At 02:18 PM 7/5/2010, RussellMc wrote: > > He's finding that the temperature rise is higher than he likes and is > > therefore looking for a Mosfet with lower RDSon. > > The circuit operates at less than 30 Vdc and he has at least 10V of > > gate drive available. > > He'd prefer to stay with the current TO-220 package if possible. Many thanks for all the suggestions. I'm checking into them right now. The problem is that the original spec was for max Id of 10A. So: the board was laid out without provision for any heat-sinking other than soldering the tab of the device to a copper flood area. Max temperature rise was predicted to be less than 30C and was actually measured to be a bit more than 20C. Now the customer wants to run somewhere between 15A to 30A through that device. Unfortunately, the customer doesn't understand (yet) that changing the spec AFTER the board design has been finished, accepted, and is now certified costs money. Real money. The easiest way to fix this is to select a different Mosfet - one that has lower RDSon. Thanks again! dwayne > > Recap: N-channel Mosfet, TO-220 package, Vds 30V max, Id 30A max, > > RDSon < 3 Milli-Ohms, > 10V gate drive available. > >www.digikey.com >Excellent parametric selection guide. > >If price is no object (and still only $US3.88 in 1/s) > >PSMN1R6-30PL,127 >568-4900-5-ND >30V, 100A, TO220 >1.7 m.ohm nominal Rdson >http://www.nxp.com/documents/data_sheet/PSMN1R6-30PL.pdf > >Even better [tm] AND cheaper (but may not sell in 1's). >IPP015N04N G >IPP015N04N G-ND >40V, 120 A >1.5 milliohm >$2.33/500 >http://www.infineon.com/dgdl/IPB015N04N_rev2+0.pdf?folderId=db3a3043156fd5730115c7d50620107c&fileId=db3a30431689f4420116c474de8f0845 -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist