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TPS61088: Minimum Duty Cycle

Prodigy 150 points

Replies: 1

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Part Number: TPS61088

Dear TI,

I am considering to use the TPS61088 to step up 9V to 10V. I am concerned that the voltage difference is too small - the resulting duty cycle will be about 10%. Section 6.5 in the datasheet states that the minimum on-time is 180ns for a switching frequency of 500kHz, which is a duty cycle of about 9%.

Will the small difference between the input and output voltages cause any issues? If so, could you please recommend a different device?

As a side note, WEBENCH suggests using a 499kOhm frequency setting resistor (when optimizing for the smallest footprint and an output current of 3A), which yields a switching frequency of about 336kHz. Consequently 10% of the period is about 300ns.

Thank you!

  • Dear Sir,

    Yes, you need to make sure the fsw is low enough to make sure the minimmum Ton is >200ns. (leave some margin to 180ns typ value).  Or the Vout can't be regulated at 10V,

    So Please follow the suggestion by Webench.

    Best Regards,
    Helen

    Boost DC/DC Solution

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