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TCA9535RTWR

TITCA9535RTWR

Texas Instruments
I/O Expander 16 I2C, SMBus 400 kHz 24-WQFN (4x4)
Active18,428 in stock
Datasheet Digi-Key Compare Prices

Overview

The TCA9535RTWR is a 16-bit I/O expander designed for I2C and SMBus applications, providing a remote GPIO solution for microcontrollers with limited pin counts. It operates over a wide voltage range of 1.65V to 5.5V and features an active-low interrupt output to notify the host of input state changes without constant polling. The device includes a polarity inversion register, allowing engineers to invert the polarity of input data in software.

Why Choose This Part

This expander offers high-current drive capability of up to 25mA per pin, allowing it to directly drive LEDs without external transistors. Its 5V-tolerant inputs provide flexibility for mixed-voltage designs, while three hardware address pins allow up to eight unique devices to share the same I2C bus for a total of 128 additional I/O ports.

Applications

User Interface Expansion
Scanning keypads, reading DIP switches, and controlling status LEDs in systems where the primary MCU lacks sufficient GPIO.
System Monitoring
Tracking hardware signals like board-level power-good indicators and fault lines via the integrated interrupt output.
Industrial Control
Interfacing with 5V sensors and actuators thanks to 5V-tolerant I/O ports even when the VDD supply is lower.
Server and Computing
Managing peripheral power sequencing and monitoring chassis status signals via the SMBus compatible interface.

Key Specifications

Features POR
Interface I2C, SMBus
Output Type Push-Pull
Mounting Type Surface Mount
Number of I/O 16
Package / Case 24-WFQFN Exposed Pad
Clock Frequency 400 kHz
Interrupt Output Yes
Voltage - Supply 1.65V ~ 5.5V
Operating Temperature -40degC ~ 85degC
Supplier Device Package 24-WQFN (4x4)
Current - Output Source/Sink 10mA, 25mA

Getting Started

Integration requires connecting the I2C SDA/SCL lines with appropriate pull-up resistors and setting the hardware address pins (A0, A1, A2). Developers can use standard I2C libraries to write to the configuration register for setting pin direction and the output register for driving pins high or low. For rapid prototyping, many TI BoosterPacks and generic QFN-to-DIP breakout boards are available to interface with common MCU dev kits.

Part of I/O expanders family » TCA9535

TCA9535 Family

Comparing specs that differ across variants. The current part is highlighted.

Part Number Package Stock
TCA9535RTWR (this part) WFQFN-24 18,428
TCA9535PWR TSSOP-24 565
TCA9535RGER VFQFN-24 —
TCA9535DBR SSOP-24 3,766

Also Consider

TCA9555RTWR TITexas Instruments - Includes internal pull-up resistors on the I/O ports, which can reduce external component count in certain input configurations.
MCP23017-E/SS MCHPMicrochip - A popular 16-bit alternative often used in the maker community with extensive library support and different package options like SSOP.