USB current limiting

Thread Starter


Joined Aug 6, 2021

I am working on circuit that will be powered using 12-24V for various FANS . I would also like to introduce 5VDC modules for the internal electronics but also to provide a USB charge port. What would be a good method to introduce a current limit on the USB ports to insure there is no shorts or high draw that could effect the remaining part of the circuit?


Joined Mar 30, 2018
Most USB outputs are current limited using PTCs or polyfuses. The advantage is that they are self-resetting (once they cool down) such that an overload does not require equipment repair.

You just need to decide how much current your USB ports are to be capable of supply and select an appropriate value PTC.