Timeline for Why were bipolar junction transistors (BJTs) better than metal oxide semiconductor field effect transistors (MOSFETs) in the past?
Current License: CC BY-SA 4.0
4 events
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| Apr 30, 2021 at 20:39 | comment | added | hacktastical | The scaling-down reduces MOS gate capacitance. The other change that goes with this is reduced threshold voltage. Taken together, these improve MOS speed (reduced transition time) and power (less f*CV dynamic dissipation). There is a trade-off however: leakage. Signal flight time in an IC is very much slower than speed-of-light. This is independent of the process technology or gate length. Smaller geometries help, as do additional metal layers. | |
| Apr 30, 2021 at 18:41 | comment | added | Enrico Migliore | Electrons will never ever reach the speed of light. They are particles. BJTs are current controlled devices. All equations depends on Ib and Ic. They are biased in a way that the control variable becomes Vbe. | |
| Apr 30, 2021 at 18:27 | comment | added | Elliot Alderson | The speed of light is not the limiting factor for logic switching speed, and is not the primary motivation for reducing feature sizes in MOSFETs. And don't let LvW hear you say that BJTs are current controlled... | |
| Apr 29, 2021 at 15:01 | history | answered | Enrico Migliore | CC BY-SA 4.0 |