MOSFET
What circuit advantage results from almost no current flowing into the gate of a MOSFET?
- AA large DC current is needed to drive the gate
- BSwitching speed no longer depends on gate capacitance
- CThe input current is nearly zero, so almost no DC power is needed to hold a state
Show answer and explanation
Answer: C. The input current is nearly zero, so almost no DC power is needed to hold a state
The gate of a MOSFET is separated by an insulator, so the DC input current needed to hold a state is nearly zero. This is why CMOS circuits consume very little power when idle. Current does flow, however, to charge and discharge the gate capacitance at each switching event.