An USB isolator aids reduce ground loops and lessens electromagnetic interference (EMI) between the pc as well as linked product.1x GND 3V3 (P2 with two pins 2.54mm) connector may be used to ability externally the WCH CH569 MCU (it is suggested to eliminate the P4/SHUNT in that case It's not required as the 3V3 LDO IC1 is protected in opposition to