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A comment on Should you fear your USB cable?. Parent comment

Re:Should you fear your USB cable? by dfox on Tuesday March 01, 2016 @09:44AM (#11202837)
Common implementation of overcurrent protection on USB ports consists of polyfuse on VBUS and feedback pin from this fused VBUS to controller (to detect tripped polyfuse), on some devices such polyfuse is even shared by multiple ports.

In theory, original USB1.1 expected the trip-point to be programmable, but most USB hosts are not implemented that way, because it requires some kind of low-drop high-side power switch that tends to be expensive.

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Re:Should you fear your USB cable? by omgtehlion on Friday March 04, 2016 @02:27AM (#11222486)
Yup, these ICs are low-resistance (low drop) mosfets with some comparators in single package (handles 2 usb ports).

Not very expensive ($.5 a piece), but at scale may become costly.

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