This PCB uses the 7447 chip to decode a common-anode 7-segment display. Current-limiting resistors are included on the board. The input pins are DCBA
(D
is the MSB and A
is the LSB) expecting a BCD value. ~LT
is an active-low lamp test input signal. The decimal point is not connected on this PCB.
Pinout
![](https://i0.wp.com/doctor-pasquale.com/wp-content/uploads/2022/12/7-segment-display-pinout.png?resize=381%2C444&ssl=1)
Hardware
This PCB uses the 7447 chip to decode a common-anode 7-segment display with 220 ohm current-limiting resistors.
Schematic
Click for a larger version.
![](https://i0.wp.com/doctor-pasquale.com/wp-content/uploads/2022/12/7-segment-display-schematic.png?resize=650%2C262&ssl=1)