I2C to GPIO IO Expander Controller CH423S SOP28

Description

I2C to GPIO IO Expander Controller CH423S SOP28

Overview

The CH423 is a universal remote I/O expansion chip with a two-wire serial interface. CH423 provides 8 bidirectional input and output pins and 16 general-purpose output pins to support input level change interrupt. CH423 built-in current drive circuit can statically drive 24 LED tubes or dynamically drive 128 LEDs (equivalent to 16 digital) Tube); CH423 exchanges data with a single-chip microcomputer through a 2-wire serial interface.

Features

• 8 general-purpose input and output pins GPIO and 16 general-purpose output pin GPOs are remotely extended through a two-wire serial interface.
• Built-in current drive stage, continuous drive current is not less than 15mA, OC pin output 1/16 pulse sink current is not less than 120mA.
• The static display drive mode supports 24 LEDs or 3 LEDs.
• The time-sharing dynamic scanning display drive mode supports 128 LEDs or 16-bit common cathode digital tubes, and supports brightness control.
• The bidirectional I/O pin has an interrupt function when the input level changes in the input mode, and the interrupt output is active low.
• The 16 general-purpose output pins can be selected for push-pull output or open-drain output.
• Supports 3V ~ 5V power supply voltage, supports low-power sleep, can be awakened by input level changes.
• High-speed 2-wire serial interface with clock speeds from 0 to 1MHz, compatible with two-wire I2C bus, saving pins.
• Available in DIP28S and SOP28 lead-free packages, compatible with RoHS.

Based on low cost chip CH423. You can replace with similar chips like PCF23017, PCF8574, etc

• 8 Bidirectional IO  ports IO0-IO7
• 16 Output-only IO ports: OC0 – OC15
• 3-5V power supply, compatible I2C interface

More chip features please see the chip page here.