I’ve been designing a protection circuit for a USB driver and was looking for a solution to protect my source against high capacitive loads or short circuit that might damage my source.
To protect your source against this kind of faults, usually designers refer to it as high side current measurement. The idea is simply based on a comparator with a sense resistor between its input terminals such that when high current occurs, a voltage drop will occur between the inverting and non inverting terminals and hence turn on the comparator. The comparator output can then be used to switch on a MOSFET to control the load and probably isolate in this case.
Many solutions are available in the market like: LTC6101 from National, FAN4101 from Fairchild and TPS2020 from TI.
LTC and FAN both need external sensing resistor unlike TPS2020 which has internal setup that will stabilize the load current to defined value and will shut the load off if a short circuit occurs.
To find more about TPS2020 click here.