128 LED Display Driver Chip CH457


Overview

CH457 is 128-LED display driver chip. CH457 has a built-in clock oscillation circuit, which can dynamically drive 128 LEDs with 32-bit 4-segment or 16-bit 8-segment structure. CH457 exchanges data with MCU via 2-wire or 3-wire serial interface.

System Block Diagram

Feature

  • Built-in display current driving stage, segment current not less than 30mA, word current not less than 120mA.
  • Dynamic display scanning control, direct drive of 128 LEDs with 32-bit 4-segment or 16-bit 8-segment structure.
  • Internal current limiting, provide 8-level brightness control through duty ratio setting.
  • High-speed 2-wire or 3-wire serial interface, clock speed from 0 to 2MHz, the universal 2-wire compatible with two-line I2C bus to save pins.
  • Built-in clock oscillator circuit, no need to provide external clock or external oscillator components, more anti-interference.
  • Automatic low-power consumption sleep, save electricity.
  • 8KV enhanced ESD performance.
  • Support low cost single panel PCB wiring.
  • Package form: SOP28, lead-free package, and be compatible with RoHS.

relation files

file name file content
CH423DS1.PDF CH423 datasheet. A remote I/O expander with 2-wire serial interface, used for 16 digital tube display or I/O expansion applications through two wires. The input terminal is a two-wire interface compatible with I2C, and the output terminal is an 8-bit bidirectional input/output port and a 16-bit high-current output port.