> Sergey Dryga wrote:
>> Vce(sat) - collector-emitter saturation voltage
>> should not be significantly higher for a darlington compared to regular
>> NPN transistor,
>
> Oh yes it is.  Consider where the base voltage for the second transistor
> comes from.
>

Also, I don't think of Darlingtons ever really going into saturation (at
least the second transistor). The Vce saturation voltage of a silicon
transistor is something like 300mV, but it takes 700mV Vbe to get the
transistor to conduct. So, the Vce for the second transistor is maybe
300mV (Vce saturation for the first transistor) plus 700mV (Vbe of the
second transistor). So, there's about 1V Vce on the second transistor,
quite a ways from saturation.

Harold


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