LT4356-1/LT4356-2 Surge Stopper FEATURES DESCRIPTION n Stops High Voltage Surges The LT 4356 surge stopper protects loads from high voltage n Adjustable Output Clamp Voltage transients. It regulates the output during an overvoltage n Overcurrent Protection event, such as load dump in automobiles, by controlling n Wide Operation Range: 4V to 80V the gate of an external N-channel MOSFET. The output is n Reverse Input Protection to 60V limited to a safe value thereby allowing the loads to con- n Low 7A Shutdown Current (LT4356-1) tinue functioning. The LT4356 also monitors the voltage n Auxiliary Amplifier for Level Detection Comparator drop between the V and SNS pins to protect against CC or Linear Regulator Controller (LT4356-2) overcurrent faults. An internal amplifier limits the current n Adjustable Fault Timer sense voltage to 50mV. In either fault condition, a timer n Controls N-channel MOSFET is started inversely proportional to MOSFET stress. If the n Shutdown Pin Withstands 60V to 100V timer expires, the FLT pin pulls low to warn of an impend- n Fault Output Indication ing power down. If the condition persists, the MOSFET is n Guaranteed Operation to 125C turned off. After a cool down period, the GATE pin pulls n Available in (4mm 3mm) 12-Pin DFN, up turning on the MOSFET again. 10-Pin MSOP or 16-Pin SO Packages The auxiliary amplifier may be used as a voltage detection comparator or as a linear regulator controller driving an external PNP pass transistor. APPLICATIONS n Back-to-back FETs can be used in lieu of a Schottky diode Automotive/Avionic Surge Protection n for reverse input protection, reducing voltage drop and Hot Swap/Live Insertion n power loss. A shutdown pin reduces the quiescent current High Side Switch for Battery Powered Systems n to less than 7A for the LT4356-1 during shutdown. The Intrinsic Safety Applications LT4356-2 differs from the LT4356-1 during shutdown by All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including XXXXX, XXXXX. reducing the quiescent current to 60A and keeping alive the auxiliary amplifier for uses such as an undervoltage lockout or always-on regulator. TYPICAL APPLICATION 4A, 12V Overvoltage Output Regulator Overvoltage Protector Regulates Output at 27V During Transient 10m IRLR2908 V OUT V IN 12V C = 6.8F 80V INPUT SURGE TMR I = 500mA LOAD 10 102k V IN V SNS GATE OUT CC 20V/DIV 383k FB V CC SHDN 4.99k 12V DC-DC 27V ADJUSTABLE CLAMP + IN LT4356DE CONVERTER V OUT 20V/DIV 100k EN SHDN 12V GND UNDERVOLTAGE A FLT FAULT OUT GND TMR 4356 TA01b 100ms/DIV 4356 TA01 0.1F Rev. C 1 Document Feedback For more information www.analog.comLT4356-1/LT4356-2 ABSOLUTE MAXIMUM RATINGS (Notes 1 and 2) V , SHDN ................................................ 60V to 100V Storage Temperature Range CC SNS ............................. V 30V or 60V to V + 0.3V DE12 .................................................. 65C to 125C CC CC OUT, A , FLT, EN ..................................... 0.3V to 80V MS, SO .............................................. 65C to 150C OUT GATE (Note 3) .................................0.3V to V + 10V Lead Temperature (Soldering, 10 sec) OUT + FB, TMR, IN ................................................ 0.3V to 6V MS, SO ............................................................. 300C + A , EN, FLT, IN ..................................................3mA OUT Operating Temperature Range LT4356C ................................................... 0C to 70C LT4356I ................................................ 40C to 85C LT4356H ............................................ 40C to 125C PIN CONFIGURATION TOP VIEW TOP VIEW + TMR 1 16 IN + TMR 1 12 IN FB 2 15 NC TOP VIEW FB 2 11 A OUT NC 3 14 A OUT 10 TMR FB 1 OUT 3 10 GND 9 GND OUT 2 OUT 4 13 NC 13 8 EN GATE 3 GATE 4 9 EN GATE 5 12 GND 7 FLT SNS 4 6 SHDN SNS 5 8 FLT V 5 CC NC 6 11 EN MS PACKAGE V 6 7 SHDN CC SNS 7 10 FLT 10-LEAD PLASTIC MSOP V 8 9 SHDN CC T = 125C, = 120C/W JMAX JA DE PACKAGE 12-LEAD (4mm 3mm) PLASTIC DFN S PACKAGE T = 125C, = 43C/W JMAX JA 16-LEAD PLASTIC SO EXPOSED PAD (PIN 13) PCB GND CONNECTION OPTIONAL T = 150C, = 100C/W JMAX JA Rev. C 2 For more information www.analog.com