SEEE1073
Simulation Assignment
Activity outcome:
-Use simulation tools (virtual-experiment) to perform analysis on related circuitry
(Course Learning Outcome(CLO) no. 3).
-Types of simulation involved are:
a) DC simulation
b) AC sweep
c) Transient
Scope of work:
Part 1:
1.1 Design a voltage divider bias (Figure 1) circuit for NPN BJT amplifier (virtual BJT: Beta can
be changed). The value of the components used in the circuit should meet the specification in
Table 1.
1.2 The result of this part is the values of R2, RC and RE.
VCC
R1
RC
ICQ
R2
RE
Figure 1: Voltage Divider Bias Circuit
Table 1: Specification of the bias circuit
Parameter
VCE
ICQ
β
RC
R1
Condition
VCE=0.5VCC
*refer Appendix A for VCC value
ICQ=0.5ICsat
*refer Appendix A for ICsat value
Refer Appendix A for β value
RC=9RE
51 kΩ
Part 2:
2.1 Based on the calculation in Part 1, choose the practical/standard resistor value by referring to
Appendix B.
2.2 By using the standard resistor values, construct the circuit in Figure 1 and simulate (DC
simulation) to obtain the ICQ and VCEQ.
2.3 For the simulation, you need to add current meter (series connection at collector terminal) and
voltage meter (parallel connection between collector and emitter).
2.4 Discuss the result by comparing with the given specification in Table 1.
Part 3:
3.1 Add AC source with source resistor and load to the amplifier circuit with capacitive coupling
(Figure 2). Add also bypass capacitor. Use the capacitor and load values shown in Figure 2.
3.2 Simulate the frequency response (maximum range: 1 Hz to 10GHz). AC SWEEP
SIMULATION
3.3 Show the Bode plot (Voltage gain against frequency). Analyze and discuss the amplifier
performance (e.g. Mid-band current gain, low cut-off frequency, high cut-off frequency. Note that
in some cases, the high cut off frequency cannot be identified within the above frequency range.
Part 4:
4.1 By using time-transient simulation, show the amplification of input signal (sine wave with
Vpp=10 mV). As for frequency of the input signal, choose any frequency value in the midband
range. In this simulation, you should show the output waveform across the load. TRANSIENT
SIMULATION
VCC
R1
Rsource
200Ω
RC
C1
5µF
C2
0.5µF
+
VS
R2
RE
C3
5µF
RL
2kΩ
Vo
-
Figure 2: Common-Emitter Amplifier Circuit
*Refer Appendix C for hints and additional information
Report submission:
The report should have the following item;
1. Result of Part 1
1.1 Hand calculation for Part 1.
2. Result of Part 2
2.1 Constructed circuit schematic for simulation in Part 2 (with current and voltage
meters). Can be print screen of the simulator.
2.2 The ICQ and VCEQ values obtained from simulation.
2.3 Comment on the comparison between simulation result (Part 2) and hand calculation
in Part 1.
3. Result of Part 3
3.1 Constructed circuit schematic for simulation in Part 3
3.2 Graph of frequency response/Bode plot (Voltage gain versus frequency).
3.3 Analysis on the amplifier performance (i.e. mid-band voltage gain, low and high cutoff frequency)
4. Result of Part 4
3.1 Constructed circuit schematic for simulation in Part 4
3.2 Graphs showing the input and output signals (voltage against time).
5. Conclusion: Reflection on what you have learned from the assignment.