We are using the TLV230AIC3007 in a design and have a echo or feedback issue we cannot seem to resolve.
We are using wired earphones (Android compatible) connected to the MIC3R input. The earpieces are being driven by the HPOUT drivers in a pseudo-differential manner (capless) exactly as per page 44 of the datasheet.
The MCU connected to the codec is an M4 so the code is a simple C test application that captures the digital audio, delays it by 1s and plays it back over the earphones.
The audio settings are:
Codec is the audio master
Format is I2S
MCLK pin driven from 16MHz clock output from the MCU.
PLL setup for 48kHz
ADC & DAC is 16kHz sample rate (Fsref/3)
We isolated the microphone from the earpieces, but keep getting the echo / feedback that decay fairly quickly.
The routing in the codec is:
MIC3R to PGA_L
ADC_L is active
No filters are active
DINL routed to DAC_L (with no digital processing or 3D processing active)
DAC_L1 routed to HPLOUT and HPROUT (via analog mixers)
VCOM set to VCM
All gains are set to 0dB
The audio (ignoring the echo) sounds really good and there does not seem to be any other issues with it at all.
Can you please suggest anything that I may look at to help resolve this issue?