ECE 3040 Microelectronic Circuits Quiz 5 - Solutions for Problems 1 and 2, Quizzes of Electrical and Electronics Engineering

Download ECE 3040 Microelectronic Circuits Quiz 5 - Solutions for Problems 1 and 2 and more Quizzes Electrical and Electronics Engineering in PDF only on Docsity! ECE 3040 Microelectronic Circuits Quiz 5 June 16, 2004 Professor Leach Name Instructions. Print your name in the space above. The quiz is closed-book and closed-notes. The quiz consists of 2 problems. Honor Code Statement: I have neither given nor received help on this quiz. Initials 1. The MOSFET has the parameters K = 0.0005A/V and VTH = 1.75V. It is given that V + = +18V, V − = −18V, R1 = 3MΩ, RS = 2kΩ, and iD = K (vGS − VTH)2. (a) Solve for R2 such that ID = 1.5mA. (b) What is the maximum value that RD can have for the MOSFET to remain in the saturation state? Answers: VGS = r ID K + VTH = 3.482V VG = VGS + IDRS + V − = −11.518V IR2 = IR1 = V + − VG R1 = 9.839µA R2 = VG − V − IR2 = 658.8 kΩ VDS = ¡ V + − IDRD ¢− ¡V − + IDRS¢ = 33− IDRD ≥ VGS − VTH =rID K = 1.732V ⇒ RD ≤ 33− 1.732 ID = 20.85 kΩ 2. The MOSFET drain current is given by the equation iD = K0 (1 + λvDS) (vGS − VTH)2. Describe how this equation is used to solve for the parameters gm and r0 in the hybrid-pi model. Assume the Q-point values ID, VGS, and VDS. You should use graphs and equations, as appropriate, in your description. Label on the graphs how the parameters are defined. Answers: gm is the slope of the iD versus vGS curve at the Q point with vDS held constant. r0 is the reciprocal of the slope of the iD versus vDS curve at the Q point with vGS held constant. 1