On Tue, May 11, 1999 at 12:43:58PM +1200, Russell McMahon wrote:
> I think that synchronous rectification is a s good as you are going
> to get in this sort of application. Even a Schottky diode gets up to
> many tenths of a volt at moderate currents - its always better than a
> standard Silicon junction (Schottky uses Silicon too in normal
> implementations - its a technique, not a material) but its not the
> ideal zero resistance switch. A switched FET (or even a bipolar
> transistor) can give you lower voltage drop. Note also that
> Schottky's tend to be fairly low voltage devices (typically <= about
> 40 volts?).

The technote at the link I gave earlier today --
http://www.microsemi.com/micnotes/400ser/401.htm -- Has
an I vs V graph for a Schottky compared to a PN junction,
and gives 100 volts for the highest working peak reverse
voltage one is likely to see in Shottky parts; they claim that
this is true "...since devices moderately above this rating
level will result in forward voltages equal to or greater
than equivalent pn junction rectifiers."

--Bob

--
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Bob Drzyzgula                             It's not a problem
bob@drzyzgula.org                until something bad happens
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