描述 Description

The PCA9554 is a CMOS device that provides 8?bit parallel input/output port expansion for I2C and SMBus compatible applications. This I/O expander provides a simple solution in applications where additional I/Os are needed: sensors, power switches, LEDs, pushbuttons, and fans. The PCA9554 consist of an input port register, an output port register, a configuration register, a polarity inversion register and an I2C/SMBus?compatible serial interface. Any of the eight I/Os can be configured as an input or output by writing to the configuration register. The system master can invert the PCA9554 input data by writing to the active?high polarity inversion register. The PCA9554 features an active low interrupt output which indicates to the system master that an input state has changed. The device’s extended addressing capability allows up to 8 devices to share the same bus.

特性 Features

? 400 kHz I2C Bus Compatible
? 2.3 V to 5.5 V Operation
? Low Standby Current
? 5 V Tolerant I/Os
? 8 I/O Pins that Default to Inputs at Power?up
? High Drive Capability
? Individual I/O Configuration
? Polarity Inversion Register
? Active Low Interrupt Output
? Internal Power?on Reset
? No Glitch on Power?up
? Noise Filter on SDA/SCL Inputs
? Cascadable up to 8 Devices
? Industrial Temperature Range
? 16?lead TSSOP Package
? These Devices are Pb?Free, Halogen Free/BFR Free and are RoHSCompliant

應(yīng)用 Application

? White Goods
? Handheld Devices
? Data Communications
? Dishwashers
? Washing Machines
? Cell Phones
? PDAs
? Digital Cameras
? Routers
? Hubs and Servers

簡介

PCA9554屬于集成電路（IC）的I/O擴(kuò)展器。由制造生產(chǎn)的PCA9554I/O 擴(kuò)展器該系列器件可與微控制器、微處理器或類似器件結(jié)合使用，目的是增加可用于連接外設(shè)的信號連接數(shù)量。典型的工作概念涉及使用串行通信，只需主機(jī)設(shè)備上的幾根 I/O 線，即可讀/寫擴(kuò)展器設(shè)備上的許多輸入/輸出引腳的狀態(tài)。該技術(shù)的通信速度不佳，但連通性較高，最適合快速響應(yīng)不是很關(guān)鍵的應(yīng)用，例如許多人機(jī)界面應(yīng)用。