Test: MOSFET In Small Signal Operation

Question 1

An NMOS technology has μ_nC_ox = 50 μA/V² and V_t = 0.7 V. For a transistor with L = 1μm, find the value of W that results in g_m 1mA/V at I_D = 0.5 mA.

Accepted Answer

20 &mu;m

Answer

10 &mu;m

Answer

30 &mu;m

Answer

40 &mu;m

Question 2

Consider an NMOS transistor having k_n= 2 mA/V². Let the transistor be biased at V_OV = 1V. For operation in saturation, what dc bias current I_D results? If a +0.1-V signal is superimposed on V_GS, find the corresponding increment in collector current by evaluating the total collector current I_D and subtracting the dc bias current I_D.

Accepted Answer

I_D = 1mA and Increment = 0.21 mA

Answer

I_D = 1mA and Increment = 0.42 mA

Answer

I_D = 2mA and Increment = 0.21 mA

Answer

I_D = 2mA and Increment = 0.42 mA

Question 3

We know I_D =1/2 k_n (V_GS + v_gs – V_t)². Let the signal v_gs be a sine wave with amplitude V_gs, and substitute v_gs = V_gs sin ω t in Eq.(5.43). Using the trigonometric identity show that the ratio of the signal at frequency 2ω to that at frequency ω , expressed as a percentage (known as the second-harmonic distortion) is

Accepted Answer

1/4V_gs/V_ov x 100%

Answer

V_gs/V_ov x 100%

Answer

1/2V_gs/V_ov x 100%

Answer

1/8V_gs/V_ov x 100%

Question 4

If in a particular application V_gs is 10 mV, find the minimum overdrive voltage at which the transistor should be operated so that the second-harmonic distortion is kept to less than 1%.

Accepted Answer

0.25V

Answer

1V

Answer

0.75V

Answer

0.5V

Question 5

(Q.5-Q.7) An NMOS amplifier is to be designed to provide a 0.50-V peak output signal across a 50-kΩ load that can be used as a drain resistor.

If a gain of at least 5 V/V is needed, what value of g_m is required?

Accepted Answer

0.1 mA/V

Answer

0.2 mA/V

Answer

0.4 mA/V

Answer

0.8 mA/V

Question 6

Using a dc supply of 3 V, what values of I_D and V_OV would you choose?

Accepted Answer

0.034 mA and 0.69 V respectively

Answer

0.34 mA and 0.35 V respectively

Answer

0.34 mA and 0.69 V respectively

Answer

0.034 mA and 0.35 V respectively

Question 7

What W/L ratio is required if μ_nC_ox = 200 μA/V²?

Accepted Answer

1.43

Answer

1.23

Answer

1.22

Answer

1.53

Question 8

(Q.8-Q.9) For a 0.8-μm CMOS fabrication process: V_tn= 0.8 V, V_tp = −0.9 V, μ_nC_ox = 90 μA/V², μ_pC_ox= 30 μA/V², Cox = 1.9 fF/μm2, V_A (n-channel devices) = 8L (μm), and |V_A| (p-channel devices) = 12L (μm).

Q. Find the small-signal model parameters (g_m, r_o and g_mb) for an NMOS transistor having W/L = 20 μm/2 μm and operating at I_D = 100 μA and |V_SB| = 1V.

Accepted Answer

g_m= 0.42mA/V, r_o= 160 kΩ, g_mb = 0.084 mA/V

Answer

g_m= 0.21mA/V, r_o= 160 kΩ, g_mb= 0.042 mA/V

Answer

g_m= 0.42mA/V, r_o= 80 kΩ, g_mb = 0.042 mA/V

Answer

g_m= 0.24mA/V, r_o= 80 kΩ, g_mb = 0.084 mA/V

Question 9

Find the small-signal model parameters (gm, ro and gmb) for a PMOS transistor having W/L = 20 μm/2 μm and operating at ID = 100 μA and |VSB| = 1V.

Accepted Answer

g_m= 0.24mA/V, r_o=240 kΩ, g_mb = 0.048 mA/V

Answer

g_m= 0.24mA/V, r_o= 240 kΩ, g_mb = 0.024 mA/V

Answer

g_m= 0.12mA/V, r_o= 240 kΩ, g_mb = 0.048 mA/V

Answer

none

Question 10

The overdrive voltage at which each device must be operating is

Accepted Answer

NMOS = 0.48V and PMOS = 0.83V

Answer

NMOS = 0.83V and PMOS = 0.48V

Answer

NMOS = 0.24V and PMOS = 0.41V

Answer

NMOS = 0.41V and PMOS = 0.24V

MOSFET In Small Signal Operation - Free MCQ Practice Test with solutions,

MCQ Practice Test & Solutions: Test: MOSFET In Small Signal Operation (10 Questions)

An NMOS technology has μ_nC_ox = 50 μA/V² and V_t = 0.7 V. For a transistor with L = 1μm, find the value of W that results in g_m 1mA/V at I_D = 0.5 mA.

If in a particular application V_gs is 10 mV, find the minimum overdrive voltage at which the transistor should be operated so that the second-harmonic distortion is kept to less than 1%.

(Q.5-Q.7) An NMOS amplifier is to be designed to provide a 0.50-V peak output signal across a 50-kΩ load that can be used as a drain resistor.
If a gain of at least 5 V/V is needed, what value of g_m is required?

Using a dc supply of 3 V, what values of I_D and V_OV would you choose?

What W/L ratio is required if μ_nC_ox = 200 μA/V²?

Find the small-signal model parameters (gm, ro and gmb) for a PMOS transistor having W/L = 20 μm/2 μm and operating at ID = 100 μA and |VSB| = 1V.

The overdrive voltage at which each device must be operating is

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MOSFET In Small Signal Operation - Free MCQ Practice Test with solutions,

MCQ Practice Test & Solutions: Test: MOSFET In Small Signal Operation (10 Questions)

An NMOS technology has μnCox = 50 μA/V2 and Vt = 0.7 V. For a transistor with L = 1μm, find the value of W that results in gm 1mA/V at ID = 0.5 mA.

If in a particular application Vgs is 10 mV, find the minimum overdrive voltage at which the transistor should be operated so that the second-harmonic distortion is kept to less than 1%.

(Q.5-Q.7) An NMOS amplifier is to be designed to provide a 0.50-V peak output signal across a 50-kΩ load that can be used as a drain resistor.If a gain of at least 5 V/V is needed, what value of gm is required?

Using a dc supply of 3 V, what values of ID and VOV would you choose?

What W/L ratio is required if μnCox = 200 μA/V2?

Find the small-signal model parameters (gm, ro and gmb) for a PMOS transistor having W/L = 20 μm/2 μm and operating at ID = 100 μA and |VSB| = 1V.

The overdrive voltage at which each device must be operating is

Analog Circuits

Analog Circuits

Top Courses for Electronics and Communication Engineering (ECE)

About this Electronics and Communication Engineering (ECE) Practice Test

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An NMOS technology has μ_nC_ox = 50 μA/V² and V_t = 0.7 V. For a transistor with L = 1μm, find the value of W that results in g_m 1mA/V at I_D = 0.5 mA.

If in a particular application V_gs is 10 mV, find the minimum overdrive voltage at which the transistor should be operated so that the second-harmonic distortion is kept to less than 1%.

(Q.5-Q.7) An NMOS amplifier is to be designed to provide a 0.50-V peak output signal across a 50-kΩ load that can be used as a drain resistor.
If a gain of at least 5 V/V is needed, what value of g_m is required?

Using a dc supply of 3 V, what values of I_D and V_OV would you choose?

What W/L ratio is required if μ_nC_ox = 200 μA/V²?