Digital tube driver and keyboard control chip CH455


The CH455 is a digital tube display driver and a keyboard scan control chip. The CH455 has a built-in clock oscillating circuit that can dynamically drive a 4-bit digital tube or 32 LEDs. It can also perform a 28-key keyboard scan. The CH455 exchanges data with a microcontroller via a 2-wire serial interface consisting of SCL and SDA.


  • Built-in display current drive stage, segment current is not less than 25mA, word current is not less than 160mA.
  • Dynamic display scan control, support 8 × 4 or 7 × 4, direct drive 4-digit digital tube or 32 LED.
  • Internal current limit, providing 8 levels of brightness control through duty cycle setting.
  • Built-in 28-key keyboard controller based on 7×4 matrix keyboard scan.
  • Built-in debounce circuit with pull-down resistor for built-in button status input.
  • Provides an active low keyboard interrupt and provides a button release flag for querying and releasing the button.
  • High-speed 2-wire serial interface with clock speeds from 0 to 4MHz, compatible with two-wire I2C bus, saving pins.
  • Built-in power-on reset, support 2.7V ~ 5V power supply voltage.
  • Supports low-power sleep, saves power, can be woken up by a button or wake up by a command operation.
  • Built-in clock oscillating circuit, no need to provide external clock or external oscillating components, more anti-interference.
  • Available in DIP18, SOP18 and SOP16 lead-free packages, RoHS compliant, functional and pin compatible with CH450 chips.

relation files

file name file content
CH450DS1.PDF CH450 datasheet. CH450 is used for driver of 48 LEDs or 6 digital tubes and for 48-key keyboard scan control, compatible with high-speed two-wire interface.
CH422DS1.PDF CH422 datasheet. Remote I/O expander chip of two-wire serial interface, used for display of 4 digital tubes and I/O expansion application. The input is a two-wire interface compatible with I2C, and the output is an 8-bit bidirectional I/O port and 4-bit large-current output port.
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.
CH453DS1.PDF CH453 datasheet. CH453 can be used for 128 LEDs or 16×8 segment digital tube drive and 64-key keyboard scanning control.
CH452DS1.PDF CH452 datasheet. CH452 can be used for 64 LEDs or 8×8 segment digital tube drive and 64-key keyboard scanning control, simplifying the workload of MCU.
CH454DS1.PDF CH454 datasheet. CH454 is used for display driver of 16-segment LED displays or 8 alphanumeric displays and for keyboard scan control, supports 17 segments x 7 digital tubes, 16 segments x 8 digital tubes and 8 segments x 16 digital tubes.
CH456DS1.PDF CH456 datasheet. CH456 is used for 16 digital tubes display drive and 64-key keyboard scanning. CH456 supports 2-wire serial interface, and is compatible with IIC, simplifying the workload of MCU.