1 Features

• Low Standby Current Consumption
• I²C to Parallel Port Expander
• Open-Drain Active-Low Interrupt Output
• Active-Low Reset Input
• Operating Power-Supply Voltage Range of 1.65 V to 5.5 V
• 5-V Tolerant I/O Ports
• 400-kHz Fast I²C Bus
• Two Hardware Address Pins Allow up to Four Devices on the I²C/SMBus
• Input and Output Configuration Register
• Polarity Inversion Register
• Power-Up With All Channels Configured as Inputs
• No Glitch on Power Up
• Noise Filter on SCL/SDA Inputs
• Latched Outputs With High-Current Drive Maximum Capability for Directly Driving LEDs
• Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
• ESD Protection Exceeds JESD 22
  • 2000-V Human-Body Model (A114-A)
  • 1000-V Charged-Device Model (C101)

2 Applications

• Servers
• Routers (Telecom Switching Equipment)
• Personal Computers
• Personal Electronics (example: Gaming Consoles)
• Industrial Automation
• Products With GPIO-Limited Processors

3 Description

The TCA9538 is a 16-pin device that provides 8 bits of general purpose parallel input and output (I/O) expansion for the two-line bidirectional I²C bus (or SMBus) protocol. The device can operate with a power supply voltage ranging from 1.65 V to 5.5 V. The device supports both 100-kHz (Standard-mode) and 400-kHz (Fast-mode) clock frequencies. I/O expanders such as the TCA9538 provide a simple solution when additional I/Os are needed for switches, sensors, push-buttons, LEDs, fans, etc.

The features of the TCA9538 include an interrupt that is generated on the INT pin whenever an input port changes state. The A0 and A1 hardware selectable address pins allow up to four TCA9538 devices on the same I²C bus. The device can also be reset to its default sate by using the RESET feature or by cycling the power supply and causing a power-on reset.

1. For all available packages, see the orderable addendum at the end of the datasheet.

Simplified Block Diagram