The LTC4223 positive voltage Hot SwapTM controller allows a board to be safely inserted and removed from a live AMC or MicroTCA backplane. It controls the main 12V supply with an external N-channel MOSFET and the 3.3V auxiliary supply with an integrated switch. The 12V output ramp rate is adjustable and includes inrush current limiting. The 12V output is also protected against short circuit faults with a fast acting current limit and a 5% accurate timed circuit breaker. The 3.3V output includes both soft start and overcurrent protection. The LTC4223 features a current monitor output for the 12V supply, and reports fault and power-good status for both supplies. It also detects card presence and allows independent control of the 12V and auxiliary 3.3V supply outputs. The LTC4223-1 features a latch-off circuit breaker, while the LTC4223-2 provides automatic retry after a fault.