STM32F407 VBUS sensing 5-20V (fast charge)

ymak · ‎2024-03-26

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?

Peter BENSCH · ‎2024-03-27

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

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Peter BENSCH · ‎2024-03-27

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

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.