MAX4370 19-1472 Rev 0 4/99 Current-Regulating Hot-Swap Controller with DualSpeed/BiLevel Fault Protection General Description Features The MAX4370 is a circuit-breaker IC designed to offer DualSpeed/BiLevel Protection During Normal protection in hot-swap applications using Maxims Operation DualSpeed/BiLevel detection. This controller, Inrush Current Regulated at Start-Up designed to reside either on the backplane or on the removable card, is used to protect a system from start- Resides Either on the Backplane or on the up damage when a card or board is inserted into a rack Removable Card with the main system power supply turned on. The cards discharged filter capacitors provide a low Programmable Start-Up Period and Response impedance that can momentarily cause the main power Time supply to collapse. The MAX4370 prevents this start-up Allows Safe Board Insertion and Removal from condition by providing inrush current regulation during Live Backplane a programmable start-up period, allowing the system to stabilize safely. In addition, two on-chip comparators Protection for +3V to +12V Single Supplies provide DualSpeed/BiLevel short-circuit protection and Latched Off After Fault Condition overcurrent protection during normal operation. Status Output Pin The MAX4370 provides protection for a +3V to +12V single supply. An internal charge pump generates the Internal Charge Pump Generates Gate Drive for controlled gate drive for an external N-channel MOS - External N-Channel MOSFET FET 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 Ordering Information indicate a fault condition, an adjustable overcurrent response time, and a power-on reset comparator. PART TEMP. RANGE PIN-PACKAGE The MAX4370 is specified for the extended-industrial MAX4370ESA -40C to +85C 8 SO temperature range (-40C to +85C) and is available in an 8-pin SO package. Pin Configuration appears at end of data sheet. Applications Hot Board Insertion Solid-State Circuit Breaker Typical Operating Circuit BACKPLANE REMOVABLE CARD M1 R SENSE N V CC V OUT C BOARD V VSEN GATE IN STAT STAT GND MAX4370 ON ON CSPD CTIM GND C C SPD TIM DualSpeed/BiLevel is a trademark of Maxim Integrated Products. Pg Maxim Integrated Products 1 For free samples & the latest literature: Current-Regulating Hot-Swap Controller with DualSpeed/BiLevel Fault Protection ABSOLUTE MAXIMUM RATINGS V to GND...........................................................................+15V Current into Any Other Pin................................................50mA IN STAT to GND..........................................................-0.3V to +14V Continuous Power Dissipation (T = +70C) A GATE to GND ..............................................-0.3V to (V + 8.5V) SO (derate 5.9mW/C above +70C)........................... 471mW IN ON to GND (Note 1) ................................................. -1V to +14V Operating Temperature Range ...........................-40C to +85C CSPD to GND.............-0.3V to the lower of (V + 0.3V) or +12V Storage Temperature Range .............................-65C to +150C IN VSEN, CTIM to GND ....................................-0.3V to (V + 0.3V) Lead Temperature (soldering, 10sec) ............................ +300C IN Current into ON...................................................................2mA Note 1: ON can be pulled below ground. Limiting the current to 2mA ensures that this pin is never lower than about -0.8V. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = +2.7V to +13.2V, T = -40C to +85C, unless otherwise noted. Typical values are at V = +5V and T = +25C.) (Note 2) IN A IN A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWER SUPPLIES Input Voltage Range V 2.7 13.2 V IN Supply Current I ON = V 0.6 1 mA Q IN CURRENT CONTROL T = +25C 45 50 55 Slow Comparator A V V - V mV SC,TH IN SEN Threshold TA = TMIN to TMAX 43.5 56 CSPD = floating 10 20 40 s Slow Comparator Response t CSPD Time 100nF on CSPD to GND 10 20 40 ms Fast Comparator Threshold V V - VSEN 180 200 220 mV FC,TH IN Fast Comparator Response 10mV overdrive, from overload condition to GATE t 460 ns FCD Time discharging VSEN Input Bias Current I VSEN = V 0.2 10 A B,VSEN IN MOSFET DRIVER 100nF on CTIM 21 31 41 ms Start-Up Period t START (Note 3) CTIM = floating 5.5 s Gate Charge Current I V = V (Note 4) 100 A GATE GATE IN Time from current overload to V < 0.1V, GATE Turn-Off Time t C = 1000pF to GND (triggered by the fast 60 s OFF GATE comparator during normal operation) During start-up (current regulation provided by 80 fast comparator) Gate Discharge Current I A GATE,DIS During turn-off, triggered by a fault in normal 75 225 550 operation or ON falling edge Measured with respect to V voltage at which IN Maximum Gate Voltage 6.7 7.5 V internal clamp circuitry is triggered V 5V 5 IN Minimum Gate Drive Voltage I = 8.5A, measured above V V GATE IN V 2.7V 2.7 IN Start-up is initiated only if V is less than this GATE Gate Overvoltage Threshold 0.1 V voltage 2 MAX4370