Dual Hot Swap Controller with IC Compatible Monitoring

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 on-board 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.

Applications

* Live Board Insertion

* Electronic Circuit Breakers

* Computers, Servers

* Platform Management

* Allows Safe Insertion Into a Live Backplane

* 10-Bit ADC Monitors Currents and Voltages

* I2C/SMBus Interface

* Wide Operating Voltage Range: 2.9V to 29V

* dI/dt Controlled Soft-Start

* High Side Drive for External N-Channel MOSFETs

* No External Gate Capacitors Required

* Input Overvoltage/Undervoltage Protection

* Optional Latchoff or Auto-Retry After Faults

* Alert Host After Faults

* Inrush Current Limit with Foldback

* Available in 32-Pin (5mm × 5mm) QFN and 36-Pin SSOP Packages