Other Parts Discussed in Thread: PCM2900C, PCM2900
Hi everyone!
I designed a board that among other things uses a TPA3144D2 to drive a pair of 8Ω / 2-watt speakers. The source for the audio is a PCM2900C audio codec.
It's configured in the following way:
GAIN: 20dB / LIMRATE: fast / LIMTHRES: 1.46V / SSCTRL: SS2 Modulation / 1SPW: BD-modulation
It basically works as intended, but I ran into one problem.
As soon as the TPA3144D2 is enabled there is a rather clean tone around 4.6kHz on the speakers. The noise disappears if I short the inputs to ground.
This is the relevant part of the schematic:
And this is the corresponding part of the layout:
Trying to solve the problem I first changed the input network to the following configuration. This didn't solve the problem.:
I then started to remove power from other parts of the board until the lone TPA3144D2 was left, powered by a battery, the 4.6 kHz tone still emanating from the speakers.
Any suggestions would be appreciated.
Best Regards, Raoul