LTC4252-1/LTC4252-2 LTC4252A-1/LTC4252A-2 Negative Voltage Hot Swap Controllers Fea T Descrip T TM n Allows Safe Board Insertion and Removal from a The LTC 4252 negative voltage Hot Swap controller Live 48V Backplane allows a board to be safely inserted and removed from a n Floating Topology Permits Very High Voltage Operation live backplane. Output current is controlled by three stages n Current Limit With Circuit Breaker Timer of current limiting: a timed circuit breaker, active current n Fast Response Time Limits Peak Fault Current limiting and a fast feedforward path that limits peak current n Programmable Soft-Start Current Limit under worst-case catastrophic fault conditions. n Programmable Timer with Drain Voltage Adjustable undervoltage and overvoltage detectors dis- Accelerated Response connect the load whenever the input supply exceeds the n 1% Undervoltage/Overvoltage Threshold Accuracy desired operating range. The LTC4252s supply input is (LTC4252A) shunt regulated, allowing safe operation with very high Adjustable Undervoltage/Overvoltage Protection supply voltages. A multifunction timer delays initial start- LTC4252-1/LTC4252A-1: Latch Off After Fault up and controls the circuit breakers response time. The LTC4252-2/LTC4252A-2: Automatic Retry After Fault circuit breakers response time is accelerated by sensing Available in 8-Pin and 10-Pin MSOP Packages excessive MOSFET drain voltage, keeping the MOSFET within its safe operating area (SOA). An adjustable soft- a T start circuit controls MOSFET inrush current at start-up. n Hot Board Insertion The LTC4252-1/LTC4252A-1 latch off after a circuit breaker n Electronic Circuit Breaker fault times out. The LTC4252-2/LTC4252A-2 provide au- n 48V Distributed Power Systems tomatic retry after a fault. The LTC4252A-1/LTC4252A-2 n Negative Power Supply Control feature tight 1% undervoltage/overvoltage threshold n Central Office Switching accuracy. The LTC4252 is available in either an 8-pin n High Availability Servers or 10-pin MSOP, while the LTC4252A is available in the n ATCA 10-pin MSOP. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Hot Swap is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Typical a T Start-Up Behavior 48V/2.5A Hot Swap Controller 48RTN R IN + C L 3 1.8k IN SERIES 100F GATE 1/4W EACH 5V/DIV C R3 LOAD IN D IN 48RTN ** 1F 5.1k DDZ13B (SHORT PIN) V R1 IN EN SENSE 402k LTC4252-1 V OUT * 2.5A/DIV 1% OV PWRGD R 1M D UV DRAIN R2 Q1 TIMER GATE V 32.4k OUT IRF530S 20V/DIV C 1% T SS SENSE V EE 0.33F R R C S C1 C SS 10 0.02 10nF 68nF C C 18nF PWRGD 10V/DIV 425212 TA01 48V * M0C207 RECOMMENDED FOR HARSH ENVIRONMENTS 1ms/DIV 425212 TA01a **DIODES, INC 425212fe 1 For more information www.linear.com/LTC4252-1 ion pplica ions pplica ion uresLTC4252-1/LTC4252-2 LTC4252A-1/LTC4252A-2 a Te Maxi Mu M r a T All Voltages Referred to V (Note 1) EE Current into V (100s Pulse) .............................100mA Operating Temperature Range IN V , DRAIN Pin Minimum Voltage ........................ 0.3V LTC4252-1C/LTC4252-2C IN Input/Output Pins LTC4252A-1C/LTC4252A-2C .................... 0C to 70C (Except SENSE and DRAIN) Voltage .......... 0.3V to 16V LTC4252-1I/LTC4252-2I SENSE Pin Voltage .................................... 0.6V to 16V LTC4252A-1I/LTC4252A-2I ................. 40C to 85C Current Out of SENSE Pin (20s Pulse) .......... 200mA Storage Temperature Range .................. 65C to 150C Current into DRAIN Pin (100s Pulse) ...................20mA Lead Temperature (Soldering, 10 sec) ...................300C Maximum Junction Temperature .......................... 125C p in c F T TOP VIEW TOP VIEW V 1 10 TIMER IN V 1 8 TIMER IN PWRGD 2 9 UV SS 2 7 UV/OV SS 3 8 OV SENSE 3 6 DRAIN SENSE 4 7 DRAIN V 4 5 GATE EE V 5 6 GATE EE MS8 PACKAGE MS PACKAGE 8-LEAD PLASTIC MSOP 10-LEAD PLASTIC MSOP T = 125C, = 160C/W JMAX JA T = 125C, = 160C/W JMAX JA o r Der i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC4252-1CMS8 PBF LTC4252-1CMS8 TRPBF LTWM 8-Lead Plastic MSOP 0C to 70C LTC4252-2CMS8 PBF LTC4252-2CMS8 TRPBF LTWP 8-Lead Plastic MSOP 0C to 70C LTC4252-1IMS8 PBF LTC4252-1IMS8 TRPBF LTRQ 8-Lead Plastic MSOP 40C to 85C LTC4252-2IMS8 PBF LTC4252-2IMS8 TRPBF LTRR 8-Lead Plastic MSOP 40C to 85C LTC4252-1CMS PBF LTC4252-1CMS TRPBF LTWN 10-Lead Plastic MSOP 0C to 70C LTC4252-2CMS PBF LTC4252-2CMS TRPBF LTWQ 10-Lead Plastic MSOP 0C to 70C LTC4252A-1CMS PBF LTC4252A-1CMS TRPBF LTAFX 10-Lead Plastic MSOP 0C to 70C LTC4252A-2CMS PBF LTC4252A-2CMS TRPBF LTAGE 10-Lead Plastic MSOP 0C to 70C LTC4252-1IMS PBF LTC4252-1IMS TRPBF LTRS 10-Lead Plastic MSOP 40C to 85C LTC4252-2IMS PBF LTC4252-2IMS TRPBF LTRT 10-Lead Plastic MSOP 40C to 85C LTC4252A-1IMS PBF LTC4252A-1IMS TRPBF LTAFY 10-Lead Plastic MSOP 40C to 85C LTC4252A-2IMS PBF LTC4252A-2IMS TRPBF LTAGF 10-Lead Plastic MSOP 40C to 85C Consult LTC Marketing for parts specified with wider operating temperature ranges. For more information on lead free part marking, go to: