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E-Leaning
2.1.2. Common Source (CS) amplifier
EX1: Consider the common-source
(CS) amplifier in the figure besides,
where RI = 1.00 K, R1 = 180.00 K,
R2 = 82.00 K, RS = 33.00 K, R3 =
68.00 K, RD = 22.00 K, VSS = 10 V.
MOSFET có Kp = 0.3 mA/V2, Vtp = 1 V,
T = 0.5x109 rad/s, Cgd = 5 pF.
a/ Determine the Q-point of this circuit.
b/ Draw the small-signal highfrequency equivalent circuits for this
amplifier.
c/ Find the transfer function Av(s) =
vo/vI at high frequency and plot Bode
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E-Leaning
2.1.3. Common Emitter (CE) amplifier
EX2: Transistor operates at
high frequency, given  = 100,
r = 1000Ω, C = 5pF, ωT = 109
rad/s.
a/ Draw the high-frequency
small-signal equivalent circuit.
b/ Find the voltage transfer
function at high frequency
c/ Plot Bode for low (fL) and
high (fH) cut-off frequency for
circuit.
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VCC
Rc
1k
Ri
Cb →∞
Cc
Vout
10µF
Q
RL
1k
1k
Vi
0
R2
100k
10µF
Re
0
Ce
1k
VBB
0
0
402060 – Chapter 2. The high-Frequency Response in Transistor Amplifiers
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E-Learning
2.1.3. Common Emitter (CE) amplifier
EX3: Consider the figure besides,
where RI = 1.00 K, RB = 68 K, RE
= 47.00 K, R3 = 33.00 K, VCC =
12 V, VEE = 12 V. BJT has  = 75, T
= 0.5x109 rad/s, C = 25 pF.
a/ Determine the Q-point of this
circuit.
b/ Draw the small-signal equivalent
circuit at high frequency.
c/ Determine the voltage transfer
function Gv(s) = vo/vI at high
frequency.
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402060 – Chapter 2. The high-Frequency Response in Transistor Amplifiers
40
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