LTC4282IUH#PBF Analog Devices

LTC4282 High Current Hot Swap 2 Controller with I C Compatible Monitoring FEATURES DESCRIPTION n Allows Safe Board Insertion Into Live Backplane The LTC 4282 hot swap controller allows a board to be n 12-/16-Bit ADC with 0.7% Total Unadjusted Error safely inserted and removed from a live backplane. Using n Monitors Current, Voltage, Power and Energy one or more external N-channel pass transistors, board n Controls Two Parallel N-Channel MOSFETs for SOA supply voltage and inrush current are ramped up at an 2 Sharing in High Current Applications adjustable rate. An I C interface and onboard ADC allows n Internal EEPROM for Nonvolatile Configuration for monitoring of board current, voltage, power, energy n Wide Operating Voltage Range: 2.9V to 33V and fault status. 2 n I C/SMBus Digital Interface (Coexists with PMBus The device features analog foldback current limiting and Devices) supply monitoring for applications from 2.9V to 33V. n 12V Gate Drive for Lower MOSFET R DS(ON) Dual 12V gate drive allows high power applications to n Programmable Current Limit with 2% Accuracy either share safe operating area across parallel MOSFETs n MOSFET Power Limiting with Current Foldback or support a 2-stage start-up that first charges the load n Continuously Monitors MOSFET Health capacitance followed by enabling a low on-resistance path n Stores Minimum and Maximum Measurements to the load. n Alerts When Alarm Thresholds Exceeded n The LTC4282 is well suited to high power applications Input Overvoltage and Undervoltage Protection n because the precise monitoring capability and accurate Three General Purpose Input/Outputs n current limiting reduce the extremes in which both loads Internal 5% or External Timebases n and power supplies must safely operate. Non-volatile con- 32-Pin 5mm 5mm QFN Package figuration allows for flexibility in the autonomous genera- APPLICATIONS tion of alerts and response to faults. All registered trademarks and trademarks are the property of their respective owners. Patents n Enterprise Servers and Data Storage Systems pending. n Network Routers and Switches n Base Stations n Platform Management TYPICAL APPLICATION 12V, 100A Plug-In Board Application Start-Up Waveforms 0.25m V OUT 12V 12V CONTACT BOUNCE + V DD 100A 10 0.25m 10V/DIV SMCJ15CA 1 1 1 1 2 V 10 GATE 10V/DIV + + + V SENSE2 ADC SENSE1 SENSE1 ADC SENSE2 GATE1 GATE2 50ms DE-BOUNCE DD NC UV V SOURCE NC OV SOURCE 10V/DIV SDAI FB NC SDA SDAO GPIO1(PG) SCL SCL LTC4282 POWER GPIO1 10V/DIV ALERT ALERT GOOD NC ADR0 4282 TA01b GP GPIO2 ADR1 20ms/DIV ADR2 GPIO3 GP ON 12V INTV TIMER WP CLKIN CLKOUT GND CC 4282 TA01 100k NC 4.7F 10nF GND BACKPLANE PLUG-IN BOARD Rev. A 1 Document Feedback For more information www.analog.com CONNECTOR 2 CONNECTOR 1LTC4282 TABLE OF CONTENTS FET Bad Fault ..........................................................21 Features ..................................................... 1 FET Short Fault .......................................................22 Applications ................................................ 1 Power Bad Fault ......................................................22 Typical Application ........................................ 1 Fault Alerts .............................................................22 Description.................................................. 1 Resetting Faults in FAULT_LOG ..............................23 Absolute Maximum Ratings .............................. 3 Reboot ....................................................................23 Order Information .......................................... 3 Data Converters ......................................................23 Electrical Characteristics ................................. 3 Crystal Oscillator/External Clock .............................25 Pin Configuration .......................................... 3 Configuring the GPIO Pins ......................................25 Electrical Characteristics ................................. 4 Supply Transients ...................................................26 Timing Diagram ............................................ 6 Design Example ......................................................26 Typical Performance Characteristics ................... 7 Layout Considerations ............................................28 Pin Functions ............................................... 9 Digital Interface ......................................................29 Functional Diagram ...................................... 11 START and STOP Conditions ..................................29 Operation................................................... 12 2 I C Device Addressing ............................................29 Applications Information ................................ 13 Acknowledge ..........................................................29 Turn-On Sequence ................................................. 13 Write Protocol.........................................................29 Turn-Off Sequence .................................................. 14 Read Protocol .........................................................29 Current Limit Adjustment ........................................ 15 Data Synchronization ..............................................31 Constant Current Start-Up Using GATE R-C Alert Response Protocol .........................................31 Networks ................................................................ 15 EEPROM .................................................................31 Current Limit Stability ............................................. 15 Register Set ............................................... 33 Parasitic MOSFET Oscillations ................................ 15 2 Detailed I C Command Register Descriptions ....... 34 Overcurrent Fault .................................................... 16 Typical Applications ...................................... 46 Advantages of Dual Gate Drivers ............................ 16 Package Description ..................................... 48 Overvoltage Fault .................................................... 17 Revision History .......................................... 49 Undervoltage Fault ..................................................20 Typical Application ....................................... 50 ON/OFF Control .......................................................20 Related Parts .............................................. 50 Rev. A 2 For more information www.analog.com