Damned protection diodes...

A project log for 4014 LED minimodule

A cheap, small module that displays two 7-segments digits with simple multiplexing

Yann Guidon / YGDESYann Guidon / YGDES 08/21/2016 at 23:300 Comments

OK, @al1 found a major hicup in my design. The reverse diodes mess with my idea.

The cool news is that the #DYPLED uses another style of multiplexing and is immune to the problem.

The bad news is that I have wasted some PCB surface.

But this is only a little setback. And if parallel wiring doesn't work, serial might !

I measured about 0.7V reverse voltage. There needs to be about 3.5V to turn one of the LEDs on. This might be possible...


It works !

At 3.3V, without limiting resistors, the luminosity is quite good, giving a bit of headroom for multiplexing.