4

Question 1

V_il is threshold voltage for n transistor

Question 2

V_ih is threshold voltage of pmos

Answer 2

Noise margins

Question 3

Propagation delay is with respect to

Answer 3

Output. T_phl

Question 4

Propagation average

Answer 4

T_phl + T_plh /2

Question 5

Rise and Fall time for input can be different from

Answer 5

Rise and fall times in output.

Question 6

An nmos inverter (not cmos) consists of

Answer 6

A pull up resistor with a nmos as pull down

Question 7

Pmos inverter consists of

Answer 7

Pmos as pull up and resistor as pull down

Question 8

The larger the resistor

Answer 8

The larger the area on chip than transistors.

Question 9

Diode mode configuration of mosfet

Answer 9

Drain and gate of mosfet get shorted to get it to be like a diode or a resistor.

Question 10

How can resistance be adjusted in a mosfet

Answer 10

Reduce W and L or size of transistor.

Question 11

CMOS has drawback

Answer 11

Larger area on chip than nmos circuits but cmos allows us to control rise and fall time.

Question 12

Drawback of nmos circuits

Answer 12

Large power consumption because there is resistance now. P = v^2 / R

Question 13

In CMOS there is no current (i=0)

Answer 13

So static power of CMOS is 0!! But in reality there is a slight resistance in fets (in picoAmpere range) that cannot be avoided.

Question 14

Static power =

Answer 14

P_s = VDD ×Idd

Question 15

Dynamic power loss =

Answer 15

P_d = C×(Vdd^2) ×f

Question 16

Transient voltage

Answer 16

Voltage range of which power supply oscillates

Question 17

Dynamic power loss cannot be avoided

Answer 17

Only reduced

Question 18

Voltage has a bigger role in power consumption and we can always reduce voltage

Answer 18

Voltage scaling is used. We can reduce voltage although we cannot reduce too much since we need a threshold voltage.

Question 19

With C_l large, slow rise and fall time

Answer 19

With C_l small, fast rise and fall time.

Question 20

Increasing width in on condition, R is reduced and faster rise and fall time.

Question 21

Lump capacitor

Answer 21

Combines multiple capacitors into one capacitor. In Power consumption, c represents internal capacitors as well as C_l.

Question 22

Crowbar current

Answer 22

V shape current. In transition state it turns on every time the switch from 0 to 1 happens. Or leakage current. Faster rise and fall times lead to less area under current and less power.

Question 23

Pullup network takes circuit to logic 1

Question 24

Pull down network takes to logic 0

Question 25

There is a tradeoff between static power and dynamic power consumption.

Answer 25

Decreasing static increases dynamic power.

Question 26

Lithography

Answer 26

Process using light exposure in which we create a pattern on a silicon wafer (remove silicon dioxide insulation layer)