Explain the various MOSFET Capacitances & their
significance?
Answer / arpit raj
There are different MOSFET capacitance they are as follows:
1) Cgs : it is the capacitance due to the overlap of the
source and the channel regions by the polsilicon gate and is
independent of applied voltage.
2) Cgd : it consists of 2 parts, first is the capacitance
associated with the overlap of the polysilicon gate and the
silicon below. second is the capacitance associated with the
depletion region immediately under the gate. Cgd is
nonlinear function of voltage.
3) Cds : it is the capacitance associated with the
body-drift diode. it varies inversely with the square root
of drain-source bias.
Significance:
input capacitance : Ciss = Cgs + Cgd, Cds shorted
output capacitance : Coss = Cgd
reverse transfer capacitance : Crss = Cds + Cgd
Cgd provides feedback loop between the output and the input
of the circuit, also called Miller capacitance.
other capacitance are responsible for charging and
discharging , or for switcing purposes
| Is This Answer Correct ? | 37 Yes | 15 No |
Why does the present vlsi circuits use mosfets instead of bjts?
Basic Stuff related to Perl?
Explain Cross section of a PMOS transistor?
In what cases do you need to double clock a signal before presenting it to a synchronous state machine?
Give the various techniques you know to minimize power consumption?
Implement D flip-flop with a couple of latches? Write a VHDL Code for a D flip-flop?
Explain the working of 4-bit Up/down Counter?
Draw the Differential Sense Amplifier and explain its working. Any idea how to size this circuit? (Consider Channel Length Modulation)
Explain about 6-T XOR gate?
For f = AB+CD if B is S-a-1, what r the test vectors needed to detect the fault?
Explain the Charge Sharing problem while sampling data from a Bus?
For an AND-OR implementation of a two input Mux, how do you test for Stuck-At-0 and Stuck-At-1 faults at the internal nodes? (You can expect a circuit with some redundant logic)