TAS5421EVM: DC offset fault

david sun1

Part Number: TAS5421EVM

Hi Audio Expert,

I am evaluating TAS5421EVM. the final application is to use it to drive a transformer, which may have a core saturation problem by the application note. before I connect to the transformer, I try to use a 56ohm, 1/2 W resistor to check the platform.

power is 12.2V, the input is 50mV 1KHz sine wave, default gain of the evaluation board I think is 26dB. I kept having DC offset shutdown fault condition.

I connected two scope probes to the electrode of the load and ground. You can see yellow trace is OUTN, blue is OUTP. pink is the input. the input is single-ended, I shorted the R6 on the EVM board.

did I do something wrong or the board got damaged?

Thanks,

David Sun

over 5 years ago

0 Gregg Scott over 5 years ago

TI__Mastermind 45035 points

Hi David,

Can you please try the same test with no load? Remove any load from across the outputs. Shorting R6 is not a problem.

The screenshot of the output shows the output has a large DC offset. This is why you are getting the DC offset to trip.

0 david sun1 over 5 years ago in reply to Gregg Scott

Intellectual 340 points

Hi Gregg,

Thank you for your prompt response, please see the waveform, and screen catch

0 david sun1 over 5 years ago in reply to david sun1

Intellectual 340 points

0 Gregg Scott over 5 years ago in reply to david sun1

TI__Mastermind 45035 points

David,

Use a voltmeter and check the voltage across the input pins. It shoujd be zero volts. If it is not, then you have a problem at the input. If is zero and you have the DC Offset, then the IC maybe damaged.

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TAS5421EVM: DC offset fault