Rbe test circuit?

[Grant Richter]

To clarify that, I meant the comparator switching time can be neglected
on a qualitative test. That is trying different pairs in the same
circuit. For a quantitative test (arriving at some measured number)
The switching time should be reduced as small as possible.

That circuit you see in Electronotes that is a 3080 followed
by back to back diodes, appears in an RCA publication
"Circuit ideas for linear ICs" under the title "High speed comparator"
and claims a delay time of 45 nanoseconds.


> 
> I think an exponential VCO is probably your best test circuit.
> The effect of the Rbe is known (VCO goes flat on high end).
> You can at least qualify the effect for different trannie pairs.
> 
> You could almost look at it as a custom current to frequency
> converter for testing Rbe. Since the frequency is easy to
> measure on a counter. That is how many of the meter circuits
> work anyway, integrate the current with a comparator and counter.
> You can neglect the comparator switching time since that is
> fixed.
>