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HiperTFS-2 used as standard two transistor forward driver, with bootstrap high side drive

Posted by: treez on Sun, 05/09/2021


It looks to me that HiperTFS-2 can simply be used as a standard two transistor forward driver, with duty cycle between 0 - 49%. Is this correct?

The high side drive bootstrap capacitor just needs a bootstrap diode to charge the bootstrap cap...would you agree?

This in fact makes HiperTFS-2 the only 2TFC driver in the world i believe.

The HiperTFS-2 works out the duty cycle from the sensed voltages on the R and L pins...would  you agree?

Also, there is no need to use the internal flyback driver if not wanted?

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Submitted by PI-csbabu on Mon, 05/10/2021

Hi Treez,

    HiperTFS-2 is a two switch forward converter including internal forward driver plus forward converter power Mosfets. As stated in the datasheet, for 66kHz operation external bias is circuit is not necessary but needed for 132 kHz operation. To simplify the circuit, you can use single diode to connect Bootstap capacitor but additional R-C is recommended to avoid discharge of boost strap capacitor during burst mode of operation. HiperTFS-2 can operate >50% duty cycle and operating duty cycle was computed based on feedback pin voltage.  If you have standby converter to support bias voltage, no need to use internal Flyback but need to follow certain power-up sequence in-order start converter properly.