Question

Notify Me Bookmark

Q1. The circuit below has I = 0.5 mA, VA = 30 V, and β = 150. (a) Specify what is this circuit? (b) Find Gm, Ro, Ad and Rid. (c) (b) If the bias-current source is implemented with a simple npn current mirror, find REE, Acap and CMRR. (d) If the amplifier is fed differentially with a source having a total of 20 kΩ resistance (i.e. 10 kQ in series with the base lead of each of Q1 and Q2), find the overall differential voltage gain.

Q1. The circuit below has I = 0.5 mA, VA = 30 V, and β = 150. (a) Specify what is this circuit? (b) Find Gm, Ro, Ad and Rid. (c) (b) If the bias-current source is implemented with a simple npn current mirror, find REE, Acap and CMRR. (d) If the amplifier is fed differentially with a source having a total of 20 kΩ resistance (i.e. 10 kQ in series with the base lead of each of Q1 and Q2), find the overall differential voltage gain.

Image text
Q1. The circuit below has I = 0.5 m A , V A = 30 V , and β = 150 . (a) Specify what is this circuit? (b) Find G m , R o , A d and R i d . (c) (b) If the bias-current source is implemented with a simple npn current mirror, find R E E , A cap and CMRR. (d) If the amplifier is fed differentially with a source having a total of 20 k Ω resistance (i.e. 10 kQ in series with the base lead of each of Q1 and Q2), find the overall differential voltage gain.

Detailed Answer

0 0

Please enter your email here. You will get email when this question is answered by our tutor.

Doubtrix Logo

Problem is not yet solved!

Click on Notify me to get email when question is answered.

Join Doubtrix with 7-days free trial

  • Icon Correct & Verified Answers
  • Icon No AI-Generated Answers
  • Icon Video Solution for Difficult Questions
  • Icon Work With Experts to Reach at Correct Answers
Notify me Login Sign Up

Similar/Related Questions

11.65 The feedback transresistance amplifier in Fig. P11.65 utilizes two identical MOSFETs biased by ideal current sources I = 0.4 mA. The MOSFETs are sized to operate at VOV = 0.2 V and have Vt = 0.5 V and VA = 16 V. The feedback resistance RF = 10 kΩ. (a) If Is has a zero dc component, find the dc voltage at the input, at the drain of Q1, and at the output. (b) Find gm and ro of Q1 and Q2. (c) Provide the A circuit and derive an expression for A in terms of gm1, ro1, gm2, ro2, and RF. (d) What is β ? Give an expression for the loop gain Aβ and the amount of feedback (1+Aβ). (e) Derive an expression for Af. (f) Derive expressions for Ri, Rin , Ro, and Rout . (g) Evaluate A, β, Aβ, Af, Ri, Ro, Rin , and Rout for the component values given. Figure P11.65 11.65 The feedback transresistance amplifier in Fig. P11.65 utilizes two identical MOSFETs biased by ideal current sources I = 0.4 mA. The MOSFETs are sized to operate at VOV = 0.2 V and have Vt = 0.5 V and VA = 16 V. The feedback resistance RF = 10 kΩ. (a) If Is has a zero dc component, find the dc voltage at the input, at the drain of Q1, and at the output. (b) Find gm and ro of Q1 and Q2. (c) Provide the A circuit and derive an expression for A in terms of gm1, ro1, gm2, ro2, and RF. (d) What is β ? Give an expression for the loop gain Aβ and the amount of feedback (1+Aβ). (e) Derive an expression for Af. (f) Derive expressions for Ri, Rin , Ro, and Rout . (g) Evaluate A, β, Aβ, Af, Ri, Ro, Rin , and Rout for the component values given. Figure P11.65

Solution
0 0

The feedback transresistance amplifier utilizes two identical MOSFETs biased by ideal current sources I. The MOSFETs have the parameters, gm1, ro1 for Q1 and gm2, ro2 for Q2, respectively. The feedback resistance RF. (a) Provide the A circuit and derive an expression for A in terms of gm1, ro1, gm2, ro2, and RF. (b) What is β ? (c) Derive an expression for Af = Vo/Is. (d) Derive expressions for Rin and Rout . When the current sources I = 0.4 mA, the MOSFETs are sized to operate at VOV = 0.2 V and have Vt = 0.5 V and VA = 16 V. The feedback resistance RF = 10 kΩ. (e) If IS has a zero de component, find the dc voltage at the input, and at the drain of Q1. (f) Find gm and ro of Q1 and Q2. (g) Evaluate Af, Rin and Rout for the component values given.
Solution
0 0

For an NMOS differential pair with a common-mode voltage VCM applied, as shown below. Let VDD = VSS = 1.0 V, kn’ = 0.4 mA/V2, (W/L) = 12.5, Vtn = 0.5 V, I = 0.2 mA, RD = 10 kΩ, and neglect channel-length modulation. (a) Find VOV and VGS for each transistor. (b) For VCM = +0.3 V, find VS, ID1, ID2, VD1, and VD2. (c) What is the highest value of VCM for which Q1 and Q2 remain in saturation? (d) If current source / requires a minimum voltage of 0.2 V to operate properly, what is the lowest value allowed for Vs and hence for VCM ?
Solution
1 0