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UCC28251: 2 dual PWM generation with a 5V signal as reference

Maximin BLANC
Prodigy 20 points
Part Number: UCC28251

Dear everybody,

I hope I am doing in a proper way to ask my question as it is my first time on this forum.

I am looking for an IC to generate 2 PWM which are dual from each other. I would like to set deadtime(around 50-100ns) and frequency (50kHz) with external component (RC filter or other). And more important I would like to have an input which accept a voltage between 0V and 5V for example to generate a 0 to 100% duty cycle.

Most of IC I can find include feedback control (like synchronous buck : UCC28251 Advanced PWM Controller). But I don't want the regulation.

If there is any possibilities to bypass this feedback control on that reference UCC28251 and use an external signal to lead the PWM, please let me know.

Best Regards to all,

M. BLANC

  • 0
    TI__Mastermind 31580 points
    Hi Maximin,

    If the UCC28251 is configured in voltage mode control, then the error amp can be configured as an non-inverting amp, we can set the gain to 2 for example. Then the duty cycle can be controlled by changing the input to the non- inverting input.

    Have you looked at the UCC2808 as another option. Tie the FB pin low, then COMP will be pulled high and the IC will give maximum duty cycle. By pulling the COMP low with an external signal the PWM duty cycle can be controlled.
  • 0 in reply to Peter Meaney
    Prodigy 20 points

    Hi Peter,

    I found an other option with the LTC6992 IC which creates a PWM based on 0-1V signal. There are 4 references depend on what you want to do (0% to 100% duty cycle, or 100% to 0%, or 5 to 95% when boost mode must be limited...)

    Thanks again

    Maximin