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Visitor II
March 26, 2024
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STM32F407 VBUS sensing 5-20V (fast charge)

  • March 26, 2024
  • 1 reply
  • 961 views

Hello

I'm developing a self-powered device with "fast charge" feature, which assumes that USB VBUS pin can supply up to 20V. In this case, a simple voltage divider will not be able to provide an acceptable logic level within the range of 5–20 V. Additional voltage comparators, suppressors are not an option as I want to keep things simple.

What if calculate a simple resistor divider for 20V, pass the lowered voltage to ADC, measure it and set the state of a VBUS sensing pin programmatically?

    This topic has been closed for replies.
    Best answer by Peter BENSCH

    Welcome @ymak, to the community!

    Presumably you don't want to use a transistor (or two, since one only inverts and inverse operation of a single one is certainly out of the question) because that's all extra stuff, right?

    From my point of view, there is actually nothing to be said against your approach.

    Regards
    /Peter

    1 reply

    Technical Moderator
    March 27, 2024

    Welcome @ymak, to the community!

    Presumably you don't want to use a transistor (or two, since one only inverts and inverse operation of a single one is certainly out of the question) because that's all extra stuff, right?

    From my point of view, there is actually nothing to be said against your approach.

    Regards
    /Peter