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PCA9538: 8-bit I²C-bus and SMBus low power I/O port with interrupt and reset

The PCA9538 is a 16-pin CMOS device that provides 8 bits of General Purpose parallel Input/Output (GPIO) expansion with interrupt and reset for I²C-bus/SMBus applications and was developed to enhance the NXP Semiconductors family of I²C-bus I/O expanders. I/O expanders provide a simple solution when additional I/O is needed for ACPI power switches, sensors, push-buttons, LEDs, fans, etc.

The PCA9538 consists of an 8-bit Configuration register (input or output selection), 8-bit Input Port register, 8-bit Output Port register and an 8-bit Polarity Inversion register (active HIGH or active LOW operation). The system master can enable the I/Os as either inputs or outputs by writing to the I/O configuration bits. The data for each input or output is kept in the corresponding Input Port or Output Port register. The polarity of the Input Port register can be inverted with the Polarity Inversion register. All registers can be read by the system master.

The PCA9538 is identical to the PCA9554 except for the removal of the internal I/O pull-up resistor which greatly reduces power consumption when the I/Os are held LOW, replacement of A2 with RESET and different address range.

The PCA9538 open-drain interrupt output (INT) 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. The power-on reset sets the registers to their default values and initializes the device state machine. The RESET pin causes the same reset/initialization to occur without de-powering the device.

Two hardware pins (A0 and A1) vary the fixed I²C-bus address and allow up to four devices to share the same I²C-bus/SMBus.

PCA9538: Product Block Diagram

sot629-1_3d

Data Sheets (1)

Application Notes (4)

Users Guides (4)

Brochures (3)

Package Information (3)

Packing (3)

Supporting Information (3)

IBIS Model

• PCA9538 IBIS model (REV 1.1) ZIP PCA9538_1 8/13/2014

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	EFR	IFR(FIT)	MTBF(hour)	MSL	MSL LF
PCA9538BS		SOT629-1		Reel 13" Q1/T1	Active	PCA9538BS,118 (9352 774 17118)	9538	PCA9538BS		Always Pb-free	0.0	2.0	5E8	1	1
PCA9538D		SOT162-1	SO-SOJ-REFLOW SO-SOJ-WAVE SO-SOJ-REFLOW SO-SOJ-WAVE	Reel 13" Q1/T1	Active	PCA9538D,118 (9352 774 18118)	PCA9538D	PCA9538D		week 13, 2005	0.0	2.0	5E8	1	1
				Bulk Pack	Active	PCA9538D,112 (9352 774 18112)	PCA9538D	PCA9538D		week 13, 2005	0.0	2.0	5E8	1	1
PCA9538PW		SOT403-1	SSOP-TSSOP-VSO-WAVE	Reel 13" Q1/T1	Active	PCA9538PW,118 (9352 774 19118)	PCA9538	PCA9538PW		week 13, 2005	0.0	2.0	5E8	1	1
				Bulk Pack	Active	PCA9538PW,112 (9352 774 19112)	PCA9538	PCA9538PW		week 13, 2005	0.0	2.0	5E8	1	1
PCA9538PW/Q900		SOT403-1	SSOP-TSSOP-VSO-WAVE	Reel 13" Q1/T1	Active	PCA9538PW/Q900,118 (9352 968 62118)	PCA9538	PCA9538PW/Q900		Always Pb-free	0.0	2.0	5E8	1	1