LTC4214-1/LTC4214-2 Negative Low Voltage Hot Swap Controllers FEATURES DESCRIPTIO TM n Allows Safe Board Insertion and Removal from a The LTC 4214 negative voltage Hot Swap controller Live Backplane allows a board to be safely inserted and removed from a n Controls Supplies from 0V to 16V live backplane. Output current is controlled by three stages n Adjustable Analog Current Limit With Circuit of current limiting: a timed circuit breaker, active current Breaker Timer limiting and a fast feedforward path that limits peak n Fast Response Time Limits Peak Fault Current current under worst-case catastrophic fault conditions. n Adjustable Soft-Start Current Limit Adjustable undervoltage and overvoltage detectors dis- n Adjustable Timer with Drain Voltage Accelerated connect the load whenever the input supply exceeds the Response desired operating range. The LTC4214 controls negative n Adjustable Undervoltage/Overvoltage Protection supplies ranging from near zero to 16V. A multifunction n LTC4214-1: Latch Off After Fault timer delays initial start-up and controls the circuit breakers n LTC4214-2: Automatic Retry After Fault response time. This response time is accelerated by n Available in the 10-Pin MSOP Package sensing excessive MOSFET drain voltage, keeping the MOSFET within its safe operating area (SOA). An adjust- U able soft-start circuit controls MOSFET inrush current at APPLICATIO S start-up. A power good status output can enable a power n Hot Board Insertion module at start-up or disable it if the circuit breaker trips. n Electronic Circuit Breaker The LTC4214-1 latches off after a circuit breaker fault times n Negative Power Supply Control out. The LTC4214-2 provides automatic retry after a fault. n Central Office Switching The LTC4214 is available in the 10-pin MSOP package. n High Availability Servers , LTC and LT are registered trademarks of Linear Technology Corporation. n Disk Arrays Hot Swap is a trademark of Linear Technology Corporation. n Optical Networking/Switching n ECL TYPICAL APPLICATIO 5.2V/5A ECL Supply Hot Swap Controller Start-Up Behavior 3.3V EN 2k BSS138 GND GND GATE + 10 470 5V/DIV C LOAD SMAJ7A 100F 100nF 5.2V 1 ECL GND SENSE V IN 0.1F (SHORT PIN) 20mV/DIV LTC4214-1 34k 2 PWRGD 1% 75k 9, 8 7 UV/OV DRAIN V OUT 10 6 32.4k 5V/DIV TIMER GATE IRF7413 1% 3 4 5.6nF SS SENSE 22 V EE 10 0.01 PWRGD 1nF PUSH 5 RESET 5V/DIV 3.3nF 10nF 4214 TA02 4214 TA01 5.2V 421412f 1 U ULTC4214-1/LTC4214-2 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO All Voltages Referred to V (Note 1) EE ORDER PART V ............................................................ 0.3V to 17V IN NUMBER Input/Output Pins (Except SENSE and DRAIN) Voltage ..........0.3V to 17V LTC4214-1CMS TOP VIEW V 1 10 TIMER SENSE Pin Voltage ................................... 0.6V to 17V IN LTC4214-2CMS PWRGD 2 9 UV Current Out of SENSE Pin (20s Pulse)........... 200mA SS 3 8 OV LTC4214-1IMS SENSE 4 7 DRAIN DRAIN Pin Minimum Voltage .............................. 0.3V LTC4214-2IMS V 5 6 GATE EE Current into DRAIN Pin (100s Pulse) ................... 5mA MS PACKAGE MS PART MARKING 10-LEAD PLASTIC MSOP Maximum Junction Temperature .......................... 125C T = 125C, = 160C/W JMAX JA Operating Temperature Range LTABH LTC4214-1C/LTC4214-2C ....................... 0C to 70C LTABK LTC4214-1I/LTC4214-2I ................... 40C to 85C LTABJ Storage Temperature Range ................. 65C to 150C LTABL Lead Temperature (Soldering, 10 sec).................. 300C Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25C. V = 12V, UV = OV = 2.5V unless otherwise noted. (Note 2) A IN SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Supply Voltage l616 V IN I V Supply Current UV = OV = 2.5V l 0.8 2 mA IN IN V V Undervoltage Lockout Coming Out of UVLO (Rising V ) l 5.1 5.6 V LKO IN IN V V Undervoltage Lockout Hysteresis 0.3 V LKH IN V Circuit Breaker Current Limit Voltage V = (V V ) l 44 50 56 mV CB CB SENSE EE V Analog Current Limit Voltage V = (V V ), SS = Open l 60 70 80 mV ACL ACL SENSE EE V Fast Current Limit Voltage V = (V V ) l 150 200 300 mV FCL FCL SENSE EE V SS Voltage After End of SS Timing Cycle 1.6 V SS R SS Output Impedance 73 k SS I SS Pin Current UV = OV = 2.5V, V = V , V = 0V (Sourcing) 22 A SS SENSE EE SS UV = OV = 0V, V = V , V = 1V (Sinking) 14 mA SENSE EE SS V Analog Current Limit Offset Voltage 10 mV OS V +V Ratio (V + V ) to SS Voltage 0.05 V/V ACL OS ACL OS V SS I GATE Pin Output Current V = V , V = 0V (Sourcing) l 30 50 70 A GATE SENSE EE GATE V V = 0.15V, V = 3V (Sinking) 17 mA SENSE EE GATE V V = 0.3V, V = 1V (Sinking) 190 mA SENSE EE GATE V External MOSFET Gate Drive V V l 10 11 12 V GATE GATE EE V Gate High Threshold V = V V for PWRGD Status 2.8 V GATEH GATEH IN GATE V Gate Low Threshold (Before Gate Ramp-Up) 0.5 V GATEL V UV Pin Threshold UV Rising l 2.137 2.25 2.363 V UVHI V UV Pin Hysteresis l 0.22 0.25 0.28 V UVHST V OV Pin Threshold OV Rising l 2.85 3 3.15 V OVHI V OV Pin Hysteresis l 0.12 0.15 0.18 V OVHST 421412f 2 U WWW