Mixing SG3525's output ti get a SINGLE PWM output [D = 0 - 99%]

Thread Starter


Joined Dec 13, 2023
Hello, i'm a beginner that is getting started with power electronics.

I had designed a synchronous buck converter with sg3525, but i ran into a problem:

I need a single PWM output who's duty cycle can go from 0 all the way to 99 or 100%. Is there a way to do that with the SG3525? Mixing its two outputs in such a way that i obtain a single PWM output. Maybe with logic Gates? Operational amplifiers?

Even if it's complicated to do, please, let me know.

I dont have any other option. I can only use sg3525 for now, because i dont have any other ICs and i cant order them. But i do have some logic gates and operational amplifiers laying around.

If there is information missing i can send it to you. Sorry in case, i'm basically just a beginner that is trying to design a circuit.

Oh and, by the way, i dont have an oscilloscope... I know, it sucks.

If it's literally IMPOSSIBILE to do, maybe suggest some other IC that works like sg3525 but has a single PWM output.

Thank you.


Joined Feb 24, 2006
The 50% duty cycle limit has a practical explanation. If you want to do a buck converter with a duty cycle above 50% there are other things you need to consider which the SG3525 is unable to accomplish. Are you prepared to deal with the problems of a buck converter with a duty cycle in excess of 50%? IMHO, I think not, but you might surprise me.


Joined Oct 7, 2019
There are some simple to use PWM that include the pass transistor.
What is the input and output voltages and current?
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