1 Features
1. I2C to Parallel Port Expander
. Open-Drain Active-Low Interrupt Output
. Operating Power-Supply Voltage Range of 1.65 V
to 5.5 V
. 5-V Tolerant I/O Ports
. 400-kHz Fast I2C Bus
. Three Hardware Address Pins Allow up to Eight
Devices on the I2C/SMBus
. Input and Output Configuration Register
. Polarity Inversion Register
. Internal Power-On Reset
. Low Standby Current Consumption
. 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 (for example: Gaming
Consoles)
. Industrial Automation
. Products With GPIO-Limited Processors

3 Description
The TCA9554A is a 16-pin device that provides 8 bits
of general purpose parallel input-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 TCA9554A provide a simple
solution when additional I/Os are needed for
switches, sensors, push-buttons, LEDs, fans, and
other similar devices.
The features of the TCA9554A include an interrupt
that is generated on the INT pin whenever an input
port changes state. The A0, A1, and A2 hardware
selectable address pins allow up to eight TCA9554A
devices on the same I2C bus. The device can also be
reset to its default sate by cycling the power supply
and causing a power-on reset.