crimson imp
Hi,
I have succesfully designed some PCB's for panels with 7 segment displays. However my current project consists of a VHF and ADF radio head on 1 panel. Therefore I would like to chain the MAX chips.
Before sending the design out to the manufacturer I would like to ask if anyone with more knowledge would like to look my schematic over.
The printscreen shows 2 chips, I would like to add 2 more in the ''chain''.
Thanks!
Stijn
proud fractal
Hi! I'm going through this process myself and the wiring is pretty much the same as mine. I think C1 and C4 should be 0.1uF, not 100uF. This is what the datasheet says:
To minimize power-supply ripple due to the peak digit driver currents, connect a 10μF electrolytic and a 0.1μF ceramic capacitor between V+ and GND as close to the device as possible.
gritty siren
100nF ceramic caps for C1 & V4 as @proud fractal has already said, and a single 10uF bulk capacitor is enough to supply both MAX7219 chips, so C2 or C3 can be eliminated if you wish.
crimson imp
Hi, thanks for the advice guys. I used the correct capacitors but never updated the schematics.
I tested the PCB’s succesfully!