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What is the input impedance of MOSFET?
The input impedance of the MOSFET primarily comes from the gate capacitance (Cgs and Cgd) as evident from the equivalent circuit. This is also reflected in the input impedance plots. The angle of Zin shows that (at low frequencies) the input impedance is purely capacitive.
Does a MOSFET act as current amplifier?
This fact makes MOSFET capable of raising the strength of a weak signal; thus acting as an amplifier. During the positive half-cycle of the signal, the positive voltage on the gate increases and produces the enhancement-mode .This increases the channel conductivity and hence the drain current .
What is the transconductance of a MOSFET?
A MOSFET is a transconductance device in that an input voltage controls an output current or, in terms of gain, current out / voltage in. Current/voltage is conductance and the word “trans” is placed in front of the word “conductance” to imply the main operating parameter of such a device.
Can a MOSFET have asymmetric source and drain?
Yes , MOSFETs can have asymmetric source and drain. Many researchers are doing such type of researches and have found some good results on especially mobility without affecting any transistor actions. Under unbiased condition, commonly MOSFET would symmetric source and drain . But under applied biased there is no symmetric between source and drain.
Can a MOSFET act as a resistor?
A MOSFET can operate as a small-signal resistor if its gate and drain are shorted. The active resistor can be used in place of polysilicon or diffused resistor to produce a DC voltage drop and /or provide small signal resistance that is linear over a small range.
What is pinch off effect of MOSFET?
Beside above, what is pinch off in Mosfet? voltage becomes large enough that the gate to substrate potential at the drain is smaller than threshold. Therefore the channel thickness at this end goes to zero. We call this pinch off. Electrically, the effect of pinch off is that the channel no longer acts. like a simple resistor.
What are the effects of MOSFET?
One of several short-channel effects in MOSFET scaling, channel length modulation ( CLM) is a shortening of the length of the inverted channel region with increase in drain bias for large drain biases. The result of CLM is an increase in current with drain bias and a reduction of output resistance .