HT1621B is a 32×4 dot matrix memory-mapped multi-functional LCD driver launched by Holtek. It is used to expand the I/O ports of the MCU and drive segment-address LCD screens. This device communicates with the main control chip via a 3-wire serial interface. The main controller only needs 3 or 4 ports to control up to 128 display segments, making it very suitable for simplifying circuit design.
It is equipped with a 256kHz RC oscillator circuit, supporting 1/2, 1/3 biasing and 1/2, 1/3, 1/4 duty cycle. It can flexibly configure to drive different types of LCD panels and can adjust the display contrast through the VLCD pin.
Features ：
• Display driver: Supports 32×4-bit display RAM, capable of driving up to 128 points of LCD panel
• Operating voltage: 2.4V to 5.2V
• Interface type: 3-wire serial interface (for communication with MCU)
• Low power consumption: Typical operating current is only 60µA, and the static current is as low as 0.1µA
• Integrated features: Built-in 256kHz RC oscillator circuit, WDT watchdog timer, time base frequency source
• Flexible driving: Supports 1/2 or 1/3 bias, 1/2, 1/3 or 1/4 duty cycle
• Additional functions: Built-in buzzer driver (optional 2kHz/4kHz), supports Power down instruction to further reduce power consumption
• Operating temperature: -25℃ to +75℃ (SSOP-48 package); -40℃ to +85℃ (LQFP-48 package)
Application：
• Consumer electronics: pedometers, humidity and temperature meters, clocks, electronic scales, digital tubes, etc.
• Household appliances: display panels for smart home appliances
• Instrumentation and meters: portable instruments, display subsystems for measurement equipment
• Embedded systems: devices that require expanded display functionality and are sensitive to power consumption
