LAb 2 Title:Time domain analysis of a lowpass filter in pspice

Lab2

Lab No. 2

Title: Time Domain Analysis of low pass filter and high pass 

filter using pspice

Objective: The objective of this lab is to observe the phenomena

of Low Pass Filtering and High Pass Filtering in time domain and 

compare it with the frequency response plot. 

Task 1:

1.  We will use the same circuit as in lab1 also shown below. 

Take the voltage across the capacitor and use three

frequencies of amplitudes A1=1V and A2=0.5V . Choose their

frequency of your choice preferably one in pass band and one 

in stop band and compare the outputs with Frequency response 

plot and justify the Type of system by your time domain 

Analysis.

2.  What is the Magnitude of the cutoff frequency/break point 

frequency/3dB frequency in Linear scale and in dB scale.

Note: choose the amplitude of cutoff frequency = 1V

Task 2:

Swap the positions of resistor with capacitor i.e. Take the 

output across the resistor and Repeat the part1 and 2 in task1 

Note: Axis must me labeled properly title should be displayed 

in your graph and reading should be taking with the 

cursore.e.g. as in part2 and it values should be displayed in 

your lab report

This Lab is demonstrated in pspice version 9.1.The discussion is on plotting of linear Frequency response and Bode plot

 

Lab1-part2 discussion

This Lab is demonstrated in pspice version 9.1.The discussion is on plotting of linear Frequency response and Bode plot

Lab1-part1 discussion

Lab No. 1

Title: Plot the frequency response of the low pass filter and high pass filter using pspice

Objective: The objective of this lab is to plot the frequency response of the circuit and observe how the input to output ratio is changing with frequency and based on that decide whether it’s a low pass, highpass or a bandpass system

Task 1:

1.  Given the following circuit with the components and their values mentioned. Plot the frequency response i.e. Magnitude response and phase response using pspice and decide

what kind of response it has i.e LPF or HPF.

2.  Now Change the y-axis to dB scale and x axis to logarithmic scale and Repeat step 1 .what is the specific name of this plot i.e. if y-axis in dB scle and x axis is in logarithmic scale. Label the axis along with the title.

3.  Find the cutoff frequency/break point frequency/3dB frequency in part1 and part2 and mention in the plot using a cursor.

4.  Find the slope of the curve after a decade from the beak point.

Task 2:

Swap the positions of resistor with capacitor and plot the magnitude response and compare it with the task1 plot.Repeat part 1,2 and 3 for this circuit. After plotting frequency response for this circuit decides what kind of system it is (LPF or HPF)

Additional task for understanding:

·        You can choose manually the frequencies from part4 in Task1 and insert them in the circuit using pspice and find the output waveform and compare it with frequency response plot.

·        Repeat the same procedure for part 4 in task1

·        Conclusion and comparison will lead to additional marks