Question

Notify Me Bookmark

Below you see an IC MOS amplifier formed by cascading two common source (CS) stages. Assuming that VAn = |VAp| and that the biasing current sources have output resistances equal to those of Q1 and Q2, find an expression for the voltage gain (Av = vo/vi) in terms of gm and ro of Q1 and Q2.

Below you see an IC MOS amplifier formed by cascading two common source (CS) stages. Assuming that VAn = |VAp| and that the biasing current sources have output resistances equal to those of Q1 and Q2, find an expression for the voltage gain (Av = vo/vi) in terms of gm and ro of Q1 and Q2.

Image text
  1. Below you see an IC MOS amplifier formed by cascading two common source (CS) stages. Assuming that V A n = | V A p | and that the biasing current sources have output resistances equal to those of Q 1 and Q 2 , find an expression for the voltage gain ( A v = v o / v i ) in terms of g m and r o of Q 1 and Q 2 .

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

A MOS differential pair operated at a bias current I of 0.8 mA employs transistors with W/L = 100 and μnCox = 0.2 mA/V2, using RD = 5 kΩ and Rss = 25 kΩ. Ignore ro of Q1 and Q2. (a) Find the overdrive voltage Vov of Q1 and Q2. Ignore the bias current through Rss. (b) Find the gm of Q1 and Q2. (c) Find the differential gain Ad using the gm found in (b). (d) Derive an expression for vo1/vicm and vo2/vicm. (e) Suppose the load of Q2 is replaced by RD+ΔRD, find an expression for the common-mode gain which is defined as Acm = vod/Vicm. (f) Find the Acm when the drain resistances have 1% mismatch. ( (g) Find CMRR in dB for the case of (f).
Solution
0 0