LT4356MP-1/LT4356MP-2 Surge Stopper FEATURESDESCRIPTION n Stops High Voltage Surges The LT®4356 surge stopper protects loads from high volt- n Adjustable Output Clamp Voltage age transients. It regulates the output during an overvolt- n Overcurrent Protection age event, such as load dump in automobiles, by control- n Wide Operation Range: 4V to 80V ling the gate of an external N-channel MOSFET. The output n Reverse Input Protection to –60V is limited to a safe value thereby allowing the loads to n Low 7µA Shutdown Current, LT4356-1 continue functioning. The LT4356MP also monitors the n Adjustable Fault Timer voltage drop between the VCC and SNS pins to protect n Controls N-Channel MOSFET against overcurrent faults. An internal amplifier limits the n Shutdown Pin Withstands –60V to 100V current sense voltage to 50mV. In either fault condition, a n Fault Output Indication timer is started inversely proportional to MOSFET stress. n Guaranteed Operation –55°C to 125°C If the timer expires, the FLT pin pulls low to warn of an n Auxiliary Amplifier for Level Detection Comparator or impending power-down. If the condition persists, the Linear Regulator Controller MOSFET is turned off. After a cooldown period, the GATE n Available in 10-Pin MSOP or 16-Pin SO Packages pin pulls up turning on the MOSFET again. The auxiliary amplifier may be used as a voltage detection APPLICATIONS comparator or as a linear regulator controller driving an n external PNP pass transistor. Automotive/Avionic Surge Protection n Hot Swap/Live Insertion Back-to-back FETs can be used in lieu of a Schottky diode n High Side Switch for Battery Powered Systems for reverse input protection, reducing voltage drop and n Intrinsic Safety Applications power loss. A shutdown pin reduces the quiescent current L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and to less than 7µA for the LT4356-1 during shutdown. The No RSENSE and ThinSOT are trademarks of Analog Devices, Inc. All other trademarks are the LT4356-2 differs from the LT4356-1 during shutdown by property of their respective owners. reducing the quiescent current to 60µA and keeping alive the auxiliary amplifier for uses such as an undervoltage lockout or always-on regulator. TYPICAL APPLICATION4A, 12V Overvoltage Output RegulatorOvervoltage Protector Regulates Output at27V During Transient 10mΩ IRLR2908 V V IN OUT 12V 80V INPUT SURGE CTMR = 6.8µF ILOAD = 500mA 10Ω 102k VIN VCC SNS GATE OUT 20V/DIV 383k FB SHDN VCC 4.99k 12V 27V ADJUSTABLE CLAMP IN+ LT4356S DC-DC CONVERTER VOUT 100k 20V/DIV EN SHDN 12V GND UNDERVOLTAGE AOUT GND TMR FLT FAULT 100ms/DIV 4356mp12 TA01b 4356mp12 TA01 0.1µF 4356mp12fc For more information www.linear.com/LT4356MP-1 1