Function Generator Circuit

admin November 9, 2018 22 Comments

In this circuit tutorial, we’re building a simple Function Generator Circuit which can generate waveforms – Sine waves, Square waves and Triangular waves. The core of this circuit is IC L8038 – which is basically a function generator chip capable of generating different waveforms.


The ICL8038 is a function generator chip, capable of generating triangular, square , sine, pulse and sawtooth waveforms . From these sine, square & triangular wave forms can be made simultaneously.There is an option to control the parameters like frequency,duty cycle and distortion of these functions.This is the best function generator circuit for a beginner to start with and is of course a must on the work bench of an electronics hobbyist.The circuit here is designed to produce waveforms from 20Hz to 20 kHz.The ICL 8038 has to be operated from a dual power supply.

Function Generator Circuit Diagram & Parts List.

Pulse Generator or Waveform Generator Circuit

Function Generator Circuit Diagram

Notes .

  • The circuit needs a dual power supply. A +15 -15 power supply as shown in the circuit is enough for the purpose.
  • The frequency of the output wave form can be adjusted using R7.It must be a 100K Log POT.
  • The duty cycle can be adjusted using R3 , a 1K POT.
  • The distortion of the wave form can be adjusted using R5 , a 100K POT.
  • Square,triangle & sine waveforms can be obtained simultaneously at pins 9,3,2 respectively.

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  • Asad
    April 6, 2018

    How can we simultaneously set pulse width of 130 to 500us and frequency of 20 to 30Hz in a rectangular waveform ? I’m trying to set them both but if I set PW to 130 to 500us, my frequency changes and vice versa. How to deal with it ?

  • zain
    November 8, 2016

    what if we want to add lcd display as well?

  • vishal
    November 5, 2014

    can we can use diode in4007?

  • October 6, 2013

    how can we increase the range so that it operates from 0Hz to 200Khz??

  • naomi
    August 29, 2013

    please tell us the substitute diode for 1N457 and its working in this ckt.
    can we use 1N914A

  • Justus
    August 13, 2012

    Can this circuit produce a triangular wave 100v (-50v to +50v)that is 50v peak to peak?

  • May 27, 2012

    We want an improved vasion of this diagram which will be controled by a computer system.

  • Heggi
    April 17, 2012

    how to change this circuit to be able to make 25kHz ?
    I’ve look through ICL8038 datasheet, and it says it is able to generate up to 100 kHz, but I can’t find how to determine the frequency


  • Emeka
    October 17, 2011

    Nice learning about this circuit. Was actually searching for a veractor circuit. Found it and found this

  • saad
    October 16, 2011

    salo koi sasta sa tarika nhe bta sktey????????

  • ejcab7
    October 12, 2011

    hello mr. SEETHARAMAN

    im trying to build this circuit. are you saying that i have to put a 10uF cap before the +V and -V? so thats 2 caps? and what is the 0.1 disc?

    thanks. i was the amplifier noob dude you helped. 🙂

  • seetharaman
    July 20, 2011

    Hi Mr Faisal is correct it important that you decouple power supply both positive and negative at the IC end to common with 10uF and a 0.1 disc (one set for positive supply and one set for negative supply).

  • Faisal shehzad
    July 20, 2011

    This circuit works.But you should use two capacitors of 10uf(polar) and connect one capacitor with V+(positive leg of capacitor) and second capacitor with V-(negative leg of capacitor) and remaining two terminals of capacitor should ground.Then this circuit will work.Don’t use this circuit as it if u use then your IC will be damage.

  • suraj
    November 6, 2010

    please send me working and associated circuitary of wave form generator

    April 18, 2010

    will you plz send me list of all components of this circuit
    (unction generator)?

  • September 30, 2009


    April 18, 2009

    we have required walkthrough metal detector circuit .

  • nunzilla555
    April 4, 2009

    could you please post a link where i can buy a couple of the 8038 chips

  • silent-core
    February 18, 2009

    any chance for showing us the output waveforms??? Thanx for the circuit, btw.

  • Alok Ghildiyal
    December 21, 2008

    please send me working and associated circuitary of wave form generator

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