Hi,
I am using TLV320AIC10 as codec to work with AMBE2000 vocoder. I configured AIC to suit AMBE2000 and tested. Audio is heard at the receiver AIC, but I found some background hissing noise. The speaker output is connected to OUTP & OUTM pins of AIC. I tried configuring AIC in digital loopback. Still the background hissing noise is heard. The OUTP and OUTM of AIC are connected to a pre-amplifier (TLV2374) and out put of this is connected to audio amplifier (LM4951). I have checked the circuit of pre-amplifier and audio amplifier without AIC. The hissing noise is NOT there. When codec is connected and tested (even in digital loopback), the hissing background noise is heard.
Can any one help me out of this issue. What could be the cause of the hissing background noise?
Thanks & Regards,
Srikanth.