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HiperTFS-2 used with <0.45 duty cycle and internal flyback used to give high side drive voltage?

Posted by: treez on Tue, 05/11/2021


I simply wish   to use the HiperTFS-2 for a 2 switch forward with duty cycle less than 0.45. Our application will be in light load most of the time so we dont want a bootstrap high side drive....we wish to use the internal flyback driver  in  HiperTFS-2 to provide a high side drive voltage to the HiperTFS-2. Is this possible?


How does the HiperTFS-2 work out what maximum duty cycle to give?

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Submitted by PI-csbabu on Wed, 05/12/2021

Hi Treez,

   Please refer to fig.30 in the HiperTFS-2 datasheet. It uses bootstrap circuit from flyback stage to bias high side driver. Alternatively you can use additional winding on the flyback transformer, to provide high side bias. 

    The maximum duty depends on the minimum input voltage. Please use PIxls tool to compute the transformer turns ratio to limit duty cycle below 45% at minimum input voltage.