> Hi all,
>
> This is OT, but just barely. In trying to make a switching amplifier
> (original design used a PIC for testing), we were using synchronous
> rectifier. Instead of its complexity, I thought maybe we can use
> something like Schottky, but much better. Is there such a creature?

If you find something faster than a Schottky, let me know.... I'll buy the
stock.
Schottky diodes are majority carrier semiconductors with very low
barriers.  They're as close as you're going to get (with current
technology) to an ideal diode for passive components.

> Basically, we were trying to switch at 80 MHz (!) and still attain
> better than 90% efficiency (inductors are the enemy!). An ideal diode
> would've saved few percent, so I guess I'm wondering if there is such a
> thing as a near-ideal diode (and minimal capacitance, too). We had
> semiconductor fab at our disposal, so new process would be Ok. However,
> a commercial product would be the best.
>
> Vf = 0 (or less than 0.1 volt) at 1 ampere
> C = 1 pf or less at 6 volts

I don't necessarily understand what you mean by 90% efficiency (assuming
power efficiency).  You could use an op-amp to model an ideal diode.  But
judging from your power requirements, you may be hard-pressed to find an
op-amp that fast.  Let me know if you still want the schematic.

You COULD put multiple diodes in parallel (to distribute the current draw),
but I wouldn't recommend it because you are still going to stress the
fastest switching diode.... it may work reliably enough for you.

Good Luck,

Vincent Deno