LTC1422 Hot Swap Controller FEATURES DESCRIPTIO TM n Allows Safe Board Insertion and Removal The LTC 1422 is an 8-pin Hot Swap controller that from a Live Backplane allows a board to be safely inserted and removed from a n System Reset Output with Programmable Delay live backplane. Using an external N-channel pass transis- n Programmable Electronic Circuit Breaker tor, the board supply voltage can be ramped up at a n User-Programmable Supply Voltage Power-Up Rate programmable rate. A high side switch driver controls the n High Side Driver for an External N-Channel FET N-channel gate for supply voltages ranging from 2.7V to n Controls Supply Voltages from 2.7V to 12V 12V. n Undervoltage Lockout A programmable electronic circuit breaker protects n Soft Reset Input against shorts. The RESET output can be used to generate n Glitch Filter on RESET a system reset when the supply voltage falls below a n Available in 8-Pin Narrow PDIP and SO Packages programmable voltage. The ON pin can be used to cycle the board power or to generate a soft reset. U APPLICATIO S The LTC1422 is available in 8-pin PDIP and SO packages. , LTC and LT are registered trademarks of Linear Technology Corporation. n Hot Board Insertion Hot Swap is a trademark of Linear Technology Corporation. n Electronic Circuit Breaker TYPICAL APPLICATIO 5V Hot Swap Q1 R1 0.005 MTB50N06V V V OUT CC + 5V C LOAD R2 R3 10 6.81k 5% 1% C1 8 76 0.1F V SENSE GATE CC 2 5 ON/RESET ON FB R4 LTC1422 2.43k 1 RESET 1% P TIMER GND RESET 34 C2 0.33F GND 1422 TA01 BACKPLANE PLUG-IN CARD 1422fb 1 CONNECTOR 2 CONNECTOR 1 U ULTC1422 ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER I FOR ATIO (Note 1) ORDER PART TOP VIEW Supply Voltage (V ) ........................................... 13.2V CC NUMBER Input Voltage (TIMER, SENSE) ... 0.3V to (V + 0.3V) CC RESET 1 8 V CC Input Voltage (FB, ON)........................... 0.3V to 13.2V ON 2 7 SENSE LTC1422CN8 Output Voltage (RESET) ........................... 0.3V to 20V TIMER 3 6 GATE LTC1422CS8 Output Voltage (GATE) ............................. 0.3V to 20V GND 4 5 FB LTC1422IN8 Operating Temperature Range LTC1422IS8 N8 PACKAGE S8 PACKAGE 8-LEAD PDIP 8-LEAD PLASTIC SO LTC1422C ............................................... 0C to 70C T = 150C, = 130C/W (N) LTC1422I........................................... 40C to 85C JMAX JA S8 PART MARKING T = 150C, = 150C/W (S) JMAX JA Storage Temperature Range ................ 65C to 150C 1422 Lead Temperature (Soldering, 10 sec)................. 300C 1422I 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 = 5V unless otherwise noted. A CC SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS DC Characteristics I V Supply Current ON = V l 0.65 1.00 mA CC CC CC V V Undervoltage Lockout l 2.40 2.47 2.55 V LKO CC V V Undervoltage Lockout Hysteresis 120 mV LKH CC V FB Pin Voltage Threshold l 1.220 1.232 1.244 V FB V FB Pin Threshold Line Regulation 3V V 12V l 0.5 2.5 mV FB CC V FB Pin Voltage Threshold Hysteresis 2.0 mV FBHST V TIMER Pin Voltage Threshold l 1.208 1.232 1.256 V TM V TIMER Pin Threshold Line Regulation 3V V 12V l 215 mV TM CC V TIMER Pin Voltage Threshold Hystersis 45 mV TMHST I TIMER Pin Current Timer On, GND V 1.5V l 2.5 2.0 1.5 A TM TIMER Timer Off, V = 1.5V 10 mA TIMER V Circuit Breaker Trip Voltage V = (V V ) l 44 50 64 mV CB CB CC SENSE I GATE Pin Output Current Charge Pump On, V = GND l 12 10 8 A CP GATE Charge Pump Off, V = V 10 mA GATE CC V External N-Channel Gate Drive V V l 10 12 14 V GATE GATE CC V ON Pin Threshold High l 1.25 1.30 1.35 V ONHI V ON Pin Threshold Low l 1.20 1.23 1.26 V ONLO V ON Pin Hysteresis 80 mV ONHYST V Output Low Voltage RESET, I = 3mA l 0.14 0.4 V OL O I Logic Output Pull-Up Current RESET = GND 12 A PU t Soft Reset Time l 22 30 48 s RST Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. 1422fb 2 U U WWW WU