Low Power Square Waveform Generator

Discussion in 'General Electronics Chat' started by learntodo, Sep 9, 2015.

  1. learntodo

    Thread Starter New Member

    Sep 9, 2015
    Hello Friends,
    I am trying to develop a circuit which is can generate Square wave of variable frequency and duty cycle at the same time.
    My frequency range is from 1-100HZ
    My Duty Cycle range is from 1- 100%
    I have tried 555 timer but it was unable to give a variable frequency and duty cycle waveform at the same time.
    The most important thing is that i want to operate this circuit as a battery powered so it must be as low power as possible.
    I therefore request you to kindly suggest me an IC which could be used in the specific purpose.
    I shall be highly thankful to you.
  2. atferrari

    AAC Fanatic!

    Jan 6, 2004
    Google electroschematics site.
  3. learntodo

    Thread Starter New Member

    Sep 9, 2015
    This site contains the same material i have already read
  4. ScottWang


    Aug 23, 2012
    What's the purpose of the Square Waveform Generator?

    You can using ICM7555 to replacing NE555, the below is both functions as you described, but they are separated, you can own both in the same time, take the R1 away, disconnect the parts from pin 7, and connecting the parts to Pin 3, shorted R2, and how to own them both in the same time, you can think about it.
    NE555 Clock Generator and PWM adjustable circuit.
  5. atferrari

    AAC Fanatic!

    Jan 6, 2004
    There is one right there.
  6. AnalogKid

    Distinguished Member

    Aug 1, 2013
    I suggest an LM324. Integrator-comparator triangle wave generator followed by an adjustable-threshold comparator for the output squarewave. In this way the two settings are independent. That is, an output duty cycle set to 65% will stay there independent of the oscillator frequency. 1 Hz to 100 Hz is a 10,000 percent range, so adjustability will be poor.

    100 Hz is low enough that a quad CMOS opamp probably will work, but I don't have part numbers in my head.

    cmartinez likes this.
  7. GopherT

    AAC Fanatic!

    Nov 23, 2012

    How rock solid accurate do you need the duty cycle to remain when adjusting frequency? Few percent or 0% drift?

    How rock solid do you want frequency to remain when adjusting duty cycle?

    What batteries and how many will be used for your power supply?

    What is the targeted lifetime of the batteries in your device (days, weeks, months, years?). Be realistic.