Sorry, I was not clear enough in my explanation. I was _contrasting_ fig 4 with figs 2 and 1. Rds only applies in the fully-on state, and fig 4 does indicate that Rds INCREASES with temperature. However, in the LINEAR region (i.e., partially-on), CURRENT increases with temperature (as figs 1 and 2 show). Sean On Fri, Apr 15, 2011 at 11:21 AM, Michael Watterson wro= te: > On 15/04/2011 15:23, Sean Breheny wrote: >> I've never been able to find a general reference which states that >> this is always the case for MOSFETs, but have a look at this >> datasheet: >> >> http://www.irf.com/product-info/datasheets/data/irfs4310.pdf >> >> Specifically, see fig 1 versus fig 2. The lowest curve is for Vgs=3D4.5 >> Volts. At Vds=3D1 volt, the 25 deg C curve is about 1.5 Amps. the 175 >> deg C curve is about 22 Amps. >> >> Compare with figure 4 which shows that Rds ON also increases with temper= ature. >> > Yes, RDS on *INCREASES* with temperature, thus they can be safely > paralleled without BJT thermal runaway and without source "ballast" > resistors. > > > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .