PCF8574PW集成电路（IC）的I/O扩展器规格书PDF中文资料

PCF8574PW属于集成电路（IC）的I/O扩展器。由德州仪器制造生产的PCF8574PWI/O 扩展器该系列器件可与微控制器、微处理器或类似器件结合使用，目的是增加可用于连接外设的信号连接数量。典型的工作概念涉及使用串行通信，只需主机设备上的几根 I/O 线，即可读/写扩展器设备上的许多输入/输出引脚的状态。该技术的通信速度不佳，但连通性较高，最适合快速响应不是很关键的应用，例如许多人机界面应用。

1 Features

• Low standby-current consumption of 10μA max

• I2C to parallel-port expander

• Open-drain interrupt output

• Compatible with most microcontrollers

• Latched outputs with high-current drive capability

for directly driving LEDs

• Latch-up performance exceeds 100mA per JESD

78, Class II

2 Applications

• Telecom shelters: filter units

• Servers

• Routers (telecom switching equipment)

• Personal computers

• Personal electronics

• Industrial automation

• Products with GPIO-limited processors

3 Description

This 8-bit input/output (I/O) expander for the two-line

bidirectional bus (I2C) is designed for 2.5V to 6V VCC

operation.

The PCF8574 device provides general-purpose

remote I/O expansion for most microcontroller families

by way of the I2C interface [serial clock (SCL), serial

data (SDA)].

The device features an 8-bit quasi-bidirectional I/O

port (P0–P7), including latched outputs with highcurrent

drive capability for directly driving LEDs. Each

quasi-bidirectional I/O can be used as an input or

output without the use of a data-direction control

signal. At power on, the I/Os are high. In this mode,

only a current source to VCC is active.