LTC4222

FEATURES n Allows Safe Insertion Into a Live Backplane n 10-Bit ADC Monitors Currents and Voltages n I2C/SMBus Interface n Wide Operating Voltage Range: 2.9V to 29V n dI/dt Controlled Soft-Start n High Side Drive for External N-Channel MOSFETs n No External Gate Capacitors Required n Input Overvoltage/Undervoltage Protection n Optional Latchoff or Auto-Retry After Faults n Alert Host After Faults n Inrush Current Limit with Foldback n Available in 32-Pin (5mm × 5mm) QFN and 36-Pin SSOP Packages APPLICATIONS n Live Board Insertion n Electronic Circuit Breakers n Computers, Servers n Platform Management LTC4222 Dual Hot Swap Controller with I2C Compatible Monitoring DESCRIPTION The LTC®4222 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 ins...