Heavy Noise on MicroMod FD Digital 1

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An36y
Posts: 1
Joined: Mon 7. Jul 2025, 20:55

Heavy Noise on MicroMod FD Digital 1

Post by An36y » Mon 14. Jul 2025, 16:29

Hello,

I am trying to send out a PWM signal using doutL on a MicroMod FD Digital 1. Right now, it is connected to a P GND and the signal is very noisy (using the oscilloscope). On the current configuration, the higher the duty cycle is set, the less noisy it gets. I have changed the wires and tried modifying the configuration multiple times, but I am still getting a ton of noise. Could it be that there is a hardware issue or is there something wrong with the configuration?

Thank you!

G.Bohlen
Hardware Development
Hardware Development
Posts: 63
Joined: Wed 22. Sep 2010, 21:38

Re: Heavy Noise on MicroMod FD Digital 1

Post by G.Bohlen » Tue 15. Jul 2025, 16:33

Hello,
could you please explain more details about your setup?
Baseboard DIgital1 has 8 Lowside drivers. If you want to see the output levels with a scope, please connect a PullUp resistors (~10kOhm) from an output to a supply (e.g.12V if you use a 12V Power supply). Without a Pullup you will always see a voltage close to 0V (only a few mV noise) because the output is either "open" (driver inactive) or 0V (driver active).
What voltage signal levels do you see on the scope?
If you want to connect a load to the output, please connect the other end of the load to a Supply.

Regards,
Gunnar Bohlen

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