Other Parts Discussed in Thread: PCM2706,
Tool/software:
I'm using a PCM2706 to generate the I2S input for TAS6584-Q1 and created the initial register configuration with PPC3 with the following settings:
- I2S, 4CH BTL 48KHz 16bit 64Fs
- PWM 384KHz, BD modulation,
- SDOUT disabled
- Class H OFF.
- Thermal foldback OFF.
- Clip detect OFF.
- Gain compensation OFF.
- PVDD foldback OFF.
Power is 12V.
When I send a 100% amplitude sinewave to the PCM2706 I see it severely clipped at the outputs.
I need to set the digital volume (registers 0x40-0x43) to approximately 0x48 (=-12dB gain) in order for the sinewave to use most 0-12V output range without being clipped.
I do not understand why 0dB gain results in a clipped sinewave. I thought 0dB meant that the full range of 16 bit sample values would cover the full PVDD output range (with some distortion and clipping due do 100% duty cycle not being possible).
Any help understanding why I need to set -12dB just to not get my waveform clipped would be much appreciated.
Thanks.
