Datasheet LTC3887, LTC3887-1, LTC3887-2 (Analog Devices) - 3

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TABLE OF CONTENTS
RCONFIG (External Resistor Temperature ..77 Configuration Pins) ... 51 External Temperature Calibration..77 Voltage Selection .. 51 External Temperature Limits ...77 Frequency and Phase Selection Timing ..78 Using RCONFIG ...52 Timing—On Sequence/Ramp ...78 Address Selection Using RCONFIG ...53 Timing—Off Sequence/Ramp ..79 Efficiency Considerations ...53 Precondition for Restart ...80 Checking Transient Response ...54 Fault Response ...81 PC Board Layout Checklist ...55 Fault Responses Al Faults ..81 PC Board Layout Debugging ...57 Fault Responses Input Voltage ...81 Design Example ..58 Fault Responses Output Voltage ...82 Additional Design Checks ...60 Fault Responses Output Current ...85 Connecting the USB to the I2C/SMBus/PMBus Fault Responses IC Temperature ..86 Control er to the LTC3887 In System ..60 Fault Responses External Temperature ...86 LTpowerPlay: An Interactive GUI for Fault Sharing ...88 Digital Power ..62 Fault Sharing Propagation ..88 PMBus Communication and Command Fault Sharing Response ..89 Processing ..62 Scratchpad ...90
PMBus Command Details ...64
Identification ...90 Addressing and Write Protect ...64 Fault Warning and Status ..91 General Configuration Registers ...66 Telemetry ..98 On/Off/Margin ..67 NVM (EEPROM) Memory Commands .. 102 PWM Config ...69 Store/Restore ... 102 Voltage ..71 Fault Logging .. 103 Input Voltage and Limits ...71 Block Memory Write/Read.. 108 Output Voltage and Limits ..72
Typical Applications .. 109
Current .. 74
Package Description ... 114
Input Current Calibration ... 74
Revision History .. 115
Output Current Calibration ...75
Typical Application ... 116
Input Current ..75
Related Parts .. 116
Output Current ..76 Rev. F For more information www.analog.com 3 Document Outline Features Applications Typical Application Description Table of Contents Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Overview Main Control Loop EEPROM (NVM) Power Up and Initialization Soft-Start Sequencing EVENT-Based Sequencing Shutdown Light Load Current Operation Switching Frequency and Phase Output Voltage Sensing Current Sensing PolyPhase Load Sharing External/Internal Temperature Sense RCONFIG (Resistor Configuration) Pins Fault Detection and Handling Internal EEPROM with CRC Protection and ECC Serial Interface Communication Protection Device Addressing Responses to VOUT and IOUT Faults Output Overvoltage Fault Response Output Undervoltage Response Peak Output Overcurrent Fault Response Responses to Timing Faults Responses to VIN OV Faults Responses to OT/UT Faults Internal Overtemperature Fault/Warn Response External Overtemperature and Undertemperature Fault Response Responses to External Faults Fault Logging Bus Timeout Protection Similarity Between PMBus, SMBus and I2C 2-Wire Interface PMBus Serial Digital Interface PMBus Command Summary PMBus Commands *Data Format Applications Information Current Limit Programming ISENSE+ and ISENSE– Pins Low Value Resistor Current Sensing Inductor DCR Current Sensing Slope Compensation and Inductor Peak Current Inductor Value Calculation Inductor Core Selection Power MOSFET and Schottky Diode (Optional) Selection Variable Delay Time, Soft-Start and Output Voltage Ramping Digital Servo Mode Soft Off (Sequenced Off) INTVCC Regulator Topside MOSFET Driver Supply (CB, DB) (LTC3887, LTC3887-2) Undervoltage Lockout CIN and COUT Selection Fault Conditions Open-Drain Pins Phase-Locked Loop and Frequency Synchronization Minimum On-Time Considerations RCONFIG (External Resistor Configuration Pins) Voltage Selection Frequency and Phase Selection Using RCONFIG Address Selection Using RCONFIG Efficiency Considerations Checking Transient Response PC Board Layout Checklist PC Board Layout Debugging Design Example Additional Design Checks Connecting the USB to the I2C/SMBus/PMBus Controller to the LTC3887 In System LTpowerPlay: An Interactive GUI for Digital Power PMBus Communication and Command Processing PMBus Command Details Addressing and Write Protect General Configuration Registers On/Off/Margin PWM Config Voltage Input Voltage and Limits Output Voltage and Limits Current Input Current Calibration Output Current Calibration Input Current Output Current Temperature External Temperature Calibration External Temperature Limits Timing Timing—On Sequence/Ramp Timing—Off Sequence/Ramp Precondition for Restart Fault Response Fault Responses All Faults Fault Responses Input Voltage Fault Responses Output Voltage Fault Responses Output Current Fault Responses IC Temperature Fault Responses External Temperature Fault Sharing Fault Sharing Propagation Fault Sharing Response Scratchpad Identification Fault Warning and Status Telemetry NVM (EEPROM) Memory Commands Store/Restore Fault Logging Block Memory Write/Read Typical Applications Package Description Revision History Typical Application Related Parts