Overview
The 7442 BCD to Decimal Decoder IC (DIP) is a robust TTL logic device that converts Binary Coded Decimal (BCD) inputs into a single active output among ten decimal outputs (0 to 9). Designed for reliable operation at standard 5V logic, the 7442 simplifies numeric decoding in digital display, counter, and microcontroller-based systems.
How it works
- Accepts 4 binary inputs (A, B, C, D) representing BCD codes 0000 to 1001.
- Activates one of ten mutually exclusive outputs corresponding to the decimal digit; outputs are active LOW.
- Unused or invalid BCD codes (1010 to 1111) result in no valid decimal output asserted.
Key Features
- BCD to Decimal decoding with 10 active-low outputs.
- TTL-compatible input thresholds for straightforward interfacing with microcontrollers and logic families.
- Fast switching: typical propagation delay ~25 ns for high-performance applications.
- Low power consumption and predictable output currents for LED and display driving.
- Standard DIP-16 package for easy prototyping on breadboards and development boards.
Specifications
- IC Number: 7442
- Logic Type: BCD to Decimal Decoder
- Inputs: 4 (A, B, C, D)
- Outputs: 10 (active LOW)
- Input Voltage (High): 2.0 V (Min)
- Input Voltage (Low): 0.8 V (Max)
- Output Current (Low): 16 mA (Max)
- Output Current (High): -0.4 mA (typ)
- Propagation Delay: 25 ns (Typical)
- Operating Voltage (Vcc): 4.75 V to 5.25 V (Typical 5 V)
- Package: DIP-16 (Dual Inline Package)
- Operating Temperature: 0°C to +70°C
Applications
- Driving LED indicators and 7-segment numeric displays via direct decoding or through driver transistors.
- Digital counters, timers, and numeric readouts in instrumentation.
- Microcontroller-based numeric display systems and front-panel indicators.
- Logic control, output multiplexing, and simple demultiplexer roles in control systems.
- Educational labs, prototyping, and industrial control projects that require reliable BCD-to-decimal conversion.
Design and Integration Tips
- Because outputs are active LOW, use pull-up resistors or connect to LED indicators with series resistors accordingly.
- For driving multiple LEDs or a 7-segment display directly, ensure output current limits are not exceeded; use driver transistors or dedicated display drivers when needed.
- Keep Vcc at a stable 5 V and decouple with a 0.1 µF ceramic capacitor close to the IC to reduce noise and ensure reliable switching.
- Place the DIP-16 device on a breadboard or socket for quick testing and replacement during development.
Why choose the 7442 BCD to Decimal Decoder IC
The 7442 delivers simple, reliable BCD-to-decimal decoding with TTL compatibility, making it a practical choice for hobbyists, educators, and engineers. Its combination of active-low outputs, fast switching, and DIP-16 packaging makes it easy to integrate into display and control applications where clear decimal outputs are required.
Note: Images are for illustration purposes only.












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