Download UC Berkeley EE 105 Midterm II - Electrical Engineering and Computer Sciences and more Exams Microelectronic Circuits in PDF only on Docsity!
University of California, Berkeley College of Engineering Dept. of Electrical Engineering and Computer Sciences
EE 105 Midterm II
Spring 2005 Prof. Roger T. Howe April 13, 2005
_____________,____________
Your Name (Last, First)
Guidelines
Closed book and notes; one 8.5” x 11” page (both sides) of your own notes is allowed. You may use a calculator. Do not unstaple the exam. Show all your work and reasoning on the exam in order to receive full or partial credit.
Score
Problem
Points Possible Score
1 15
Total 50
- Phasor Analysis
This circuit is a model of a small-signal amplifier. The element values are:
Source resistance Rs = 20 kΩ Input resistance Rin = 5 kΩ Input capacitance Cin = 25 pF Current gain A'i = 100 Load resistance RL = 25 kΩ
(a) [4 pts.] Find the phasor current I' in terms of the phasor source voltage Vs and Rs , Rin , and Cin. There is no need to substitute numerical values for the elements.
(c) [4 pts.] Sketch the phase of Vout / Vs using straight-line approximations.
(d) [3 pts.] If the phasor source voltage V s = (2.5 mV )e j 0°^ at a frequency of 10^4 rad/sec, what is v out ( t ) based on the information in your Bode plots?
- MOSFET single stage amplifier [18 pts.]
(a) [2 pts.] Find the numerical value of the bias current IBIAS such that the DC output current IOUT = 0 A. The effect of channel-length modulation can be neglected for this part.
(b) [3 pts.] Find the DC reverse bias voltage across the photodiode, VR , in Volts.
(f) [4 pts.] If the photodiode's source current is is = 15 μA, find the numerical value of the output current iout in μA.
- Voltage supply [17 points]
(a) [3 pts.] Find the numerical value of v (^) A in Volts. Neglect the backgate effect and
(b) [4 pts.] Find the width of transistor M 3 (in μm) such that the output voltage v (^) OUT
channel-length modulation.
= 1.5 V. You can neglect channel-length modulation and the backgate effect. If you couldn't solve part (a), you can assume that vA = .75 V for this part.
(e) [3 pts.] The bulk terminal of M 3 is connected to ground. Using your results from part (b) for the width of M 3 , what is the numerical value of the output voltage vOUT in Volts? Ignore channel-length modulation. If you couldn't solve part (b), you can assume that the W 3 = 20 μm for this part.
