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# TPA3110D2-Q1: the voltage of GVDD when SDB = Low

Dear all,

In our experiment, the voltage of GVDD changed when SDB be Hi to Low.

When SDB was Hi, GVDD was 6.91V.

When SDB was Low, GVDD was 5.1V.

We think that GVDD will not change the voltage by SDB from data sheet.

Will internal LDO regulator change something when SDB be Hi to Low?

Could you teach us the voltage of GVDD over temperature when SDB = Low?

Best regards,

### 14 Replies

• Hi Yamamoto-san,

I've assigned this post to the appropriate applications engineer, she will respond to your question.

Regards,
Karl
• This is normal behavior. GVDD is not needed when the device is in shutdown, so the architecture of the part causes the voltage to drop a little. I will check if there is any data about how the GVDD voltage changes over temperature. Why do you need to know how much it varies while the device is in shutdown?

Thanks,

-Clancy
• In reply to Clancy Soehren:

Dear Clancy,

We need this data because we must calculate the total power consumption of circuit.

The power consumption is key point for application.

So we need this data within a few days.

Thank you very much for your help.

Best regards,

• In reply to Takao Yamamoto:

Yamamoto-san,

I double checked all of the characterization data we have for this device and could not find anything for the GVDD voltage in standby mode. For your worst case power consumption calculations, you could use the normal voltage of GVDD. A lower voltage will actually reduce the power consumption.

The next best thing I could do would be to test one unit across temperature. If that will be helpful, please let me know and I will complete the test.

-Clancy
• In reply to Clancy Soehren:

Dear Clancy,

Thank you very much for your check.

And I could understand the way to calculate the worst power consumption.

However, I need to know the power consumption in standby mode.

Could you test one?

I would appreciate for your help.

Best regards,

• In reply to Takao Yamamoto:

Dear Clancy,

Thank you for your always help.

How is progress about the test of GVDD voltage?
I would appreciate if you teach me by when will you answer.

Best regards,
• In reply to Takao Yamamoto:

Thank you for your patience. I will be able to take the GVDD voltage measurement across temperature early next week.
• In reply to Clancy Soehren:

Dear Clancy,

Thank you for your support.
How is progress?
I am looking forward hearing from you.

Best regards,
• In reply to Clancy Soehren:

Dear Clancy,

Any update on this issue?
Your immediate response is highly appreciated.

Best regards,
• In reply to Takao Yamamoto:

Yes, here is the data:

All of this was done with the device in shutdown.

• PVCC = 8V
• T=-40C, GVDD = 4.123V
• T=25C, GVDD = 4.141V
• T=125C, GVDD = 4.149V
• PVCC = 10V
• T=-40C, GVDD = 4.902V
• T = 25C, GVDD = 5.038V
• T = 125C, GVDD = 5.136V
• PVCC = 18V
• T=-40C, GVDD = 4.939V
• T = 25C, GVDD = 5.098V
• T=125C, GVDD = 5.333V
• PVCC = 25V
• T = -40C, GVDD = 4.952V
• T=25C, GVDD = 5.104V
• T = 125C, GVDD = 5.350V

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