MOSFET comparison: TO-220 vs DPak

Thread Starter

Xavier Pacheco Paulino

Joined Oct 21, 2015
This MOSFET IRFBG30 is being used in an old design. It even has a little heat sink attached. The FET is used as a current limiter. During normal operation, a current about 13 mA passes through it. Under certain condition, the same FET is going to switch a 1.4A inductive load for a brief moment. What I'm thinking is to redesign this board and replace that FET, with this one: IPD95R1K2P7 which is a surface mount FET. I would use the PCB as heat sink. I note that the new FET has VDS: 950V and the old one 1000V. But I think this shouldn't be an issue, as I expect the max VDS to reach 900V under some critical/unwanted condition. Of course, this time the IRFBG30 wins. However, the IPD95R1K2P7 has lower RDS.

Do you think this is a good idea?