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 |
How to improve these parameters? (Cascode topology, use long channel transistors)
What is setup time and hold time?
What types of I/O have you designed? What were their size? Speed? Configuration? Voltage requirements?
What work have you done on full chip Clock and Power distribution? What process technology and budgets were used?
Differences between blocking and Non-blocking statements in Verilog?
What is clock feed through?
What happens if we delay the enabling of Clock signal?
What was your role in the silicon evaluation or product ramp? What tools did you use?
While using logic design, explain the various steps that r followed to obtain the desirable design in a well defined manner?
What types of high speed CMOS circuits have you designed?
Give the cross-sectional diagram of the cmos.
Explain the Charge Sharing problem while sampling data from a Bus?