LM5121: LM5121 for Vin>75V design

Rock Shao

Expert 2995 points

Part Number: LM5121
Other Parts Discussed in Thread: LM5020

Hi,

My customer wants to use LM5121 to design a 300W DC/DC converter, the condition as the following;

Vin: 20~75VDC
Vout: 36~75VDC
Switch frequency: 120KHz

Does TI recommend this design? Or has any solution to suggest, thanks.

Regards

Rock

over 4 years ago

0 Garrett Roecker over 4 years ago

TI__Mastermind 21720 points

Hi Rock,

Thanks for reaching out with your question and for considering the LM5121 in your design.

Please note that the LM5121 has an absolute maximum voltage rating of 75V. If the input voltage is 75V that leaves no margin to ensure the absolute maximum voltage rating is not exceeded. The recommended maximum input voltage is 65V to allow for 10V of margin.

Is the 75V a continuous case or is it a transient input voltage?

-Garrett

0 Rock Shao over 4 years ago in reply to Garrett Roecker

Expert 2995 points

Hi Garrett,

Thanks for your answer, 75Vin is a continuous case.

Did you have any recommend a solution? thanks.

0 Rock Shao over 4 years ago in reply to Rock Shao

Expert 2995 points

Hi Garrett,

Did you have any recommend a solution for continuous input voltage 75V? Thanks.

Regards

Rock

0 Brigitte over 4 years ago in reply to Rock Shao

TI__Guru 65300 points

Hello Rock,

Please excuse the late response. Please have a look at LM5020.

Power management

Power management forum

LM5121: LM5121 for Vin>75V design