TPA6138A2: input current at power supply off

Toshiro Imi

Part Number: TPA6138A2

Hello,

Our customer has asked TPA6138A2 input current in power supply shutdown..

Could you let us know the amplifier input current at power supply shutdown. He needs to estimate TPA6138A2 power consumption because it has some cases audio signal is applied in this case.

best regards,

over 2 years ago

0 Ivan Salazar over 2 years ago

TI__Guru** 100555 points

Hi Toshiro.

Can you clarify on the test case? You mean the VDD supply is powered down but there is signal present at the input of the device? In this case, you would need to know the current flowing into the inputs, but not VDD, correct?

Best regards,
-Ivan Salazar
Applications Engineer

0 Toshiro Imi over 2 years ago in reply to Ivan Salazar

TI__Expert 6420 points

Thank you for your response.

Yes. the customer needs the current flowing into the inputs, but no VDD power supply,

Best regards,

0 Ivan Salazar over 2 years ago in reply to Toshiro Imi

TI__Guru** 100555 points

Hi Toshiro,

I'll run some tests and will let you know the results later today or tomorrow.

Best regards,
-Ivan Salazar
Applications Engineer

0 Toshiro Imi over 2 years ago in reply to Ivan Salazar

TI__Expert 6420 points

Hi Ivan,

Thank you very much for your help.

I am looking forward to getting your feedback.

Best regards,

0 Ivan Salazar over 2 years ago in reply to Toshiro Imi

TI__Guru** 100555 points

Hi Toshiro,

I've been testing this with different input signals, so far I'm not able to get consistent values (not getting any current for most of the tests)

So I would say the current going into the device when it is not powered is negligible. In fact, current through the device is not considerable as the current will be demanded from VDD when it is powered for amplification. This is working like any other op amp.

Best regards,
-Ivan Salazar
Applications Engineer

0 Toshiro Imi over 2 years ago in reply to Ivan Salazar

TI__Expert 6420 points

Hi Ivan,

Thank you very much for your help. I understood that the input current when VDD power off is much less than that we thought.

I would like to know the current range or order you measured, such as few-pA or few-nA. If you tell us the current measurement accuracy or range, this is helpful for the customer.

Best regards,

0 Ivan Salazar over 2 years ago in reply to Toshiro Imi

TI__Guru** 100555 points

Toshiro,

The current meter resolution I used is down to 1uA, I can barely see some change from 0 for this resolution (it sometimes get a few uA higher and then it goes back to 0. I'm not sure if I can get a higher resolution tool.

Best regards,
-Ivan Salazar
Applications Engineer

0 Toshiro Imi over 2 years ago in reply to Ivan Salazar

TI__Expert 6420 points

Hi Ivan,

Thank you very much. It seems like less than 1uA actually, so I will tell our customer less than 1uA input current at VDD power off.

I will get back to you if he has further question.

Best regards,

Audio

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TPA6138A2: input current at power supply off