IC 7447 BCD TO 7-SEGMENT DECODER/DRIVER
The 7447 are Low Power Schottky BCD to 7-Segment Decoder/Drivers consisting of NAND gates, input buffers, and seven AND-OR-INVERT gates. They offer active LOW, high sink current outputs for driving indicators directly. Seven NAND gates and one driver are connected in pairs to make BCD data and its complement available to the seven decoding AND-OR-INVERT gates. The remaining NAND gate and three input buffers provide lamp tests, blanking input/ripple-blanking output and ripple-blanking input.( Click for wide range of Logic Gates at solicstores.in).
The circuits accept 4-bit binary-coded-decimal (BCD) and, depending on the state of the auxiliary inputs, decodes this data to drive a 7-segment display indicator. The relative positive-logic output levels, as well as conditions required at the auxiliary inputs. Output configurations of the 7447 are designed to withstand the relatively high voltages required for 7-segment indicators.
These outputs will withstand 15 V with a maximum reverse current of 250 µA. Indicator segments requiring up to 24 mA of current may be driven directly from the 7447 high-performance output transistors. Display patterns for BCD input counts above nine are unique symbols to authenticate input conditions.
The 7447 incorporates automatic leading and/or trailing-edge zero-blanking control (RBI and RBO). Lamp test (LT) may be performed at any time in which the BI/RBO node is a HIGH level. This device also contains an overriding blanking input (BI) which can be used to control the lamp intensity by varying the frequency and duty cycle of the BI input signal or to inhibit the outputs.
• Lamp Intensity Modulation Capability (BI/RBO)
• Open Collector Outputs
• Lamp Test Provision
• Leading/Trailing Zero Suppression
• Input Clamp Diodes Limit High-Speed Termination Effects
|Pin no.||Pin name||Description|
|1,2,6,7||B,C,D,A||BCD input of the IC|
|3||LT||Lamp Test Input (Active LOW)|
|4||BI/RBO||Blanking Input (Active LOW) or
Ripple Blanking Output (Active LOW)
|5||RBI||Ripple Blanking Input (Active LOW)|
|9,10,11,12,13,14,15||e,d,c,b,a,g,f||7-Segment Outputs (Active LOW)|
|16||Vcc||Positive supply input|
7447 BCD to 7-segment Driver connections:
- Lamping test and blanking capability.
- Low logic circuit power dissipation.
- Input latches for BCD code storage.
- Balanced propagation delays and transition time.
- High output sourcing capability.
- Lamp intensity modulation capability.
- A rigid structure.
Package Includes :
1 x IC 7447 BCD TO 7-SEGMENT DECODER/DRIVER