7447 IC – BCD to 7-Segment Display Decoder/Driver (Common Anode)
🔲 7447 IC – BCD to 7-Segment Display Decoder/Driver (Common Anode)
The 7447 is a TTL logic BCD (Binary-Coded Decimal) to 7-segment display decoder/driver, designed specifically for common anode displays. It takes a 4-bit binary input and converts it into control signals to display the corresponding decimal digit (0–9) on a 7-segment display.
⚙️ Technical Specifications
| Parameter | Specification |
|---|---|
| Logic Family | TTL (74 series) |
| Function | BCD to 7-Segment Decoder/Driver |
| Display Type | Common Anode |
| Input | 4-bit BCD (A, B, C, D) |
| Output | 7 segment control lines (a to g) |
| Output Drive | Active LOW (sinks current from segment) |
| Package Type | DIP-16 |
| Supply Voltage (Vcc) | 4.75V to 5.25V (typically 5V) |
| Operating Temperature | 0°C to +70°C |
📌 Pin Configuration (DIP-16)
| Pin | Function | Pin | Function |
|---|---|---|---|
| 1 | B | 16 | Vcc |
| 2 | C | 15 | a |
| 3 | LT (Lamp Test) | 14 | b |
| 4 | RBI (Ripple Blanking Input) | 13 | c |
| 5 | D | 12 | d |
| 6 | BI/RBO (Blanking Input/Output) | 11 | e |
| 7 | A | 10 | f |
| 8 | GND | 9 | g |
Inputs: A, B, C, D (BCD: Least to Most Significant Bit)
Outputs: a–g segments (active LOW, for common anode displays)
🧠 Logic Table (Simplified)
| BCD Input (DCBA) | Displayed Digit | Segment Outputs (a–g) |
|---|---|---|
| 0000 | 0 | 0 0 0 0 0 0 1 |
| 0001 | 1 | 1 0 0 1 1 1 1 |
| ... | ... | ... |
| 1001 | 9 | 0 0 0 0 1 0 0 |
(0 = segment ON; 1 = segment OFF, for common anode)
🛠️ Applications
Digital counters
Electronic clocks
Calculators
Measurement displays
Arduino and microcontroller-based displays
⚡ Note
Designed specifically for common anode 7-segment displays.
Use current-limiting resistors between the driver outputs and display segments.