PCA9555 Datasheet – 16-bit I2C and SMBus I/O port with interrupt

Part number : PCA9555,  PCA9555N,  PCA9555D,  PCA9555DB,  PCA9555PW

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

Package : DIP 24 pin, SSOP 24 pin Type

Manufacturer : NXP, Philips Semiconductor, Texas Instruments


PCA9555 IO Expander


The PCA9555 is a 24-pin CMOS device that provide 16 bits of General Purpose parallel Input/Output (GPIO) expansion for I2C/SMBus applications and was developed to enhance the Philips family of IC
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, pushbuttons, LEDs, fans, etc


PCA9555 pinout datasheet


1. Operating power supply voltage range of 2.3 V to 5.5 V
2. 5 V tolerant I/Os
3. Polarity inversion register
4. Active-LOW interrupt output
5. Low stand-by current
6. Noise filter on SCL/SDA inputs
7. No glitch on power-up
9. Internal power-on reset
10. 16 I/O pins which default to 16 inputs
11. 0 kHz to 400 kHz clock frequency


1. Servers
2. Routers (Telecom Switching Equipment)
3. Personal Computers
4. Personal Electronics
5. Industrial Automation Equipment
6. Products with GPIO-Limited Processors

Reference site : http://www.bristolwatch.com/arduino/arduino6.htm

PCA9555 Datasheet