09W-quiz-2-sol

09W-quiz-2-sol - ECE65(Winter 2009 Midterm 2 Name Notes 1...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
ECE65 (Winter 2009), Midterm 2 Name: Notes: 1. Write your answers on these three sheets. 2. For each problem, 20% of points are alloacted for the correct final answer. Problem 1. Find the state of this transistor if v GS > v t . (5pts) By KVL: v DS = v GS . Since v GS > v t , the NMOS is ON (should be either in active or ohmic). Furthermore, since v DS = v GS > v GS - v t , NMOS should be in active region.
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Problem 2. In the circuit below with Si diodes, find i for - 20 v s 20 V (13pts) S V - + i i S i D 5k 5k D1 D2 KCL: i D 1 = i D 2 = i D KCL: i s = i D + i KVL: v s = 5 × 10 3 i s + v D 1 + v D 2 KVL: v D 1 + v D 2 = 5 × 10 3 i Because the two didoes are in series, i D 1 = i D 2 = i D , the two diodes are either ON ( i D > = 0) or OFF ( i D = 0). For BOTH diodes being ON: v D 1 = v D 2 = v γ = 0 . 7 V, i D > 0. Substituting in the circuit equations we get: v s = 5 × 10 3 i s + v D 1 + v D 2 v s = 5 × 10 3 i s + 1 . 4 i s = 2 × 10 - 4 ( v s - 1 . 4) v D 1 + v D 2 = 5 × 10 3 i 1 . 4 = 5 × 10 3 i i = 0 . 28 mA i s = i D + i i D = i s - 0 . 28 × 10 - 3 = 2 × 10 - 4 ( v s - 1 . 4) - 2 . 8 × 10 - 4 i D > 0 2 × 10 - 4 ( v s - 1 . 4) - 2 . 8 × 10 - 4 > 0 v
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern