Download 3 Solved Questions on Microelectronic Circuits - Homework 6 | ECE 3040 and more Assignments Electrical and Electronics Engineering in PDF only on Docsity! ECE 3040 Homework #6
For each of the following three circuits, verify the mode of operation of the following
circuit is forward active. Determine the Q-point and all relevant smail signal parameters.
Determine the small signal AC voltage gain A,=Vout/Vin. What is the “worst-case”
maximum voltage swing of the output based on the Collector bias voltage. (NOTE: the
actual output voltage swing of this circuit may me smaller due to large input signals
driving the transistor out of active mode and into saturation.) You may want to simulate
this with PSPICE to get a feel for the circuit operation. Assume IS=1.83e-15 A (for
PSPICE) to get a turn on voltage for 1 mA current as 0.7 V and B=100.
1) OL evlcuit
Fray 00K iu
rf" T be=t2v
5 Ct, 0
2 4 Re >
weil a
| —L* v2
Ra Toc=12¥
0
Base Circuit! Oz (ov ~ I Rky— Ts +1aV
Te 24Vv a4V
Ratha ~*~ (045k
Va Rew hase Ry 3 A
sf Le 0.314 m
Vohigee = 12-7 D4
= 1a -@alte-3) 00k
= -4918 V
Rigs R3{| R4 = 8.6@K
8.8K
\
~ 4g
13K
J
O= +(-2418) — 868 Ig ~0.7 - Te Ra ~ (- lav)
1.38% = (.68k)Ig + Gr) (.3n)
100
Ig = 4,373 aA
I, = BIe= 0.4874
Te = Ge) zy 20.977 m4
Vez iav-Teki = inv — @.1e7e-3) 12K
= O.N5EV
Vez —tav +e Ra - 8 +G,447¢-3) 3k
2-107 V
Vg -4.41¢ - To( #66)
= -10V
Vee = Vo - Ve -~ O11 = Forwarol hiaseot
Vec = Ve ~ Ve = —10.156 V =7 Reverse brase
Active mode Veritied
ne fee (.4816-3)
° ve = Ot 0038 (Ay)
T= - 100
ge 7” 0,038) = a.Ga we 12
r= MatMee _ 75+ 10.056
Eo = ~fontate-3) = 87K
Ver 7s + Teoh
=-6,66 V
Vpe~ 105 HAC.) e Reverse = Eirwe rol Active
hey 5 Vi, = -0493 ~ 66.66)
ed ec
Ve> ~ Ze (seo) = 6,237V
= +0443 V
2 Vat Vc - 75-4 6.037 - oe k
tT, 1,3%7e-3
A C AC Solution :
e Pon { ro)" gm VT
solution 15 +he Same asin problem
The ae,
+ |,
Nout _ _ 5 |] Ry |} ear R )
Ain RS ers (om ell MN)
Vour
ain = ~ 44 av
vio
ince V. = ~ 6,66 V the maximustro lage.
Swing would be. 6.66V (wore: | 6:66] 1s less
than fis -€669/ = ¢. s4V)
3) OW
|
RA $ 500K |
leon i
|. Vo =
{ je W177) «(De=16¥
ct
vin LF apifare-x *L ng
RS im 4k
ampthude=t mv | 00
Frequency=10K R2 x 3 - ‘
0 im
.
G
02 $a lution ' Much ease ery
ne
-I5V
0=(15v) + Igky, +7 + te Ra,
14,3 = Te (Ry + Gr) Rs)
=Ig (soork +(o1) 300)
Tge= 26.9 uA
I, = 2.64 mA (= Ig)
Te > 2%, 7amA = (Br
2 -IbV + TeR Ve= —Lefa Vaz -I5 +16 Ry
= - 6,93V = ~0,916 V = LI55V
=> Forward active contitmec
Ve
_ 0 64e-
Vr 0,0a54
re> f= = 1632
fo- VaiMec © 75+ tly
Ze Q.64e-3) ~- 30.2" Ze
AC. fat Hoy’
V
ep vo pene]
Vout Or Neur
—=T - TT
Vin van Var
yo yy
= / Ry |[pr
Gs = \(- a” (ntelie)
| 2 - —7Aa+3 v/v
Since Ve = —~ 6.43 V the maximum ourper
Vo lrage swing woulol be 6.4A3V
