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
