TCAL9538 8-Bit I2C-Bus, SMBus I/O Expander With Interrupt Output, Reset, and Agile

I/O Configuration Registers

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 pull-

down resistors, latchable inputs, maskable interrupt,

interrupt status register, and programmable open-

drain or push-pull outputs.

Package Information

PART NUMBER

PACKAGE(1)

PACKAGE SIZE(2)

TCAL9538

TSSOP (16)

6.4 mm × 6.4 mm

UQFN (16)

2.6 mm × 1.8 mm

X2QFN (16)

1.6 mm x 1.6 mm

(1)

For more information, see Section 11.

(2)

The package size (length × width) is a nominal value and

includes pins, where applicable.

TCAL9538

I

2C or SMBus

Controller

(processor)

SDA

SCL

INT

VCC

A0

GND

P0

P1

P2

P3

P4

P5

P6

P7

RESET

Peripheral

Devices

RESET,

ENABLE,

or control

inputs

INT or

status

outputs

LEDs

Keypad

A1

Simplified Schematic

TCAL9538

SCPS280A – NOVEMBER 2022 – REVISED NOVEMBER 2023

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.