Download Step Response - Microelectronic Devices and Circuits - Solved Exam and more Exams Microelectronic Circuits in PDF only on Docsity! University of California, Berkeley Fall 2003
EECS 105 Prof. A. Namequd
Midterm Exam (closed book)
Thursday, September 25, 2003
Helpful hints appear at the end of the exam.
1. (20 points) The step response of the series LCR circuit is shown below
wt “®
IH
(a) Is the damping factor ¢ greater than or less than unity?
7 a] (over stoer, RiINel(Ne )
(b) Qualitatively, describe the effect. of decreasing the capacitance of the circuit.
t fE
= _— wo = ——
© Wg RC 9 Le
q- C. Mle
RCo K
Clb = Qt MRE RINGING
(c} If it is desired to obtain a critically damped response. find the value of the series
resistance R if “L/C = 502.
Vale a Q ++
ul
R= (gone
(d) If the cirenit is now driven with a sinusoidal voltage source of frequency w # +.
find an expression for the power dissipation in the resistor R?
2= R4 jolt vo
= ¥) = ve
Pe 3 Re (vi*)= 1 wv )
a (u(t Be f # - 4 (v)?
2 (4) e tat™
A(Z7)= R
jal =e? @-B)
2. (20 points) For the resistor shown below
The sheet resistances of the region are RL = 10k92/sq, R2 = 50kQ/sq. RE = 30k2/sq.
(10?) 10" (iw) 10° = C10”) 108
rad/sec
(a) write the transfer function.
. +5
Ho) (2
(uF) (i Ls.)
(b) Draw the phase response assuming all poles and zero occur in the left half plane
(in the provided graph).
ZERO
°
{ZO
10° 10° 10° 10’ 10°
rad/sec
on
. (20 points) Given the circuit shown below
R
° vw
oO
(a) Calculate the impedance transfer function. Identify the poles and zeros assuming
that wob/R = 10.
geet porll de |
et we cet Tee
jel i lt-Ge) be
jue
a &+
2 VC! +Gr)'tc) jek 7 PS: + jm
(+ Gwjtte
: . 2
| iE <> po Te A OY
= it KT
| QD 9 Le = R } Gey be
(b) The denominator for the transfer function is a second order function. What is the
Q of the denominator of the transfer function?
| on ie ee OB)
3 20 = © GB)?
~ al _ =
2o2 te alo 945 >|
Teo DisfincT PEWS CN iT ax is
() Q=e
t
{
(c) What happens at frequency w = VEC? Explain qualitatively the operation of the
circuit at this frequency.
L ec RESOWATE aD peoDuclE
Avy OPEN
Z= et 2uic = K-+ PEN Zo
FQ Cece R
oo
—-
2tve) : °
ol
