General description
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.

FEATUREs
■ Operating power supply voltage range of 2.3 V to 5.5 V
■ 5 V tolerant I/Os
■ Polarity Inversion register
■ Active LOW interrupt output
■ Low standby current
■ Noise filter on SCL/SDA inputs
■ No glitch on power-up
■ Internal power-on reset
■ 16 I/O pins which default to 16 inputs
■ 0 Hz to 400 kHz clock frequency
■ ESD protection exceeds 2000 V HBM per JESD22-A114, 200 V MM per JESD22-A115, and 1000 V CDM per JESD22-C101