PCA8574AN数据手册恩XP中文资料规格书

描述 Description

The PCA8574/74A provides general-purpose remote I/O expansion via the two-wirebidirectional I²C‑bus (serial clock (SCL), serial data (SDA)).
The devices consist of eight quasi-bidirectional ports, 400 kHz I²C‑bus interface, threehardware address inputs and interrupt output operating between 2.3 V and 5.5 V. Thequasi-bidirectional port can be independently assigned as an input to monitor interruptstatus or keypads, or as an output to activate indicator devices such as LEDs. The systemmaster can read from the input port or write to the output port through a single register.
The low current consumption of 4.5 μA (typical, static) is great for mobile applications andthe latched output ports have 25 mA high current sink drive capability for directly drivingLEDs.
The PCA8574 and PCA8574A are identical, except for the different fixed portion of theslave address. The three hardware address pins allow eight of each device to be on thesame I²C‑bus, so there can be up to 16 of these I/O expanders PCA8574/74A together onthe same I²C‑bus, supporting up to 128 I/Os (for example, 128 LEDs).
The active LOW open-drain interrupt output (INT) can be connected to the interrupt logicof the microcontroller and is activated when any input state differs from its correspondinginput port register state. It is used to indicate to the microcontroller that an input state haschanged and the device needs to be interrogated without the microcontroller continuouslypolling the input register via the I²C‑bus.
The internal Power-On Reset (POR) initializes the I/Os as inputs with a weak internalpull-up 100 μA current source.

特性 Features

I²C‑bus to parallel port expander
400 kHz I²C‑bus interface (Fast-mode I²C‑bus)
Operating supply voltage 2.3 V to 5.5 V with 5.5 V tolerant I/Os held to VDD with 100 μA current source
8-bit remote I/O pins that default to inputs at power-up
Latched outputs with 25 mA sink capability for directly driving LEDs
Total package sink capability of 200 mA
Active LOW open-drain interrupt output
Eight programmable slave addresses using three address pins
Low standby current (4.5 μA typical)
-40 °C to +85 °C operation
ESD protection exceeds 2000 V HBM per JESD22-A114 and 1000 V CDM per JESD22-C101
Latch-up testing is done to JEDEC standard JESD78 which exceeds 100 mA
Packages offered: SO16, TSSOP16, SSOP20

应用 Application

LED signs and displays
Servers
Key pads
Industrial control
Medical equipment
PLCs
Cellular telephones
Gaming machines
Instrumentation and test measurement