Part Number: 7447
BCD TO 7-SEGMENT DECODER-DRIVER(Low=on/ 40-mA/ 30-Volt Outputs)
Package: DIP 16 Pin Type
Manufacturer: TI, Fairchild
The 7447 is BCD to 7-Segment Decoder / Driver.
This package accepts a 1-2-4-8 positive-logic Binary coded Decimal input and converts it to the proper pattern to light a 7-segment display. A low output is intened to light the segment.
The outputs can sink 40 miliamperes in the low state and can withstand 30 volts in the high state. Note that the supply must remain at +5 volts. An output-high state can be obtained only if a display device or resistor pulls the ouput to some positive voltage less than 30 volts.
Current-limiting resistors, typically 300 ohms, must be used when drving a light emitting diode display with this package. incandesent or fluorescent readouts can be directly driven.
The Lamp Test input should remain high. Bringing the Lamp Test to ground simultaneously brings all the outputs to groud.
1. All circuit types feature lamp intensity modulation capability
2. Open-collector outputs drive indicators directly
3. Lamp-test provision
4. Leading/trailing zero suppression