Lab 2: Low Frequency Response of Common Source Amplifier
Conducted on:3/10/23 Submitted on:9/10/23
Instructor:Ass Prof M.Anis Ch
Lab Engineer:MTO Naeem uz Zaman
Group Members
1)Khawar Khan 398500
2)Samiullah Saddiqe 398367
3)Asad Hameed 398366
Aim
Understanding low frequency response of common source amplifier.
Theory
1) Topic 9.1 of microelectronic circuit 6th edition by sedra smith
Components
Cc1=Cs=Cc2=10uF, RG1=8MΩ, RG2=7MΩ, RD=RS=RL=10K, Rsig=100k, 2N7000 transistor
Task Breakdown Marks
1) Designing Common Source Amplifier 2
2) Simulation 3
3) Implementation 5
Explanation
Common Source Amplifier
Common source amplifier is characterized by following features
1) High input resistance
2) High gain (out of phase)
3) Moderate to high output resistance
4) Introducing source degeneration resistance Rs reduces gain by a factor of (1+gmRs)
however bandwidth improves
TASK
A1) for the circuit in Figure 1 write expressions for Av, fp1, fL=fp2 and fp3
Figure 1: Common Source Amplifier
A2) for following values of components calculate above expressions
Cc1=Cs=Cc2=10uF, RG1=8MΩ, RG2=7MΩ, RD=RL=10K, Rs=1k, Rsig=100k and VDD=15V
B1) simulate the above circuit in multisim and find Av
B2) Perform AC sweep analysis and find lower 3dB frequency
B3) Plot exact approximate frequency response of the circuit in MATLAB using freqs and bode
command and determine lower 3dB frequency
C1) implement above circuit in hardware and verify Av (mid band gain)
C2) Apply signal of different frequencies plot frequency response and find lower 3dB frequency
f(HZ) V0 Av Gain in dB
