PCAL9535A

PCAL9535A Low-voltage 16-bit I2C-bus I/O port with interrupt and Agile I/O Rev. 2 — 23 January 2015 Product data sheet 1. General description The PCAL9535A is a low-voltage 16-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 ACPI power switches, sensors, push buttons, LEDs, fan control, etc. In addition to providing a flexible set of GPIOs, the wide VDD range of 1.65 V to 5.5 V allows the PCAL9535A to interface with next-generation microprocessors and microcontrollers where supply levels are dropping down to conserve power. The PCAL9535A contains the PCA9535 register set of four pairs of 8-bit Configuration, Input, Output, and Polarity Inversion registers, and additionally, the PCAL9535A has Agile I/O, which are additional features specifically designed to enhance the I/O. These additional features are: programmable output drive strength, latchable inputs, programmable pull-up/pull-down resistors, maskable interrupt, interrupt status register, programmable open-drain or push-pull outputs. The PCAL9535A is a pin-to-pin replacement to the PCA9535 and PCA9535A, however, the PCAL9535A powers up with all I/O interrupts masked. This mask default allows for a board bring-up free of spurious interrupts at power-up. The PCAL9535A open-drain interrupt (INT) output is activated when any input...