Digital out channel (DOUT) high frequency buzzer noise?

J Kelly 8 months ago in Master modules / MD4 updated by Steve Liljestrand 8 months ago 2

I have connected a buzzer to my MD4-7 inch display using the DOUT channel. 

The signal receives high frequency noise when it is not triggered. Could this be related to the diagnostics tests for internal faults?  - If so how can it be switched off via IQAN design. 

Interesting. The MD4 low-side digital out is only checking for voltage to diagnose off state open load, I cannot see how this would cause the buzzer to give a noise. 

The leakage current is quite small, less than 200 uA, but I wonder if this could be enough make the buzzer give this sound. 

This is interesting, I've experienced similar issues with DOUTS on MC2's . I was using incandescent indication lights on DOUT channels. They would be ever so slightly illuminated when the DOUT was "OFF". My first workaround was adding a load resistor to across the Bulb, but eventually used a relay.