7-Segment with BCD LED Driver Problem
Posted by: Aubreyhu
on
Hi, all
Hardware:
CL5631BW - 3 Digit 7 Segment Display
CD4511BE BCD LED Driver Decoder
Attachment:
The BCDA inputs are wired with 680 Ohm Resistor and the outputs are wired with 680 Ohm Resistors to the 7 Segment correctly.
Problem:
All Numbers shown on the Display are inverted (All segments that should be illuminated are dark and vice versa).
I think the decoder is for Common Cathodes. Is it possible to change the mode for the decoder to Common Anode? Thank you in advance.
Files
Attachment | Size |
---|---|
CD4511BE BCD LED Driver Decoder | 20.35 KB |
Hi Aubreyhu,
The CD4511BE BCD decoder is used for common cathode applications. A common cathode driver such as CD4511 will switch the logic of the segments between +Vcc and open circuit to drive each individual anodes in a common cathode 7 segment LED display.
CL5631BW is a common anode 7 segment display with +Vcc supply as the common connection. Each cathode for each segment will be pulled low to ground by the transistors driven by a common anode driver.
So if you choose a common anode for a common cathode decoder, you need to invert the logic of its outputs by using an external circuit. You can also choose to use a common cathode 7 segment display for your CD4511BE BCD LED decoder to match its application without additional components or vice versa.