Re: Disabling the freewheling diode

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: dhmccauley-at-spacecatlighting-dot-com 


There are two diodes both of which typically are Schottky diodes.  There is
the schottky ultrafast diode in parallel with the FET which is used to
bypass the intrinsic diode of the FET, and there is also the series schottky
diode of which you speak of in series with the drain of the FET which is
used to help keep the internal FET diode turned off during reverse current
(freewheeling)

Dan


 > I confess to being absolutely lost. Series Schottky in parallel?? Is
 > not the Schottky diode in series with the drain? What other ON-
 > conduction path is there?
 >
 > Malcolm
 >
 >    The Rds of the FET is much lower (and less voltage drop)
 >  > then the parallel Schottky
 >  > diode, therefore, most of the current goes through the FET.  On the
 >  > otherhand, for reverse freewheeling current, the Schottky diode will
 >  > conductor first and take the bulk of
 >  > any reverse freewheeling current in the circuit.
 >  >
 >  > The Captain
 >  >
 >  >
 >  >
 >
 >
 >
 >
 >