touch information.
When self capacitance measurements are enabled, touch classification is achieved using both mutual and self
capacitance touch data. This has the advantage that both types of measurement systems can work together to detect
touches under a wide variety of circumstances.
Mutual capacitance touch data is used wherever possible to classify touches as this has greater granularity than self
capacitance measurements and provides positional information on touches.
Self capacitance measurements, on the other hand, allow for the detection of single touches in extreme cases, such as
single thick glove touches, when touches can only be detected by self capacitance data and may be missed by mutual
capacitance touch detection.
6.2
Operational Modes
The device operates in two modes: Active (touch detected) and Idle (no touches detected). Both modes operate as a
series of burst cycles. Each cycle consists of a short burst (during which measurements are taken) followed by an
inactive sleep period. The difference between these modes is the length of the cycles. Those in idle mode typically have
longer sleep periods. The cycle length is configured using the IDLEACQINT and ACTVACQINT settings in the Power
Configuration T7. In addition, an Active to Idle Timeout setting is provided.
6.3
Detection Integrator
The device features a touch detection integration mechanism. This acts to confirm a detection in a robust fashion. A
counter is incremented each time a touch has exceeded its threshold and has remained above the threshold for the
current acquisition. When this counter reaches a preset limit the sensor is finally declared to be touched. If, on any
acquisition, the signal is not seen to exceed the threshold level, the counter is cleared and the process has to start from
the beginning.
The detection integrator is configured using the appropriate touch objects (Multiple Touch Touchscreen T100, Key Array
T15).
6.4
Sensor Acquisition
The charge time for mutual capacitance measurements is set using the Acquisition Configuration T8 object. The device
combines a number of factors together to arrive at the total acquisition time for one drive line (that is, one X line for
mutual capacitance acquisitions or one axis for self capacitance acquisitions).
The following constraints apply on the mXT228UD-MAU002:
• The per X line mutual capacitance touch measurement and the per axis self capacitance measurement should
not exceed 2 ms. Furthermore, the total acquisition time for the sensor as a whole must not exceed 250 ms. In the
event of a timeout, a SIGERR may be reported.
• The high and low pulse periods must not exceed 51.26 µs each. This means that the maximum possible burst
period is 102.46 µs (that is, a minimum frequency of 9.76 kHz). In addition, the burst period must not be less than
4 µs (that is, a maximum frequency of 250 kHz).
Unpredictable system behavior might occur if any of the above constraints are not met.
Care should be taken to configure all the objects that can affect the measurement timing (for example, drift and noise
measurement interval settings) so that these limits are not exceeded.
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 19
mXT228UD-MAU002 2.0
6.5
Calibration
Calibration is the process by which a sensor chip assesses the background capacitance on each node. Calibration
occurs in a variety of circumstances, for example:
• When determined by the mutual capacitance recalibration process, as controlled by the Acquisition Configuration
T8 object
• When determined by the self capacitance recalibration process, as controlled by the Self Capacitance
Configuration T111 object
• When the Retransmission Compensation T80 object detects calibrated-in moisture has been removed
• Following a Self Capacitance Global Configuration T109 Tune command
• When the host issues a recalibrate command
• When certain configuration settings are changed
6.6
Digital Filtering and Noise Suppression
The mXT228UD-MAU002 supports on-chip filtering of the acquisition data received from the sensor. Specifically, the
Noise Suppression T72 object provides an algorithm to suppress the effects of noise (for example, from a noisy charger
plugged into the user’s product). This algorithm can automatically adjust some of the acquisition parameters during
operation to filter the Analog-to-Digital Conversions (ADCs) received from the sensor.
Additional noise suppression is provided by the Self Capacitance Noise Suppression T108 object. Similar in both design
and configuration to the Noise Suppression T72 object, the Self Capacitance Noise Suppression T108 object is the
noise suppression interface for self capacitance touch measurements.
Noise suppression is triggered when a noise source is detected.
• The host driver code can indicate when a noise source is present.
• The noise suppression is also triggered based on the noise levels detected using internal line measurements.The
Noise Suppression T72 and Self Capacitance Noise Suppression T108 object selects the appropriate controls to
suppress the noise present in the system.
6.7
EMC Reduction
The mXT228UD-MAU002 has the following mechanisms to help reduce EMC emissions and ensure that the user’s
product operates within the desired EMC limits:
• Configurable Voltage Reference Mode – Allows for the selection of voltage swing of the self capacitance
measurements.This feature is configured by the Self Capacitance Global Configuration T109 object.
• Input Buffer Power Configuration – Controls the positive/negative drive strength of the Input Buffer for self
capacitance measurements. This feature is configured by the Self Capacitance Global Configuration T109 object.
• Configurable Input Amplifier Bias – Controls the Input Amplifier Bias. This feature is configured by the Self
Capacitance Global Configuration T109 object.
6.8
Shieldless Support and Display Noise Suppression
The mXT228UD-MAU002 can support shieldless sensor design even with a noisy LCD.
The Optimal Integration feature is not filtering as such, but enables the user to use a shorter integration window. The
integration window optimizes the amount of charge collected against the amount of noise collected, to ensure an optimal
SNR. This feature also benefits the system in the presence of an external noise source. This feature is configured using
the Shieldless T56 object.
Display noise suppression allows the device to overcome display noise simultaneously with external noise. This feature
is based on filtering provided by the Lens Bending T65 object (see Section 6.11 “Lens Bending”).
DS40002409A-page 20
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
6.9
Retransmission Compensation
The device can limit the undesirable effects on the mutual capacitance touch signals caused by poor device coupling to
ground, such as poor sensitivity and touch break-up. This is achieved using the Retransmission Compensation T80
object. This object can be configured to allow the touchscreen to compensate for signal degradation due to these
undesirable effects. If self capacitance measurements are also scheduled, the Retransmission Compensation T80
object will use the resultant data to enhance the compensation process.
The Retransmission Compensation T80 object is also capable of compensating for water presence on the sensor if self
capacitance measurements are scheduled. In this case, both mutual capacitance and self capacitance measurements
are used to detect moisture and then, once moisture is detected, self capacitance measurements are used to detect
single touches in the presence of moisture.
6.10
Grip Suppression
The device has grip suppression functionality to suppress false detections from a user’s grip.
Grip suppression works by specifying a boundary around a touchscreen, within which touches can be suppressed whilst
still allowing touches in the center of the touchscreen. This ensures that an accidental hand touch on the edge is
suppressed while still allowing a “real” (finger) touch towards the center of the screen. Mutual capacitance grip
suppression is configured using the Grip Suppression T40 object.
6.11
Lens Bending
The device supports algorithms to eliminate disturbances from the measured signal.
When the sensor suffers from the screen deformation (lens bending) the signal values acquired by normal procedure
are corrupted by the disturbance component (bend). The amount of bend depends on:
• The mechanical and electrical characteristics of the sensor
• The amount and location of the force applied by the user touch to the sensor
• The Lens Bending T65 object measures the bend component and compensates for any distortion caused by the
bend. As the bend component is primarily influenced by the user touch force, it can be used as a secondary
source to identify the presence of a touch. The additional benefit of the Lens Bending T65 object is that it will
eliminate LCD noise as well.
6.12
Glove Detection
The device has glove detection algorithms that process the measurement data received from the touchscreen
classifying touches as potential gloved touches.
The Glove Detection T78 object is used to detect glove touches. In Normal Mode the Glove Detection T78 object applies
vigorous glove classification to small signal touches to minimize the effect of unintentional hovering finger reporting.
Once a gloved touch is found, the Glove Detection T78 object can enter Glove Confidence Mode. In this mode the
device expects the user to be wearing gloves so the classification process is much less stringent.
6.13
Stylus Support
The mXT228UD-MAU002 allows for the particular characteristics of passive stylus touches, whilst still allowing
conventional finger touches to be detected. The touch sensitivity and threshold controls for stylus touches are
configured separately from those for conventional finger touches so that both types of touches can be accommodated.
Stylus support ensures that the small touch area of a stylus registers as a touch, as this would otherwise be considered
too small for the touchscreen. Additionally, there are controls to distinguish a stylus touch from an unwanted
approaching finger (such as on the hand holding the stylus).
Passive stylus touches are configured by the Passive Stylus T47 object. There is one instance of the Passive Stylus
T47 object for each Multiple Touch Touchscreen T100 object present on the device.
6.14
Unintentional Touch Suppression
The Touch Suppression T42 object provides a mechanism to suppress false detections from unintentional touches from
a large body area, such as from a palm. The Touch Suppression T42 object also provides Maximum Touch Suppression
to suppress all touches if more than a specified number of touches has been detected.
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 21
mXT228UD-MAU002 2.0
6.15
Adjacent Key Suppression Technology
Adjacent Key Suppression (AKS) technology is a patented method used to detect which touch object (Multiple Touch
Touchscreen T100 or Key Array T15) is touched, and to suppress touches on the other touch objects, when touch
objects are located close together.
The device has two levels of AKS:
• The first level works between the touch objects (Multiple Touch Touchscreen T100 and Key Array T15). The touch
objects are assigned to AKS groups. If a touch occurs within one of the touch objects in a group, then touches
within other objects inside that group are suppressed. For example, if a touchscreen and a Key Array are placed in
the same AKS group, then a touch in the touchscreen will suppress touches in the Key Array, and vice versa.
Objects can be in more than one AKS group.
• The second level of AKS is internal AKS within an individual Key Array object. If internal AKS is enabled, then
when one key is touched, touches on all the other keys within the Key Array are suppressed. Note that internal
AKS is not present on other types of touch objects.
6.16
Device Encryption
For added security, the mXT228UD-MAU002 allows for the encryption of important configuration parameters within the
device, and for the encryption of messages sent by the device.
The default state of the mXT228UD-MAU002 is to be unencrypted, which allows the host to interact with the device
using the standard Object-based Protocol in the same manner as any other unencrypted maXTouch device. However,
the host can enable encryption if desired. This uses the AES 128 algorithm (Cipher Block Chaining mode) for the
encryption and decryption of data. One or more of the following encryption modes are possible:
• Encrypted configuration read/write
• Encrypted Message Processor T5 messages
Encryption is requested by downloading the encryption parameters to the Serial Data Command T68 object. Encryption
is then activated when the device is next reset. If the device has active encryption, the Variant ID is reported with bit 7
set to 1. This provides a method for the host controller to detect if encryption is in use.
The current encryption status can be read from the device using the Encryption Status T2 object.
DS40002409A-page 22
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mXT228UD-MAU002 2.0
7.0
I2C COMMUNICATIONS
Communication with the mXT228UD-MAU002 is carried out over the I2C interface.
The I2C interface is used in conjunction with the CHG line. The CHG line going active signifies that a new data packet
is available. This provides an interrupt-style interface and allows the device to present data packets when internal
changes have occurred. See Section 7.5 “CHG Line” for more information.
7.1
I2C Address
The mXT228UD-MAU002 supports one fixed I2C device address: 0x4A.
The I2C address is shifted left to form the SLA+W or SLA+R address when transmitted over the I2C interface, as shown
in Table 7-1.
TABLE 7-1:
FORMAT OF SLA+W/SLA+R
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Address: 0x4A
7.2
Bit 0
Read/write
Writing To the Device
An I2C WRITE cycle consists of the following bytes:
START
1 bit
I2C START condition
SLA+W
1 byte
I2C address of the device (see Section 7.1 “I2C Address”)
Address
(LSByte, MSByte)
2 bytes
Address of the location at which the data writing starts. This address is stored
as the address pointer.
Data Size
(only if encryption
is active)
2 bytes
If writing to an encrypted object, the size of the data to be written, including the
data CRC (if requested). Otherwise these bytes must be set to zero.
Note that these bytes will have a non-zero value only if writing one or more
byes of data to an encrypted object. In all other cases the size should be set to
zero (that is, when the object is not encrypted, or encryption is enabled for
message reads only, or the data is zero bytes in length).
NOTE
These bytes are present only if encryption is active; they are not
present if encryption is not active.
Data
0 or more The actual data to be written. The data is written to the device, starting at the
bytes
location of the address pointer. The address pointer returns to its starting value
when the I2C STOP condition is detected.
CRC (optional)
1 byte
An optional 8-bit CRC that includes all the bytes that have been sent, including
the two address bytes and the data size bytes (if encryption is active), but not
the SLA+W byte. If the device detects an error in the CRC during a write
transfer, a COMSERR fault is reported by the Command Processor T6 object.
See Section 7.3 “I2C Writes in Checksum Mode” for more details
Padding to 16 bytes Maximum
(only if encrypted 15 bytes
writes are enabled)
If writing to an encrypted object, and there are one or more bytes of data
(excluding the CRC), the data block (including the CRC, if present) must be
padded to 16 bytes.
NOTE
STOP
1 bit
If the data is zero bytes in size, the padding is not necessary and
the data block will consist of the CRC only (if present).
I2C STOP condition
Figure 7-1 and Figure 7-1 show examples of writing four bytes of data to contiguous addresses starting at 0x1234.
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 23
mXT228UD-MAU002 2.0
FIGURE 7-1:
EXAMPLE OF A FOUR-BYTE WRITE – ENCRYPTION NOT ACTIVE
START
0x34
SLA+W
0x12
0x96
0x9B
STOP
0xA5
Write Data
Write Address
(LSB MSB)
FIGURE 7-2:
0xA0
EXAMPLE OF A FOUR-BYTE WRITE – ENCRYPTION ACTIVE
Writing to an Unencrypted Object
START SLA+W
0x34
0x12
0x00
0x00
0x96 0x9B 0xA0 0xA5
Write Address Data Size = 0
(LSB MSB)
STOP
Write Data
(Unencrypted)
Writing to an Encrypted Object
START SLA+W
0x34
0x12
Write Address
(LSB MSB)
7.3
0x04
0x00
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
STOP
Write Data
(Padded to 16 bytes and encrypted)
Data Size
(LSB MSB)
I2C Writes in Checksum Mode
In I2C checksum mode an 8-bit CRC is added to all I2C writes. The CRC is sent following the last data byte. All the bytes
sent are included in the CRC, including the two address bytes and the two data size bytes (if encryption is active). Any
command or data sent to the device is processed even if the CRC fails.
To indicate that a checksum is to be sent in the write, the most significant bit of the MSByte of the write address is set
to 1. For example, the I2C command shown in Figure 7-3 writes a value of 150 (0x96) to address 0x1234 with a
checksum. The address is changed to 0x9234 to indicate checksum mode.
FIGURE 7-3:
EXAMPLE OF A WRITE TO ADDRESS 0x1234 WITH A CHECKSUM – ENCRYPTION NOT
ACTIVE
START
SLA+W
0x34
0x92
Write Address
(LSB, MSB)
DS40002409A-page 24
0x96
Checksum
STOP
Write Data
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mXT228UD-MAU002 2.0
FIGURE 7-4:
EXAMPLE OF A WRITE TO ADDRESS 0x1234 WITH A CHECKSUM – ENCRYPTION ACTIVE
Writing to an Unencrypted Object
START SLA+W
0x34
0x92
0x00
0x00
0x96 0x9B 0xA0 0xA5 CRC
Write Address Data Size = 0
(LSB MSB)
Write Data
(Unencrypted)
STOP
Data CRC
(Unencrypted)
Writing to an Encrypted Object
START SLA+W
0x34
0x92
Write Address
(LSB MSB)
7.4
0x05
0x00
Data Size
(LSB MSB)
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
STOP
Write Data
(Padded to 16 bytes and encrypted)
Reading From the Device
Two I2C bus activities must take place to read from the device. The first activity is an I2C write to set the address pointer
(LSByte then MSByte). The second activity is the actual I2C read to receive the data. The address pointer returns to its
starting value when the read cycle NACK or STOP is detected.
It is not necessary to set the address pointer before every read. The address pointer is updated automatically after every
read operation. The address pointer will be correct if the reads occur in order. In particular, when reading multiple
messages from the Message Processor T5 object, the address pointer is automatically reset to the address of the
Message Processor T5 object, in order to allow continuous reads (see Section 7.4.2 “Reading Status Messages with
DMA”).
NOTE
Encryption functionality on the mXT228UD-MAU002 means that if the host read request falls within the
Message Processor T5 address space, but not at its start address, the device considers it a valid
Message Processor T5 message read. The device therefore sends the entire Message Processor T5
message.
Note that the message may be encrypted or unencrypted, depending on the message encryption setting.
The WRITE and READ cycles consist of a START condition followed by the I2C address of the device (SLA+W or
SLA+R respectively).
Figure 7-5 and Figure 7-6 show the I2C commands to read four bytes starting at address 0x1234.
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 25
mXT228UD-MAU002 2.0
FIGURE 7-5:
EXAMPLE OF A FOUR-BYTE READ – ENCRYPTION NOT ACTIVE
Set Address Pointer
START
0x12
0x34
SLA+W
STOP
Read Address
(LSB, MSB)
Read Data
START
SLA+R
0x96
0x9B
0xA0
0xA5
STOP
Read Data
FIGURE 7-6:
EXAMPLE OF A FOUR-BYTE READ – ENCRYPTION ACTIVE
Set Address Pointer
START SLA+W
0x34
0x12
0x00
0x00
STOP
Data Size = 0
Read Address
(LSB, MSB)
Read Data – Unencrypted Object
START SLA+R
0x96
0x9B
0xA0
0xA5
STOP
Read Data
(Unencrypted)
Read Data – Encrypted Object
START SLA+R
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
STOP
Read Data
(Padded to 16 bytes and encrypted)
NOTE
DS40002409A-page 26
At least one data byte must be read during an I2C READ transaction; it is illegal to abort the
transaction with an I2C STOP condition without reading any data.
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mXT228UD-MAU002 2.0
7.4.1
READING A MESSAGE FROM THE MESSAGE PROCESSOR T5 OBJECT
An I2C read of the Message Processor T5 object contains the following bytes:
START
1 bit
I2C START condition
SLA+R
1 byte
I2C address of the device (see Section 7.1 “I2C Address”)
1 byte
Message report ID
Report ID
Data
9 bytes
The message data (that is, the Message Processor T5 MESSAGE field)
CRC (optional)
1 byte
An 8-bit CRC (if requested) for the Message Processor T5 report
ID and message data
See Section 7.3 “I2C Writes in Checksum Mode” for more details on how to
request a checksum
Padding to 16 bytes 5 or 6 bytes If the encryption of Message Processor T5 messages is enabled, the data
(only if encrypted
block (including the CRC, if present) is padded to 16 bytes.
messages enabled)
STOP
I2C STOP condition
1 bit
Figure 7-7 shows an example read from the Message Processor T5 object. To read multiple messages using Direct
Memory Access, see Section 7.4.2 “Reading Status Messages with DMA”.
FIGURE 7-7:
EXAMPLE READ FROM MESSAGE PROCESSOR T5 WITH A CHECKSUM –
ENCRYPTION NOT ACTIVE
Set Address Pointer
START
SLA+W
LSB
MSB
CRC
STOP
Address of Message Processor T5 Object
Read Data
START
SLA+R
Report ID
Data 0
...
Data n
CRC
STOP
Message Processor T5 Object
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 27
mXT228UD-MAU002 2.0
FIGURE 7-8:
EXAMPLE READ FROM MESSAGE PROCESSOR T5 WITH A CHECKSUM –
ENCRYPTION ACTIVE
Set Address Pointer
START
SLA+W
LSB
0x00
MSB | 0x80
0x00
CRC
STOP
Data Size = 0
Address of
Message Processor T5 Object
Read Data – Unencrypted Message
START SLA+R Rpt ID Data 0 Data 1 Data 2 Data 3 Data 4 Data 5 Data 6 Data 7 Data 8
CRC
STOP
Message Processor T5 Object
(Unencrypted)
Read Data – Encrypted Message
START SLA+R
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
STOP
Message Processor T5 Object
(Padded to 16 bytes and encrypted)
7.4.2
READING STATUS MESSAGES WITH DMA
The device facilitates the easy reading of multiple messages using a single continuous read operation. This allows the
host hardware to use a Direct Memory Access (DMA) controller for the fast reading of messages, as follows:
1.
2.
3.
4.
5.
6.
The host uses a write operation to set the address pointer to the start of the Message Count T44 object, if
necessary. Note that the STOP condition at the end of the read resets the address pointer to its initial location,
so it may already be pointing at the Message Count T44 object following a previous message read. If a checksum
is required on each message, the most significant bit of the MSByte of the read address must be set to 1.
The host starts the read operation of the message by sending a START condition.
The host reads the Message Count T44 object (one byte) to retrieve a count of the pending messages.
The host calculates the number of bytes to read, as follows:
- If encryption is not enabled, by multiplying the message count by the size of the Message Processor T5
object. Note that the host should have already read the size of the Message Processor T5 object in its
initialization code.
- If encryption is enabled, by multiplying the message count by 16. Note that, in order to decrypt the
message data, the host will still need to know the size of the Message Processor T5 object.
Note that the size of the Message Processor T5 object as recorded in the Object Table includes the checksum. If
a checksum has not been requested, one byte should be deducted from the size of the object.
That is: number of bytes = count × (size – 1).
The host reads the calculated number of message bytes. It is important that the host does not send a STOP
condition during the message reads, as this will terminate the continuous read operation and reset the address
pointer. No START and STOP conditions must be sent between the messages.
The host sends a STOP condition at the end of the read operation after the last message has been read. The
NACK condition immediately before the STOP condition resets the address pointer to the start of the Message
Count T44 object.
DS40002409A-page 28
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
Figure 7-9 shows an example of using a continuous read operation to read three messages from the device without a
checksum. Figure 7-10 shows the same example with a checksum.
FIGURE 7-9:
CONTINUOUS MESSAGE READ EXAMPLE – NO CHECKSUM
Set Address Pointer
START
SLA+W
LSB
STOP
MSB
Address of
Message Count T44 Object
Read Message Count
Continuous
Read
START
SLA+R
Count = 3
Message Count T44 Object
Read Message Data
size bytes
Report ID
Data
Data
Message Processor T5 Object – Message # 1
Report ID
Data
Data
Message Processor T5 Object – Message # 2
Report ID
Data
Data
STOP
Message Processor T5 Object – Message # 3
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 29
mXT228UD-MAU002 2.0
FIGURE 7-10:
CONTINUOUS MESSAGE READ EXAMPLE – I2C CHECKSUM MODE
Set Address Pointer
START
SLA+W
LSB
MSB | 0x80
Checksum
STOP
Address of
Message Count T44 Object
Read Message Count
Continuous
Read
START
SLA+R
Count = 3
Message Count T44 Object
Read Message Data
size bytes
Report ID
Data
Data
Checksum
Message Processor T5 Object – Message # 1
Report ID
Data
Data
Checksum
Message Processor T5 Object – Message # 2
Report ID
Data
Data
Checksum
STOP
Message Processor T5 Object – Message # 3
DS40002409A-page 30
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
If encryption is enabled for Message Processor T5 message reads, then each message read using DMA will need to
be decrypted. An example of this is shown in Figure 7-11. Note that this example also assumes the use of a CRC on
the message reads, although this is not necessary.
FIGURE 7-11:
EXAMPLE READ FROM MESSAGE PROCESSOR T5 – ENCRYPTION ACTIVE
Set Address Pointer
START
SLA+W
LSB
0x00
MSB | 0x80
Address of
Message Count T44 Object
0x00
CRC
STOP
Data Size = 0
Read Message Count
Continuous
Read
START SLA+R Count=3
Message Count T44 Object
Read Message Data
X
X
X
X
Encrypted CRC
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Message Processor T5 Object – Message # 1
(Padded to 16 bytes and encrypted)
X
X
X
X
X
X
X
X
X
X
X
X
Message Processor T5 Object – Message # 2
(Padded to 16 bytes and encrypted)
X
X
X
X
X
X
X
X
X
X
X
X
STOP
Message Processor T5 Object – Message # 3
(Padded to 16 bytes and encrypted)
NOTE:
7.5
Example assumes CRC mode is being used.
CHG Line
The CHG line is an active-low, open-drain output that is used as an interrupt to alert the host that the client is ready to
send a response or that an OBP message is pending and ready to be read from the host. This provides the host with
an interrupt-style interface with the potential for fast response times. It reduces the need for wasteful I2C
communications.
NOTE
The host should always use the CHG line as an indication that a message is ready to be read from the
Message Processor T5 object; the host should never poll the device for messages.
The CHG line should always be configured as an input on the host during normal usage. This is particularly important
after power-up or reset (see Section 5.0 “Power-up / Reset Requirements”).
A pull-up resistor is required to VddIO (see Section 2.0 “Schematic”).
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 31
mXT228UD-MAU002 2.0
The CHG line operates in two modes when it is used with I2C communications, as defined by the Communications
Configuration T18 object.
FIGURE 7-12:
CHG LINE MODES FOR I2C-COMPATIBLE TRANSFERS
Mode 0
I2C Interface
ACK
STARTSLA+R
B0
NACK
B1
...
Bn
B0
Message #1
B1
...
Bn
...
B0
Message #2
B1
...
Bn
STOP
Message #m
CHG Line
...
CHG line High or Low; see text
Mode 1
I2C Interface
ACK
STARTSLA+R
B0
B1
...
Message #1
CHG Line
Bn
B0
B1
...
Bn
...
Message #2
B0
B1
...
Bn
STOP
Message #m
...
CHG line High or Low; see text
In Mode 0 (edge-triggered operation):
1.
2.
3.
The CHG line goes low to indicate that a message is present.
The CHG line goes high when the first byte of the first message (that is, its report ID) has been sent and
acknowledged (ACK sent) and the next byte has been prepared in the buffer.
The STOP condition at the end of an I2C transfer causes the CHG line to stay high if there are no more messages.
Otherwise the CHG line goes low to indicate a further message.
Note that Mode 0 also allows the host to continually read messages by simply continuing to read bytes back without
issuing a STOP condition. Message reading should end when a report ID of 255 (“invalid message”) is received.
Alternatively the host ends the transfer by sending a NACK after receiving the last byte of a message, followed by a
STOP condition. If there is another message present, the CHG line goes low again, as in step 1. In this mode the state
of the CHG line does not need to be checked during the I2C read.
In Mode 1 (level-triggered operation):
1.
2.
3.
The CHG line goes low to indicate that a message is present.
The CHG line remains low while there are further messages to be sent after the current message.
The CHG line goes high again only once the first byte of the last message (that is, its report ID) has been sent
and acknowledged (ACK sent) and the next byte has been prepared in the output buffer.
Mode 1 allows the host to continually read the messages until the CHG line goes high, and the state of the CHG line
determines whether or not the host should continue receiving messages from the device.
NOTE
The state of the CHG line should be checked only between messages and not between the bytes of a
message. The precise point at which the CHG line changes state cannot be predicted and so the state of
the CHG line cannot be guaranteed between bytes.
The Communications Configuration T18 object can be used to configure the behavior of the CHG line. In addition to the
CHG line operation modes described above, this object allows direct control over the state of the CHG line.
7.6
SDA and SCL
The I2C bus transmits data and clock with SDA and SCL respectively. These are open-drain. The device can only drive
these lines low or leave them open. The termination resistors (Rp) pull the line up to VddIO if no I2C device is pulling it
down.
DS40002409A-page 32
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
The termination resistors should be chosen so that the rise times on SDA and SCL meet the I2C specifications for the
interface speed being used, bearing in mind other loads on the bus. For best latency performance, it is recommended
that no other devices share the I2C bus with the maXTouch controller.
7.7
Clock Stretching
The device supports clock stretching in accordance with the I2C specification. It may also instigate a clock stretch if a
communications event happens during a period when the device is busy internally. The maximum clock stretch is 2 ms
and typically less than 350 µs.
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 33
mXT228UD-MAU002 2.0
8.0
PCB DESIGN CONSIDERATIONS
8.1
Introduction
The following sections give the design considerations that should be adhered to when designing a PCB layout for use
with the mXT228UD-MAU002. Of these, power supply and ground tracking considerations are the most critical.
By observing the following design rules, and with careful preparation for the PCB layout exercise, designers will be
assured of a far better chance of success and a correctly functioning product.
8.2
Printed Circuit Board
Microchip recommends the use of a four-layer printed circuit board for mXT228UD-MAU002 applications. This, together
with careful layout, will ensure that the board meets relevant EMC requirements for both noise radiation and
susceptibility, as laid down by the various national and international standards agencies.
8.2.1
PCB CLEANLINESS
Modern no-clean-flux is generally compatible with capacitive sensing circuits.
CAUTION!
8.3
8.3.1
If a PCB is reworked to correct soldering faults relating to any device, or to any associated traces or
components, be sure that you fully understand the nature of the flux used during the rework process.
Leakage currents from hygroscopic ionic residues can stop capacitive sensors from functioning. If you
have any doubts, a thorough cleaning after rework may be the only safe option.
Power Supply
SUPPLY QUALITY
While the device has good Power Supply Rejection Ratio properties, poorly regulated and/or noisy power supplies can
significantly reduce performance.
Particular care should be taken of the AVdd supply, as it supplies the sensitive analog stages in the device.
8.3.2
SUPPLY RAILS AND GROUND TRACKING
Power supply and clock distribution are the most critical parts of any board layout. Because of this, it is advisable that
these be completed before any other tracking is undertaken. After these, supply decoupling, and analog and high speed
digital signals should be addressed. Track widths for all signals, especially power rails should be kept as wide as
possible in order to reduce inductance.
The Power and Ground planes themselves can form a useful capacitor. Flood filling for either or both of these supply
rails, therefore, should be used where possible. It is important to ensure that there are no floating copper areas
remaining on the board: all such areas should be connected to the ground plane. The flood filling should be done on the
outside layers of the board.
8.3.3
POWER SUPPLY DECOUPLING
Decoupling capacitors should be fitted as specified in Section 2.2 “Schematic Notes”.
The decoupling capacitors must be placed as close as possible to the pin being decoupled. The traces from these
capacitors to the respective device pins should be wide and take a straight route. They should be routed over a ground
plane as much as possible. The capacitor ground pins should also be connected directly to a ground plane.
Surface mounting capacitors are preferred over wire-leaded types due to their lower ESR and ESL. It is often possible
to fit these decoupling capacitors underneath and on the opposite side of the PCB to the digital ICs. This will provide
the shortest tracking, and most effective decoupling possible.
8.3.4
VOLTAGE PUMP
The traces for the voltage pump capacitor between EXTCAP0 and EXTCAP1 (Cd on the schematic in Section 2.0
“Schematic”) should be kept as short and as wide as possible for best pump performance. They should also be routed
as parallel and as close as possible to each other in order to reduce emissions, and ideally the traces should be the
same length.
DS40002409A-page 34
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
8.3.5
VOLTAGE REGULATORS
Each supply rail requires a Low Drop-Out (LDO) voltage regulator, although an LDO can be shared where supply rails
share the same voltage level.
Figure 8-1 shows an example circuit for an LDO.
FIGURE 8-1:
EXAMPLE LDO CIRCUIT
SUPPLY FROM HOST
SUPPLY TO MAXTOUCH DEVICE
VIN
VOUT
SENSE/ADI
GND
SHDN
GND
BYP
GND
GND
An LDO regulator should be chosen that provides adequate output capability, low noise, no-load stability, good load
regulation and step response. The mXT228UD-MAU002 has been qualified for use only with the Microchip LDOs listed
in Table 8-1. However, some alternative LDOs with similar specifications are listed in Table 8-2. Microchip has not tested
this maXTouch controller with any of these alternative LDOs. Microchip cannot guarantee the functionality or
performance of this maXTouch controller with these or any other LDO besides those listed in Table 8-1.
NOTE
Microchip recommends that a minimum of a 1.0 µF ceramic, low ESR capacitor at the input and output of
these devices is always used. The datasheet for the device should always be referred to when selecting
capacitors and the typical recommended values, types and dielectrics adhered to.
Sufficient output capacitance should be provided such that the output rate of rise is compatible with the
mXT228UD-MAU002 power rail specifications (see Section 11.2.1 “DC Characteristics”). This can be
achieved by a combination of output capacitance on the pins of the LDO and bulk capacitance at the
inputs to the mXT228UD-MAU002.
.
TABLE 8-1:
LDO REGULATORS – QUALIFIED FOR USE
Manufacturer
Device
Current Rating (mA)
Microchip Technology Inc.
MCP1824
300
Microchip Technology Inc.
MCP1824S
300
Microchip Technology Inc.
MAQ5300
300
Microchip Technology Inc.
MIC5504
300
Microchip Technology Inc.
MCP1725
500
Microchip Technology Inc.
MIC5514
300
Microchip Technology Inc.
MIC5323
300
.
TABLE 8-2:
LDO REGULATORS – OTHER DEVICES
Manufacturer
Device
Current Rating (mA)
Analog Devices
ADP122/ADP123
300
Diodes Inc.
AP2125
300
Diodes Inc.
AP7335
300
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 35
mXT228UD-MAU002 2.0
TABLE 8-2:
8.3.6
LDO REGULATORS – OTHER DEVICES (CONTINUED)
Manufacturer
Device
Current Rating (mA)
Linear Technology
LT1763CS8-3.3
500
NXP
LD6836
300
Texas Instruments
LP3981
300
SINGLE SUPPLY OPERATION
When designing a PCB for an application using a single LDO, extra care should be taken to ensure short, low inductance
traces between the supply and the touch controller supply input pins. Ideally, tracking for the individual supplies should
be arranged in a star configuration, with the LDO at the junction of the star. This will ensure that supply current variations
or noise in one supply rail will have minimum effect on the other supplies. In applications where a ground plane is not
practical, this same star layout should also apply to the power supply ground returns.
Only regulators with a 300 mA or greater rating can be used in a single-supply design.
Refer to the following application note for more information:
• Application Note: MXTAN0208 – Design Guide for PCB Layouts for maXTouch Touch Controllers
8.3.7
MULTIPLE VOLTAGE REGULATOR SUPPLY
The AVdd supply stability is critical for the device because this supply interacts directly with the analog front end. If noise
problems exist when using a single LDO regulator, Microchip recommends that AVdd is supplied by a regulator that is
separate from the digital supply. This reduces the amount of noise injected into the sensitive, low signal level parts of
the design.
8.4
Driven Shield Line
The driven shield line is used to provide a guard track around the touchscreen panel that serves as Ground in mutual
capacitance operation and as a driven shield in self capacitance operation.
The guard track must be routed between the groups of X tracks and the groups of Y tracks, as well as between the
combined group of X/Y tracks and Ground. It should be fairly wide to avoid X-to-Y coupling in mutual capacitance
operation, as the guard track will act as Ground in this circumstance.
A guard track is also needed between any self capacitance X/Y lines and mutual capacitance only X/Y lines (for
example, between Multiple Touch Touchscreen T100 and Key Array T15 lines).
DS40002409A-page 36
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
FIGURE 8-2:
EXAMPLE DRIVEN SHIELD ROUTING
Driven Shield and GND
should have overlaps
rather than be continuous
loops to avoid making a
loop antenna.
Touchscreen
Driven Shield separates
X and Y lines from each
other and from GND
GND
GND
X
Y
X
Y
X
Driven Shield
NOTE: Sample touchscreen for illustrative purposes only. The number of X/Y lines available on any given device might differ from that shown here.
Similarly, the routing of the X/Y lines shown should not be taken as indicative of any preferred layout and the user’s layout may vary.
8.5
ESD Ground Routing
To avoid damage due to ESD strikes, the outermost track on the sensor should be an ESD ground (see Figure 8-2). Like
the driven shield, this should completely surround the sensor but with an overlap at the top rather than forming a
complete loop.
To avoid electromagnetic induction of currents into the driven shield trace, a minimum separation of 0.3 mm should be
maintained between the ESD GND trace and the Driven Shield.
The ESD ground traces should be connected to a dedicated ground trace in the PCB, and routed such that ESD strike
currents do not flow under or close to the touch controller or the connecting wiring between it and the touchscreen array.
The ESD ground should be connected in to the main system ground at a star point at the main GND connection to the
PCB.
See also:
• MXTAN0208 – Design guide for PCB Layouts for maXTouch Touch Controllers
8.6
Analog I/O
In general, tracking for the analog I/O signals from the device should be kept as short as possible. These normally go
to a connector which interfaces directly to the touchscreen.
Ensure that adequate ground-planes are used. An analog ground plane should be used in addition to a digital one. Care
should be taken to ensure that both ground planes are kept separate and are connected together only at the point of
entry for the power to the PCB. This is usually at the input connector.
8.7
Component Placement and Tracking
It is important to orient all devices so that the tracking for important signals (such as power and clocks) are kept as short
as possible.
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 37
mXT228UD-MAU002 2.0
8.7.1
DIGITAL SIGNALS
In general, when tracking digital signals, it is advisable to avoid sharp directional changes on sensitive signal tracks
(such as analog I/O) and any clock or crystal tracking.
A good ground return path for all signals should be provided, where possible, to ensure that there are no discontinuities.
8.7.2
QFN PACKAGE RESTRICTIONS
The central pad on the underside of the QFN device should be connected to ground. Do not run any tracks underneath
the body of the device on the top layer of the PCB, only ground. Figure 8-3 shows examples of good and bad tracking.
FIGURE 8-3:
EXAMPLES OF GOOD AND BAD TRACKING
Note: The number of
pins and their functions
is shown for example
purposes only and may
not reflect the actual
number or function on
the device.
Good Tracking
8.8
Bad Tracking
EMC and Other Observations
The following recommendations are not mandatory, but may help in situations where particularly difficult EMC or other
problems are present:
• Try to keep as many signals as possible on the inside layers of the board. If suitable ground flood fills are used on
the top and bottom layers, these will provide a good level of screening for noisy signals, both into and out of the
PCB.
• Ensure that the on-board regulators have sufficient tracking around and underneath the devices to act as a
heatsink. This heatsink will normally be connected to the 0 V or ground supply pin. Increasing the width of the
copper tracking to any of the device pins will aid in removing heat. There should be no solder mask over the
copper track underneath the body of the regulators.
• Ensure that the decoupling capacitors, especially high capacity ceramic type, have the requisite low ESR, ESL
and good stability/temperature properties. Refer to the regulator manufacturer’s datasheet for more information.
DS40002409A-page 38
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
9.0
GETTING STARTED WITH MXT228UD-MAU002
9.1
Establishing Contact
9.1.1
COMMUNICATION WITH THE HOST
The host can use the following interface to communicate with the device:
• I2C interface (see Section 7.0 “I2C Communications”)
9.1.2
POWER-UP SEQUENCE
The power-up sequence is as follows:
1.
2.
3.
9.1.3
After the device has reset, the CHG line goes low to indicate to the host that a message is available. If the CHG
line does not go low within a suitable timeout, there is a problem with the device. The timeout should be chosen
to be, for example, three times the relevant typical values for the system as defined in Section 11.5.3 “Reset
Timings” (for example, 1 second if all POST tests are performed).
Once the CHG line goes low, the host should attempt to read the first 7 bytes of memory from location 0x0000
(that is, the ID Information portion of the Information Block) to establish that the device is present and running
following power-up. This should be done as part of the host’s initialization sequence (see Section 9.1.3 “Host
Initialization”).
The device performs a checksum on the configuration settings held in the non-volatile memory. If the checksum
does not match a stored copy of the last checksum, then this indicates that the settings have become
corrupted. The host should write a correct configuration to the device, and issue a Command Processor T6
Backup command, if the read checksum does not match the expected checksum, or if the configuration error bit
in the message data from the Command Processor T6 object is set.
HOST INITIALIZATION
Once the device has powered up, the host should perform the following initialization steps so that it can communicate
with the device:
1.
Immediately after start-up (once the CHG line goes low), the host attempts to read the ID Information portion of
the Information Block. The ID Information bytes are the first 7 bytes of memory, located at address 0x0000. This
will be used to determine whether the device is encrypted or not, and therefore which communications protocol
to use. A successful read will also confirm that the device is present and running following power-up.
The write transfer to set the address pointer to 0x0000 must be sent using the encryption communications
protocol, even if the device is currently unencrypted. If the device is expecting an encrypted format write transfer,
it will expect, and accept, the entire write transfer. If, however, the device is not currently encrypted it will simply
ignore the extra bytes in the write transfer (see Figure 9-1).
FIGURE 9-1:
WRITE TRANSFER
Address
LSByte
START
SLA+W
0x00
Data Size
MSByte
0x00
LSByte
0x00
MSByte
0x00
STOP
The device ignores these bytes
if the device is not currently encrypted
2.
3.
Once the host has read the Information Block, the host should examine the Variant ID and use it to determine if
encrypted communications are active. The Variant ID is the second byte in the Information Block (read in Step 1.).
- If encryption is not active (default), the most significant bit will be set to 0 (that is, the Variant ID is 0x1D).
- If encryption is active, the most significant bit will be set to 1 (that is, the Variant ID is 0x9D).
The host can now read the start positions of all the objects in the device from the Object Table and build up a list
of the object addresses. Note that the number of Object Table elements was read by the host at start-up as part
of the ID Information bytes. If encryption is active:
a) Record the start position of the User Data T38 object (found in Step 3.).
b) If encrypted configuration read/writes are enabled, use the address of the User Data T38 object to determine
which objects will use encryption. These are the objects that are located after the User Data T38 object (that
is, they have higher addresses).
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 39
mXT228UD-MAU002 2.0
4.
Read the Encryption Status T2 object to determine which mode of encryption is enabled (that is, encrypted
configuration read/writes and/or encrypted messages). This will determine the communications protocol to use
to read or write configuration parameters and to read messages from the device. See Section 7.0 “I2C
Communications” for more information.
Use the Object Table to calculate the report IDs so that messages from the device can be correctly interpreted.
Finally, read any pending messages generated during the start-up process. Note that Step 4. will have
determined the communications protocol to use for reading messages.
5.
6.
9.2
Using the Object-based Protocol
The device has an object-based protocol (OBP) that is used to communicate with the device. Typical communication
includes configuring the device, sending commands to the device, and receiving messages from the device.
9.2.1
CLASSES OF OBJECTS
The mXT228UD-MAU002 contains the following classes of objects:
•
•
•
•
•
9.2.2
Debug objects – provide a raw data output method for development and testing.
General objects – required for global configuration, transmitting messages and receiving commands.
Touch objects – operate on measured signals from the touch sensor and report touch data.
Signal processing objects – process data from other objects (typically signal filtering operations).
Support objects – provide additional functionality on the device.
OBJECT INSTANCES
TABLE 9-1:
OBJECTS ON THE MXT228UD-MAU002
Object
Description
Number of
Instances
Usage
Debug Objects
Diagnostic Debug T37
Allows access to diagnostic debug data to
aid development.
1
Debug commands only; Read-only
object. No configuration or tuning
necessary. Not for use in production.
Debug data is not encrypted.
Encryption Status T2
Provides information on the configuration
encryption status.
1
Read-only object; no configuration
necessary. Object is not encrypted.
Message Processor T5
Handles the transmission of messages. This
object holds a message in its memory space
for the host to read.
1
Read-only object; no configuration
necessary. Messages can be
encrypted.
Command Processor T6
Performs a command when written to.
Commands include reset, calibrate and
backup settings.
1
No configuration necessary. Object is
not encrypted.
Power Configuration T7
Controls the sleep mode of the device.
Power consumption can be lowered by
controlling the acquisition frequency and the
sleep time between acquisitions.
1
Must be configured before use.
Configuration read/writes may be
encrypted.
Acquisition Configuration T8
Controls how the device takes each
capacitive measurement.
1
Must be configured before use.
Configuration read/writes may be
encrypted.
Key Array T15
Defines a rectangular array of keys. A Key
Array T15 object reports simple on/off touch
information.
1
Enable and configure as required.
Configuration read/writes may be
encrypted.
Multiple Touch Touchscreen
T100
Creates a touchscreen that supports the
tracking of more than one touch.
1
Enable and configure as required.
Configuration read/writes may be
encrypted.
General Objects
Touch Objects
DS40002409A-page 40
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
TABLE 9-1:
OBJECTS ON THE MXT228UD-MAU002 (CONTINUED)
Object
Description
Number of
Instances
Usage
Signal Processing Objects
Grip Suppression T40
Suppresses false detections caused, for
example, by the user gripping the edge of a
touchscreen.
1
Enable and configure as required.
Configuration read/writes may be
encrypted.
Touch Suppression T42
Suppresses false detections caused by
unintentional large touches by the user.
1
Enable and configure as required.
Configuration read/writes may be
encrypted.
Passive Stylus T47
Processes passive stylus input.
1
Enable and configure as required.
Configuration read/writes may be
encrypted.
Shieldless T56
Allows a sensor to use true single-layer coplanar construction.
1
Enable and configure as required.
Configuration read/writes may be
encrypted.
Lens Bending T65
Compensates for lens deformation (lens
bending) by attempting to eliminate the
disturbance signal from the reported deltas.
3
Enable and configure as required.
Configuration read/writes may be
encrypted.
Noise Suppression T72
Performs various noise reduction
techniques during sensor signal acquisition.
1
Enable and configure as required.
Configuration read/writes may be
encrypted.
Glove Detection T78
Allows for the reporting of glove touches.
1
Enable and configure as required.
Configuration read/writes may be
encrypted.
Retransmission Compensation Limits the negative effects on touch signals
T80
caused by poor device coupling to ground or
moisture on the sensor.
1
Enable and configure as required.
Configuration read/writes may be
encrypted.
Self Capacitance Noise
Suppression T108
Suppresses the effects of external noise
within the context of self capacitance touch
measurements.
1
Enable and configure as required.
Configuration read/writes may be
encrypted.
Self Test Control T10
Controls the self-test routines to find faults
on the touch sensor.
1
Enable and configure as required.
Configuration read/writes may be
encrypted.
Self Test Pin Faults T11
Specifies the configuration settings for the
Pin Fault self tests.
1
Configure as required. Configuration
read/writes may be encrypted.
Self Test Signal Limits T12
Specifies the configuration settings for the
Signal Limit self tests.
2
Configure as required. Configuration
read/writes may be encrypted.
Communications Configuration Configures additional communications
T18
behavior for the device.
1
Check and configure as necessary.
Configuration read/writes may be
encrypted.
GPIO Configuration T19
Allows the host controller to configure and
use the general purpose I/O pins on the
device.
1
Enable and configure as required.
Configuration read/writes may be
encrypted.
User Data T38
Provides a data storage area for user data.
1
Configure as required. Object is not
encrypted.
Message Count T44
Provides a count of pending messages.
1
Read-only object; no configuration
necessary. Object is not encrypted.
CTE Configuration T46
Controls the capacitive touch engine for the
device.
1
Must be configured. Configuration
read/writes may be encrypted.
Timer T61
Provides control of a timer.
6
Enable and configure as required.
Configuration read/writes may be
encrypted.
Support Objects
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 41
mXT228UD-MAU002 2.0
TABLE 9-1:
OBJECTS ON THE MXT228UD-MAU002 (CONTINUED)
Object
Description
Number of
Instances
Usage
Serial Data Command T68
Provides an interface for the host driver to
deliver various data sets to the device.
1
Enable and configure as required.
Object is not encrypted.
Dynamic Configuration
Controller T70
Allows rules to be defined that respond to
system events.
20
Enable and configure as required.
Configuration read/writes may be
encrypted.
Dynamic Configuration
Container T71
Allows the storage of user configuration on
the device that can be selected at runtime
based on rules defined in the Dynamic
Configuration Controller T70 object.
1
Configure if Dynamic Configuration
Controller T70 is in use. Configuration
read/writes may be encrypted.
Auxiliary Touch Configuration
T104
Allows the setting of self capacitance gain
and thresholds for a particular measurement
to generate auxiliary touch data for use by
other objects.
1
Enable and configure if using self
capacitance measurements.
Configuration read/writes may be
encrypted.
Self Capacitance Global
Configuration T109
Provides configuration for self capacitance
measurements employed on the device.
1
Check and configure as required (if
using self capacitance measurements).
Configuration read/writes may be
encrypted.
Self Capacitance Tuning
Parameters T110
Provides configuration space for a generic
set of settings for self capacitance
measurements.
4
Use under the guidance of Microchip
field engineers only. Configuration
read/writes may be encrypted.
Self Capacitance
Configuration T111
Provides configuration for self capacitance
measurements employed on the device.
2
Check and configure as required (if
using self capacitance measurements).
Configuration read/writes may be
encrypted.
Self Capacitance
Measurement Configuration
T113
Configures self capacitance measurements
to generate data for use by other objects.
1
Enable and configure as required.
Configuration read/writes may be
encrypted.
9.2.3
CONFIGURING AND TUNING THE DEVICE
The objects are designed such that a default value of zero in their fields is a “safe” value that typically disables
functionality. The objects must be configured before use and the settings written to the non-volatile memory using the
Command Processor T6 object.
Perform the following actions for each object:
1.
2.
3.
9.3
Enable the object, if the object requires it.
Configure the fields in the object, as required.
Enable reporting, if the object supports messages, to receive messages from the object.
Writing to the Device
The following mechanism can be used to write to the device:
• Using an I2C write operation (see Section 7.2 “Writing To the Device”).
Communication with the device is achieved by writing to the appropriate object:
• To send a command to the device, an appropriate command is written to the Command Processor T6 object.
• To configure the device, a configuration parameter is written to the appropriate object. For example, writing to the
Power Configuration T7 configures the power consumption for the device and writing to the Multiple Touch
Touchscreen T100 object sets up the touchscreen. Some objects are optional and need to be enabled before use.
DS40002409A-page 42
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
IMPORTANT!
When the host issues any command within an object that results in a flash write to the device NonVolatile Memory (NVM), that object should have its CTRL RPTEN bit set to 1, if it has one. This
ensures that a message from the object writing to the NVM is generated at the completion of the
process and an assertion of the CHG line is executed.
The host must also ensure that the assertion of the CHG line refers to the expected object report
ID before asserting the RESET line to perform a reset. Failure to follow this guidance may result in
a corruption of device configuration area and the generation of a CFGERR.
9.3.1
WRITING A CONFIGURATION TO THE DEVICE
During a configuration download, device operation may be based upon only part of that configuration because it is yet
to finish downloading. In rare circumstances, the total processing time might exceed the WDT reset time. This is more
likely to happen when measurements take a long time to perform due to the partial configuration.
To ensure that the configuration is written safely, follow these steps:
1.
2.
3.
9.4
Set Power Configuration T7 IDLEACQINT and ACTVACQINT to 0 (that is, deep sleep) as a temporary measure.
Download the rest of the configuration, except those Power Configuration T7 controls.
Finally, set the Power Configuration T7 acquisition interval controls to the required values.
Reading from the Device
Status information is stored in the Message Processor T5 object. This object can be read to receive any status
information from the device.
The CHG line is asserted whenever a new message is available in the Message Processor T5 object (see Section 7.5
“CHG Line”). See Section 7.4 “Reading From the Device” for information on the format of the I2C read operation.
NOTE
The host should always wait to be notified of messages; the host should not poll the device for messages,
either by polling the Message Processor T5 object or by polling the CHG line.
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 43
mXT228UD-MAU002 2.0
10.0
DEBUGGING AND TUNING
10.1
SPI Debug Interface
The SPI Debug Interface is used for tuning and debugging when running the system and allows the development
engineer to use Microchip maXTouch Studio to read the real-time raw data. This uses the low-level debug port.
The SPI Debug Interface consists of the DBG_SS, DBG_CLK and DBG_DATA lines. These lines should be routed to
test points on all designs such that they can be connected to external hardware during system development. These lines
should not be connected to power or GND. See Section 2.2.12 “SPI Debug Interface” for more details.
The SPI Debug Interface is enabled by the Command Processor T6 object and by default will be off.
NOTE
10.2
When the DBG_SS, DBG_CLK and DBG_DATA lines are in use for debugging, any alternative function
for the pins cannot be used. The touch controller will take care of the pin configuration.
Object-based Protocol
The device provides a mechanism for obtaining debug data for development and testing purposes by reading data from
the Diagnostic Debug T37 object.
NOTE
10.3
The Diagnostic Debug T37 object is of most use for simple tuning purposes. When debugging a design, it
is preferable to use the SPI Debug Interface, as this will have a much higher bandwidth and can provide
real-time data.
Self Test
The Self Test Control T10, Self Test Pin Faults T11 and Self Test Signal Limits T12 objects run self-test routines in the
device to find hardware faults in the device both at power-on/reset and during normal operation. These self-test routines
can be configured to check the power supplies of the devices, as well as the signal levels. The tests can also check for
pin shorts between sensor X and Y pins, and between the sensor lines and DS0, power or GND pins.
The Self Test Control T10 object can also provide continuous monitoring of the health of the device while it is in
operation. A periodic Built-In Self Test (BIST) test can be run at a user-specified interval and reports the global pass
and specific fail messages (as determined by the device configuration). Reporting is achieved either by standard Self
Test Control T10 object protocol messages or by a configurable hardware GPIO pin, configured using the GPIO
Configuration T19 object.
For a list of the self tests available on the mXT228UD-MAU002, see Table 10-1.
TABLE 10-1:
SELF TESTS
Run as
Self Test Group
Power
Pre-Operation Self Test
(POST)
Built-In Self Test (BIST)
On
Demand Test
Yes
Yes
Yes
Pin Faults
Yes
Yes
Yes
Signal Limits
Yes
Yes
Yes
DS40002409A-page 44
}
Internal System
CTE and
Touch System
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
11.0
SPECIFICATIONS
11.1
Absolute Maximum Specifications
Vdd
3.6V
VddIO
3.6V
AVdd
3.6V
Maximum continuous combined pin current, all GPIOn pins
40 mA
Voltage forced onto any pin
–0.3 V to (Vdd, VddIO or AVdd) + 0.3 V
Configuration parameters maximum writes
10,000
Maximum junction temperature
125C
CAUTION!
11.2
Stresses beyond those listed under Absolute Maximum Specifications may cause permanent damage
to the device. This is a stress rating only and functional operation of the device at these or other
conditions beyond those indicated in the operational sections of this specification is not implied.
Exposure to absolute maximum specification conditions for extended periods may affect device
reliability.
Recommended Operating Conditions
Operating temperature
–40C to +85C
Storage temperature
–60C to +150C
Vdd
3.3 V
VddIO
1.8 V to 3.3 V
AVdd
3.3 V
XVdd with internal voltage doubler
2 × AVdd
XVdd low voltage operation
(without internal voltage doubler)
Connected to AVdd
Temperature slew rate
10C/min
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 45
mXT228UD-MAU002 2.0
11.2.1
DC CHARACTERISTICS
11.2.1.1
Analog Voltage Supply – AVdd
Parameter
Min
Typ
Max
Units
Notes
3.0
3.3
3.47
V
–
–
0.036
V/µs
For example, for a 3.3 V rail, the
voltage should take a minimum of
92 µs to rise
Min
Typ
Max
Units
Notes
Operating limits – Normal Voltage
2.7
3.3
3.47
V
Operating limits – Low Voltage
1.71
1.8
1.89
V
–
–
0.036
V/µs
AVdd
Operating limits
Supply Rise Rate
11.2.1.2
Digital Voltage Supply – VddIO, Vdd
Parameter
VddIO
Supply Rise Rate
For example, for a 3.3 V rail, the
voltage should take a minimum
of 92 µs to rise
Vdd
Operating limits
2.7
3.3
3.47
V
Supply Rise Rate
–
–
0.036
V/µs
For example, for a 3.3 V rail, the
voltage should take a minimum
of 92 µs to rise
Supply Fall Rate
–
–
0.05
V/µs
For example, for a 3.3 V rail, the
voltage should take a minimum
of 66 µs to fall
Min
Typ
Max
Units
Notes
Operating limits – voltage doubler enabled
–
2 × AVdd
–
V
Operating limits – voltage doubler disabled
–
AVdd
–
V
Min
Typ
Max
Units
Vdd
–
–
±50
mV
Across frequency range
1 Hz to 1 MHz
AVdd
–
–
±40
mV
Across frequency range
1 Hz to 1 MHz, with Noise
Suppression enabled
11.2.1.3
XVdd Voltage Supply – XVdd
Parameter
XVdd
11.2.2
POWER SUPPLY RIPPLE AND NOISE
Parameter
DS40002409A-page 46
Notes
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
11.3
Test Configuration
The configuration values listed below were used in the reference unit to validate the interfaces and derive the
characterization data provided in the following sections.
TABLE 11-1:
TEST CONFIGURATION
Object/Parameter or Feature
Description/Setting (Numbers in Decimal)
Power Configuration T7
CFG2
0 (Power Monitor Enabled)
Acquisition Configuration T8
CHRGTIME
40
MEASALLOW
11
Self Test Control T10
Object Enabled; Reporting Enabled; BIST Reporting Enabled;
POST Reporting Enabled
POSTCFG
All Power, Signal Limits and Pin Fault tests enabled
BISTCFG
All Power, Signal Limits and Pin Fault tests enabled
GPIO Configuration T19
Object Enabled
Touch Suppression T42
Object Enabled
CTE Configuration T46
IDLESYNCSPERX
8
ACTVSYNCSPERX
8
Passive Stylus T47
Object Enabled
Shieldless T56
INTTIME
Lens Bending T65 Instance 0
22
Object Instance Enabled
Noise Suppression T72
Object Enabled
Glove Detection T78
Object Enabled
Retransmission Compensation T80
Object Enabled
Multiple Touch Touchscreen T100
Object Enabled; Reporting Enabled
XSIZE
14
Auxiliary Touch Configuration T104
Object Enabled
Self Capacitance Noise Suppression T108
Object Enabled
Self Capacitance Configuration T111 Instance 0
INTTIME
50
IDLESYNCSPERL
24
ACTVSYNCSPERL
24
Self Capacitance Configuration T111 Instance 1
INTTIME
50
IDLESYNCSPERL
32
ACTVSYNCSPERL
32
Self Capacitance Measurement Configuration T113
Object Enabled
Device Encryption
Not active
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 47
mXT228UD-MAU002 2.0
11.4
Current Consumption – I2C Interface
NOTE
The characterization charts show typical values based on the configuration in Table 11-1. Actual power
consumption in the user’s application will depend on the circumstances of that particular project and will
vary from that shown here. Further tuning will be required to achieve an optimal performance.
Note also that the use of encryption has no noticeable effect on power consumption.
11.4.1
AVDD 3.3V
Current Consumption (mA)
Acquisition Rate (ms)
0 Touches
1 Touch
2 Touches
5 Touches
10 Touches
Free-run
5.9
5.8
5.8
5.8
4.4
10
4.8
4.8
4.8
4.8
4.4
16
3
3
3
3
3
32
1.5
1.5
1.5
1.5
1.5
64
0.8
0.8
0.8
0.8
0.8
100
0.5
0.5
0.5
0.5
0.5
128
0.4
0.4
0.4
0.4
0.4
254
0.2
0.2
0.2
0.2
0.2
10
Current Consumption (mA)
9
8
7
6
0 Touches
5
1 Touch
2 Touches
4
5 Touches
3
10 Touches
2
1
0
Free-run
10
16
32
64
100
128
254
Acquisition Rate (ms)
DS40002409A-page 48
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
11.4.2
VDD 3.3V
Current Consumption (mA)
Acquisition Rate (ms)
0 Touches
1 Touch
2 Touches
5 Touches
10 Touches
Free-run
5.8
6.5
5.8
5.8
7.7
10
4.8
5.5
5
4.9
7.7
16
3.1
3.5
3.2
3.2
5.3
32
1.7
1.9
1.8
1.8
2.8
64
1
1.1
1
1
1.5
100
0.8
0.8
0.8
0.8
1.1
128
0.7
0.7
0.7
0.7
0.7
254
0.5
0.4
0.5
0.5
0.6
10
Current Consumption (mA)
9
8
7
6
0 Touches
5
1 Touch
2 Touches
4
5 Touches
3
10 Touches
2
1
0
Free-run
10
16
32
64
100
128
254
Acquisition Rate (ms)
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 49
mXT228UD-MAU002 2.0
11.4.3
VDDIO 1.8V
Current Consumption (mA)
Acquisition Rate (ms)
0 Touches
1 Touch
2 Touches
5 Touches
10 Touches
Free-run
0.56
0.55
0.57
0.55
0.51
10
0.56
0.54
0.56
0.55
0.49
16
0.55
0.54
0.56
0.55
0.51
32
0.55
0.53
0.54
0.56
0.53
64
0.58
0.56
0.54
0.57
0.54
100
0.53
0.53
0.54
0.54
0.53
128
0.54
0.54
0.56
0.57
0.57
254
0.56
0.57
0.58
0.56
0.54
1.00
Current Consumption (mA)
0.90
0.80
0.70
0.60
0 Touches
0.50
1 Touch
2 Touches
0.40
5 Touches
0.30
10 Touches
0.20
0.10
0.00
Free-run
10
16
32
64
100
128
254
Acquisition Rate (ms)
11.4.4
DEEP SLEEP
TA = 25C
Power Monitoring On
Parameter
Sampling Mode
Continuous Mode
Power Monitoring
Off
Units
Deep Sleep Current
0.73
1.52
0.59
mA
Deep Sleep Power
1.61
3.97
1.14
mW
DS40002409A-page 50
Notes
Vdd = 3.3V, AVdd = 3.3V,
VddIO = 1.8V
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
11.5
Timing Specifications
NOTE
11.5.1
The figures below show typical values based on the test configuration. Actual timings in the user’s
application will depend on the circumstances of that particular project and will vary from those shown
below. Further tuning will be required to achieve an optimal performance.
TOUCH LATENCY
Conditions: XSIZE = 14; CHRGTIME = 40; IDLESYNCSPERX = 8; ACTVSYNCSPERX = 8;
T = ambient temperature; Finger center of screen; Reporting off (except T100)
Idle Primary = Mutual Capacitance; Active Primary = Mutual Capacitance
Pipelining Off
Pipelining On
T100 TCHDIDOWN
Min
Typ
Max
Min
Typ
Max
Units
3
28.6
32.1
36.8
31.1
35.4
38.9
ms
2
20.7
24.9
39.4
22.1
26.8
30.7
ms
1
12.7
16.5
20.2
12.4
16.2
20.4
ms
Idle Primary = Self Capacitance; Active Primary = Mutual Capacitance
Pipelining Off
Pipelining On
T100 TCHDIDOWN
Min
Typ
Max
Min
Typ
Max
Units
3
28.7
31.8
34.9
30.6
33.4
36.9
ms
2
20.4
23.3
26.4
22.7
25.8
28.9
ms
1
12.3
15
17.7
12.6
15.4
23.3
ms
Idle Primary = Self Capacitance; Active Primary = Self Capacitance
Pipelining Off
Pipelining On
T100 TCHDIDOWN
Min
Typ
Max
Min
Typ
Max
Units
3
26.6
28.2
30.5
27.8
30.5
32.7
ms
2
18.7
21.5
24.4
20.6
23.3
26.6
ms
1
12.3
15.1
18.1
12
15.1
18.2
ms
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 51
mXT228UD-MAU002 2.0
11.5.2
11.5.2.1
REPORT RATE
Encryption Not Active
Conditions: XSIZE = 14; CHRGTIME = 40; IDLESYNCSPERX = 8; ACTVSYNCSPERX = 8; T = ambient temperature
160
Touchscreen Active Mode Pipelining
On
140
Touchscreen Active Mode Pipelining
Off
Refresh Rate [Hz]
120
100
80
60
40
20
0
1
2
3
4
5
6
7
8
9
10
Number of Moving Touches
11.5.2.2
Encryption Active
Conditions: XSIZE = 14; CHRGTIME = 40; IDLESYNCSPERX = 8; ACTVSYNCSPERX = 8; T = ambient temperature
160
Touchscreen Active Mode Pipelining
On
140
Touchscreen Active Mode Pipelining
Off
Refresh Rate [Hz]
120
100
80
60
40
20
0
1
2
3
4
5
6
7
8
9
10
Number of Moving Touches
DS40002409A-page 52
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
11.5.3
RESET TIMINGS
Power-on Features (Typ) (2)
Parameter
11.6
Disabled
Enabled
Units
Power on to CHG line low
48
70
ms
Triggered by Vdd supply at start up
Hardware reset to CHG line low
47
70
ms
Triggered by RESET
Software reset to CHG line low
69
90
ms
Triggered by Command Processor T6
Reset command
Note 1:
Any CHG line activity before the power-on or reset period has expired should be ignored by the host. Operation of this
signal cannot be guaranteed before the power-on/reset periods have expired.
2:
Power-on features include POST self tests and device encryption. Figures show typical values for extreme cases; that
is, with all features disabled and with all features enabled.
Touch Accuracy and Repeatability
Parameter
11.7
Min
Typ
Linearity
–
±0.5
–
mm
Finger diameter 8 mm
Accuracy (across all areas of screen)
–
0.5
–
mm
Finger diameter 8 mm
Repeatability
–
±0.25
–
%
Max
Units
Notes
X axis with 12-bit resolution
Touchscreen Sensor Characteristics
Parameter
Description
Value
Cm
Mutual capacitance
Typical value is between 0.15 pF and 10 pF on a single node.
Cpx
Mutual capacitance load to X
Microchip recommends a maximum load of 300 pF on each X or
Y line. (1)
With Internal Voltage Pump
Maximum recommended load on each X line: (2)
Cpx + (num_Y × Cm) < 240 pF
With Internal Voltage Pump and Dual X
Maximum recommended load on each X line: (2)
Cpx + (2 × num_Y × Cm) < 120 pF
Cpy
Mutual capacitance load to Y
Microchip recommends a maximum load of 300 pF on each X or
Y line. (1)
Cpx
Self capacitance load to X
Cpy
Self capacitance load to Y
Microchip recommends a maximum load of 130 pF on each X or
Y line. (1)
Cpx
Self capacitance imbalance on X
Cpy
Self capacitance imbalance on Y
Cpds0
Self capacitance load to Driven Shield
Note 1:
2:
11.8
Notes
Nominal value is 14.8 pF. Value increases by 1 pF for every
45 pF reduction in Cpx/Cpy (based on 100 pF load)
Microchip recommends a maximum load of 130 pF on the Driven
Shield line. (1)
Please contact your Microchip representative for advice if you intend to use higher values.
num_Y = Number of active Y lines defined by Multiple Touch Touchscreen T100.
Input/Output Characteristics
Parameter
Description
Min
Typ
Max
Units
Notes
Input (All input pins connected to the VddIO power rail)
Vil
Low input logic level
–0.3
–
0.3 ×
VddIO
V
VddIO = 1.8 V to Vdd
Vih
High input logic level
0.7 ×
VddIO
–
VddIO
V
VddIO = 1.8 V to Vdd
Iil
Input leakage current
–
–
1
µA
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 53
mXT228UD-MAU002 2.0
Parameter
RESET
/GPIO
Description
Min
Typ
Max
Units
9
10
16
k
Internal pull-up resistor
Notes
Input (All input pins connected to the Vdd power rail)
Vil
Low input logic level
–0.3
–
0.3 × Vdd
V
Vih
High input logic level
0.7 × Vdd
–
Vdd
V
Iil
Input leakage current
–
–
1
µA
Internal pull-up/pull-down resistor
9
10
16
k
GPIOs
Pull-up resistors disabled
Output (All output pins connected to the VddIO power rail)
Vol
Low output voltage
0
–
0.2 ×
VddIO
V
VddIO = 1.8 V to Vdd
Iol = max 0.4 mA
Voh
High output voltage
0.8 ×
VddIO
–
VddIO
V
VddIO = 1.8 V to Vdd
Ioh = 0.4 mA
Output (All output pins connected to the Vdd power rail)
11.9
Vol
Low output voltage
0
–
0.2 × Vdd
V
Iol = max 0.4 mA
Voh
High output voltage
0.8 × Vdd
–
Vdd
V
Ioh = 0.4 mA
I2C Specification
Parameter
Value
Address
0x4A
I2C specification (1)
Revision 6.0
Maximum bus speed (SCL) (2)
1 MHz
Standard Mode (3)
100 kHz
Fast Mode (3)
400 kHz
Fast Mode Plus (3)
Note 1:
2:
3:
1 MHz
2
More detailed information on I C operation is available from UM10204, I2C bus specification and user manual,
available from NXP.
In systems with heavily laden I2C lines, even with minimum pull-up resistor values, bus speed may be limited by
capacitive loading to less than the theoretical maximum.
The values of pull-up resistors should be chosen to ensure SCL and SDA rise and fall times meet the I2C specification.
The value required will depend on the amount of capacitance loading on the lines.
11.10 Thermal Packaging
11.10.1
THERMAL DATA
Parameter
Description
Typ
Unit
Condition
Package
JA
Junction to ambient thermal
resistance
33.7
C/W
Still air
56-pin XQFN 6 × 6 × 0.4 mm
JC
Junction to case thermal
resistance
10.1
C/W
DS40002409A-page 54
56-pin XQFN 6 × 6 × 0.4 mm
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
11.10.2
JUNCTION TEMPERATURE
The maximum junction temperature allowed on this device is 125C.
The average junction temperature in C (TJ) for this device can be obtained from the following:
T J = T A + P D JA
If a cooling device is required, use this equation:
T J = T A + P D HEATSINK + JC
where:
• JA= package thermal resistance, Junction to ambient (C/W) (see Section 11.10.1 “Thermal Data”)
• JC = package thermal resistance, Junction to case thermal resistance (C/W) (see Section 11.10.1 “Thermal
Data”)
• HEATSINK = cooling device thermal resistance (C/W), provided in the cooling device datasheet
• PD = device power consumption (W)
• TA is the ambient temperature (C)
11.11 ESD Information
Parameter
Value
Reference Standard
Human Body Model (HBM)
±2000V
JEDEC JS–001
Charge Device Model (CDM)
±250V
JEDEC JS–001
11.12 Soldering Profile
Profile Feature
Green Package
Average Ramp-up Rate (217C to Peak)
3C/s max
Preheat Temperature 175C ±25C
150 – 200C
Time Maintained Above 217C
60 – 150 s
Time within 5C of Actual Peak Temperature
30 s
Peak Temperature Range
260C
Ramp down Rate
6C/s max
Time 25C to Peak Temperature
8 minutes max
11.13 Moisture Sensitivity Level (MSL)
MSL Rating
Package Type(s)
Peak Body Temperature
Specifications
MSL3
56-pin XQFN
260C
IPC/JEDEC J-STD-020
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 55
mXT228UD-MAU002 2.0
12.0
PACKAGING INFORMATION
12.1
Package Marking Information
12.1.1
56-PIN XQFN
Pin 1 ID
Abbreviation of Part Number
MXT228UD
MAU
Date (Year and Week)
and Die Revision
Lot Traceability Code
12.1.2
yywwR CCC
Country Code
yywwNNN
ORDERABLE PART NUMBERS
The product identification system for maXTouch devices is described in “Product Identification System” on page 64.
That section also lists example part numbers for the device.
DS40002409A-page 56
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
12.2
Package Details
56-Lead Extremely Thin Quad Flatpack No-Lead Package (TWB) - 6x6x0.4 mm Body
[XQFN] Wlth 4.5x4.5 mm Exposed Pad; Atmel Legacy Global Package Code ZIX
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
56X
0.08 C
D
NOTE1
A
0.10 C
B
N
1
2
E
(DATUM B)
(DATUM A)
2X
0.10 C
2X
A1
TOP VIEW
0.10 C
0.10
C A B
D2
0.10
(A3)
A
SEATING
C
PLANE
C A B
SIDE VIEW
E2
e
2
(K)
2
1
N
NOTE 1
L
e
BOTTOM VIEW
56X b
0.07
0.05
C A B
C
Microchip Technology Drawing C04-21448 Rev A Sheet 1 of 2
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 57
mXT228UD-MAU002 2.0
56-Lead Extremely Thin Quad Flatpack No-Lead Package (TWB) - 6x6x0.4 mm Body
[XQFN] Wlth 4.5x4.5 mm Exposed Pad; Atmel Legacy Global Package Code ZIX
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
Notes:
Units
Dimension Limits
Number of Terminals
N
e
Pitch
Overall Height
A
Standoff
A1
A3
Terminal Thickness
Overall Length
D
Exposed Pad Length
D2
Overall Width
E
E2
Exposed Pad Width
Terminal Width
b
Terminal Length
L
Terminal-to-Exposed-Pad
K
MIN
–
0.00
4.40
4.40
0.13
0.35
MILLIMETERS
NOM
MAX
56
0.35 BSC
–
0.400
–
0.05
0.127 REF
6.00 BSC
4.50
4.60
6.00 BSC
4.50
4.60
0.18
0.23
0.40
0.45
0.35 REF
1. Pin 1 visual index feature may vary, but must be located within the hatched area.
2. Package is saw singulated
3. Dimensioning and tolerancing per ASME Y14.5M
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
REF: Reference Dimension, usually without tolerance, for information purposes only.
Microchip Technology Drawing C04-21448 Rev A Sheet 2 of 2
DS40002409A-page 58
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
56-Lead Extremely Thin Quad Flatpack No-Lead Package (TWB) - 6x6x0.4 mm Body
[XQFN] Wlth 4.5x4.5 mm Exposed Pad; Atmel Legacy Global Package Code ZIX
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
C1
X2
EV
56
ØV
1
2
EV
C2
G2
Y2
G1
Y1
SILK SCREEN
X1
E
RECOMMENDED LAND PATTERN
Units
Dimension Limits
E
Contact Pitch
Optional Center Pad Width
X2
Optional Center Pad Length
Y2
Contact Pad Spacing
C1
Contact Pad Spacing
C2
Contact Pad Width (X56)
X1
Contact Pad Length (X56)
Y1
Contact Pad to Center Pad (X56)
G1
Contact Pad to Contact Pad (X52)
G2
Thermal Via Diameter
V
Thermal Via Pitch
EV
MIN
MILLIMETERS
NOM
0.35 BSC
MAX
4.60
4.60
5.90
5.90
0.15
0.85
0.23
0.20
0.33
1.20
Notes:
1. Dimensioning and tolerancing per ASME Y14.5M
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
2. For best soldering results, thermal vias, if used, should be filled or tented to avoid solder loss during
reflow process
Microchip Technology Drawing C04-23448 Rev A
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 59
mXT228UD-MAU002 2.0
APPENDIX A:
ASSOCIATED DOCUMENTS
Microchip maXTouch Web Site
For general information on the mXT228UD-MAU002, please visit the following:
• https://www.microchip.com/wwwproducts/en/ATMXT228UD
Microchip maXTouch Documents
The following documents are available on the Microchip website.
Touchscreen Design and PCB/FPCB Layout Guidelines
• Application Note: MXTAN0208 – Design Guide for PCB Layouts for maXTouch Touch Controllers
• Application Note: QTAN0080 – Touchscreens Sensor Design Guide
• Application Note: AN2683 – Edge Wiring for Self Capacitance maXTouch Touchscreens
Configuring and Tuning the Device
• Application Note: MXTAN0213 – Interfacing with maXTouch Touchscreen Controllers
Tools
• maXTouch Studio User Guide (accessible as on-line help from within maXTouch Studio)
External Documents
The following documents are not supplied by Microchip. To obtain any of the following documents, please contact the
relevant organization.
Communication Interface
• UM10204, I2C bus specification and user manual, Rev. 6 — 4 April 2014
Available from NXP
DS40002409A-page 60
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
APPENDIX B:
REVISION HISTORY
Revision A (March 2022)
Initial edition for firmware revision 2.0.AA – Release
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 61
mXT228UD-MAU002 2.0
INDEX
A
SDA pin .........................................................................10, 32
specification.........................................................................54
writes in checksum mode ....................................................24
writing to the device.............................................................23
Input/Output characteristics .........................................................53
Internet Address ..........................................................................65
Absolute maximum specifications ............................................... 45
Adjacent key suppression technology......................................... 22
AKS. See Adjacent key suppression
Analog I/O ................................................................................... 37
Analog voltage supply ................................................................. 46
AVdd voltage supply ................................................................... 46
J
C
Junction temperature ...................................................................55
Calibration ................................................................................... 20
Capacitive Touch Engine (CTE).................................................... 8
Charge time................................................................................. 19
Checksum in I2C writes............................................................... 24
CHG line...................................................................................... 31
mode 0 operation ................................................................ 32
mode 1 operation ................................................................ 32
on power up ........................................................................ 17
Clock stretching........................................................................... 33
Component placement and tracking ........................................... 37
Connection Information see Pinouts ............................................. 3
Customer Change Notification Service ....................................... 65
Customer Notification Service..................................................... 65
Customer Support ....................................................................... 65
L
D
O
DC characteristics ....................................................................... 46
Debugging................................................................................... 44
object-based protocol.......................................................... 44
self test................................................................................ 44
SPI Debug Interface...................................................... 11, 44
Decoupling capacitors........................................................... 10, 34
Detailed operation ....................................................................... 19
Detection integrator..................................................................... 19
Device
overview ................................................................................ 8
Digital filtering.............................................................................. 20
Digital signals .............................................................................. 38
Digital voltage supply .................................................................. 46
Direct Memory Access ................................................................ 28
Driven shield lines ........................................................... 11, 15, 36
Object-based protocol (OBP).................................................40, 44
Operational modes ......................................................................19
Overview of the mXT228UD-MAU002...........................................8
E
EMC problems ............................................................................ 38
EMC Reduction ........................................................................... 20
Encryption ................................................................................... 22
ESD information .......................................................................... 55
G
Glove detection ........................................................................... 21
GPIO pins.................................................................................... 11
Grip suppression ......................................................................... 21
Ground tracking........................................................................... 34
H
Host initialization procedure ........................................................ 39
I
I/O pins........................................................................................ 10
I2C communications .............................................................. 23–33
CHG line........................................................................ 17, 31
clock stretching ................................................................... 33
reading from the device....................................................... 25
reading messages with DMA .............................................. 28
SCL pin ......................................................................... 10, 32
DS40002409A-page 62
latency, touch...............................................................................51
Lens bending ...............................................................................21
M
Microchip Internet Web Site.........................................................65
Moisture sensitivity level (msl) .....................................................55
Multiple function pins ...................................................................11
Mutual capacitance measurements ...............................................8
N
Noise suppression .......................................................................20
display .................................................................................20
Number of available nodes ..........................................................10
P
PCB cleanliness...........................................................................34
PCB design..................................................................................34
analog I/O ............................................................................37
component placement and tracking.....................................37
decoupling capacitors ..........................................................34
digital signals .......................................................................38
EMC problems.....................................................................38
ground tracking....................................................................34
PCB cleanliness ..................................................................34
power supply .......................................................................34
QFN package restrictions ....................................................38
supply rails...........................................................................34
voltage pump .......................................................................34
voltage regulator..................................................................35
Pinouts...........................................................................................3
Power supply
I/O pins ................................................................................10
PCB design..........................................................................34
Power supply ripple and noise.....................................................46
Power-up sequence.....................................................................39
Power-up/reset ............................................................................16
hardware reset.....................................................................17
power-on reset (POR) .........................................................16
software reset ......................................................................17
VddIO enabled after Vdd .....................................................18
Pull-up resistors ...........................................................................10
Q
QFN package restrictions ............................................................38
R
Reading from the Device .............................................................43
Recommended operating conditions ...........................................45
Repeatability ................................................................................53
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
Report rate .................................................................................. 52
Reset timings ............................................................................. 53
Retransmission compensation .................................................... 21
S
Schematic ..................................................................................... 9
decoupling capacitors ......................................................... 10
GPIO pins............................................................................ 11
I2C interface ........................................................................ 10
number of available nodes .................................................. 10
pull-up resistors................................................................... 10
voltage pump....................................................................... 10
SCL pin ................................................................................. 10, 32
SDA pin ................................................................................. 10, 32
Self capacitance measurements ................................................... 8
Self test ....................................................................................... 44
Sensor acquisition....................................................................... 19
Sensor layout ........................................................................ 14–15
electrodes............................................................................ 14
sensors................................................................................ 14
touch panel.......................................................................... 14
Shieldless support....................................................................... 20
Soldering profile .......................................................................... 55
Specifications ........................................................................ 45–55
absolute maximum specifications ....................................... 45
analog voltage supply ......................................................... 46
DC characteristics ............................................................... 46
digital voltage supply........................................................... 46
ESD information .................................................................. 55
I2C specification .................................................................. 54
input/output characteristics ................................................. 53
junction temperature ........................................................... 55
moisture sensitivity level (msl) ............................................ 55
power supply ripple and noise............................................. 46
recommended operating conditions .................................... 45
repeatability......................................................................... 53
reset timings ....................................................................... 53
soldering profile................................................................... 55
test configuration................................................................. 47
thermal data ........................................................................ 54
timing specifications ............................................................ 51
2022 Microchip Technology Inc. and its subsidiaries
touch accuracy ....................................................................53
touchscreen sensor characteristics .....................................53
XVdd voltage supply ............................................................46
SPI Debug Interface ..............................................................11, 44
Start-up procedure.......................................................................39
Stylus support ..............................................................................21
Supply rails ..................................................................................34
SYNC pin .....................................................................................11
T
Test configuration specification ...................................................47
Thermal data................................................................................54
Timing specifications ...................................................................51
report rate ............................................................................52
touch latency .......................................................................51
Touch accuracy ...........................................................................53
Touch detection .......................................................................8, 19
Touch latency ..............................................................................51
Touchscreen sensor characteristics ............................................53
Touchscreen Size size.................................................................15
Tuning..........................................................................................44
U
Unintentional touch suppression..................................................21
V
Vdd voltage supply ......................................................................46
VddCore supply ...........................................................................10
VddIO voltage supply...................................................................46
Voltage pump.........................................................................10, 34
Voltage regulator .........................................................................35
multiple supply operation.....................................................36
single supply operation........................................................36
W
Writing to the Device....................................................................42
WWW Address ............................................................................65
X
XVdd voltage supply ....................................................................46
DS40002409A-page 63
mXT228UD-MAU002 2.0
PRODUCT IDENTIFICATION SYSTEM
The table below gives details on the product identification system for maXTouch devices. See “Orderable Part Numbers”
below for example part numbers for the mXT228UD-MAU002.
To order or obtain information, for example on pricing or delivery, refer to the factory or the listed sales office.
PART NO.
–XXX
[X]
[X]
[XXX]
Device
Package
Temperature
Range
Tape and
Reel Option
Pattern
Device:
Base device name
Package:
CC
C2
NH
C4
MA
MA5
=
=
=
=
=
=
UFBGA (Ultra Thin Fine-pitch Ball Grid Array)
UFBGA (Ultra Thin Fine-pitch Ball Grid Array)
UFBGA (Ultra Thin Fine-pitch Ball Grid Array)
X1FBGA (Extra Thin Fine-pitch Ball Grid Array)
XQFN (Super Thin Quad Flat No Lead Sawn)
XQFN (Super Thin Quad Flat No Lead Sawn)
Temperature Range:
U
T
B
=
=
=
–40C to +85C (Grade 3)
–40C to +85C (Grade 3)
–40C to +105C (Grade 2)
Tape and Reel Option:
Blank
R
=
=
Standard Packaging (Tube or Tray)
Tape and Reel (1)
Pattern:
Extension, QTP, SQTP, Code or Special Requirements
(Blank Otherwise)
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. See “Orderable Part Numbers” below or
check with your Microchip Sales Office for package availability with the Tape and Reel option.
Orderable Part Numbers
Orderable Part Number
Firmware Revision
ATMXT228UD-MAU002
(Supplied in trays)
2.0.AA
Description
56-pin XQFN 6 × 6 × 0.4 mm, RoHS compliant
Industrial grade; not suitable for automotive characterization
ATMXT228UD-MAUR002
(Supplied in tape and reel)
DS40002409A-page 64
2022 Microchip Technology Inc. and its subsidiaries
mXT228UD-MAU002 2.0
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 – Datasheets 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
THE MAXTOUCH WEB SITE
Information on Microchip’s maXTouch product line can be accessed via the microchip web site at www.microchip.com,
This information is also available for direct access via a short-cut at www.maxtouch.com. The maXTouch web pages
contain the following information:
• Product Information – Product specifications, brochures, datasheets, protocol guides
• Tools and Software – Evaluation kits, maXTouch Studio, software libraries for individual maXTouch touch
controllers
• Training and Support – Generic application notes and training material for the maXTouch product range
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://microchip.com/support
2022 Microchip Technology Inc. and its subsidiaries
DS40002409A-page 65
mXT228UD-MAU002 2.0
NOTES:
DS40002409A-page 66
2022 Microchip Technology Inc. and its subsidiaries
Note the following details of the code protection feature on Microchip products:
•
Microchip products meet the specifications contained in their particular Microchip Data Sheet.
•
Microchip believes that its family of products is secure when used in the intended manner, within operating specifications, and under
normal conditions.
•
Microchip values and aggressively protects its intellectual property rights. Attempts to breach the code protection features of Microchip
products is strictly prohibited and may violate the Digital Millennium Copyright Act.
•
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of its code. Code protection does not mean that
we are guaranteeing the product is “unbreakable”. Code protection is constantly evolving. Microchip is committed to continuously
improving the code protection features of our products.
This publication and the information herein may be used only with
Microchip products, including to design, test, and integrate
Microchip products with your application. Use of this information
in any other manner violates these terms. Information regarding
device applications 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. Contact your
local Microchip sales office for additional support or, obtain
additional support at https://www.microchip.com/en-us/support/
design-help/client-supportservices.
THIS INFORMATION IS PROVIDED BY MICROCHIP "AS IS".
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 ANY IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTABILITY, AND FITNESS FOR A
PARTICULAR PURPOSE, OR WARRANTIES RELATED TO ITS
CONDITION, QUALITY, OR PERFORMANCE.
IN NO EVENT WILL MICROCHIP BE LIABLE FOR ANY
INDIRECT,
SPECIAL,
PUNITIVE,
INCIDENTAL,
OR
CONSEQUENTIAL LOSS, DAMAGE, COST, OR EXPENSE OF
ANY KIND WHATSOEVER RELATED TO THE INFORMATION
OR ITS USE, HOWEVER CAUSED, EVEN IF MICROCHIP HAS
BEEN ADVISED OF THE POSSIBILITY OR THE DAMAGES
ARE FORESEEABLE. TO THE FULLEST EXTENT ALLOWED
BY LAW, MICROCHIP'S TOTAL LIABILITY ON ALL CLAIMS IN
ANY WAY RELATED TO THE INFORMATION OR ITS USE WILL
NOT EXCEED THE AMOUNT OF FEES, IF ANY, THAT YOU
HAVE PAID DIRECTLY TO MICROCHIP FOR THE
INFORMATION. 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 unless otherwise
stated.
Trademarks
The Microchip name and logo, the Microchip logo, Adaptec, AnyRate, AVR,
AVR logo, AVR Freaks, BesTime, BitCloud, CryptoMemory, CryptoRF,
dsPIC, flexPWR, HELDO, IGLOO, JukeBlox, KeeLoq, Kleer, LANCheck,
LinkMD, maXStylus, maXTouch, MediaLB, megaAVR, Microsemi,
Microsemi logo, MOST, MOST logo, MPLAB, OptoLyzer, PIC, picoPower,
PICSTART, PIC32 logo, PolarFire, Prochip Designer, QTouch, SAM-BA,
SenGenuity, SpyNIC, SST, SST Logo, SuperFlash, Symmetricom,
SyncServer, Tachyon, TimeSource, tinyAVR, UNI/O, Vectron, and XMEGA
are registered trademarks of Microchip Technology Incorporated in the
U.S.A. and other countries.
AgileSwitch, APT, ClockWorks, The Embedded Control Solutions
Company, EtherSynch, Flashtec, Hyper Speed Control, HyperLight Load,
IntelliMOS, Libero, motorBench, mTouch, Powermite 3, Precision Edge,
ProASIC, ProASIC Plus, ProASIC Plus logo, Quiet-Wire, SmartFusion,
SyncWorld, Temux, TimeCesium, TimeHub, TimePictra, TimeProvider,
TrueTime, WinPath, and ZL are registered trademarks of Microchip
Technology Incorporated in the U.S.A.
Adjacent Key Suppression, AKS, Analog-for-the-Digital Age, Any
Capacitor, AnyIn, AnyOut, Augmented Switching, BlueSky, BodyCom,
CodeGuard, CryptoAuthentication, CryptoAutomotive, CryptoCompanion,
CryptoController, dsPICDEM, dsPICDEM.net, Dynamic Average Matching,
DAM, ECAN, Espresso T1S, EtherGREEN, GridTime, IdealBridge,
In-Circuit Serial Programming, ICSP, INICnet, Intelligent Paralleling, InterChip Connectivity, JitterBlocker, Knob-on-Display, maxCrypto, maxView,
memBrain, Mindi, MiWi, MPASM, MPF, MPLAB Certified logo, MPLIB,
MPLINK, MultiTRAK, NetDetach, NVM Express, NVMe, Omniscient Code
Generation, PICDEM, PICDEM.net, PICkit, PICtail, PowerSmart,
PureSilicon, QMatrix, REAL ICE, Ripple Blocker, RTAX, RTG4, SAM-ICE,
Serial Quad I/O, simpleMAP, SimpliPHY, SmartBuffer, SmartHLS,
SMART-I.S., storClad, SQI, SuperSwitcher, SuperSwitcher II, Switchtec,
SynchroPHY, Total Endurance, TSHARC, USBCheck, VariSense,
VectorBlox, VeriPHY, ViewSpan, WiperLock, XpressConnect, 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.
The Adaptec logo, Frequency on Demand, Silicon Storage Technology,
Symmcom, and Trusted Time are registered trademarks of Microchip
Technology Inc. in other countries.
GestIC is a registered trademark 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.
© 2022, Microchip Technology Incorporated and its subsidiaries.
All Rights Reserved.
ISBN: 978-1-6683-0114-2
For information regarding Microchip’s Quality Management
Systems, please visit www.microchip.com/quality.
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DS40002409A-page 67
Worldwide Sales and Service
AMERICAS
ASIA/PACIFIC
ASIA/PACIFIC
EUROPE
Corporate Office
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-792-7200
Fax: 480-792-7277
Technical Support:
http://www.microchip.com/
support
Web Address:
www.microchip.com
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Tel: 61-2-9868-6733
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Tel: 91-80-3090-4444
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Fax: 43-7242-2244-393
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DS40002409A-page 68
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