TAS5766M: PWM frequency

The attached image is broken, so I will post it again.

Hi customer,

May you check the resistor value again or whether GVDD voltage is different between good and not good board.

BR,

Alix Wan.

Thank you for your teaching.

However, it seems that there is no big difference between the values.

The measured values are as follows.

The resistance values are the value measured by removing the parts from the footprint.

Thank you.

Hi Customer,

Thanks for the results. It is quite abnormal on my side.

Do you have an EVM board in your hand for correlation?

Further, on Good/NG board, may you capture the waveform below in one screen:

1. Voltage between Ra and Rb
2. GVDD voltage

Br,

Alix 

Hi Alix,

Thank you for your teaching.

The voltage waveforms of the GVDD and FSW pins are shown below.

Good

Not Good

Thank you.

Hi Customer,

Thanks. I see no difference between Good and NG, which is abnormal to me.

Per my discuss with designer, may you offer Good and NG waveform during the start up process of GVDD, Voltage between Ra and Rb? It will give us extra details for analysis. THanks!

BR,

Alix 

Hi Alix,

Thank you for discussing with the designer.

The voltage waveforms of GVDD and FSW during the startup process are shown below.

The voltage value was low until the smartamp wake command was entered.

GOOD

NG

Thank you.

Hi,

There is additional information.
Even with the NG board, the PWM output became 768kHz about once every 10 times.

Thank you.

Hi Customer,

The waveform and the NG issue look abnormal to me. Do you have a EVM board in your hand, can you take off the NG device and then solder it to EVM and try again.

I will do some experiments too on my hand in parallel.

Br,

Alix Wan.