LPC1788 + Codec TFA9879

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by uLipe on Mon May 11 13:42:26 MST 2015
Hello all,

We currently working on an Audio application using LPC1788 + TFA9879. We implemented successfuly the audio processor communication, I2C for configuration and linked the GPDMA to transfer audio samples to I2S TXFIFO.

But, we having some trouble about the output power provided by codec, the datasheet says the volume control ranges from -70db to +24db, but when we apply a audio signal with a volume setting below -10db the sound appears clear and correct, but when changes the volume towards to amplification (volume >= 0db) we get a low volume sound but distorted.

We tried to do:

- Bypass DRC, Equalizer;
- Disable power limiter;
- Use another I2S sample rate provided by LPC17;
- Replace the codec IC.

Without success, so any suggestions about these low output power /volume ? Is there any I2C configuration steps? (currently the firmware is updating all register map of CODEC to set its operation properly at once I2C transaction).

Thanks in advance.