EVALUATION KIT AVAILABLE MAX6397/MAX6398 Overvoltage Protection Switch/Limiter Controllers Operate Up to 72V General Description Features The MAX6397/MAX6398 are small, high-voltage over- 5.5V to 72V Wide Supply Voltage Range voltage protection circuits. These devices disconnect Overvoltage Protection Controllers Allow User to Size the output load or limit the output voltage during an External n-Channel MOSFETs input overvoltage condition. These devices are ideal for Internal Charge-Pump Circuit Ensures MOSFET applications that must survive high-voltage transients Gate-to-Source Enhancement for Low R DS(ON) such as those found in industrial applications. Performance The MAX6397/MAX6398 monitor the input or output Disconnect or Limit Output from Input During voltages and control an external n-channel MOSFET to Overvoltage Conditions isolate or limit the load from overvoltage transient energy. Adjustable Overvoltage Threshold When the monitored input voltage is below the user- adjustable overvoltage threshold, the external n-channel Thermal-Shutdown Protection MOSFET is turned on by the GATE output. In this mode, Always-On, Low-Current (37A) Linear Regulator the internal charge pump fully enhances the n-channel Sources Up to 100mA (MAX6397) MOSFET with a 10V gate-to-source voltage. Fully Specified from -40C to +125C (T ) J When the input voltage exceeds the overvoltage threshold, Small, Thermally Enhanced 3mm x 3mm TDFN Package the protection can disconnect the load from the input by quickly forcing the GATE output low. In some applications, Ordering Information disconnecting the output from the load is not desirable. In these cases, the protection circuit can be configured to PART TEMP RANGE PIN-PACKAGE act as a voltage limiter where the GATE output sawtooths MAX6397 ATA-T* -40C to +125C 8 TDFN-EP** to limit the voltage to the load. MAX6398ATT-T* -40C to +125C 6 TDFN-EP** The MAX6397 also offers an always-on linear regulator *Replace -T with +T for lead(Pb)-free/RoHS-compliant packages. that is capable of delivering up to 100mA of output current. **EP = Exposed pad. This high-voltage linear regulator consumes only 37A of The MAX6397 linear regulator is offered in four output quiescent current. voltage options and a choice of a 92.5% or 87.5% POK threshold assertions. See the Selector Guide. The regulator is offered with output options of 5V, 3.3V, 2.5V, or 1.8V. An open-drain, power-good output (POK) Selector Guide and Typical Operating Circuit appear at end of data sheet. asserts when the regulator output falls below 92.5% or 87.5% of its nominal voltage. Pin Configurations The MAX6397/MAX6398 include internal thermal- REG OUT GATE GND shutdown protection, disabling the external MOSFET TOP VIEW 8 7 6 5 and linear regulator if the chip reaches overtemperature conditions. The devices operate over a wide 5.5V to *EP 72V supply voltage range, are available in small TDFN packages, and are fully specified from -40C to +125C. MAX6397 Applications Industrial FireWire 1 2 3 4 Notebook Computers IN SHDN SET POK Wall Cube Power Devices TDFN *EXPOSED PAD. CONNECT TO GND. Pin Configurations continued at end of data sheet. FireWire is a registered trademark of Apple Computer, Inc. 19-3668 Rev 6 7/14MAX6397/MAX6398 Overvoltage Protection Switch/Limiter Controllers Operate Up to 72V Absolute Maximum Ratings (All pins referenced to GND, unless otherwise noted.) Continuous Power Dissipation (T = +70C) A IN, GATE, OUT ......................................................-0.3V to +80V 6-Pin TDFN (derate 18.2mW/C above +70C) ........1455mW SHDN .........................................................-0.3V to (V + 0.3V) 8-Pin TDFN (derate 18.2mW/C above +70C) ........1455mW IN GATE to OUT .......................................................... -0.3 to +20V Operating Temperature Range (T ) ................. -40C to +125C A SET, REG, POK ....................................................-0.3V to +12V Junction Temperature ......................................................+150C Maximum Current: Storage Temperature Range ............................ -65C to +150C IN, REG ........................................................................350mA Lead Temperature ...........................................................+300C All Remaining Pins .............................................................50mA 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 = 14V C = 6000pF, C = 4.7F, T = T = -40C to +125C, unless otherwise noted. Typical values are at T = T = +25C.) IN GATE REG A J A J (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage Range V 5.5 72 V IN SHDN = high, no load (MAX6397) 118 140 SHDN = high, (MAX6398) 104 130 Input Supply Current A SHDN = low, no load (MAX6397) 37 45 SHDN = low, (MAX6398) 11 20 IN Undervoltage Lockout V rising, enables GATE 4.66 5 5.50 V IN IN Undervoltage-Lockout V falling, disables GATE 175 mV IN Hysteresis SET Threshold Voltage V With respect to GND 1.181 1.215 1.248 V TH SET Threshold Hysteresis V 4 % HYST SET Input Current I -50 +50 nA SET Startup Response Time t SHDN rising (Note 2) 100 s START GATE rising from GND to V + 8V, OUT GATE Rise Time 1 ms C = 6000pF, OUT = GND GATE SET-to-GATE Propagation t SET rising from V - 100mV to V + 100mV 0.75 s OV TH TH Delay V + V + V + IN IN IN V = V = 6V, R to IN = 1M OUT IN GATE 3.8V 4.2V 4.6V GATE Output High Voltage V V OH V + V + V + IN IN IN V = V V 14V, R to IN = 1M OUT IN IN GATE 8.5V 9.2V 11.5V GATE Output Low Voltage V GATE sinking 20mA, V = GND 0.38 V OL OUT GATE Charge-Pump Current I GATE = GND 75 A GATE GATE-to-OUT Clamp Voltage V 13 18 V CLMP SHDN Logic-High Input Voltage V 1.4 IH SHDN Logic-Low Input Voltage V 0.4 IL V = 2V, SHDN is internally pulled SHDN SHDN Input Pulldown Current 1 A down to GND Thermal Shutdown (Note 3) +150 C Thermal-Shutdown Hysteresis 20 C REGULATOR (MAX6397) I = 1mA 40 48 REG Ground Current I SHDN = GND A GND I = 100mA 60 REG Maxim Integrated 2 www.maximintegrated.com