74LS247 DIP BCD-to-Seven-Segment Decoder/Driver
The 74LS247 is a high speed TTL integrated circuit designed to decode a 4-bit Binary Coded Decimal (BCD) input and drive a 7-segment display. This device features open-collector outputs, making it specifically suitable for driving common-anode LED displays or other indicators requiring high-voltage or high-current sinks. A notable feature of the 74LS247 is its ability to render "6" and "9" with tails, providing a more natural and readable numeric character set compared to older decoders.
The IC includes several specialized control functions for display management. The Lamp Test (LT) input allows for a quick check of all segments, while the Blanking Input/Ripple Blanking Output (BI/RBO) and Ripple Blanking Input (RBI) allow for automatic leading or trailing zero suppression in multi-digit displays. These features make it an essential component for digital clocks, counters, and any instrumentation where numeric data must be presented clearly to a user.
KEY FEATURES
- Decodes BCD to 7-segment format for numeric displays
- Open-collector outputs for direct drive of common-anode LEDs
- Enhanced character set with tails on the numbers 6 and 9
- Automatic leading and trailing zero suppression capability
- Lamp test feature for easy segment verification
- Standard 16 pin dual in line package
SPECIFICATIONS
- Supply Voltage 4.75V to 5.25V
- Operating Temperature 0 to 70 Celsius
- Logic Type TTL Low Power Schottky
- Output Off-State Voltage 15V Maximum
- Low Level Output Current 24mA
- Typical Power Dissipation 50mW
- Input Voltage High 2.0V Minimum
INTERFACES
- A B C D BCD data inputs
- LT BAR Lamp test input active low
- RBI BAR Ripple blanking input active low
- BI/RBO BAR Blanking input or ripple blanking output
- a b c d e f g 7-segment driver outputs active low
- VCC Positive supply voltage
- GND Ground reference
