This preview shows pages 1–6. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: EECS40 _ Spring 2004 Midterm Exam # 2
April 15, 2004
Time Allowed: 80 minutes g olA/ﬁt‘m Name: ,
Last First Student ID #: , Signature: Discussion Section: This is a closed—book exam, except for use of two 8.5 x 11 inch sheets of your notes.
Show all your work to receive full or partial credit. Write your answers clearly in the spaces provided. EE40‘mt2_SO4.fm a) (5 points)
A silicon sample is uniformly doped with Boron to a concentration of 1016 atoms/cm} Determine the resistivity of the sample at room temperature.
Use electron mobility : u" = 1000 cmzfy—s, hole mobility = up = 400 cmglvs, q = 1.6 10—]9 C and ni = 1010 at room temperature. lb
: 10 b3 _ [5 ..
N0 W (3"[0 Cm; >> m‘
Pal”pr .
t“ "‘r ' ‘
“.119”? beto'”(; r{o“01n'3.c4aooh%_s 2 0.54 31‘0" b) (5 points) :: LS6 Jb om
The same sample is then to be counter doped to a depth of 5 pm with Arsenic atoms to create a resistor technology with resistance of 1009/ II]. Determine the required Arsenic doping density.
,2 Rs:’[‘: F " awnt am " a?th " €<'W"\l>f""
N \J I i
‘ g; :2 h = ‘3 W
0‘ 0‘ (Ext/[,1 {V M, #0432 .a IUWOMX/u: * 0.051242%
17 —; EE40_mt?._SO4.fm ideal rectifier iL(t)
l L _9
    —+1
__’___‘__‘__Vsm . 12:19
—10V
4————>
T = 1 1118 Figure 2(3) 3) (10 points)
The diode in Figure 2(a) is ideal. The waveform V30) is a balanced square wave with amplitude of 10 V and period of 11118. Take L = 50 pH and R = 19. The circuit operates in a periodic steady state. Sketch and carefully dimension one
period of the iL(t) waveform on the axes below. Make reasonable approximations. L
'C':———:0.ow.;'
R ’i 09? 1; t O_ {"1 5 3 {MS EE40_mt2_SO4.fm b) ( 10 points) Figure 2(b) In the circuit of Figure 2(b), switch SI is initially closed and the circuit is in equilib
rium. Switch 81 is then opened and switch 82 is closed for a sufficiently long time so
that the circuit can be considered to be in equilibrium. How much energy is dissi—
pated in the le resistor during the transient? Hint: Think in terms of net charge and energy ﬂow. Detailed transient analysis is
NOT needed. changed in Wad”
. r
5N0: EL cvzz ~ 3; cvf : El attain/)4» 23W") : \[2 C C’Vz— CV1) U... '2: £ J‘IO“ A Energy dn‘rs:}n+ai u'n pesl'sfm— EE40_mt2_SO4.fm 3.
120M;
1)
— US + 0
M1
VG A = 0.1V’1
VT = 0.5V
Figure3 kl = lOOpA/V2
W
L — 2
. . . . _ 1 'W 2 A . . .
MosfetMl 1nF1gure 3 is modeled by 1D — 5k 1(DGS— VT) (1 + DDS) 1n saturation With parameters listed in Figure 3. a) (5 points)
Determine the requires bias voltage VG so that M1 is biased in saturation with VDS = 2V. Take '05 = O for this calculation. .. ,w. L
(It): 1); I" T: (was'Vr) (“10?”) pop/wit =— 3? x WON/4%: x 2 2" (v05 — 0SV)1C 1+ c.1v"»2v) EEtwithLSOdfm b) (10 points)
Draw the small signal model for this circuit. Compute the parameters of this small signal model. «~43 K
G.)
U} a h {Jig 3‘ “Q' a ’ .. ...L—
r."
jo at?
a»? p = W—EWag—wrw—rN/p‘u : {WIMA/V: x2 1Kl«5V"l\.f)( H 0*lVHI’2V) : 2.4 Ho"? 3
 .11 c __ CE 2
3°“ >03; 1k L(UZA$”VT)A,
.. l ,
“ 3 “MFA/U: *2 ‘(JJ'V’lfo 0.1v'
c) (5 points) 2 {0'5 9
1)
Determine the small signal gain A0 = D—0 .
s Av: EL _ _ 3h 2‘4— ’Uohqv—S
ﬂ 2 b :: "2
Us 30 {Ojg 4 EE40_ml2_SU1.frn ...
View Full
Document
 Spring '07
 ChangHasnain

Click to edit the document details