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PCA9554B; PCA9554C: Low-voltage 8-bit I²C-bus and SMBus low power I/O port with interrupt, weak pull-up

The PCA9554B and PCA9554C are low-voltage 8-bit General Purpose Input/Output (GPIO) expanders with interrupt for I²C-bus/SMBus applications. The only difference between the PCA9554B and PCA9554C is their I²C fixed address allowing a larger number of the same device on the I²C-bus with no chance of address conflict. NXP I/O expanders provide a simple solution when additional I/Os are needed while keeping interconnections to a minimum, for example, in ACPI power switches, sensors, push buttons, LEDs, fan control, etc.

In addition to providing a flexible set of GPIOs, the wide VDD range of 1.65 V to 5.5 V allow the PCA9554B/PCA9554C to interface with next-generation microprocessors and microcontrollers where supply levels are dropping down to conserve power.

The PCA9554B/PCA9554C contain a register set of 8-bit Configuration, Input, Output, and Polarity Inversion registers.

The PCA9554B is a pin-to-pin replacement for the PCA9554, while the PCA9554C replaces the PCA9554A. Both of these devices replace other industry-standard part numbers. More fully-featured parts PCAL9554B and PCAL9554C are also available with Agile I/O features. See the respective data sheet for more details.

The PCA9554B/PCA9554C open-drain interrupt (INT) output is activated when any input state differs from its corresponding Input Port register state and is used to indicate to the system master that an input state has changed.

INT can be connected to the interrupt input of a microcontroller. By sending an interrupt signal on this line, the remote I/O can inform the microcontroller if there is incoming data on its ports without having to communicate via the I²C-bus. Thus, the PCA9554B/PCA9554C can remain a simple slave device.

The device outputs have 25 mA sink capabilities for directly driving LEDs while consuming low device current.

The power-on reset sets the registers to their default values and initializes the device state machine.

All input/output pins have weak pull-up resistors connected to them to eliminate external components.

Three hardware pins (A0, A1, A2) select the fixed I²C-bus address and allow up to eight devices to share the same I²C-bus/SMBus. The PCA9554B and PCA9554C differ only in their base I²C-bus addresses permitting a total of 16 devices on the I²C-bus, minimizing the chance for address conflict, even in the most complex system.

Outline 3d SOT403-1

Data Sheets (1)

Application Notes (1)

Package Information (2)

Packing (1)

Supporting Information (1)

Design Support

• Expert mode sample code for 8-bit Totem Pole (REV 1.0) TXT 8-BIT-TOTEM-POLE-READ-WRITE 12/10/2014
• Expert mode sample code for PCA9554A and PCA9554C (REV 1.0) TXT 8-BIT-PCA9554A-C-TOTEM-POLE-RE 12/10/2014

Ordering Information

Package Information

Product ID	Package Description	Outline Version	Reflow/Wave Soldering	Packing	Product Status	Part NumberOrdering code(12NC)	Marking	Chemical Content	RoHS / Pb Free / RHF	LeadFree Conversion Date	MSL	MSL LF
PCA9554BBS		SOT758-1		Reel 13" Q2/T3	Active	PCA9554BBSHP (9352 993 86128)	P4B	PCA9554BBS		Always Pb-free	1	1
PCA9554CPW		SOT403-1	SSOP-TSSOP-VSO-WAVE	Reel 13" Q1/T1	Active	PCA9554CPWJ (9352 993 83118)	PA9554C	PCA9554CPW		Always Pb-free	1	1
PCA9554CBS		SOT758-1		Reel 13" Q2/T3	Active	PCA9554CBSHP (9352 993 84128)	P4C	PCA9554CBS		Always Pb-free	1	1
PCA9554BPW		SOT403-1	SSOP-TSSOP-VSO-WAVE	Reel 13" Q1/T1	Active	PCA9554BPWJ (9352 993 85118)	PA9554B	PCA9554BPW		Always Pb-free	1	1