Dear e2e,
on behalf of my customer I'm wondering if you got across a similar error pattern in the past for TLV320AIC3106. When checking the boards that were returned from the field (running for quites some time) the microphone input seems to be damaged. Migrating to a new test set-up recently, they see an increased failure rate of ~5% from the manufactured boards already before leaving the factory.
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- we use the audio input MIC1LP/MIC1LM as input for a dynamic microphone
- the inputs are decoupled with 0.47µ capacitors from the microphone (sse schematics)
- when there is a problem with the Mic input not working, the signal from the microphone is very small and there there is a lot of noise. In such case when the PGA is set for a gain of more than 25dB we have no signal at the output at all.
- when the microphone input seems to be damaged we can´t measure a DC-voltage at this pins. With working devices there is a DC voltage of 1.35V at both pins.
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Any advice is appreciated.
Best regards,
Uli
