LM5069: LM5069 turn off time is too long, about 200us

Hi Eggsy Pang,

Is it during short-circuit event ? Have you checked the design SOA using LM5069 design calculator?

Please add additional components as shown below to improve the turn-off response.

Best Regards, Rakesh

Hi Rakesh,

Thanks for your so quickly replying!

It is in overcurrent rather than short short-circuit event. If we set the overcurrent=10A rather than 20A, everything work fine.

May I know how to checked the design SOA using LM5069 design calculator?

BTW, customer use the MOSFET part number HGN042N10S.

Thanks!

Hi Eggsy Pang,

Please fill your system inputs in the attachment and send me for review.

snvu050d.zip

Hi Rakesh,

We doubt the root issue because of red here in below picture from datasheet. It spend too long time. If we cut down it by TIMER pin. But the time too short to power up.

But when Gradual Overcurrent, it don't have the processor like red here in below picture from datasheet "Figure 38. Gradual Overcurrent".

Do you know why and have any suggestions?

Hi Eggsy Pang,

No issue for the FET SOA in case of slow overloads as long as the design takes care of the FET SOA for the selected timer period. 

Can you please elaborate on your above questions.