The LTC4215-1/LTC4215-3 Hot Swap™ controllers allow a board to be safely inserted and removed from a live backplane. Using an external N-channel pass transistor, board supply voltage and inrush current are ramped up at an adjustable rate. An I2C interface and onboard ADC allow for monitoring of load current, voltage and fault status. The device features adjustable foldback current limit and a soft-start pin that sets the dI/dt of the inrush current. An I2C interface may configure the part to latch off or automatically restart after the LTC4215-1/LTC4215-3 detect a current limit fault. The controller has additional features to interrupt the host when a fault has occurred, provide three general purpose outputs, 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. The LTC4215-1 has a 20Μs circuit breaker filter for applications that require a fast fault response time. The LTC4215-3 has an extended 420Μs circuit breaker filter for applications where supply transients may exceed 20Μs.
