Download Differentiator.epb


  To design and simulate a Differentiator circuit.



EDWin Components Used


Number of components required

RES RC05 Resistor 1
CAP CASE-A600 Capacitor 1
VGEN VGEN Ac voltage source 1
GND SPL0 Ground 1



   A circuit in which output voltage is directly proportional to the derivative of input is known as a differentiating circuit. A differentiating circuit is a simple RC series circuit with output taken across the resistor R.

In order to achieve good differentiation, the following conditions should be satisfied:

  1. The time constant RC of the circuit should be smaller than the time period of the input wave.
  2. The value of Xc should be 10 or more times larger than R at operating frequency.

   Let ei be the input alternating voltage and i be the resulting alternating current. The charge q on the capacitor at any instant is


C ec


   Since capacitive reactance is very much larger than R, the input voltage can be considered to be equal to the capacitor voltage with negligible

   error. i.e. ec = ei


Output Voltage, eo = iR

ei ei


   Hence the output is proportional to the time derivative of the input.


  EDWinXP-> Schematic Editor: The circuit diagram is drawn by loading components from the library. Wiring and proper net assignment has been made.

  The values are assigned for relevant components.

  EDWinXP-> Mixed Mode Simulator: The circuit is preprocessed. The test points and waveform markers are placed in input and output of the circuit. GND net is set as reference net. The Transient Analysis parameters have been set. The Transient Analysis is executed and output waveform is observed in Waveform Viewer.


   The output waveform may be observed in the waveform viewer.