TAS5634EVM: PWM output couldn't consistent with datasheet

Kailyn Chen

Part Number: TAS5634EVM

Hello，

One customer who used TAS5634EVM tested the SNR and THD+N, and he found that the results are different with the datasheet.

He used Pure path with default configuration, changed CH1 AD or BD modulation, used USB cable to connect PC and EVM board, BTL output mode, 16V power supply and 0.5A current, 44.1Khz input sine wave, the volume registers are all configured with 0dB, and connect PWM output to AP for performance test. But he didn't get 105dB SNR. So he would like if he missed some configuration about the measurement.

Best regards

Kailyn

over 1 year ago

0 Shadow He over 1 year ago

TI__Mastermind 31560 points

Hi Kailyn

May I know what is his testing results? The data in the datasheet is not tested on the EVM, they are from our validation testing board, which has a very large size and try to remove all the affection from the outside. The results maybe a little affected by the bench settings. Such as their power supply quality, also the unshielded connecting line.

0 Kailyn Chen over 1 year ago in reply to Shadow He

TI__Genius 9560 points

Hi Shadow，

Thank you for your reply, the SNR result of AD modulation is about 77dB, while BD modulation is about 73dB.

Best regards

Kailyn

0 Kailyn Chen over 1 year ago in reply to Shadow He

TI__Genius 9560 points

Hi Shadow，

If he didn't use analog section, and only used PWM output for analysis, does it affect a lot as this？

Best regards

Kailyn

0 Shadow He over 1 year ago in reply to Kailyn Chen

TI__Mastermind 31560 points

Hi Kailyn

Do you mean they test without LC filter at the output side? For AP using, seems the especial AP filter needed when send in PWM signal directly. Also when testing, they should use AES17 filter for audio signal test. Can you check with them?

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TAS5634EVM: PWM output couldn't consistent with datasheet