TPA6304-Q1: The test background noise is large. How to optimize it

Sam Sun

Part Number: TPA6304-Q1

When testing the signal-to-noise ratio of TPA6304, it was found that the signal-to-noise ratio at the output of 1Vrms was only 74dB (>80dB is required), and the bottom noise was 220uV (the SPEC of 6304 is 60uV). Please provide optimization suggestions. Thank you. Attached are the test report, PCB and schematic diagram.

AMP LAYOUT.docx 7673.AMP.pdf TPA6304-.docx

over 2 years ago

0 Yanming Gong over 2 years ago

TI__Mastermind 19830 points

Hi,

Firstly, the AP setting side, you should also select a-weighting filter.

Second, I think the noise is from input side. You can short all audio inputs to GND through 1uF capacitors, and double check again. This can avoid input noise influence.

The audio inputs layout should follow datasheet 7.3.1 Single-Ended Analog Inputs.

The 1.5K and 7.5Kohm resistors on inputs can be removed, it may bring pop noise risk.

The 10uF DC caps on inputs is too large, 1uF is fine.

Regards,

Derek