Hi team,
There are two kinds of MIC input for customer AIC3204 application, one is electret Mic (bias voltage is required externally), the other is analog silicon Mic (R1 / R2 is removed), and the 3204 internal uplink is configured with differential input.
(1) From the integrated measurement, the single end audio signal is injected directly to the p-end, the internal uplink gain is configured as 17dB, and the measured output / input gain is also 17dB, the same as the configured gain.
(2) After removing the resistance of R1 and R2, the audio signal is injected from the integrated measurement to the p-terminal, and the downlink output gain is about 9dB less than the actual configuration gain.
When there is no bias voltage, why is the measured gain not consistent with the gain configured ? How is this attenuation caused?
