Timeline for Why does this PNP BJT use dual supply but the NPN not?
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Feb 19, 2020 at 18:26 | vote | accept | Blargian | ||
| Feb 17, 2020 at 19:04 | comment | added | TimWescott | Oh -- you also see them in really old circuits, because in the dawn of the transistor age PNP transistors were more common. I'm pretty sure that PNP is the only way to make a point-contact transistor. Just after the point-contact era I'm not sure whether it was easier to make a PNP germanium epitaxial transistor, or whether selling PNPs was dictated by a market that had gotten used to transistors being PNP. | |
| Feb 17, 2020 at 19:02 | comment | added | TimWescott | Is it common to see dual positive/negative supplies with PNP transistors? For the most part PNP transistors are avoided, because for the most part they're not as good as their NPN counterparts. Usually you only see them in theoretical discussions (which may be where the dual supplies crop up) and in circuits that can (for instance) use one PNP where you'd need two or more NPN's to do the same job. | |
| Feb 17, 2020 at 18:36 | comment | added | user16324 | Just re-label V+ as GND and V- as VCC or -5V. (note for PNP circuitry, the positive terminal is the more logical choice for GND, especially with a common emitter amp) | |
| Feb 17, 2020 at 18:36 | answer | added | Marcus Müller | timeline score: 5 | |
| Feb 17, 2020 at 18:32 | history | asked | Blargian | CC BY-SA 4.0 |