> > On Nov 26, 2008, at 12:30 AM, Xiaofan Chen wrote: > > On Wed, Nov 26, 2008 at 2:18 PM, Michael Algernon > wrote: >> The current path when TG is high ( which means the P channel FET is >> off ) is thru the inductor , thru the schottky diode and thru the >> 10uf >> cap. The 10uf cap keeps the inductor from blowing up the LT3517 when >> TG turns off the the P channel FET. The PWM input can cause TG to >> turn off the P channel FET. > > Read again Russel's answer as well as reading the datasheet > again. The PMOS is not the switch in the DC/DC converter. I did not say it was. It is used for PWM control. MA -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist