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PCF8574PWR

TIPCF8574PWR

Texas Instruments
Interface - I/O Expanders 8bit I/O Expndr A 59 5-PCF8574PW A 595-P A 595-PCF8574PW
NRND2,827 in stock
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Overview

The PCF8574PWR is an 8-bit I/O expander for the I2C bus designed to provide remote I/O expansion for most microcontroller families. It features an open-drain interrupt output that alerts the master to input changes, eliminating the need for constant polling of the bus.

Why Choose This Part

This device simplifies PCB routing by requiring only two I2C lines for eight additional I/O ports. It features a low standby current consumption and allows up to eight devices to be addressed on the same bus for a total of 64 I/O ports.

Applications

LCD Interface
Driving 16x2 or 20x4 character LCDs in 4-bit mode to save microcontroller GPIO pins.
Keypad Scanning
Monitoring matrix keypads by using the interrupt pin to detect key presses across 8 bits.
LED Control
Driving status LEDs or small indicator arrays via the quasi-bidirectional I/O pins.
System Monitoring
Reading DIP switches or hardware jumpers for configuration sensing during boot-up.

Getting Started

To use this part, connect the SCL and SDA pins to your microcontroller's I2C bus with appropriate pull-up resistors. Set the hardware address using pins A0, A1, and A2, and utilize standard I2C libraries such as Wire.h for Arduino or HAL_I2C for STM32 to read and write 8-bit data bytes.

PCF8574 Family

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

Part Number Package Stock
PCF8574PWR (this part) — 2,827
PCF8574AN DIP-16 3,770
PCF8574DWR SOIC-16 11,603
PCF8574RGTR Tape & Reel VFQFN-16 —