PCF8574T Datasheet – Remote 8-bit I/O Expander

Part number : PCF8574T

Function : Remote 8-bit I/O expander for I2C-bus with interrupt

Package : SO 16 Pin Type

Manufacturer : NXP Semiconductor


PCF8574T io expander


The PCF8574T, PCF8574A provides general-purpose remote I/O expansion via the two-wire bidirectional I2C-bus (serial clock (SCL), serial data (SDA)). The devices consist of eight quasi-bidirectional ports, 100 kHz I2C-bus interface, three hardware address inputs and interrupt output operating between 2.5 V and 6 V. The quasi-bidirectional port can be independently assigned as an input to monitor interrupt status or keypads, or as an output to activate indicator devices such as LEDs. System master can read from the input port or write to the output port through a single register.


PCF8574T Datasheet pinout


1. I2C-bus to parallel port expander
2. 100 kHz I2C-bus interface (Standard-mode I2C-bus)
3. Operating supply voltage 2.5 V to 6 V with non-overvoltage tolerant I/O held to VDD with 100 uA current source
4. 8-bit remote I/O pins that default to inputs at power-up
5. Latched outputs directly drive LEDs
6. Total package sink capability of 80 mA
7. Active LOW open-drain interrupt output
8. Eight programmable slave addresses using three address pins

PCF8574T Datasheet