The ISO1640-Q1 includes Hot Swap circuitry on Side 2 of the isolator to prevent loading on the I²C bus lines while VCC2 is either unpowered or in the process of being powered on. While VCC2 is below the UVLO threshold, the ISO1640-Q1 bus lines will not load the bus to avoid disrupting or corrupting an active I²C bus. If the isolator is plugged into a live backplane using a staggered connector, where VCC2 and GND2 make connection first followed by the bus lines, the SDA and SCL lines are pre-charged to VCC2 / 2 to minimize the current required to charge the parasitic capacitance of the device. Once the device is fully powered on, the device bus pins become active providing bidirectional, isolated, SCL and SDA lines.