IC BCD to 7-Segment Decoders/Drivers Common Anode
Display patterns for BCD input counts above nine are unique symbols to authenticate input conditions. All of the circuits incorporate automatic leading and/or trailing-edge, zero-blanking control (RBI and RBO). Lamp test (LT) of these devices may be performed at any time when the BI/RBO node is at a high logic level. All types contain an overriding blanking input (BI) which can be used to control the lamp intensity (by pulsing) or to inhibit the outputs.
Features
- All circuit types feature lamp intensity modulation capability
- Open-collector outputs drive indicators directly
- Lamp-test provision
- Leading/trailing zero suppression
Pinout:
Pin Configuration:
Here’s a typical pinout for the 7447 IC (assuming it’s in a 16-pin DIP package):
| Pin Number | Pin Name | Description |
|---|---|---|
| 1 | a | Segment ‘a’ output (controls segment a) |
| 2 | b | Segment ‘b’ output (controls segment b) |
| 3 | c | Segment ‘c’ output (controls segment c) |
| 4 | d | Segment ‘d’ output (controls segment d) |
| 5 | e | Segment ‘e’ output (controls segment e) |
| 6 | f | Segment ‘f’ output (controls segment f) |
| 7 | g | Segment ‘g’ output (controls segment g) |
| 8 | Vss | Ground |
| 9 | BL | Blanking input (active low) |
| 10 | D | BCD input (D) |
| 11 | C | BCD input (C) |
| 12 | B | BCD input (B) |
| 13 | A | BCD input (A) |
| 14 | Vcc | Positive voltage supply (typically +5V) |
| 15 | LE | Lamp test input (active low) |
| 16 | LT | Lamp test input (active low) |
Technical Specifications
| Physical | |
| Case/Package | PDIP |
| Number of Pins | 16 |
| Technical | |
| High-Level Output Current | -200 µA |
| Independent Circuits | 1 |
| Logic Function | Decoder |
| Low-Level Output Current | 8 mA |
| Max Input Voltage | 5.25 V |
| Max Operating Temperature | 70 °C |
| Min Input Voltage | 4.75 V |
| Min Operating Temperature | 0 °C |
| Operating Supply Voltage | 5.25 V |
| Supply Type | Single |
How To Use This Chip
Like every other chip in the 7400 series, this IC needs to be connected to power before you can use it. Most 7400 ICs support a VCC voltage of 5V. One difference between the HC and LS versions of the chip is that the 74HC47 supports 2V to 6V, while the 74LS47 supports only 5V.
