YILDIRIM BEYAZIT UNIVERSITY
Week 12
ECE 204 - ELECTRICAL CIRCUITS II PRELIMINARY WORK – 5 – TRANSFER FUNCTIONS How we plot frequency response on 5spice 1) Firstly, we draw circuit diagram on 5spice program.
Figure 1- Circuit Diagram 2) Second, we choose Analyze and then we select AC-New, we adjust frequency 100Hz to 10kHz , step/ decade will be 10 Hz
Figure 2- Analysis
YILDIRIM BEYAZIT UNIVERSITY
Week 12
3) Thirdly, we select Graph/Table , Plot 1 will be Vout and Axis will be left and then we select amplitude in dB
Figure 3- Graph/ Table
4) Finally, Click Apply and Run and you will see frequency response, in there X axis is frequency and Y axis is dB magnitude .
Figure 4- Frequency Response
YILDIRIM BEYAZIT UNIVERSITY
Week 12
For all circuits select component values as R=10kΩ and C = 10nF. A) According to the circuits in fig.1.a and 1.b. 1) For each circuit, derive the sinusoidal steady-state transfer function. (Both magnitude and phase).
2) Assume that the input is (A*sinwt) sinusoidal wave. Find the input frequency where the output voltage will be 45° out of phase, than the input voltage. Calculate the amplitude of the output voltage at this frequency.
3) Find the input frequency where the amplitude of the output voltage is ¼ of the amplitude of the input voltage. ( Calculate output frequency for this frequency )
B) According to the circuits in figures 2 and 3. 1) For figures 2&3, write the transfer functions. 2) Assume sinusoidal input. Find the frequencies where the phase difference of input and output voltages is either +90 or -90 degrees. Find the amplitude of the output voltage at these frequencies.
3) Repeat part (2) for 0° or 180° phase shift.
YILDIRIM BEYAZIT UNIVERSITY
Week 12
C)
Figure 4
1) For the above circuit, derive the transfer function Vout/Vin. Show your calculations. 2) Simulate the frequency response from 100 Hz to 20 kHz. (i.e. 5spice simulation)