The MIC signal is 300mV , the line output signal is 2V , help recommend integrated conversion chip?
Hi Stenve-Wilson,
Sorry, the reply is too late. I used the op amp AD828 to amplify the signal and found that the audio signal could not be amplified to the desired volts. So I would like to use the integrated chip solution and ask our local TI technical support, there is no integrated solution. The latter analysis is that the AD828 power rail is relatively small.
We currently use the wide voltage rail OPA1642, The principle is shown in the picture. The input is the MIC signal. The output load is the audio power amplifier. The input impedance is 10k. The J19 is a 20k rotatable potentiometer connected to our instruments panel. The current problem is that the potentiometer is within 10k，the sound can be amplified normally. When the potentiometer is adjusted to 10k or more, most of the time the sound is getting smaller，in a few cases it can be enlarged normally. Please help analyze it.
best regards,
Rengui
