Hi All,
Currently I am using the TLV320AIC3254 with single ended inputs on IN3_L, and IN3_R (Microphones) and then this signal is processed in the miniDSP and outputed on the HPL and HPR. Both input and output are AC coupled.
However the system that it is used in, can also work when the circuit is turned off, as in POWER is removed from the DSP. This means that:
1.There is a signal present after the ac coupled cap of the HPR amplifier only (not the HPL only on 1 side when powered down).
2. There a secondary microphone bias applied to the microphone which means that there is a signal present before the ac couple cap of the IN3L and IN3R input.
What we experience is that we then get some cross talk on the HPL side which should not have a signal present on it at all. We are equating this to the fact that we can be certian what the output/input states are of the DSP when shut down, and there is some bleed through the device.
Is there any recommendations/known problems with this. We are currently trying different modes of operation standby/sleep/shutdown etc.
BR
George