The LTC4222 Hot Swap controller allows two power paths to be safely inserted and removed from a live backplane. Using external N-channel pass transistors, board supply voltages and inrush currents are ramped up at an adjustable rate. An I2C interface and onboard ADC allows for monitoring of current, voltage and fault status for each channel. The device features adjustable, analog, foldback current limit circuits and a Soft-Start circuit that sets the dI/dt of the inrush currents. An I2C interface may configure the part to latch off or automatically restart after the LTC4222 detects a fault on either channel. The controller has additional features to interrupt the host when a fault has occurred, notify when output power is good, detect insertion of a load card and power-up either automatically upon insertion or wait for an I2C command to turn on.
