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I want to generate 4 phase pwm for interleaved buck converter with independently controllable duty on each channel. I am using stm32f103 series mcu. I want to know if its possible with this micro controller .

Arg.1
Associate II

I am told by that configuring a timer as master and others as slaves can generate multiphase pwm . but I cant figure out how exactly to set the configuration. I am aware its possible in few of the advanced MCU with HRTIM. But I want to use stm32f103 since its available as bluepill board. If 4 phase is not possible at lease 2phase with 180 deg phase shift will do.

5 REPLIES 5
Javier1
Principal

Timer1 is what youre looking for.

Think of every pwm phase you need as a timmer1´s channel (1,2,3,4)

Every timer channel in PWM generation mode has the option to produce a single pwm signal with adjustable duty CH1 or a pair of pwm signals CH1 and CH1N for example where CH1N is the inverse of CH1 but respecting the programmed switching deadtimes.

0693W000008zu6EQAQ.png 

sadly the CH4 doesnt have the option of producing also CH4N....

we dont need to firmware by ourselves, lets talk
Arg.1
Associate II

I think the channels won't give the required phase shift(all though duty can be independently controlled) between each other say I will use 3 channels itself , the phase shift between each channel should be 120 degree if its four channels the phase shift should be 90 degree between each channel. but still I will try it out and get back.

https://youtu.be/wN9_ZczShyI this is the type of waveform which I am trying to generate.

I see.. the solution i gave you gives you perfectly in sync pwms, so no bueno for you.

we dont need to firmware by ourselves, lets talk

@Arg.1​ I have no experience with it but there is some trigger-source magic about timers.

https://www.eevblog.com/forum/projects/stmf303-phase-shifted-pwm/msg3085185/?PHPSESSID=67k405n6aje8tf24818tcd8mg7#msg3085185

One master timer is used as a trigger for the rest this way you can sync and programm variable phase delays

we dont need to firmware by ourselves, lets talk
Arg.1
Associate II

yess this might help , I will try it out

thanks