WCH CH455G

CH455 is a digital tube display driver and keyboard scan controller IC. CH455 integrates an internal clock oscillator circuit, capable of dynamically driving 4-digit numerical display tubes or 32 LEDs, while also supporting 28-key keyboard scanning. CH455 exchanges data with MCUs and other devices via a 2-wire serial interface consisting of SCL and SDA.

• Built-in display current drive stage, segment current ≥25mA, digit current ≥160mA.
• Dynamic display scan control, supports 8×4 or 7×4 configuration, directly drives 4-digit seven-segment displays or 32 LEDs.
• Internal current limiting, 8-level brightness control via duty cycle setting.
• Built-in 28-key keyboard controller based on 7×4 matrix keyboard scan.
• Built-in pull-down resistors for key state input, with integrated debounce circuit.
• Active-low keyboard interrupt, with key release flag for polling key press and release events.
• High-speed 2-wire serial interface, clock speed from 0 to 4MHz, compatible with I²C bus, minimizing pin count.
• Built-in POR, supports 2.7V~5V supply voltage.
• Low-power sleep mode support for power saving, wake-up via keypress or command.
• Built-in clock oscillator circuit, no external clock source or oscillator components required, improved noise immunity.
• Available in DIP18, SOP18, and SOP16 lead-free packages, RoHS compliant, partially compatible with CH450 in function and pinout.