LM5050-1: how to understand VS=0.8V if 3.3V provided for OFF pin?

Aki Li

Part Number: LM5050-1

Customer tested LM5050-1 in their PSU output, with output voltage =0 V, and when they provided 3.3V logic for OFF pin, they found there was 0.8V measured at VS pin. Could you please help explain how the 0.8V was obtained? Thank you.

over 4 years ago

0 Praveen GD over 4 years ago

TI__Guru 57737 points

Hi Aki,

Do you mean in the test condition below the voltage on VS pin rises to 0.8V ?

the Voltage on IN, OUT and VS is 0V and you applied 3.3V on OFF pin w.r.t GND

0 Aki Li over 4 years ago in reply to Praveen GD

TI__Genius 9815 points

Yes

0 Praveen GD over 4 years ago in reply to Aki Li

TI__Guru 57737 points

Hi Aki,

There could be some leakage in the from the internal path of the IC. But there shouldn't be any issue if there is 0.8V on VS pin.

0 Aki Li over 4 years ago in reply to Praveen GD

TI__Genius 9815 points

Praveen,

Thank you. Is it possible to share more details on how the leakage current affects on the VS pin?

0 Praveen GD over 4 years ago in reply to Aki Li

TI__Guru 57737 points

Hi Aki Li,

Can you let us know how a voltage of 0.8V on VS can effect your system ?

0 Aki Li over 4 years ago in reply to Praveen GD

TI__Genius 9815 points

Praveen,

There was no issue with this voltage now. Customer just wanted to understand how this voltage came out from block diagram level.

0 Praveen GD over 4 years ago in reply to Aki Li

TI__Guru 57737 points

Hi Aki,

There could be leakage through the internal path which we cannot reveal more here due to confidentiality of the internal circuit. If it is critical for customer, I would recommend you to reach out on email.

0 Praveen GD over 4 years ago in reply to Praveen GD

TI__Guru 57737 points

Hi Aki,

Closing this thread as we have replied to this offline.

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LM5050-1: how to understand VS=0.8V if 3.3V provided for OFF pin?