1 Features

• Operating power-supply voltage range of 1.08 V to

3.6 V

• Low standby current consumption of 1 μA typical

at 1.8 V

• 1-MHz fast mode plus I2C bus

• Hardware address pin allows two devices on the

same I2C, SMBus bus

• Active-low reset input (RESET )

• Open-drain active-low interrupt output (INT )

• Input or output configuration register

• Polarity inversion register

• Configurable I/O drive strength register

• Pull-up and pull-down resistor configuration

register

• Internal power-on reset

• Noise filter on SCL or 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

– 4000-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

• Gaming consoles

• Products with GPIO-limited processors

3 Description

The TCAL9538 device provides general purpose

parallel input/output (I/O) expansion for the two-line

bidirectional I2C bus (or SMBus) protocol and is

designed for 1.08-V to 3.6-V VCC operation.

The device supports 100-kHz (Standard-mode), 400-

kHz (Fast-mode), and 1-MHz (fast-mode-plus) I2C

clock frequencies. I/O expanders such as the

TCAL9538 provide a simple solution when additional

I/Os are needed for switches, sensors, push-buttons,

LEDs, fans, and so on.

The TCAL9538 has Agile I/O ports which include

additional features designed to enhance the I/O

performance in terms of speed, power consumption

and EMI. The additional features are: programmable

output drive strength, programmable pull-up and pulldown

resistors, latchable inputs, maskable interrupt,

interrupt status register, and programmable opendrain

or push-pull outputs.