If you were designing a circuit to switch a low sided load using a npn transistor or n channel fet how would you calculate the following.
You know the load will draw 100ma at 12v so you choose a fet or trans which is well within the max current rating i get that bit but what about calculating the expected voltage on the emitter or drain when saturated in order to calculate the P how is that calculated ?
If a npn transistor is biased at a different voltage to that of the collector ie switching higher voltage with a low voltage then how is the expected voltage on the emitter calculated ?
You know the load will draw 100ma at 12v so you choose a fet or trans which is well within the max current rating i get that bit but what about calculating the expected voltage on the emitter or drain when saturated in order to calculate the P how is that calculated ?
If a npn transistor is biased at a different voltage to that of the collector ie switching higher voltage with a low voltage then how is the expected voltage on the emitter calculated ?