3 ms·
>Electric power is current times voltage, that means with higher voltage you need less current. It just do not work like this. Logic gates are constructed fro
by thesz 8y ago
>Electric power is current times voltage, that means with higher voltage you need less current.
It just do not work like this.
Logic gates are constructed from voltage-controlled variable resistors, to simplify things. When input voltage is 0 (Vgnd), some transistors have high resistance and some other low one. When you switch the voltage to Vcc (5V/12V), they revert roles and these that had high resistance now have low one.
The resistance they have at different input voltages is fixed in the manufacturing process and cannot be changed.
Thus if you put power voltage Vcc=12V you will have (for same input voltage) 12/5 higher current than for Vcc=5V.
- varjag 8y agoThe PN boundary (assuming that's what you are trying to explain) doesn't work like that. The current at given voltage is determined by the work which has to be done for switching the load. For signal electronics, we're talking microamperes here, that's not anywhere near "high current". Even the TTY loop I mentioned, a 1920s tech used to drive large relays and solenoids directly is just 40mA.
- thesz 8y agoThe load is either 0V or Vcc. Which is 0 and 5V and 0 and 12V and you can easily guess everything else. Also look here: https://en.wikipedia.org/wiki/Low-power_electronics https://en.wikipedia.org/wiki/Low-power_electronics Energy dissipated by change of voltage in the capacitor is E=CU^2/2. Now I stop.