Description

The 7447 BCD to 7-Segment Decoder / Driver is a reliable TTL logic IC designed to convert binary-coded decimal (BCD) inputs into the corresponding 7-segment display outputs. This IC features open-collector outputs rated up to 15V, making it compatible with a wide range of common-anode 7-segment displays and suitable for digital display systems, counters, clocks, and numerical indicators. Housed in a 16-pin Dual Inline Package (DIP), the 7447 is widely used in both educational and professional digital electronics projects.

The 7447 simplifies displaying numeric values from a BCD source by directly driving a 7-segment display without additional logic components. It is highly compatible with TTL voltage levels, ensuring seamless integration with other 7400 series ICs, microcontrollers, and digital circuits. Its open-collector outputs allow high-voltage displays or multiple ICs to share a common output line through external pull-up resistors.

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⚙️ Key Features:

• Function: BCD (Binary-Coded Decimal) to 7-segment decoder / driver

• Logic Family: TTL (Transistor-Transistor Logic)

• Inputs: 4 BCD inputs (A, B, C, D)

• Outputs: 7 open-collector outputs (a–g) for 7-segment display

• Open Collector Outputs: Supports up to 15V, suitable for high-voltage displays

• Active Low Outputs: Designed for common-anode 7-segment displays

• Standard 16-Pin DIP Package: Easy for breadboard and PCB integration

• Operating Voltage: 4.75V to 5.25V typical (5V TTL standard)

• Low Power Consumption: Efficient and reliable operation

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🧩 Pin Configuration (16-Pin DIP):

This configuration ensures easy connection to standard BCD sources and 7-segment displays.

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⚡ Electrical Characteristics:

• Supply Voltage (VCC): 5V TTL standard

• Input High Voltage (VIH): ≥ 2V

• Input Low Voltage (VIL): ≤ 0.8V

• Output Current (IOL): 20 mA max per segment

• Propagation Delay: ~25 ns typical

• Power Dissipation: ~50 mW

The open-collector design allows driving higher-voltage displays with proper external pull-up resistors, providing flexibility in display design.

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🧠 How It Works:

The 7447 IC accepts a 4-bit BCD input (0000–1001) and decodes it into 7 outputs (a–g) to illuminate a common-anode 7-segment display and show digits 0–9.

• BCD Inputs (A–D): Represent the decimal number (0–9) in binary

• Segment Outputs (a–g): Drive the corresponding display segments

• Active LOW Outputs: A LOW signal turns ON the segment in a common-anode configuration

• Lamp Test (LT): Turns on all segments when LOW for display testing

• Blanking Input (BI) and Ripple Blanking Input (RBI): Control leading-zero suppression in multiple-digit displays

This IC effectively reduces the circuit complexity by eliminating the need for multiple logic gates to drive a 7-segment display.

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🛠️ Applications:

• Digital Counters and Clocks – Display numeric values directly

• Electronic Meters – Show readings from sensors or microcontrollers

• Educational Projects – Teaching BCD-to-7-segment conversion

• Embedded Systems – Simple numeric output without additional circuitry

• Scoreboards and Digital Indicators – Drive high-voltage displays with 15V open-collector outputs

• Test Equipment – Lamp test and blanking features for display verification

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💡 Advantages:

• Directly drives common-anode 7-segment displays

• Supports high-voltage displays up to 15V

• Reduces component count for BCD-to-7-segment conversion

• TTL compatible for seamless integration with standard logic circuits

• Includes lamp test and blanking inputs for flexible display control

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📦 Package Includes:

• 1 × 7447 BCD to 7-Segment Decoder / Driver IC (DIP-16)

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📘 Conclusion:

The 7447 DIP BCD to 7-Segment Decoder / Driver is a high-performance, versatile IC for digital display applications. With open-collector outputs rated for 15V, it supports high-voltage common-anode displays while simplifying circuit design. Its TTL compatibility, lamp test, and blanking features make it a trusted choice for digital counters, clocks, scoreboards, and educational projects, delivering reliable and efficient performance.

7447 Decoder Datasheet