PNP versus NPN bipolar transistors

[cabrera]

Hi,

Could anybody explain me why the base current of a pnp is higher than a npn for the same collector current?

Regards,
David

 

[tfr000]

It depends a great deal on the particular transistors. Some are designed for high current, some for low, and the current gain varies with many different influences: current, voltage, temperature for starters.
Some manufacturers do make complementary pairs of transistors in NPN and PNP which are designed to match each other reasonably well, for push-pull applications.

 

[jsgruszynski]

The simple reason traces to hole mobility - which translates to a lower beta - which translates to a higher Ib for the same Ic value compared to an NPN.

 

[vk6kro]

A transistor which has less current gain than another will require more base current for the same collector current.

PNP and NPN transistors come in a variety of current gain versions, so you couldn't claim PNP types have lower gain without producing some evidence that this is true.