xr2206 questions

Discussion in 'Electronics Resources' started by shortbus, Oct 24, 2010.

  1. shortbus

    Thread Starter AAC Fanatic!

    Sep 30, 2009
    I have some questions about the xr2206 chip and it's use. Data sheet here; http://www.jaycar.com.au/images_uploaded/XR2206V1.PDF

    1. The first page says that it can adjust the out put duty cycle from "1% to 99%". But the closest thing to duty cycle on the pin outs is called "syma1(pin15) and syma2(pin16)", is symmetry the same as duty cycle?

    2. All I want from this IC is the square wave, do I need to ground the sine and triangle wave out puts or leave them floating?

    3. I want to make the frequency adjustable with a pot from 5Khz to 50Khz. Do I hook the pot between the R1(pin7) and R2(pin8) or how is this done?

    I'm sure I'll have other questions, but this is a start. Thank you, cary
  2. bertus


    Apr 5, 2008

    They talk about duty cycle if the wave is a square wave.
    It is called symetry when the wave is a triangle or sinewave.
    At a triangle wave it can be from a rising sawtooth via a real triangle to a lowering sawtooth signal.

  3. SgtWookie


    Jul 17, 2007
    The "Sync Out" is a 50% duty cycle square wave, and the symmetry of it is not adjustable. You can only adjust the symmetry of the sine/triangle wave outputs.

    Consider using a 555 timer instead; it can easily do what you wish.

    What kind of output voltage/current were you requiring?
  4. shortbus

    Thread Starter AAC Fanatic!

    Sep 30, 2009
    Sgt-the voltage out - 12VDC, current out - 40uA, to drive a IR2110 mosfet gate driver.

    I was going to use this circuit; http://www.rmcybernetics.com/projects/DIY_Devices/homemade_signal_generator2.htm
    Then I saw the XR2206 and thought it might be better.

    thanks ,cary
  5. Audioguru

    AAC Fanatic!

    Dec 20, 2007
    Yes, the symmetry and the duty cycle adjustments are the same for the triangle and sine-wave outputs.

    You never ever connect the output of an IC to ground. If you do then the very high current will blow up the output transistors. If you don't want the outputs then leave them floating.

    Figure 5 and figure 11 show the output frequency adjustment.