General description
The PCA9538A is a low-voltage 8-bit General Purpose Input/Output (GPIO) expander with interrupt and reset for I2C-bus/SMBus applications. NXP I/O expanders provide a simple solution when additional I/Os are needed while keeping interconnections to a minimum, for example, in ACPIpower switches, sensors, push buttons, LEDs, fan control, etc.
In addition to providing a flexible set of GPIOs, the wide VDDrange of 1.65 V to 5.5 V allows the PCA9538A to interface with next-generation microprocessors and microcontrollers where supply levels are dropping down to conserve power.
The PCA9538A contains the PCA9538A register set of four 8-bit Configuration, Input, Output, and Polarity Inversion registers.

FEATUREs and benefits
 I2C-bus to parallel port expander
 Operating power supply voltage range of 1.65 V to 5.5 V
 Low standby current consumption:
  1.5A (typical at 5 V VDD)
  1.0A (typical at 3.3 V VDD)
 Schmitt-trigger action allows slow input transition and better switching noise immunity at the SCL and SDA inputs
  Vhys=0.10VDD(typical)
 5 V tolerant I/Os
 Active LOW reset input (RESET)
 Open-drain active LOW interrupt output (INT)
 400 kHz Fast-mode I2C-bus
 Internal power-on reset
 Power-up with all channels configured as inputs
 No glitch on power-up
 Latched outputs with 25 mA drive maximum capability for directly driving LEDs
 Latch-up performance exceeds 100 mA per JESD78, Class II
 ESD protection exceeds JESD22
  2000 V Human Body Model (A114-A)
  1000 V Charged-Device Model (C101)
 Packages offered: TSSOP16 and HVQFN16