The TM1638 is a dedicated LED display driver and keyboard scan controller IC designed for driving multi-digit 7-segment LED displays. It integrates an LED driver, key scan interface, data latch, and serial communication interface into a single chip, reducing MCU I/O requirements and simplifying circuit design. It is widely used in consumer electronics, industrial control panels, and home appliances. Key Features • SOIC-28 (SOP-28) SMD package • Drives 10 segments × 8 digits • Built-in 8 × 3 key scan interface • 3-wire serial interface (STB, CLK, DIO) • 8-level PWM brightness control • Built-in power-on reset • RC internal oscillator • Operating voltage: 4.5V to 5.5V • Operating temperature: -40°C to +80°C • Low external component count • High noise immunity and reliable performance Technical Specifications Parameter Specification Package SOIC-28 (SMD) Supply Voltage 4.5V–5.5V Display Configuration 10 Segment × 8 Digit Interface 3-Wire Serial (CLK, STB, DIO) Segment Drive Current Up to 20mA Grid Drive Current Up to 80mA Brightness Control 8-Level PWM Operating Temperature -40°C to +80°C Applications • LED Digital Displays • Home Appliances • Microwave Ovens • Air Conditioners • Refrigerators • Washing Machines • Audio Equipment • Industrial Control Panels • Electronic Measuring Instruments • Smart Meters