One Response to “Help with MOSFET sub..”

1. admin says:

   January 26 at 3:26 pm

   I also have the same problem when I need to replace switching PS
   transistor.
   My solution is rather simple :
   – the substitute must have Vgs treshold = original Vgs treshold
   – the substitute must have Vds max >= original Vds max
   – the substitute must have Id max >= original Id max
   and the last, the same as you said :
   – the substitute must have package = original package
   

   Wicaksono

   - Hide quoted text — Show quoted text -

   Radius wrote:
   > Hi there..
   

   >  Sometime lurker first time poster.

   >  I’m working on an older mid 90′s vintage cnc motor controller board.

   >  The magic smoke has been let out of several of the 2SK1277 MOSFETs on
   > this board along with the IR2110 high/low controllers.

   >  The problem I’m having is finding a suitable substitute for the
   > 2SK1277. I’ve found some IR2110 ICs, but cannot find any of the
   > 2SK1277.

   >  In all honesty I’m not that great at this stuff, although I do manage
   > to get most of the stuff working I attempt to repair. What I’m looking
   > for is some help in determining a good sub for the MOSFET I need. One
   > caveat, it does need to be in a TO-3P package due to how the board/
   > heatsink combo is built.

   > Data sheet for the 2SK1277 is here:
   > http://www.ortodoxism.ro/datasheets/fuji/2SK1277.pdf

   > A possible replacement that may or may not work (help!) is here:
   > http://www.fairchildsemi.com/ds/FQ%2FFQA30N40.pdf

   > Thank you for any help!
   > Michael