RC-Coupled-Amplifier

RC-Coupled-Amplifier

RC COUPLED AMPLIFIER

Aim

To simulate the RC coupled amplifier.

 

Components required

Transistor – BC107A (1), Resistor – RC05 (5), Capacitor – CK05 (2), CASE-AA100 (1), AC Voltage Source – VGEN (1), DC Voltage Source – VDC (1), Ground – SPL0 (2)

 

Circuit Diagram

Procedure

 

1. Draw the circuit diagram after loading components from library. Assign net names for connections wherever necessary. Place waveform markers on input and output nodes.
2. For placing waveform markers, select Tools --> Instruments --> set Wave form Contents --> Voltage waveform --> Click on the required net and place the waveform marker.

 

Preprocess

3. Preprocess allows the simulator to recognize components and their simulation models used in the circuit. Preprocess must be done before performing analysis, or after any update to the circuit schematic. To preprocess, select Simulation → Preprocess, check and close the Info window that pops up.

4. To proceed with the simulation, the steps are as follows.

Select Tools --> Components --> Component properties --> Change simulation parameters --> Click on the required component and change its values.

The values to be provided to the components are

Transistor
: BC107A (Click on the Set up Model of the Model Type. Click on Accept to get the default values assigned)

Resistors
: R1 = 47k, R2 = 10k, RC = 2.2k, RE = 680 Ohm, RL = 820 Ohm
Capacitors
: CC1 = 15µF, CC2 = 10µF, CE = 22µF
VDC/1 (+Vcc)
: 10V
VGEN
: Select the source function as SIN and set its Properties as follows
VA (Amplitude)
: 10mV
FREQ (Frequency)
: 10kHz

Analysis

Transient Analysis

1. Select Simulation --> Analysis.

2. Select Transient Analysis from the tree view.

3. Expand Transient Analysis and select Waveform Viewer.

4. Click on the As Marked button and then on Accept.

5. Click on the Transient Analysis

6. Enter the values as

Step
: 10µ
Final time
: 10m
Start time
: 0

7. Select Waveform from the Results field for displaying the output

8. Click Accept button after entering the values.

9. Click Run button to start simulation.

Small Signal AC Analysis

This analysis is used to obtain the small signal AC behaviour of the circuit.

1.      Select Simulation --> Analysis.

2.      Select Small Signal AC Analysis from the tree view.

3.      Expand Small Signal AC Analysis and select Waveform Viewer.

4.      Click on As Marked button.

5.      Select the required Complex values and then click on Accept.

6.      Enter the values for the Small-Signal AC Analysis as

Variation
: Decade
Total points
: 100
Start frequency
: 10 Hz
End frequency
: 10G

7.     Select Waveformfor displaying the output.

8.     Click Accept button after entering the values to automatically switch to Analysis.

9.      Click Run  button to start simulation

DC Transfer Function Analysis

DC Transfer Function Analysis gives the behaviour of the circuit with respect to the varied voltage/current.

  1. Select Simulation --> Analysis.
  1. Select DC Transfer Function Analysis from the tree view.
  1. Set the values as
Start Voltage
: 0V
Stop Voltage
: 12V
Step
: 1
  1. Select Waveform for displaying the output.
  1. Click Accept button after entering the values to automatically switch to Analysis.
  1. Click Run  button to start simulation

Distortion Analysis

The distortion analysis computes steady state harmonic and intermodulation products for small input signal magnitude. If signals of a single frequency are specified as the input to the circuit, the complex values of the second and third harmonics are determined at every point in the circuit. If two frequencies are specified at the input of the circuit the analysis finds out the complex values of the circuit variables at the sum and difference of the input frequencies, and at the difference of the smaller frequency from the second harmonic of the larger frequency.

  1. Set the frequency, Select  Component parameters (function tool) Change Simulation Parameters option tool.
  2. Select Simulation --> Analysis.
  3. Select Distortion analysis from the tree view.
  4. Inorder to run distortion analysis, specify the analysis parameters by selecting Distortion Analysis from the tree view on the left side of the Analysis Setup.
  5. Set the values as
Total points
: 100
Start frequency
: 10Hz
End frequency
: 10Meg
              
  1. Click Accept button after entering the values to automatically switch to Analysis.
  2. Click Run button to start simulation. The output obtained is a text file.
  3. Before performing the analysis, Set the F2 frequency source distortion [DISTOF2] of the VGEN to Yes.

Output File

Operating Point Analysis

Operating Point Analysis is used to determine the DC behaviour of a circuit. This is done automatically when an AC analysis and Transient Analysis is done.

  1. Select Simulation --> Analysis.
  2. Select Operating point Analysis from the tree view.
  3. The default selection is ‘As marked’ means that results will be displayed at all markers placed on the circuit schematic. After analysis, the values will be presented by updating the markers.
  4. If we want to know  the values at all nodes and branches of the circuit, select ‘All Points’ the results can be viewed in the RAWSPICE.RAW file, For that Select Options → View EDSpice Files → Raw file, from that Open rawspice.raw file.

Noise Analysis

Noise Analysis is used to analyse the noise existing at any point in a circuit, due to the combined effect of all noise sources in the circuit.

  1. Select Simulation --> Analysis.
  2. Select Noise Analysis from the tree view.

  1. Set the simulation parameters such as start frequency, end frequency, total points etc.
  2. After analysis the Noise Spectral Density Curves will be presented in the Waveform viewer as shown below.

  1. The total integrated Noise will be presented in the rawspice.raw file. It can be viewed from Options → View EDSpice Files → Raw file, this .raw file is pasted below.

DC / AC Sensitivity Analysis

This analysis helps to calculate sensitivity of an output variable (voltage and current) with respect to all circuit variables, including model parameters.

  1. Select Simulation --> Analysis.
  2. Select DC / AC Sensitivity Analysis from the tree view.

  1. Click Accept button after entering the values to automatically switch to Analysis.
  2. Click Run button to start simulation
  1. After analysis the results of the DC Sensitivity Analysis will be presented in the rawspice.raw file, open this file from Options → View EDSpice Files Rawfile.
  2. The results of AC Sensitivity Analysis will be presented in the Wave form viewer.

Transfer Function Analysis

The transfer function analysis calculates the small signal ratio of the output node to the input source, and also the input and output impedance of the circuit.

  1. Select Simulation --> Analysis.
  2. Select Transfer function Analysis from the tree view.
  3. Set parameters and click Accept to accept these values.

  1. Click Run button to execute the analysis.
  2. After the analysis, the results will be displayed in the .raw file. Open this file from Options → View EDSpice Files → Rawfile.

Pole- Zero Analysis

Pole- Zero Analysis is most commonly used for determining the stability of control circuits. This computes the poles and / or zeros in the small signal ac transfer function.

  1. Select Simulation --> Analysis.
  2. Select the Pole Zero Analysis from the tree view.

  1. Click Accept button to accept these values.
  2. Click Run button to execute the analysis.
  3. After analysis, the results will be displayed in the .raw file .For opening this file select Options →View EDSpice Files →Rawfile.