Anthony said:
<woosh like blue angels fly by> I'm pretty dense here, so it's not yet
becoming obvious to me how something like this works. I can't begin to
fathom how a quad analog switch will let you generate thousands of precisely
different time delays (different R values) to trigger the ADC.
It's used as controlled resistors. But that chip has become nearly
unobtanium so you'd be pretty much back to single FETs. If you happen to
have a fast small FET you can try it out. You'll need something like a
BF998 or another from that series. In a pinch they can be found in TV
tuners. Who needs TV anyhow...
For simplicity use a L-R where the FET is the R. 330nH or something
around that value connected to the output of the inverter where the fast
transition comes from. Drain to other side of the cap, source to GND,
then place a variable DC voltage onto both gates (or to the one if it's
a single-gate FET). Input of another inverter to the drain. Now connect
probes to both digital outputs and see one of them scoot when you vary
the gate voltage. I don't know whether your Hitachi scope is able to do
that though, I use a 1GHz scope for that kind of stuff.
Regular switching FETs such as the 2N7000/7002 aren't very suitable. Too
much capacitance.
I'll be doing this with my old analog scope, probably only at night. ;-)
If it's one of those 100MHz Hitachis don't expect much in time
resolution. Other than that they are good scopes.