However it turns out NPN transistors are about 3 times faster than PNP (same for n-channel over p-channel FETs) in silicon due to the ~3 times greater mobility of electrons over holes. So NPN andn-channel are preferred when there's a choice. Often you need both (CMOS circuitry for exampleuses n-FETs and p-FETs equally).
Quotewhat is the diff between positive voltages and negative voltages??Negatives are only used for audio amplifiers
what is the diff between positive voltages and negative voltages??
For us digitals, GND is the most negative we deal with.
If you tied all Positive supplies together and call them GND, you have everything else more or less negative.And had problems using NPN transistors the usual way
Just to add a bit about identifying an NPN or PNP transistor in a schematic quickly without tracing the circuit, look at the arrow in the symbol. If its "Not Pointing iN", then its an NPN. If its "Point iN Please", then its a PNP.