PCM1690: The PCM1690 output is too small and going to clip very quickly

Johnny Du

Part Number: PCM1690

The following is the schematic and output waveform. We used the hardware working mode. Why did the output signal of 1690 go out when it clip 3V? The power supply VCC is 5V, and according to the data manual, the analog output should work up to 8VPP.

over 1 year ago

0 Arash Loloee over 1 year ago

TI__Mastermind 22660 points

Hi Johnny,

Have you verified and confirmed the following voltages at the pin of the device and made sure they are what you would expect: VCOM, VCC and VDD

Can you plot both outputs, say Vout1+ and Vout1-, and if converting DE to SE , show that as well?

If VCOM and supplies are correct , can you apply the input to different channels and see what you get? Table 1. shows Pin Assignments in Differential Output Mode.

Have you tried sending a 0V signal in and see how the outputs look individually, assuming your VCOM is reading correctly?

Along with that can you tell me the freq of different clks .

Regards,

Arash

0 Johnny Du over 1 year ago in reply to Arash Loloee

Prodigy 10 points

Hi Arash,

Thanks for your reply, but I have no board now, please help to confirm whether the circuit behind has any impact?

0 Johnny Du over 1 year ago in reply to Arash Loloee

Prodigy 10 points

Hi Arash,

We modified the parameters of the Buffer circuit of the later stage, and now it is normal.

0 Arash Loloee over 1 year ago in reply to Johnny Du

TI__Mastermind 22660 points

Thanks for the update. So I close the thread.

Regards,

Arash

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PCM1690: The PCM1690 output is too small and going to clip very quickly