DC2024A-A 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 Internal 5% or External Timebases n current limiting reduce the extremes in which both loads 32-Pin 5mm 5mm QFN Package n and power supplies must safely operate. Non-volatile con- AEC-Q100 Qualified for Automotive Applications figuration allows for flexibility in the autonomous genera- APPLICATIONS tion of alerts and response to faults. n All registered trademarks and trademarks are the property of their respective owners. Patents 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 + 100A 10 CONTACT BOUNCE 0.25m V DD 10V/DIV SMCJ15CA 1 1 1 1 2 10 V GATE 10V/DIV + + + V SENSE2 ADC SENSE1 SENSE1 ADC SENSE2 GATE1 GATE2 DD 50ms DE-BOUNCE NC UV V NC OV SOURCE SOURCE 10V/DIV SDAI FB NC SDA SDAO GPIO1(PG) SCL SCL LTC4282 POWER GPIO1 10V/DIV ALERT ALERT GOOD 4282 TA01b NC ADR0 GP GPIO2 20ms/DIV ADR1 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. B 1 Document Feedback For more information www.analog.com CONNECTOR 2 CONNECTOR 1LTC4282 TABLE OF CONTENTS Features ..................................................... 1 FET Bad Fault ..........................................................21 Applications ................................................ 1 FET Short Fault .......................................................22 Typical Application ........................................ 1 Power Bad Fault ......................................................22 Description.................................................. 1 Fault Alerts .............................................................22 Absolute Maximum Ratings .............................. 3 Resetting Faults in FAULT LOG ..............................23 Order Information .......................................... 3 Reboot ....................................................................23 Electrical Characteristics ................................. 3 Data Converters ......................................................23 Pin Configuration .......................................... 3 CLKIN, CLKOUT: Crystal Oscillator/External Clock ..25 Electrical Characteristics ................................. 4 Configuring the GPIO Pins ......................................25 Timing Diagram ............................................ 6 Supply Transients ...................................................26 Typical Performance Characteristics ................... 7 Design Example ......................................................26 Pin Functions ............................................... 9 Layout Considerations ............................................28 Functional Diagram ...................................... 11 Digital Interface ......................................................29 Operation................................................... 12 START and STOP Conditions ..................................29 2 Applications Information ................................ 13 I C Device Addressing ............................................29 Turn-On Sequence ................................................. 13 Acknowledge ..........................................................29 Turn-Off Sequence .................................................. 14 Write Protocol.........................................................29 Current Limit Adjustment ........................................ 15 Read Protocol .........................................................29 Constant Current Start-Up Using GATE R-C Data Synchronization ..............................................31 Networks ................................................................ 15 Alert Response Protocol .........................................31 Current Limit Stability ............................................. 15 EEPROM .................................................................31 Parasitic MOSFET Oscillations ................................ 15 Register Set ............................................... 33 2 Overcurrent Fault .................................................... 16 Detailed I C Command Register Descriptions ....... 34 Advantages of Dual Gate Drivers ............................ 16 Typical Applications ...................................... 46 Overvoltage Fault .................................................... 17 Package Description ..................................... 48 Undervoltage Fault ..................................................20 Revision History .......................................... 49 ON/OFF Control .......................................................20 Typical Application ....................................... 50 Related Parts .............................................. 50 Rev. B 2 For more information www.analog.com