TPS23754 output MOSFET failing.

I provided capacitor at input of Q4 not Q3, also tried to vary the R10 to higher value but nothing worked out

Hi Pavan,

Can you attached your schematic that we can review? Thanks!

TI_sch.pdf

Thanks for reply...Here we go check schematics

Hi Pavan,

Can you try removing C719 and the snubbers in your schematic and then test again it's performance? This should make the schematic perform more like the EVM.

Hi Darwin,

I tried that experiment too. But it did not help.

But one work around is I used a high current and low resistance MOSFET(12A and 9.4mOhm) instead of 8.5A and 22mOhm (Si4850EY). We are seeing stable results till now.

Please let me know if you think any other changes or placement of MOSFETs physically is causing any issue.

regards,

Pavan

Hi Pavan,

Did you remove C725 and short L51? I noticed a different transformer as well but couldn't find it online; is it similar to the EVM's transformer? However, it looks like you found a working solution. What is the voltage rating of the new FET? Be sure to check the VDSs of the FETs and make sure it doesn't violate their ABS MAX ratings.

Actually a similar design is used in previous project. So we are confident that this should work.

How high current MOSFET IRF7855 looks stable.

Thanks and Regards,

Pavan G