Current-Regulating Hot-Swap Controller with DualSpeed/BiLevel Fault Protection

The MAX4370 is a circuit-breaker IC designed to offer protection in hot-swap applications using Maxim's DualSpeed/BiLevel™ detection. This controller, designed to reside either on the backplane or on the removable card, is used to protect a system from start-up damage when a card or board is inserted into a rack with the main system power supply turned on. The card's discharged filter capacitors provide a low impedance that can momentarily cause the main power supply to collapse. The MAX4370 prevents this start-up condition by providing inrush current regulation during a programmable start-up period, allowing the system to stabilize safely. In addition, two on-chip comparators provide DualSpeed/BiLevel short-circuit protection and overcurrent protection during normal operation.

The MAX4370 provides protection for a +3V to +12V single supply. An internal charge pump generates the controlled gate drive for an external N-channel MOSFET power switch. The MAX4370 latches the switch off after a fault condition until an external reset signal clears the device. Other features include a status pin to indicate a fault condition, an adjustable overcurrent response time, and a power-on reset comparator.

The MAX4370 is specified for the extended-industrial temperature range (-40°C to +85°C) and is available in an 8-pin SO package.

Applications

* Hot Board Insertion * Solid-State Circuit Breakers

* DualSpeed/BiLevel Protection During Normal Operation

* Inrush Current Regulated at Start-Up

* Resides Either on the Backplane or on the Removable Card

* Programmable Start-Up Period and Response Time

* Allows Safe Board Insertion and Removal from Live Backplane

* Protection for +3V to +12V Single Supplies

* Latched Off After Fault Condition

* Status Output Pin

* Internal Charge Pump Generates Gate Drive for External N-Channel MOSFET