Topic: ADI-2/4 Pro SE analog inputs protection questions
Hello everyone,
Can someone explain to me how analog input protection works?
Flowcharts and some logic behind would be even better.
Here's some explanation of the problem:
I feed some loopback and unity gain signals (pink / white noises) into the analog input of the ADI-2/4 Pro SE, taking into account the signal levels. Such signals are usually -6...-12 dB less than the reference settings in the analog inputs (+1 dBU, +7 dBU, +13 dBU, +19 dBU).
But from time to time it triggers some input protection circuits that block them from any signals until I reset the power.
I tried the manual reference input settings as well as the Auto mode. But it's still happening. Sometimes I hear the relay click and then it turns off the inputs. Another time, the right channel goes into what looks like a self-excitation of amplifier. The high frequency amplitude increases logarithmically until it reaches a certain limit and turns off the inputs.