You are here:

Electronics/NPN VS PNP replacment



A blog at the above post seems to indicate that a NPN can be swapped with a PNP by simply using a negative power supply.

So, lets say I have the original NPN circuit with a 9v battery connected with +Vcc at the top of the circuit, and ground at the bottom. Can the NPN be swapped with a PNP and the polarity of the battery switched? Making The bottom of the circuit +VCC and the top GND? Is that really all that needs to be done? - Thanks

Yes, it is possible; at least theoretically.

If you assume a one transistor circuit biased for class A operation and the operating characteristics (beta, biasing voltages, etc.) are similar in each transistor it will work.

In practice, however, it is more likely the circuit will need to be rebiased in order to get the NPN centered up for class A operation.  And, the gain or distortion of the circuit may be little different.

One would probably never want to do such a swap in practice; only for theory of operation, perhaps.

Hope this helps.  


All Answers

Answers by Expert:

Ask Experts




Electronics questions about AC, DC and digital theory.


Graduate electrical engineer with over 40 years in electronic design, manufacturing, project organization and patent review. Experience in fields of industrial and consumer electronics (audio, video, acoustics, etc.)

IEEE (Institute of Electrical and Electronics Engineers); Senior Life member AES (Audio Engineering Society), Fellow Life member

BSEE University of North Dakota

©2016 All rights reserved.