4 ms·
I have similar theory regarding bipolar junction transistors. In schools NPN is often taught first in great detail and PNP is then just glanced over. That's why
by dvh 6y ago
I have similar theory regarding bipolar junction transistors. In schools NPN is often taught first in great detail and PNP is then just glanced over. That's why most circuits use NPN and fewer use PNP because people understand NPN better.
- photojosh 6y agoNPN BJTs (and N-channel FETs) are more efficient (and cheaper), and IIRC it was an enormous difference years back. This is to the extent that many integrated circuits that drive external transistors will actually have a charge pump to allow them to generate the voltage greater than the main supply in order to use N over P on the high side. [0] is an example of one I was looking at recently. It's also tricky to match N and P transistors because there's always tradeoffs on the P side, so if you can just use Ns across the board it can make the analysis component selection easier. Arguably they are just glanced over because they really do just apply the same principles. I still would reach for a P-channel to do power rail switching on my lower power designs, fwiw, but that's about the only situation. [0] https://www.analog.com/en/products/lt4320.html https://www.analog.com/en/products/lt4320.html