PCA9846
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
Rev. 1.1 — 4 April 2017
Product data sheet
1. General description
The PCA9846 is an ultra-low voltage, quad bidirectional translating switch controlled via
the I2C-bus. The SCL/SDA upstream pair fans out to four downstream pairs, or channels.
Any or all SCx/SDx channels can be selected, determined by the programmable control
register. This feature allows multiple devices with the same I2C-bus address to reside on
the same bus. The switch device can also separate a heavily loaded I2C-bus into separate
bus segments, eliminating the need for a bus buffer.
An active LOW reset input allows the PCA9846 to recover from a situation where one of
the downstream I2C-buses is stuck in a LOW state. Pulling the RESET pin LOW resets
the I2C-bus state machine and deselects all the channels, as does the internal
Power-On Reset (POR) function.
The pass gates of the switches are constructed such that the VDD1 pin is used to limit the
maximum high voltage which is passed by the PCA9846. This allows the use of different
bus voltages on each channel, so that 0.8 V, 1.8 V, 2.5 V or 3.3 V parts can communicate
without any additional protection. External pull-up resistors pull the bus up to the desired
voltage level for each channel. All I/O pins are 3.6 V tolerant.
2. Features and benefits
Ultra-low voltage operation, down to 0.8 V to interface with next-generation CPUs
1-of-4 bidirectional translating switch
Fm+ I2C-bus interface logic; compatible with SMBus standards
Active LOW reset input
2 address pins allowing up to 16 devices on the I2C-bus
Channel selection via I2C-bus
Power-up with all switch channels deselected
Low Ron switches
Allows voltage level translation between 0.8 V, 1.8 V, 2.5 V and 3.3 V buses
Reset via I2C-bus software command
I2C Device ID function
No glitch on power-up
Supports hot insertion since all channels are de-selected at power-on
Low standby current
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
3.6 V tolerant inputs
0 Hz to 1 MHz clock frequency
ESD protection exceeds 6000 V HBM per JESD22-A114 and 1000 V CDM per
JESD22-C101
Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA
Two packages offered: TSSOP16 and HVQFN16
3. Ordering information
Table 1.
Ordering information
Type number
Topside
marking
Package
Name
Description
Version
PCA9846BS[1]
846
HVQFN16
plastic thermal enhanced very thin quad flat package;
no leads; 16 terminals; body 4 4 0.85 mm
SOT629-1
PCA9846PW
PCA9846
TSSOP16
plastic thin shrink small outline package; 16 leads;
body width 4.4 mm
SOT403-1
[1]
Package is in development. Contact NXP for availability.
3.1 Ordering options
Table 2.
Ordering options
Type number
Orderable
part number
Package
Packing method
Minimum
order
quantity
Temperature range
PCA9846BS[1]
PCA9846BSJ
HVQFN16
Reel 13” Q1/T1
*Standard mark SMD
6000
Tamb = 40 C to +85 C
PCA9846PW
PCA9846PWJ
TSSOP16
Reel 13” Q1/T1
*Standard mark SMD
2500
Tamb = 40 C to +85 C
PCA9846PW
PCA9846PWZ
TSSOP16
Reel 13” Q1/T1
*Standard mark SMD
500
Tamb = 40 C to +85 C
[1]
Package is in development. Contact NXP for availability.
PCA9846
Product data sheet
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Rev. 1.1 — 4 April 2017
© NXP Semiconductors N.V. 2017. All rights reserved.
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PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
4. Block diagram
PCA9846
SC0
SC1
SC2
SC3
SD0
SD1
SD2
SD3
VSS
VDD2
RESET
SWITCH CONTROL LOGIC
RESET
CIRCUIT
VDD1
SCL
SDA
INPUT
FILTER
A0
I2C-BUS
CONTROL
A1
aaa-017304
Fig 1.
PCA9846
Product data sheet
Block diagram of PCA9846
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PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
5. Pinning information
13 SDA
14 VDD2
2
3
14 SCL
SD0
4
13 A1
SC0
5
SD1
6
11 SD3
7
8
SC1
7
10 SC2
VSS
8
SD2
SC2
2
A0
RESET
6
SD0
12 SCL
VSS
1
5
1
RESET
16 VDD2
15 SDA
SC1
VDD1
16 A0
terminal 1
index area
15 VDD1
5.1 Pinning
PCA9846PW
12 SC3
9
SC0
3
10 SC3
SD1
4
9
SD2
aaa-017305
Fig 2.
11 A1
PCA9846ABS
SD3
aaa-017306
Transparent top view
Pin configuration for TSSOP16
Fig 3.
Pin configuration for HVQFN16
5.2 Pin description
Table 3.
Symbol
Product data sheet
Pin
Description
TSSOP16
HVQFN16
VDD1
1
15
logic level power supply
A0
2
16
address input 0
RESET
3
1
active LOW reset input
SD0
4
2
serial data 0
SC0
5
3
serial clock 0
SD1
6
4
serial data 1
SC1
7
5
serial clock 1
supply ground
VSS
8
6[1]
SD2
9
7
serial data 2
SC2
10
8
serial clock 2
SD3
11
9
serial data 3
SC3
12
10
serial clock 3
A1
13
11
address input 1
SCL
14
12
serial clock line
SDA
15
13
serial data line
VDD2
16
14
core logic power supply
[1]
PCA9846
Pin description
HVQFN16 package die supply ground is connected to both the VSS pin and the exposed center pad. The
VSS pin must be connected to supply ground for proper device operation. For enhanced thermal, electrical,
and board-level performance, the exposed pad needs to be soldered to the board using a corresponding
thermal pad on the board, and for proper heat conduction through the board thermal vias need to be
incorporated in the printed-circuit board in the thermal pad region.
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PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
6. Functional description
Refer to Figure 1 “Block diagram of PCA9846”.
6.1 Device address
Following a START condition, the bus master must output the address of the slave it is
accessing. The address of the PCA9846 is shown in Figure 4. the device pins A0 and A1
must be connected to a valid logic signal — HIGH, LOW, SCL or SDA — to ensure a valid
slave address, since no internal pull-up resistors are provided.
1
X
1
X
X
X
X
R/W
X = programmable by hardware
aaa-011933
See Table 4.
Fig 4.
PCA9846
Product data sheet
Slave address
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PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
Table 4.
Address selection
PCA9846
address pins
A1
A0
8-bit
I2C-bus
address
Slave address/bit pattern
master must send
0
SCL
0xE0h
1
1
1
0
0
0
0
0/1
0
0
0xE2h
1
1
1
0
0
0
1
0/1
0
SDA
0xE4h
1
1
1
0
0
1
0
0/1
0
1
0xE6h
1
1
1
0
0
1
1
0/1
1
SCL
0xE8h
1
1
1
0
1
0
0
0/1
1
0
0xEAh
1
1
1
0
1
0
1
0/1
1
SDA
0xECh
1
1
1
0
1
1
0
0/1
1
1
0xEEh
1
1
1
0
1
1
1
0/1
SCL
SCL
0xB0h
1
0
1
1
0
0
0
0/1
SCL
0
0xB2h
1
0
1
1
0
0
1
0/1
SCL
SDA
0xB4h
1
0
1
1
0
1
0
0/1
SCL
1
0xB6h
1
0
1
1
0
1
1
0/1
SDA
SCL
0xB8h
1
0
1
1
1
0
0
0/1
SDA
0
0xBAh
1
0
1
1
1
0
1
0/1
SDA
SDA
0xBCh
1
0
1
1
1
1
0
0/1
SDA
1
0xBEh
1
0
1
1
1
1
1
0/1
A7
A6
A5
A4
A3
A2
A1
A0 - R/W
6.2 Software Reset General Call, and device ID addresses
Two other different addresses can be sent to the device.
• General Call address: allows to reset the device through the I2C-bus upon reception
of the right I2C-bus sequence. See Section 6.2.1 “Software Reset” for more
information.
• Device ID address: allows to read ID information from the device (manufacturer, part
identification, revision). See Section 6.2.2 “Device ID (PCA9846 ID field)” for more
information.
R/W
0
0
0
0
0
0
0
0
1
1
1
1
1
002aac115
Fig 5.
PCA9846
Product data sheet
General Call address
0
R/W
002aac116
Fig 6.
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0
Device ID address
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PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
6.2.1 Software Reset
The Software Reset Call allows all the devices in the I2C-bus to be reset to the power-up
state value through a specific formatted I2C-bus command. To be performed correctly, it
implies that the I2C-bus is functional and that there is no device hanging the bus.
The Software Reset sequence is defined as following:
1. A START command is sent by the I2C-bus master.
2. The reserved General Call I2C-bus address ‘0000 000’ with the R/W bit set to 0 (write)
is sent by the I2C-bus master.
3. The device acknowledges after seeing the General Call address ‘0000 0000’ (00h)
only. If the R/W bit is set to 1 (read), no acknowledge is returned to the I2C-bus
master.
4. Once the General Call address has been sent and acknowledged, the master sends
1 byte. The value of the byte must be equal to 06h.
a. The device acknowledges this value only. If the byte is not equal to 06h, the device
does not acknowledge it.
If more than 1 byte of data is sent, the device does not acknowledge any more.
5. Once the right byte has been sent and correctly acknowledged, the master sends a
STOP command to end the Software Reset sequence: the device then resets to the
default value (power-up value) and is ready to be addressed again within the specified
bus free time. If the master sends a Repeated START instead, no reset is performed.
The I2C-bus master must interpret a non-acknowledge from the device (at any time) as a
‘Software Reset Abort’. The device does not initiate a reset of its registers.
The unique sequence that initiates a Software Reset is described in Figure 7.
SWRST Call I2C-bus address
S
0
0
0
0
0
START condition
0
0
SWRST data = 06h
0
A
0
0
R/W
acknowledge
from slave(s)
0
0
0
1
1
0
A
P
acknowledge
from slave(s)
PCA9846 is reset.
Registers are set to default power-up values.
aaa-017308
Fig 7.
PCA9846
Product data sheet
Software Reset sequence
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PCA9846
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4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
6.2.2 Device ID (PCA9846 ID field)
The Device ID field is a 3-byte read-only (24 bits) word giving the following information:
• 12 bits with the manufacturer name, unique per manufacturer (for example, NXP).
• 9 bits with the part identification, assigned by manufacturer.
• 3 bits with the die revision, assigned by manufacturer (for example, Rev X).
The Device ID is read-only, hardwired in the device and can be accessed as follows:
1. START command
2. The master sends the Reserved Device ID I2C-bus address followed by the R/W bit
set to 0 (write): ‘1111 1000’.
3. The master sends the I2C-bus slave address of the slave device it needs to identify.
The LSB is a ‘Don’t care’ value. Only one device must acknowledge this byte (the one
that has the I2C-bus slave address).
4. The master sends a Re-START command.
Remark: A STOP command followed by a START command will reset the slave state
machine and the Device ID read cannot be performed. Also, a STOP command or a
Re-START command followed by an access to another slave device will reset the
slave state machine and the Device ID Read cannot be performed.
5. The master sends the Reserved Device ID I2C-bus address followed by the R/W bit
set to 1 (read): ‘1111 1001’.
6. The Device ID Read can be done, starting with the 12 manufacturer bits (first byte +
4 MSB of the second byte), followed by the 9 part identification bits (4 LSBs of the
second byte + 5 MSBs of the third byte), and then the 3 die revision bits (3 LSBs of
the third byte).
7. The master ends the reading sequence by NACKing the last byte, thus resetting the
slave device state machine and allowing the master to send the STOP command.
Remark: The reading of the Device ID can be stopped anytime by sending a NACK
command.
If the master continues to ACK the bytes after the third byte, the slave rolls back to the
first byte and keeps sending the Device ID sequence until a NACK has been
detected.
For the PCA9846, the Device ID is shown in Figure 8.
manufacturer
0
0
part identification
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
1
0
1
1
0
0
revision
0
aaa-017527
Fig 8.
PCA9846
Product data sheet
PCA9846 Device ID field
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PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
acknowledge from
one or several slaves
Device ID address
S 1
1
1
1
START condition
1
0
0
I2C-bus slave address
of the device to be identified
acknowledge from
slave to be identified
Device ID address
0 A A7 A6 A5 A4 A3 A2 A1 0 A Sr 1
R/W
acknowledge from
slave to be identified
don’t care
1
1
1
1
repeated START
condition
acknowledge
from master
0
0
1 A
R/W
acknowledge
from master
no acknowledge
from master
M M M9 M8 M7 M6 M5 M4 A M3 M2 M1 M0 P8 P7 P6 P5 A P4 P3 P2 P1 P0 R2 R1 R0 A P
11 10
STOP condition
manufacturer name = 000000000000
part identification = 100001010
revision = 000
aaa-011781
If more than 3 bytes are read, the slave device loops back to the first byte (manufacturer byte) and keeps sending data until the
master generates a ‘no acknowledge’.
Fig 9.
Device ID field read operation
6.3 Control register
Following the successful acknowledgement of the slave address, the bus master will send
a byte to the PCA9846, which will be stored in the control register. If multiple bytes are
received by the PCA9846, it will save the last byte received. This register can be written
and read via the I2C-bus.
channel selection bits
(read/write)
7
6
5
4
3
2
1
0
X
X
X
X
B3
B2
B1
B0
channel 0
channel 1
channel 2
channel 3
002aab190
Fig 10. Control register
PCA9846
Product data sheet
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PCA9846
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4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
6.3.1 Control register definition
A SCx/SDx downstream pair, or channel, is selected by the contents of the control
register. This register is written after the PCA9846 has been addressed. All 8 bits of the
control byte are used to determine which channel or channels are to be selected. When a
channel is selected, it will become active after a STOP condition has been placed on the
I2C-bus. This ensures that all SCx/SDx lines will be in a HIGH state when the channel is
made active, so that no false conditions are generated at the time of connection. Notice
that multiple channels may simultaneously be selected.
Table 5.
Control register
Write = channel selection; Read = channel status
D7
D6
D5
D4
B3
B2
B1
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
0
0
0
0
1
0
0
0
1
B0
Command
0
channel 0 disabled
1
channel 0 enabled
X
X
X
X
X
X
0
0
0
1
channel 1 disabled
channel 1 enabled
channel 2 disabled
channel 2 enabled
channel 3 disabled
channel 3 enabled
no channel selected;
power-up/reset default state
Remark: Several channels can be enabled at the same time. Example: B3 = 0, B2 = 1,
B1 = 1, B0 = 0, means that channel 0 and channel 3 are disabled and channel 1 and
channel 2 are enabled. Care should be taken not to exceed the maximum bus
capacitance.
6.4 RESET input
The RESET input is an active LOW signal which may be used to recover from a bus fault
condition. By asserting this signal LOW for a minimum of tw(rst)L, the PCA9846 will reset its
registers and I2C-bus state machine and will deselect all channels.
6.5 Power-on reset
When power is applied to VDD, an internal Power-On Reset (POR) holds the PCA9846 in
a reset condition until VDD2 has reached VPOR. At this point, the reset condition is released
and the PCA9846 registers and I2C-bus state machine are initialized to their default states
(all zeroes) causing all the channels to be deselected.
6.6 Power-on reset requirements
In the event of a glitch or data corruption, PCA9846 can be reset to its default conditions
by using the power-on reset feature. Power-on reset requires that the device go through a
power cycle to be completely reset. This reset also happens when the device is
powered on for the first time in an application.
Power-on reset is shown in Figure 11.
PCA9846
Product data sheet
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PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
VDD2
ramp-up
ramp-down
td(rst)
VI drops below POR levels
(dV/dt)f
time
time to re-ramp
when VDD2 drops
to VPOR(min) − 50 mV or
below 0.2 V to VSS
(dV/dt)r
aaa-014361
Fig 11. VDD2 is lowered below the POR threshold, then ramped back up to VDD2
Table 6 specifies the performance of the power-on reset feature for PCA9846 for both
types of power-on reset.
Table 6.
Recommended supply sequencing and ramp rates
Tamb = 25 C (unless otherwise noted). Not tested; specified by design.
Symbol
Parameter
Condition
Min
Typ
Max
Unit
(dV/dt)f
fall rate of change of voltage
Figure 11
0.1
-
2000
ms
(dV/dt)r
rise rate of change of voltage
Figure 11
0.1
-
2000
ms
td(rst)
reset delay time
Figure 11; re-ramp time when VDD2
drops to VPOR(min) 50 mV) or below
0.2 V to VSS
1
-
-
s
VDD(gl)
glitch supply voltage difference
Figure 12
[1]
-
-
1.0
V
[2]
-
-
10
s
tw(gl)VDD
supply voltage glitch pulse width
Figure 12
VPOR(trip)
power-on reset trip voltage
falling VDD2
0.7
-
-
V
rising VDD2
-
-
1.5
V
[1]
Level that VDD2 can glitch down to with a ramp rate = 0.4 s/V, but not cause a functional disruption when tw(gl)VDD < 1 s.
[2]
Glitch width that will not cause a functional disruption when VDD(gl) = 0.5 VDD2.
Glitches in the power supply can also affect the power-on reset performance of this
device. The glitch width (tw(gl)VDD) and glitch height (VDD(gl)) are dependent on each
other. The bypass capacitance, source impedance, and device impedance are factors that
affect power-on reset performance. Figure 12 and Table 6 provide more information on
how to measure these specifications.
VDD2
∆VDD(gl)
tw(gl)VDD
time
aaa-014362
Fig 12. Glitch width and glitch height
VPOR is critical to the power-on reset. VPOR is the voltage level at which the reset condition
is released and all the registers and the I2C-bus/SMBus state machine are initialized to
their default states. The value of VPOR differs based on the VDD2 being lowered to or from
0 V. Figure 13 and Table 6 provide more details on this specification.
PCA9846
Product data sheet
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PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
VDD2
VPOR (rising VDD2)
VPOR (falling VDD2)
time
POR
time
aaa-014363
Fig 13. Power-on reset voltage (VPOR)
PCA9846
Product data sheet
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PCA9846
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4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
6.7 Voltage level translation between I2C-buses
Today’s complex systems often use multiple power supplies to maximize power savings
and to meet the operating specifications of the devices used. This means that various
I2C-buses are also operating at differing voltage levels and cannot simply connect
together. In addition, modern microcontrollers operate down to 0.8 V to save power,
further complicating the connection of I2C-buses.
The PCA9846 is specifically designed to seamlessly handle these voltage level translation
issues. Any combination of bus voltages can be intermixed on the PCA9846 and correctly
translated to the other bus at Fm+ (1 MHz) speed.
Figure 14 shows a typical application. The microcontroller acts as the master and
operates at 0.8 V with its I2C-bus swinging between 0 V and 0.8 V. The temperature
sensor on channel 0 of the PCA9846 has a operates at 3.3 V, while the GPIO Expander
on channel 1 operates down to 1.8 V to interface with chip select and reset inputs on
various other ICs also operating at 1.8 V. Channel 2 of the PCA9846 is connected to the
I2C-bus of a power management device, operating at 2.5 V. The other channels of
PCA9846 are simply left unconnected.
In this example, VDD1 of the PCA9846 is a bias supply and is set at the lowest bus voltage,
or 0.8 V of the microcontroller. VDD1 sets the input switching points of each SCL and SDA
at 0.3 VDD1 for a LOW level and 0.7 VDD1 for a HIGH level.
VDD2 is the core logic supply from which most of the PCA9846 circuitry runs and must be
greater than 1.65 V.
The I2C-bus is open-drain, so pull-up resistors are needed on each I2C-bus segment. This
is where the voltage level translation happens. The pass transistor internal to the
PCA9846 limit the output voltage to the lower of VDD1 or VDD2. The pull-up resistors will
then limit the HIGH level of each bus segment to the power supply of the devices on that
segment. Note that the pull-up resistors on channel 0 are connected to 3.3 V, the and
resistors on channel 1 are connected to 1.8 V, while the resistors on channel 2 are
connected to 2.5 V — effectively translating the 0.8 V signal swing of the microcontroller
to the correct voltage level for each peripheral.
It is possible to level shift from a higher voltage microcontroller connected to VDD1 to lower
voltage peripherals on the downstream side — the opposite of this particular example, as
long as VDD1 > 0.8 V and VDD2 > 1.65 V.
One thing to note is noise margin on each I2C-bus segment is somewhat reduced due to
the input levels set by VDD1. Especially in this example, the I2C-bus LOW level is
0.3 VDD1 or 0.24 V, so extreme care must be taken to ensure all bus segments meet this
specification. It also means that static offset buffers may not work correctly if the offset
side is connected to the PCA9846.
Another point to examine is that there is no buffering capability between the upstream and
the downstream buses. This is simply a pass transistor, which acts like a switch and a
series resistor, between these bus segments. The series resistance is the Ron of the pass
transistor and is inversely proportional to the minimum of VDD1 + VTH or VDD2, where VTH
is approximately 0.8 V. Refer to Table 8 for some representative Ron values. An upcoming
application note will explain Ron more thoroughly. Therefore, a careful analysis of bus
capacitance and pull-up resistor values is called for.
PCA9846
Product data sheet
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13 of 32
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
A further point to consider is pull-up resistor selection. Since multiple channels can be
simultaneously selected, the pull-up resistors on each channel are connected in parallel.
Ensure each device can correctly drive the effective pull-up resistor value and still meet
the LOW-level specifications.
0.8 V
1.8 V
3.3 V
3.3 V 3.3 V
VDD1
0.8 V
0.8 V
SC0
TEMP
SENSOR
SCL
SD0
SDA
VDD2
0.8 V
1.8 V
1.8 V 1.8 V
VDD
PCA9846
SDA
SDA
SCL
SCL
MICROCONTROLLER
GPIO
SC1
SCL
SD1
SDA
2.5 V
2.5 V 2.5 V
SC2
POWER MGMT
CONTROLLER
SCL
SD2
SDA
0.8 V to 3.6 V
0.8 V to 3.6 V
SC3
I2C-BUS
PERIPHERAL
SCL
SD3
SDA
aaa-017307
Fig 14. Typical application for PCA9846 with differing bus voltages
PCA9846
Product data sheet
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14 of 32
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
7. Characteristics of the I2C-bus
The PCA9846 is an I2C slave device. Data is exchanged between the master and the
PCA9846 through write and read commands conforming to the I2C-bus protocol. The two
communication lines are SCL (serial clock) and SDA (serial data), both of which must be
connected to VDD1 through pull-up resistors.
7.1 Write commands
Data is transmitted to the PCA9846 by sending its device address and setting the Least
Significant Bit (LSB) to a logic 0 (see Table 4 for device addresses), which the PCA9846
acknowledges (ACK). The control register byte is sent after the address that determines
which downstream channel is connected to the upstream channel by bit 0 through bit 2.
Bit 7 through bit 3 are ignored and can be written with any data. There is no limit on the
number of bytes sent after the address and before a STOP condition, only the last byte
written before the STOP condition is recognized and the selected channel is enabled only
at the following STOP condition.
slave address
SDA
S
1
1/0
1
1/0
1/0
control register
1/0
1/0
START condition
0
R/W
A
B7
B6
B5
B4
B3
B2
B1
B0
A
P
acknowledge
from slave
acknowledge
from slave
STOP condition
aaa-019449
Refer to Table 4.
Fig 15. Write control register
7.2 Read commands
Data is read from the PCA9846 by sending its device address and setting the Least
Significant Bit (LSB) to a logic 1 (see Table 4 for device addresses), which the PCA9846
acknowledges. The control register byte is read by the master with each byte either ACK
or NACK by the master. If the master ACKs the control register byte, it continues to send
register data until the master NACKs, signaling the transaction is complete. There is no
limit on the number of bytes read from the PCA9846.
The control register bit definitions are shown in Figure 10. Bit 0 through bit 2 will show the
enabled channels (as determined by the last write).
slave address
SDA
S
1
1/0
1
1/0
1/0
START condition
last byte
control register
1/0
1/0
1
R/W
A
B7
B6
acknowledge
from slave
B5
B4
B3
B2
B1
B0
NA
P
no acknowledge
from master
STOP condition
aaa-019450
Refer to Table 4.
Fig 16. Read control register
PCA9846
Product data sheet
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PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
8. Limiting values
Table 7.
Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Voltages are referenced to VSS (ground = 0 V)[1].
Symbol
Parameter
Min
Max
Unit
VDD
supply voltage
0.5
+4.0
V
VI
input voltage
0.5
+4.0
V
II
input current
-
20
mA
IO
output current
-
25
mA
IDD
supply current
-
100
mA
ISS
ground supply current
-
100
mA
Ptot
total power dissipation
-
400
mW
Tstg
storage temperature
60
+150
C
Tamb
ambient temperature
40
+85
C
[1]
Conditions
operating
The performance capability of a high-performance integrated circuit in conjunction with its thermal environment can create junction
temperatures which are detrimental to reliability. The maximum junction temperature of this integrated circuit should not exceed 125 C.
9. Static characteristics
Table 8.
Static characteristics
VSS = 0 V; Tamb = 40 C to +85 C; unless otherwise specified.
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
Supply
VDD1
supply voltage 1
0.8
-
3.6
V
VDD2
supply voltage 2
1.65
-
3.6
V
IDD(VDD2)
supply current on pin VDD2
IDD(VDD1)
supply current on pin VDD1
VDD1 = 3.6 V, VDD2 = 3.6 V; SC0 to SC7
and SD0 to SD7 not connected;
RESET = VDD1; A0 = A1 = SCL;
continuous register read/write
fSCL = 0 kHz
-
5
12
A
fSCL = 100 kHz
-
8
20
A
fSCL = 1000 kHz
-
65
150
A
5
2
+2
A
VDD1 = 3.6 V, VDD2 = 3.6 V; SC0 to SC7
and SD0 to SD7 not connected;
RESET = VDD1; A0 = A1 = SCL;
continuous register read/write
fSCL = 0 kHz
VPOR
fSCL = 100 kHz
-
5
15
A
fSCL = 1000 kHz
-
45
100
A
-
1.2
1.5
V
power-on reset voltage
PCA9846
Product data sheet
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PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
Table 8.
Static characteristics …continued
VSS = 0 V; Tamb = 40 C to +85 C; unless otherwise specified.
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
Input SCL; input/output SDA
LOW-level input voltage
VIL
HIGH-level input voltage
VIH
LOW-level output current
IOL
leakage current
IL
input capacitance
Ci
VDD1 1.1 V
0.5
-
+0.2VDD1 V
VDD1 > 1.1 V
0.5
-
+0.3VDD1 V
VDD1 = 1.1 V
0.8VDD1 -
3.6
V
VDD1 > 1.1 V
0.7VDD1 -
3.6
V
VOL = 0.4 V; VDD2 2 V
15
-
-
mA
VOL = 0.4 V; VDD2 > 2 V
20
-
-
mA
1
-
+1
A
-
20
40
pF
VDD1 1.1 V
0.5
-
+0.2VDD1 V
VDD1 > 1.1 V
0.5
-
+0.3VDD1 V
VI = VDD or VSS
VI = VSS; all channels disabled
[1]
Select inputs A0 to A1, RESET
VIL
LOW-level input voltage
VIH
HIGH-level input voltage
VDD1 1.1 V
0.8VDD1 -
VDD1 > 1.1 V
0.7VDD1 -
3.6
V
ILI
input leakage current
pin at VDD2 to 3.6 V or VSS
1
-
+1
A
-
5
10
pF
VDD1 = 0.8 V; VDD2 1.65 V;
Vi(sw) = 0.16 V; IO = 3 mA
-
15
24
VDD1 = 1.2 V; VDD2 1.8 V;
Vi(sw) = 0.24 V; IO = 6 mA
-
12
18
VDD1 > 2 V; VDD2 2.5 V;
Vi(sw) = 0.4 V; IO = 20 mA
-
7
10
0
-
100
A
1
-
+1
A
-
8
15
pF
Ci
input capacitance
VI = VSS or VDD1
ON-state resistance
ON resistance of the pass transistor
between SCL and SCx, and SDA and
SDx
[1]
3.6
Pass gate
Ron
Io(sw)
switch output current
IL
leakage current
VI = VDD or VSS
Cio
input/output capacitance
VI = VSS; all switches disabled
[1]
VDD2 = 1.65 V to 3.6 V;
Vi(sw) = VDD1 to 3.6 V;
Vo(sw) = VDD1 to 3.6 V
[1]
Not tested in production. Guaranteed by design and characterization.
PCA9846
Product data sheet
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PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
VDD1
VDD2
DUT
Vi(sw) = 0.2 VDD1
SDA or
SCL
SDx or
SCx
Measured Vo(sw)
IO
aaa-015928
Ron = (Vo(sw) (Vi(sw)) / Io; Vi(sw) and Io are defined in Table 8
Fig 17. Ron test circuit
PCA9846
Product data sheet
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Rev. 1.1 — 4 April 2017
© NXP Semiconductors N.V. 2017. All rights reserved.
18 of 32
xxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx x xxxxxxxxxxxxxx xxxxxxxxxx xxx xxxxxx xxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxx
xxxxx xxxxxx xx xxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxx xxxxxxx xxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxx xxxxxxxxxxxxxx xxxxxx xx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxx xxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxx xxxxx x x
Symbol
Parameter
tPD
propagation delay
fSCL
SCL clock frequency
tBUF
bus free time between a STOP and
START condition
tHD;STA
hold time (repeated) START condition
Conditions
Standard-mode
I2C-bus
from SDA to SDx,
or SCL to SCx
[2]
Min
Max
-
1[1]
Fast-mode
I2C-bus
Fast-mode Plus
I2C-bus
Min
Max
Min
Max
-
1[1]
-
1[1]
Unit
ns
0
100
0
400
0
1000
4.7
-
1.3
-
0.5
-
kHz
s
4.0
-
0.6
-
0.26
-
s
LOW period of the SCL clock
4.7
-
1.3
-
0.5
-
s
HIGH period of the SCL clock
4.0
-
0.6
-
0.26
-
s
tSU;STA
set-up time for a repeated START
condition
4.7
-
0.6
-
0.26
-
s
tSU;STO
set-up time for STOP condition
4.0
-
0.6
-
0.26
-
s
tHD;DAT
data hold time
0[3]
3.45
0[3]
0.9
0
-
s
tSU;DAT
data set-up time
250
-
100
-
50
-
ns
tr
rise time of both SDA and SCL signals
-
1000
20
(VDD / 5.5 V)[4]
300
-
120
ns
tf
fall time of both SDA and SCL signals
-
300
20
(VDD / 5.5 V)[4]
300
20
(VDD / 5.5 V)[4]
120[5]
ns
Cb
capacitive load for each bus line
-
400
-
400
-
550
pF
ns
tSP
pulse width of spikes that must be
suppressed by the input filter
tVD;DAT
data valid time
tVD;ACK
[7]
data valid acknowledge time
-
50
-
50
0
50[6]
-
3.45
-
0.9
-
0.45
s
s
1
-
1
-
100
-
100
-
100
-
ns
500
-
500
-
500
-
ns
0
-
0
-
0
-
ns
RESET
19 of 32
© NXP Semiconductors N.V. 2017. All rights reserved.
tw(rst)L
LOW-level reset time
trst
reset time
tREC;STA
recovery time to START condition
SDA clear
PCA9846
-
0.45[8]
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
Rev. 1.1 — 4 April 2017
All information provided in this document is subject to legal disclaimers.
tLOW
tHIGH
NXP Semiconductors
Dynamic characteristics
10. Dynamic characteristics
PCA9846
Product data sheet
Table 9.
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
[1]
Pass gate propagation delay is calculated from the 20 typical Ron and the 50 pF load capacitance.
[2]
After this period, the first clock pulse is generated.
[3]
A device must internally provide a hold time of at least 300 ns for the SDA signal (referred to the VIH(min) of the SCL signal) in order to
bridge the undefined region of the falling edge of SCL.
[4]
Necessary to be backwards compatible to Fast-mode.
[5]
In Fast-mode Plus, fall time is specified the same for both output stage and bus timing. If series resistors are used, designers should
allow for this when considering bus timing.
[6]
Input filters on the SDA and SCL inputs suppress noise spikes of less than 50 ns.
[7]
Measurements taken with 1 k pull-up resistor and 50 pF load.
[8]
The maximum tHD;DAT could be 3.45 s and 0.9 s for Standard-mode and Fast-mode, but must be less than the maximum of tVD;DAT or
tVD;ACK by a transition time. This maximum must only be met if the device does not stretch the LOW period (tLOW) of the SCL signal. If
the clock stretches the SCL, the data must be valid by the set-up time before it releases the clock.
0.7 × VDD
SDA
0.3 × VDD
tr
tBUF
tf
tHD;STA
tSP
tLOW
0.7 × VDD
SCL
0.3 × VDD
tHD;STA
P
tSU;STA
tHD;DAT
S
tHIGH
tSU;DAT
tSU;STO
Sr
P
002aaa986
Fig 18. Definition of timing on the I2C-bus
ACK or read cycle
START
SCL
SDA
30 %
trst
RESET
50 %
50 %
tREC;STA
50 %
tw(rst)L
002aac549
Fig 19. Definition of RESET timing
PCA9846
Product data sheet
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20 of 32
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
protocol
START
condition
(S)
tSU;STA
bit 7
MSB
(A7)
tLOW
bit 6
(A6)
tHIGH
bit 0
(R/W)
acknowledge
(A)
STOP
condition
(P)
1 / fSCL
0.7 × VDD
SCL
0.3 × VDD
tBUF
tf
tr
0.7 × VDD
SDA
0.3 × VDD
tSU;DAT
tHD;STA
tHD;DAT
tVD;DAT
tVD;ACK
tSU;STO
002aab175
Rise and fall times refer to VIL and VIH.
Fig 20. I2C-bus timing diagram
PCA9846
Product data sheet
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21 of 32
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
11. Package outline
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Fig 21. Package outline SOT403-1 (TSSOP16)
PCA9846
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 1.1 — 4 April 2017
© NXP Semiconductors N.V. 2017. All rights reserved.
22 of 32
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
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Fig 22. Package outline SOT629-1 (HVQFN16)
PCA9846
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 1.1 — 4 April 2017
© NXP Semiconductors N.V. 2017. All rights reserved.
23 of 32
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
12. Soldering of SMD packages
This text provides a very brief insight into a complex technology. A more in-depth account
of soldering ICs can be found in Application Note AN10365 “Surface mount reflow
soldering description”.
12.1 Introduction to soldering
Soldering is one of the most common methods through which packages are attached to
Printed Circuit Boards (PCBs), to form electrical circuits. The soldered joint provides both
the mechanical and the electrical connection. There is no single soldering method that is
ideal for all IC packages. Wave soldering is often preferred when through-hole and
Surface Mount Devices (SMDs) are mixed on one printed wiring board; however, it is not
suitable for fine pitch SMDs. Reflow soldering is ideal for the small pitches and high
densities that come with increased miniaturization.
12.2 Wave and reflow soldering
Wave soldering is a joining technology in which the joints are made by solder coming from
a standing wave of liquid solder. The wave soldering process is suitable for the following:
• Through-hole components
• Leaded or leadless SMDs, which are glued to the surface of the printed circuit board
Not all SMDs can be wave soldered. Packages with solder balls, and some leadless
packages which have solder lands underneath the body, cannot be wave soldered. Also,
leaded SMDs with leads having a pitch smaller than ~0.6 mm cannot be wave soldered,
due to an increased probability of bridging.
The reflow soldering process involves applying solder paste to a board, followed by
component placement and exposure to a temperature profile. Leaded packages,
packages with solder balls, and leadless packages are all reflow solderable.
Key characteristics in both wave and reflow soldering are:
•
•
•
•
•
•
Board specifications, including the board finish, solder masks and vias
Package footprints, including solder thieves and orientation
The moisture sensitivity level of the packages
Package placement
Inspection and repair
Lead-free soldering versus SnPb soldering
12.3 Wave soldering
Key characteristics in wave soldering are:
• Process issues, such as application of adhesive and flux, clinching of leads, board
transport, the solder wave parameters, and the time during which components are
exposed to the wave
• Solder bath specifications, including temperature and impurities
PCA9846
Product data sheet
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Rev. 1.1 — 4 April 2017
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24 of 32
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
12.4 Reflow soldering
Key characteristics in reflow soldering are:
• Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to
higher minimum peak temperatures (see Figure 23) than a SnPb process, thus
reducing the process window
• Solder paste printing issues including smearing, release, and adjusting the process
window for a mix of large and small components on one board
• Reflow temperature profile; this profile includes preheat, reflow (in which the board is
heated to the peak temperature) and cooling down. It is imperative that the peak
temperature is high enough for the solder to make reliable solder joints (a solder paste
characteristic). In addition, the peak temperature must be low enough that the
packages and/or boards are not damaged. The peak temperature of the package
depends on package thickness and volume and is classified in accordance with
Table 10 and 11
Table 10.
SnPb eutectic process (from J-STD-020D)
Package thickness (mm)
Package reflow temperature (C)
Volume (mm3)
< 350
350
< 2.5
235
220
2.5
220
220
Table 11.
Lead-free process (from J-STD-020D)
Package thickness (mm)
Package reflow temperature (C)
Volume (mm3)
< 350
350 to 2000
> 2000
< 1.6
260
260
260
1.6 to 2.5
260
250
245
> 2.5
250
245
245
Moisture sensitivity precautions, as indicated on the packing, must be respected at all
times.
Studies have shown that small packages reach higher temperatures during reflow
soldering, see Figure 23.
PCA9846
Product data sheet
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Rev. 1.1 — 4 April 2017
© NXP Semiconductors N.V. 2017. All rights reserved.
25 of 32
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
temperature
maximum peak temperature
= MSL limit, damage level
minimum peak temperature
= minimum soldering temperature
peak
temperature
time
001aac844
MSL: Moisture Sensitivity Level
Fig 23. Temperature profiles for large and small components
For further information on temperature profiles, refer to Application Note AN10365
“Surface mount reflow soldering description”.
PCA9846
Product data sheet
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Rev. 1.1 — 4 April 2017
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26 of 32
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
13. Soldering: PCB footprints
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Fig 24. PCB footprint for SOT403-1 (TSSOP16); reflow soldering
PCA9846
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 1.1 — 4 April 2017
© NXP Semiconductors N.V. 2017. All rights reserved.
27 of 32
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
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Fig 25. PCB footprint for SOT629-1 (HVQFN16); reflow soldering
PCA9846
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 1.1 — 4 April 2017
© NXP Semiconductors N.V. 2017. All rights reserved.
28 of 32
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
14. Abbreviations
Table 12.
Abbreviations
Acronym
Description
CDM
Charged-Device Model
CPU
Central Processing Unit
ESD
ElectroStatic Discharge
Fm+
Fast-mode Plus
HBM
Human Body Model
IC
Integrated Circuit
I2C-bus
Inter-Integrated Circuit bus
LSB
Least Significant Bit
MSB
Most Significant Bit
PCB
Printed-Circuit Board
SMBus
System Management Bus
15. Revision history
Table 13.
Revision history
Document ID
Release date
Data sheet status
Change notice
Supersedes
PCA9846 v.1.1
20170404
Product data sheet
201703016I
PCA9846 v.1
Modifications:
PCA9846 v.1
PCA9846
Product data sheet
•
Section 6.7 “Voltage level translation between
operation of device.
•
Table 1 “Ordering information”: Corrected topside marking for PCA9846PW; no change to
device.
20151109
Product data sheet
I2C-buses”:
-
All information provided in this document is subject to legal disclaimers.
Rev. 1.1 — 4 April 2017
Minor text edits to clarify
-
© NXP Semiconductors N.V. 2017. All rights reserved.
29 of 32
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
16. Legal information
16.1 Data sheet status
Document status[1][2]
Product status[3]
Definition
Objective [short] data sheet
Development
This document contains data from the objective specification for product development.
Preliminary [short] data sheet
Qualification
This document contains data from the preliminary specification.
Product [short] data sheet
Production
This document contains the product specification.
[1]
Please consult the most recently issued document before initiating or completing a design.
[2]
The term ‘short data sheet’ is explained in section “Definitions”.
[3]
The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status
information is available on the Internet at URL http://www.nxp.com.
16.2 Definitions
Draft — The document is a draft version only. The content is still under
internal review and subject to formal approval, which may result in
modifications or additions. NXP Semiconductors does not give any
representations or warranties as to the accuracy or completeness of
information included herein and shall have no liability for the consequences of
use of such information.
Short data sheet — A short data sheet is an extract from a full data sheet
with the same product type number(s) and title. A short data sheet is intended
for quick reference only and should not be relied upon to contain detailed and
full information. For detailed and full information see the relevant full data
sheet, which is available on request via the local NXP Semiconductors sales
office. In case of any inconsistency or conflict with the short data sheet, the
full data sheet shall prevail.
Product specification — The information and data provided in a Product
data sheet shall define the specification of the product as agreed between
NXP Semiconductors and its customer, unless NXP Semiconductors and
customer have explicitly agreed otherwise in writing. In no event however,
shall an agreement be valid in which the NXP Semiconductors product is
deemed to offer functions and qualities beyond those described in the
Product data sheet.
16.3 Disclaimers
Limited warranty and liability — Information in this document is believed to
be accurate and reliable. However, NXP Semiconductors does not give any
representations or warranties, expressed or implied, as to the accuracy or
completeness of such information and shall have no liability for the
consequences of use of such information. NXP Semiconductors takes no
responsibility for the content in this document if provided by an information
source outside of NXP Semiconductors.
In no event shall NXP Semiconductors be liable for any indirect, incidental,
punitive, special or consequential damages (including - without limitation - lost
profits, lost savings, business interruption, costs related to the removal or
replacement of any products or rework charges) whether or not such
damages are based on tort (including negligence), warranty, breach of
contract or any other legal theory.
Notwithstanding any damages that customer might incur for any reason
whatsoever, NXP Semiconductors’ aggregate and cumulative liability towards
customer for the products described herein shall be limited in accordance
with the Terms and conditions of commercial sale of NXP Semiconductors.
Right to make changes — NXP Semiconductors reserves the right to make
changes to information published in this document, including without
limitation specifications and product descriptions, at any time and without
notice. This document supersedes and replaces all information supplied prior
to the publication hereof.
PCA9846
Product data sheet
Suitability for use — NXP Semiconductors products are not designed,
authorized or warranted to be suitable for use in life support, life-critical or
safety-critical systems or equipment, nor in applications where failure or
malfunction of an NXP Semiconductors product can reasonably be expected
to result in personal injury, death or severe property or environmental
damage. NXP Semiconductors and its suppliers accept no liability for
inclusion and/or use of NXP Semiconductors products in such equipment or
applications and therefore such inclusion and/or use is at the customer’s own
risk.
Applications — Applications that are described herein for any of these
products are for illustrative purposes only. NXP Semiconductors makes no
representation or warranty that such applications will be suitable for the
specified use without further testing or modification.
Customers are responsible for the design and operation of their applications
and products using NXP Semiconductors products, and NXP Semiconductors
accepts no liability for any assistance with applications or customer product
design. It is customer’s sole responsibility to determine whether the NXP
Semiconductors product is suitable and fit for the customer’s applications and
products planned, as well as for the planned application and use of
customer’s third party customer(s). Customers should provide appropriate
design and operating safeguards to minimize the risks associated with their
applications and products.
NXP Semiconductors does not accept any liability related to any default,
damage, costs or problem which is based on any weakness or default in the
customer’s applications or products, or the application or use by customer’s
third party customer(s). Customer is responsible for doing all necessary
testing for the customer’s applications and products using NXP
Semiconductors products in order to avoid a default of the applications and
the products or of the application or use by customer’s third party
customer(s). NXP does not accept any liability in this respect.
Limiting values — Stress above one or more limiting values (as defined in
the Absolute Maximum Ratings System of IEC 60134) will cause permanent
damage to the device. Limiting values are stress ratings only and (proper)
operation of the device at these or any other conditions above those given in
the Recommended operating conditions section (if present) or the
Characteristics sections of this document is not warranted. Constant or
repeated exposure to limiting values will permanently and irreversibly affect
the quality and reliability of the device.
Terms and conditions of commercial sale — NXP Semiconductors
products are sold subject to the general terms and conditions of commercial
sale, as published at http://www.nxp.com/profile/terms, unless otherwise
agreed in a valid written individual agreement. In case an individual
agreement is concluded only the terms and conditions of the respective
agreement shall apply. NXP Semiconductors hereby expressly objects to
applying the customer’s general terms and conditions with regard to the
purchase of NXP Semiconductors products by customer.
No offer to sell or license — Nothing in this document may be interpreted or
construed as an offer to sell products that is open for acceptance or the grant,
conveyance or implication of any license under any copyrights, patents or
other industrial or intellectual property rights.
All information provided in this document is subject to legal disclaimers.
Rev. 1.1 — 4 April 2017
© NXP Semiconductors N.V. 2017. All rights reserved.
30 of 32
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
Export control — This document as well as the item(s) described herein
may be subject to export control regulations. Export might require a prior
authorization from competent authorities.
Non-automotive qualified products — Unless this data sheet expressly
states that this specific NXP Semiconductors product is automotive qualified,
the product is not suitable for automotive use. It is neither qualified nor tested
in accordance with automotive testing or application requirements. NXP
Semiconductors accepts no liability for inclusion and/or use of
non-automotive qualified products in automotive equipment or applications.
In the event that customer uses the product for design-in and use in
automotive applications to automotive specifications and standards, customer
(a) shall use the product without NXP Semiconductors’ warranty of the
product for such automotive applications, use and specifications, and (b)
whenever customer uses the product for automotive applications beyond
NXP Semiconductors’ specifications such use shall be solely at customer’s
own risk, and (c) customer fully indemnifies NXP Semiconductors for any
liability, damages or failed product claims resulting from customer design and
use of the product for automotive applications beyond NXP Semiconductors’
standard warranty and NXP Semiconductors’ product specifications.
Translations — A non-English (translated) version of a document is for
reference only. The English version shall prevail in case of any discrepancy
between the translated and English versions.
16.4 Trademarks
Notice: All referenced brands, product names, service names and trademarks
are the property of their respective owners.
I2C-bus — logo is a trademark of NXP Semiconductors N.V.
17. Contact information
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
PCA9846
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 1.1 — 4 April 2017
© NXP Semiconductors N.V. 2017. All rights reserved.
31 of 32
PCA9846
NXP Semiconductors
4-channel ultra-low voltage, Fm+ I2C-bus switch with reset
18. Contents
1
2
3
3.1
4
5
5.1
5.2
6
6.1
6.2
6.2.1
6.2.2
6.3
6.3.1
6.4
6.5
6.6
6.7
7
7.1
7.2
8
9
10
11
12
12.1
12.2
12.3
12.4
13
14
15
16
16.1
16.2
16.3
16.4
17
18
General description . . . . . . . . . . . . . . . . . . . . . . 1
Features and benefits . . . . . . . . . . . . . . . . . . . . 1
Ordering information . . . . . . . . . . . . . . . . . . . . . 2
Ordering options . . . . . . . . . . . . . . . . . . . . . . . . 2
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Pinning information . . . . . . . . . . . . . . . . . . . . . . 4
Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 4
Functional description . . . . . . . . . . . . . . . . . . . 5
Device address . . . . . . . . . . . . . . . . . . . . . . . . . 5
Software Reset General Call, and device ID
addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Software Reset . . . . . . . . . . . . . . . . . . . . . . . . . 7
Device ID (PCA9846 ID field) . . . . . . . . . . . . . . 8
Control register . . . . . . . . . . . . . . . . . . . . . . . . . 9
Control register definition . . . . . . . . . . . . . . . . 10
RESET input . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Power-on reset . . . . . . . . . . . . . . . . . . . . . . . . 10
Power-on reset requirements . . . . . . . . . . . . . 11
Voltage level translation between I2C-buses . 13
Characteristics of the I2C-bus . . . . . . . . . . . . 15
Write commands. . . . . . . . . . . . . . . . . . . . . . . 15
Read commands . . . . . . . . . . . . . . . . . . . . . . 15
Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . 16
Static characteristics. . . . . . . . . . . . . . . . . . . . 16
Dynamic characteristics . . . . . . . . . . . . . . . . . 19
Package outline . . . . . . . . . . . . . . . . . . . . . . . . 22
Soldering of SMD packages . . . . . . . . . . . . . . 24
Introduction to soldering . . . . . . . . . . . . . . . . . 24
Wave and reflow soldering . . . . . . . . . . . . . . . 24
Wave soldering . . . . . . . . . . . . . . . . . . . . . . . . 24
Reflow soldering . . . . . . . . . . . . . . . . . . . . . . . 25
Soldering: PCB footprints. . . . . . . . . . . . . . . . 27
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Revision history . . . . . . . . . . . . . . . . . . . . . . . . 29
Legal information. . . . . . . . . . . . . . . . . . . . . . . 30
Data sheet status . . . . . . . . . . . . . . . . . . . . . . 30
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Trademarks. . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Contact information. . . . . . . . . . . . . . . . . . . . . 31
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
© NXP Semiconductors N.V. 2017.
All rights reserved.
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
Date of release: 4 April 2017
Document identifier: PCA9846
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