LTC4280 Hot Swap Controller with 2 I C Compatible Monitoring FEATURES DESCRIPTION n Allows Safe Insertion into Live Backplane The LTC 4280 Hot Swap controller allows a board to be n 8-Bit ADC Monitors Current and Voltage safely inserted and removed from a live backplane. Using 2 n I C/SMBus Interface an external N-channel pass transistor, board supply voltage n Wide Operating Voltage Range: 2.9V to 15V and inrush current are ramped up at an adjustable rate. 2 n Adjustable Overcurrent Filter Time An I C interface and onboard ADC allow for monitoring n High Side Drive for External N-Channel MOSFET of load current, voltage and fault status. n No External Gate Capacitor Required The device features adjustable analog foldback current n Input Overvoltage/Undervoltage Protection limit and a FILTER pin which con gures the time spent in n Optional Latchoff or Auto-Retry After Faults 2 overcurrent before declaring a fault. An I C interface may n Alerts Host After Faults con gure the part to latch off or automatically restart after n Inrush Current Limit with Foldback the LTC4280 detects a current limit fault. n Available in 24-Pin 4mm 5mm QFN Package The controller has additional features to interrupt the host when a fault has occurred, notify when output power is APPLICATIONS good, detect insertion of a load card, and power-up either 2 n automatically upon insertion or wait for an I C command Live Board Insertion n to turn on. Electronic Circuit Breakers n Computers, Servers n Platform Management L, LT, LTC, LTM, Linear Technology, the Linear logo and Hot Swap are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION 12V Application with 5A Circuit Breaker Start-Up Waveform 0.005 FDC653N V OUT 12V 12V V + DD 10V/DIV C L 34.8k 30.1k 0.1F 10 CONTACT BOUNCE 1.18k 3.57k INRUSH CURRENT P6KE16A + UV V SENSE SENSE GATE SOURCE DD 2.5A/DIV 3.4k OV FB V SDAO OUT INTV EN CC 10V/DIV SDAI SDA LTC4280 SCL SCL ADIN V 24k GPIO ALERT ALERT (POWERGOOD) INTV CC GPIO 10V/DIV INTV CC ON TIMER FILTER GND 4280 TA02 C = 12000F 50ms/DIV 47nF L 0.1F GND 4280 TA01 BACKPLANE PLUG-IN CARD 4280f 1 CONNECTOR 2 CONNECTOR 1LTC4280 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Notes 1, 2) TOP VIEW Supply Voltage (V ) ................................. 0.3V to 24V DD Supply Voltage (INTV ) ........................... 0.3V to 6.5V CC 24 23 22 21 20 Input Voltages UV 1 19 FB GATE-SOURCE (Note 3) ........................... 0.3V to 5V OV 2 18 GPIO + SENSE , SENSE ................ V 0.3V to V + 0.3V FILTER 3 17 INTV CC DD DD 25 GND 4 16 TIMER SOURCE .................................................... 5V to 24V ON 5 15 ADIN EN, FB, ON, OV, UV ................................ 0.3V to 12V EN 6 14 ADR2 ADR0, ADR1, ADR2, TIMER, SDAO 7 13 ADR1 8 9 10 11 12 ADIN, FILTER .........................0.3V to INTV + 0.3V CC ALERT SCL, SDA, SDAI, SDAO ............. 0.3V to 6.5V UFD PACKAGE Output Voltages 24-LEAD (4mm s 5mm) PLASTIC QFN GATE, GPIO ............................................ 0.3V to 24V T = 125C, = 34C/W JMAX JA EXPOSED PAD (PIN 25) NOT GUARANTEED LOW IMPEDANCE TO GND, Operating Temperature Range ELECTRICAL CONNECTION OPTIONAL LTC4280C ................................................ 0C to 70C LTC4280I..............................................40C to 85C Storage Temperature Range SSOP .................................................65C to 150C QFN ....................................................65C to 125C Lead Temperature (Soldering, 10 sec) SSOP ................................................................300C ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC4280CUFD PBF LTC4280CUFD TRPBF 4280 0C to 70C 24-Lead (4mm 5mm) Plastic QFN LTC4280IUFD PBF LTC4280IUFD TRPBF 4280 24-Lead (4mm 5mm) Plastic QFN 40C to 85C LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC4280CUFD LTC4280CUFD TR 4280 0C to 70C 24-Lead (4mm 5mm) Plastic QFN LTC4280IUFD LTC4280IUFD TR 4280 40C to 85C 24-Lead (4mm 5mm) Plastic QFN Consult LTC Marketing for parts speci ed with wider operating temperature ranges. *The temperature grade is identi ed by a label on the shipping container. For more information on lead free part marking, go to: