Actually it might not have one, there is no law.


** Every darlington power transistor made has a reverse diode from C to E -
it is part if the structure of the chip.

All power mosfets have a similar diode.


With two resistors, a DVM and a 12 volt supply you can measure the hfe
quite easily.

** But you gotta be real quick or the device will cook.


That 100 ohm resistor is much more important, otherwise the Icex of the
first transistor at the very least will always be applied to the base of
the second transistor. The Ice leakage numbers for the whole device would
look like germanium.


** Hogwash.

The 100ohm resistor is there to improve the switch off speed of the power
transistor plus increase the breakdown voltage a little.

Leakage current in the driver transistor is only a few microamps, at most, a
current level the output device can barely amplify at all.


..... Phil