Hot-Swap Controller Ensures Proper Power-Up

Available in an MSOP package, the LTC4212 Hot Swap controller disconnects the power supply if a dc-dc converter fails to enter into regulation within a programmable period. Its Power Good input can be tied directly to a dc-dc converter's PGOOD output or to a power-supply monitor's Reset output. This enables several dc-dc converters to be monitored at the same time for proper power-up and operation. After normal power-up, it can be configured to trip the circuit breaker if any of the converters exit regulation for longer than a programmable delay. An internal high-side switch driver controls the gate of an external N-channel MOSFET for supply voltages from 2.5 to 16.5 V. Two on-chip current comparators provide an enhanced dual-level circuit breaker function by differentiating between slight overcurrent faults or catastrophic short-circuit conditions. The LTC4212 provides a programmable soft-start with inrush current limiting during the start-up period. Also, no external gate is required. Available in a 10-pin MSOP, the LTC4212 can be configured to either latch-off or auto-retry after a fault condition. Pricing starts at $2.55 each in 1000-unit quantities.