BQ40Z80: MOSFET burning up

Hello,

What is the load being applied that is causing the burn up? If possible, can you please share a schematic of the current design?

Regards,

Anthony

Hello,

The schematic was the one which was verified below. Will share it to your mail now. It was 3 before, one got removed due to some issues, Out of the remaining two, one got burnt.

I have shared it in a private message. Any reason why it might get burnt as there were two ?

Hello,

Thank you for sharing, what is the load being applied that is causing the FETs to burn up?

Regards,

Anthony Baldino

Hello,

The load is drone.

Hello,

What is the maximum current being passed through the FET system from the load? Is there a possibility that another FET in parallel is needed?

Regards,

Anthony

Hello,

It was around 15 - 20 A if I remember

Hello,

I do not believe this should be a large enough current split between three FETs to burn them up. Is wide tracing used for the power path going from pack to the FETs? Also, the document below has more information regarding using FETs in parallel.

https://www.ti.com/lit/pdf/slpa020 

Hello,

Yes, that's our question too, we tried in other board which has 3 MOSFET that is working fine till 32 A, Hence reached out to the forum.

Hello,

Are there any differences in the way the previous board's FET system was designed or routed within the layout? This could give us a better idea of why this is burn up is occurring.

Regards,

Anthony

Hello,

No It is the same design, everything is same.

Hello,

Understood, since the FET in use is a TI part, it would be possible to use this forum to reach out to their team to see if there are any differences that could be causing this. This can be done by placing a new thread under the part number of the FET. 

Regards,

Anthony

Hello,

Sure, that would be great.