I'm implementing a buck boost converter. I need a variabe duty cycle with constant frequency of 200kHz(without using a ardino board in which I suppose I would have to upload a program everytime to get a new duty cycle ) to drive the igbt. I was thinking if using a opm comparator with one input as Vref with a potentiometer to get variable duty cycle and another input as a constant frequency sawtooth wave from microcontroller . But can i give such high frequency wave to opm in the first place n get a decent pwm signal? Isnt there another way ?

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    \$\begingroup\$ There is a tool to draw circuits, it would be advantagues to improve you question by drawing a nice, good looking circuit \$\endgroup\$
    – Voltage Spike
    Mar 24, 2017 at 0:06
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    \$\begingroup\$ There are hundreds of switching controller ICs available that will do most of the hard work for you. \$\endgroup\$
    – The Photon
    Mar 24, 2017 at 0:27
  • \$\begingroup\$ As suggested by @laptop2d draw your circuit. If you tell us your input and output requirements we can probably suggest a suitable control IC, Linear Tech make quite a good range. \$\endgroup\$ Mar 24, 2017 at 11:36

1 Answer 1


Isnt there another way ?

You can always buy an off the shelf solution such as the LTC6992: -

enter image description here

Inside the chip is pretty much what you have described for what you believe is necessary for building one.

  • \$\begingroup\$ I'll definitely try with this IC. Thank you so much for ur help..! \$\endgroup\$ Mar 28, 2017 at 12:04

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