LM5121-Q1: LM5121 efficiency improvement

ANCY MUHAMMED

Part Number: LM5121-Q1

We had assemble the board and tested with upto 10A. Initially we got efficiency less than 90%. After the removal of snubber circuit parallel to high side N channel MOSFET, we got efficiency upto 93%. Is there any method such that we can increase the efficiency further.

We need efficiency near to 96%

over 1 year ago

0 Haroon Wardak over 1 year ago

TI__Genius 10375 points

Hi Ancy,

Thank you for using E2E forums, could you please give me the specs of your design and the your design schematics? It would be hard for me to give suggestion based on no information.

Thank you

BR,

Haroon

0 ANCY MUHAMMED over 1 year ago in reply to Haroon Wardak

Prodigy 160 points

The details & schematics we had shared to TI for review. The link is given below

LM5121-Q1: Kindly review the Boost Converter schematics - Power management forum - Power management - TI E2E support forums

0 Haroon Wardak over 1 year ago in reply to ANCY MUHAMMED

TI__Genius 10375 points

Hi Ancy,

Changing the mode of operation can help with losses. Is that a possibility for your design to change the mode of operation?

BR,

Haroon

0 ANCY MUHAMMED over 1 year ago

Prodigy 160 points

In our design the MODE pin is connected to ground

0 ANCY MUHAMMED over 1 year ago in reply to ANCY MUHAMMED

Prodigy 160 points

Currently the high side MOSFET is turning ON, so it is working in synchronous mode. The MODE pin is connected to ground. We are using the MOSFET NTMTS0D7N04CTXG for high side & low side

0 Haroon Wardak over 1 year ago in reply to ANCY MUHAMMED

TI__Genius 10375 points

Hi Ancy,

I see, so that means you are running the device in the DEM mode, I believe you can lower the losses by running in SOM or FPWM mode especially when having a higher load current. Other suggestion would be increasing your source voltage could also reduce your losses.

Regarding your FET switches, maybe using a switch with lower Rds(on) could be an idea to reduce the losses.

BR,

Haroon