I'm using some chipset via USB which allows an input voltage between 4 - 20V
In order to block 12V from injecting to the 5V power circuit I'm using a diode on the 5V supply.
While this works fine with 12V (since the current is low), when I power the chipset with 5V the current is quite high which results that this diode is heating up quite a lot.
Does anyone know any better way to isolate the main input voltage?