1 Features

1• Low Standby-Current Consumption of

3.5 μA Maximum

• I2C to Parallel Port Expander

• Open-Drain Active-Low Interrupt Output

• 5-V Tolerant I/O Ports

• Compatible With Most Microcontrollers

• 400-kHz Fast I2C Bus

• Configurable Slave Address with 3 Address Pins

• Polarity Inversion Register

• Latched Outputs With High-Current Drive

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

. Industrial Automation Equipment

. Products with GPIO-Limited Processors

3 Description

This 16-bit I/O expander for the two-line bidirectional

bus (I2C) is designed for 1.65-V to 5.5-V VCC

operation. It provides general-purpose remote I/O

expansion for most microcontroller families via the I2C

interface.

The TCA9555 consists of two 8-bit Configuration

(input or output selection), Input Port, Output Port,

and Polarity Inversion (active high or active low

operation) registers. At power on, the I/Os are

configured as inputs. The system master can enable

the I/Os as either inputs or outputs by writing to the

I/O configuration bits. The data for each input or

output is kept in the corresponding Input or Output

register. The polarity of the Input Port register can be

inverted with the Polarity Inversion register.