"Roy Lewallen" wrote in message
...
Connect it exactly the same as you would an NPN, but reverse the
polarity of the power supply voltage. If there's a bias circuit using a
diode, the diode (and bias supply polarity, if it's a separate supply)
should also be reversed.

If it's necessary for you to use the PNP with a positive supply voltage,
it's still possible, but it complicates the circuit, and adequate
bypassing becomes essential and sometimes difficult. In that case, a
diagram (and preferably a layout) of a known working circuit is desirable.

All other things being equal, a PNP generally has lower ft and higher
capacitance than an NPN, which is probably why they're less commonly
used. This difference is due to the basic physics of the device (lower
mobility of the carriers, as I recall).

Roy Lewallen, W7EL



I always wondered why Motorola (of all peopled) used PNP RF
transistors in the final and two driver stages in their Micor base
station and mobile radios.

Pete