LM5050-1: LM5050-1 for Higher DC Bus

JILANI BASHA SHAIK

Part Number: LM5050-1
Other Parts Discussed in Thread: LM5051

Hi Sir,

Can we use LM5050-1 for Oring of Power supplies with 130VDC by adding Zener in series with GND to create GND Offset. Please suggest.

2 months ago

0 Shiven Dhir 2 months ago

TI__Guru 58485 points

Hi Jilani,

Please use LM5051 for 130VDC.

Although LM5051 says that it is a negative side driver but it can also work on positive side with these workarounds.

Regards,

Shiven Dhir

0 JILANI BASHA SHAIK 2 months ago

Prodigy 30 points

Dear Shiven Dhir,

Thank you.

May I request you to please share the complete image of this configuration. And need clarification why the additional MOSFET used here and what should be the ratings of that MOSFET.

Note: The GND side connections are not seen in this image.

0 Shiven Dhir 2 months ago in reply to JILANI BASHA SHAIK

TI__Guru 58485 points

Hi Jilani,

This is the complete image.

LINE,OFF,NFGD are floating.

Sorry I missed 1 crucial point.

Additional MOSFET is used to keep the controller abs-max ratings safe as it is rated for 100V max.

Please use a 200V rated small signal FET as high current will not flow through it.

Regards,

Shiven Dhir

0 JILANI BASHA SHAIK 2 months ago in reply to Shiven Dhir

Prodigy 30 points

Thank you so much for clarification. It needs an isolated supply. We thought to go like this as shown below so that we don't need additional isolated supply and the device is operated in recommended range only unless the zener fails. Please check and suggest.

0 Shiven Dhir 2 months ago in reply to JILANI BASHA SHAIK

TI__Guru 58485 points

Hi Jilani,

We are not sure about the complication it "may" add. The idea I proposed has been tested and verified by me.

Theoretically, your design looks okay.

Regards,

Shiven Dhir

+1 JILANI BASHA SHAIK 2 months ago in reply to Shiven Dhir

Prodigy 30 points

Thank you.

We will check both though we prefer your suggestion.

Power management

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LM5050-1: LM5050-1 for Higher DC Bus