NAME MASTER
(PRINT)
EE11 FINAL
FALL 09
1
2
3
4
5
6
7
TOTAL
TOTAL
1.4
GRADE
Put your answers in the space provided
PROBLEM 1
Find Vo and Zo in the circuit of Fig.1.
Vo = 6
Zo = 6.67K
Choose R1 in the circuit of Choose R1 in the circuit of
Fig.2 so that Vo/Vs = -5 Fig.3 so that Vo/Vs = 5
R1 = 4K R1 = 5K
Choose R1 in the circuit of Fig.4 so that Vo/Vs = -50
R1 = 870 ohms
PROBLEM 2
Choose the resistors in Fig.1 so that
Vo = V1 + 3V2 - 4V3 - 2V4
One resistor is not needed. Set its value to .
R1 = 20K R2 = 6.66K R3 = 5K
R4 = 10K R5 = 6.66K R6 =
Choose the resistors of the circuit so that
for Vs = 0V, Vo= -5 and for Vs=1, Vo=+5.
R1 = 20K R2 = 2.5K
Choose the resistors of Fig.3 so that
For Vs = 1 + (0.2V/OF)T, Vo = -(1V/OF)T
One resistor is not needed. Set its value to .
R1 = 20K R2 = 4K R3 = 4K R4 = ∞
PROBLEM 3
Determine the trip points for the circuit in Fig.1.
UTP = 3V LTP = -3V
Determine the trip points for the circuit in Fig.2.
UTP = 2.44V LTP = -2.44V
Determine the trip points for the circuit in Fig.3.
UTP = 0 LTP = -6V
Find the frequency of the multivibrator of Fig.4.
fo = 65.4Hz
PROBLEM 4
A filter with the Bode plot of Fig.1 has the transfer function H(jω) = K (1+jω/ω1)
(1+jω/ω2)
Find K, ω1, ω2.
K = 1 ω1= 2 ω2 = 200
Find the differential equation that relates Vo to Vs for the filter in Fig.2.
[ _0__ (d2/dt2) + __1__ (d/dt) + __0__ ] Vo =
[ ___ (d2/dt2) + __-2__ (d/dt) + _-100__ ] Vs
H(s) = - (20K + 106/s)/10K
PROBLEM 5
Choose R1 and V1 in the circuit of Fig.1 so that for the input, shown as a broken line in Fig.2, the output follows the solid line of the figure. The diode drops a constant 0.6Vwhen it conducts.
R1 = 7.5K V1 = 2.4V
Determine the gain of the amplifier in Fig.3 when the diode of the circuit is off.
∆Vo/∆Vs (Diode off) = 2
The diode on voltage is 0.6V. Determine Vo when the diode begins to conduct.
Vo = Vs+0.6
Vo = 2Vs
Vo(Diode on.) = 1.2V
Determine the gain of the amplifier when the diode is
on.
ΔVo/ΔVs (Diode on) = 1.5V
Draw a Bridge rectifier in the block of Fog.4
PROBLEM 6
In the power supply of Fig.1,
Vin = 170Cos(377t) VcMAX = 33V <Vc> = 30V
Vo = 20V IZ = 12ma. IA = 1ma IL = 100ma
The transistor beta = 100 and the VBE = 0.7V.
Find the transformer turns ratio
N1/N2= 4.94 (or 4.7)
Find the value of Ro
Ro = 892 ohms
Find the value of R1
R1 = 10K
Find the current IC
IC = 114ma
Find the value of C
C= 158uf
Find the value of -IE
-IE = 101ma
Find the value of IB
IB = 1ma
Find the value of VB
VB = 20.7V
PROBLEM 7
In the circuit of Fig.1,Choose RE so that the amplifier has an AC gain of -5.
RE = 4K
Neglect the transistor base current and choose
VEQ so that the transistor is optimally biased for sinusoidal operation. Take VBEQ as 0.6V
VEQ= 2.5V
Find the D.C. collector voltage VCQ VCQ= 17.5V
Find the value of R1for optimal sinusoidaloperation.
R1 = 434K
Neglect base current and find the
transistor D.C. collector current ICQ.
ICQ = 0.625ma
Find the maximum value of Vs for which
the amplifier output is not distorted.
VsMAX = 2.5V
(or 5Vp-p)
Complete the truth table of Fig.3 for the MOS logic gate of Fig.3. Take VDD as logical one and 0V as logical zero.
AB
00 01 11 10
CD
00 1 1 X 1 X=undefined
01 X X 0 X
11 X X 0 X
10 X X 0 X Z
Write the logical expression for the circuit.
Z(A,B,C,D) = undefined. (Oops!)