PCA9535PW

Overview

The PCA9535PW is a 16-bit general-purpose I/O expander for I2C-bus or SMBus applications, designed to provide a simple solution when additional I/O is needed for ACPI power switches, sensors, push-buttons, and LEDs. It operates across a wide voltage range of 2.3V to 5.5V and features an active-low interrupt output to notify the host of input state changes. The device includes a Polarity Inversion register and is 5V tolerant, making it highly flexible for mixed-voltage systems.

Why Choose This Part

This expander offers high flexibility with its 16 configurable I/O pins and a wide supply voltage range from 2.3V to 5.5V. It features a low standby current of 1uA and an internal power-on reset that ensures no glitches occur during startup. The push-pull output stage simplifies circuit design by eliminating the need for external pull-up resistors on output pins.

Applications

Getting Started

Engineers can interface this device to any I2C-capable microcontroller or SBC like a Raspberry Pi or Arduino using standard I2C libraries at clock speeds up to 400 kHz. Address pins allow multiple devices on the same bus, and the interrupt pin should be connected to a GPIO with an external pull-up for event-driven programming. Ensure the 24-TSSOP package footprint is correctly implemented in your PCB layout with decoupling capacitors close to the VDD pin.

Also Consider

TCA9535PWR TITexas Instruments - A pin-compatible alternative often used for its similar 1.65V to 5.5V operating range and robust I2C performance.

PCA9555PW NXP Semiconductors - A similar 16-bit expander that includes internal pull-up resistors, which may be preferable depending on the hardware default state requirements.