I need 4 output with pwm feature. All pwm are the same period T of 200 Hz. All pwm have independent dc ( duty cycle ) and independent dt ( dead time ) . Is it possible configure the timer peripheral and the clock to have dead time configurable betwee

[stst9187]

Posted on August 31, 2017 at 08:12

I need 4 output with pwm feature.

All pwm are the same period T of 200 Hz.

All pwm have independent dc ( duty cycle ) and independent dt ( dead time ) .

Is it possible configure the timer peripheral and the clock to have dead time configurable between 0 to T/2 ( half period )?

I'm using stm32f052 or stm32f072

thanks

Marco

[Vangelis Fortounas]

Posted on August 31, 2017 at 10:24

Hello !

Dead Time can not be adjusted independently for each channel.

Dead time means at each PWM channel,  are exists two complementary outputs.

Only Timer 1 and 8 have 3 channels with 2 complementary outputs per timer. The other timers don't have this functionality.

Timer 8 is not available in your MCUs

So ..   the answer is  no.

Regards

vf

[waclawek.jan]

Posted on August 31, 2017 at 10:40

I'd go for 4 timers, all set to the same period; TRGO-TRGI linked to each other in daisly-chain fashion, TRGO always taken from an unused channel and determining the phase shift between two successive timers.

JW

[stst9187]

Posted on August 31, 2017 at 11:11

Hi Jan

sorry but I 'don't' understand, please tell me more thanks ..

[Robert Poor]

Posted on August 31, 2017 at 19:46

Frankly, if your PWM period is only 200 Hz and your system doesn't have other time critical processes, you can create software PWMs to do exactly what you need.  You didn't mention what resolution you need, but for 8 bit resolution, your inner loop only needs to run at 51.2Khz, which should be easy on a 48MHz part.

If you do have other time critical processes, you can run them in lock step with the PWM routine.  I used this technique on a lowly PIC processor running at 4MHz to generate 3 PWM channels at 100 Hz, so four channels on a 48MHz part should be a piece of cake...