how to generate pwm for push-pull converter

[bernat_f]

Posted on November 02, 2009 at 12:26

how to generate pwm for push-pull converter

[bernat_f]

Posted on May 17, 2011 at 13:28

Hi,

I'm trying to genereta 3 independent PWMs signals in which each one has 2 alternate outputs like this ones(with the same clock frequency):

____|**|__________|**|______

____________|**|__________|**|______

The objective is to controlate thre diferent push-pull converters like the old UC3525 did.

If been looking in the manual but I haven't found what I'm looking for. Because if I use 2 channels of the same timer I got this:

____|**|__________|**|______

____|*****|_______|*****|______

And the opposite channels aren't also the solution:

____|**|__________|**|______

****|__|**********|__|******

I now that the solution should be easy but I haven't found it, can anyone help?

[akaiser9]

Posted on May 17, 2011 at 13:28

You could use 2 timers with 3 outputs each. Each timer handles one half of the PWM pairs. Let the second timer start exactly T/2 later as the first and use bidirectional PWM to center the pulses. A precise startup delay can probably be implemented by timer event linking.

[ This message was edited by: prx on 02-11-2009 16:35 ]

[bernat_f]

Posted on May 17, 2011 at 13:28

Thanks for the answer, I've seen that using the timer synchronization function (setting one tiner as slave of the other one) and prefixing a value in the counter of the slave I can handle this as you said.

[pete23]

Posted on August 10, 2011 at 01:34

Did you get anywhere with this?  I'm trying to do something similar.