On 06/02/2011 02:50, IVP wrote:
>> >  I'm kind of confused; Isn't a Schottky diode a fast recovery diode?
> Yes
>
>> >  Could you give an example as to what diodes you would have used
>> >  for this ?
> Common types would be UF400x, UF540x. I also use the BYx ultra-
> fast in small SMPS. There are many varieties of eg BYV, BYW
>
> For reference
>
> 1N540x, Standard Recovery>  500ns
>
> http://parts.digikey.com/1/parts/412455-diode-standard-3a-100v-do-201ad-1=
n5401-e3-54.html
>
> UF400x, Reverse recovery time 50ns/75ns
>
> www.fairchildsemi.com/ds/UF%2FUF4007.pdf
>
> UF540x, Reverse recovery time 50ns/75ns
>
> www.ygchina.com/sdygpdf/zxejg/uf/UF5400THRUUF5408.pdf
>
> BYV28, Reverse recovery time 50ns max
>
> www.vishay.com/docs/86043/86043.pdf
>
> Which you choose depends on specific requirements especially re
> amperage. A Schottky is perfectly acceptable, but I suspect that it
> is more applicable to protect FETs rather than BJTs, due to its low
> Vf rather than speed

yes, All Schottky are "fast". But many have high reverese leakage or low=20
PIV rating.
But not all Fast Recovery diodes are Schottky type.

low voltage SMPSU, series protection etc will be Schottky.

Higher voltage SMPSU ( > 25V?) and parallel protection might not be=20
Schottky.

--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.