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PCA9555: 16-bit I2C-bus and SMBus I/O port with interrupt

The PCA9555 is a 24-pin CMOS device that provides 16 bits of General Purpose parallel Input/Output (GPIO) expansion for I²C-bus/SMBus applications and was developed to enhance the NXP Semiconductors family of I²C-bus I/O expanders. The improvements include higher drive capability, 5 V I/O tolerance, lower supply current, individual I/O configuration, and smaller packaging. I/O expanders provide a simple solution when additional I/O is needed for ACPI power switches, sensors, push buttons, LEDs, fans, etc.

The PCA9555 consists of two 8-bit Configuration (Input or Output selection); Input, Output and Polarity Inversion (active HIGH or active LOW operation) registers. 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 or Output register. The polarity of the read register can be inverted with the Polarity Inversion register. All registers can be read by the system master. Although pin-to-pin and I²C-bus address compatible with the PCF8575, software changes are required due to the enhancements, and are discussed in Application Note AN469.

The PCA9555 open-drain interrupt 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. The power-on reset sets the registers to their default values and initializes the device state machine.

Three hardware pins (A0, A1, A2) vary the fixed I²C-bus address and allow up to eight devices to share the same I²C-bus/SMBus. The fixed I²C-bus address of the PCA9555 is the same as the PCA9554, allowing up to eight of these devices in any combination to share the same I²C-bus/SMBus.

PCA9555: Product Block Diagram

Outline 3d SOT137-1

Data Sheets (1)

Application Notes (5)

Users Guides (4)

Brochures (5)

Package Information (5)

Packing (5)

Reports or Presentations (1)

Supporting Information (3)

Design Support

• Expert mode sample code for 16-bit Totem Pole (REV 1.0) TXT 16-BIT-TOTEM-POLE-READ-WRITE 12/10/2014

IBIS Model

• PCA9555 IBIS model (REV 1.0) ibs PCA9555BS 8/13/2014
• PCA9555 IBIS model (REV 1.0) ibs PCA9555HF 8/13/2014
• PCA9555 IBIS model (REV 1.0) ibs PCA9555R 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
PCA9555D		SOT137-1	SO-SOJ-WAVE	Reel 13" Q1/T1	Active	PCA9555D,118 (9352 695 67118)	PCA9555D	PCA9555D		week 11, 2005	0.0	2.0	5E8	1	1
				Bulk Pack	Active	PCA9555D,112 (9352 695 67112)	PCA9555D	PCA9555D		week 11, 2005	0.0	2.0	5E8	1	1
PCA9555DB		SOT340-1	SSOP-TSSOP-VSO-REFLOW SSOP-TSSOP-VSO-WAVE SSOP-TSSOP-VSO-REFLOW SSOP-TSSOP-VSO-WAVE	Reel 13" Q1/T1	Active	PCA9555DB,118 (9352 695 68118)	PCA9555	PCA9555DB		week 12, 2005	0.0	2.0	5E8	1	1
				Bulk Pack	Active	PCA9555DB,112 (9352 695 68112)	PCA9555	PCA9555DB		week 12, 2005	0.0	2.0	5E8	1	1
PCA9555BS		SOT616-1		Reel 13" Q2/T3	Active	PCA9555BSHP (9352 720 04128)	9555	PCA9555BS		Always Pb-free	0.0	2.0	5E8	1	1
				Reel 13" Q1/T1	Active	PCA9555BS,118 (9352 720 04118)	9555	PCA9555BS		Always Pb-free	0.0	2.0	5E8	1	1
PCA9555PW		SOT355-1	SSOP-TSSOP-VSO-WAVE	Reel 13" Q1/T1	Active	PCA9555PW,118 (9352 695 69118)	PCA9555	PCA9555PW		week 47, 2004	0.0	2.0	5E8	1	1
				Bulk Pack	Active	PCA9555PW,112 (9352 695 69112)	PCA9555	PCA9555PW		week 47, 2004	0.0	2.0	5E8	1	1
PCA9555PW/DG		SOT355-1	SSOP-TSSOP-VSO-WAVE	Reel 13" Q1/T1	Withdrawn	PCA9555PW/DG,118 (9352 869 39118)	PCA9555			Always Pb-free	0.0	2.0	5E8	1	1
PCA9555HF		SOT994-1		Reel 13" Q1/T1	Active	PCA9555HF,118 (9352 844 58118)	P55H	PCA9555HF		Always Pb-free	0.0	2.0	5E8	1	1