link to page 27 link to page 27 link to page 27 link to page 27 link to page 28 link to page 28 link to page 28 link to page 28 link to page 28 link to page 28 link to page 29 link to page 29 link to page 29 link to page 29 link to page 29 link to page 29 link to page 29 link to page 30 link to page 33 link to page 33 link to page 38 link to page 39 link to page 39 link to page 39 link to page 40 link to page 41 link to page 42 link to page 42 link to page 43 link to page 43 link to page 43 link to page 44 link to page 44 link to page 45 link to page 45 link to page 46 link to page 1 link to page 1 link to page 1 link to page 1 link to page 2 link to page 4 link to page 4 link to page 4 link to page 5 link to page 10 link to page 14 link to page 16 link to page 17 link to page 17 link to page 17 link to page 18 link to page 18 link to page 19 link to page 19 link to page 20 link to page 20 link to page 21 link to page 21 link to page 22 link to page 22 link to page 22 link to page 22 link to page 22 link to page 23 link to page 23 link to page 24 link to page 25 link to page 26 link to page 26 link to page 26 link to page 26 LTC3883/LTC3883-1 TABLE OF CONTENTS Features ... 1 Responses to VOUT and IOUT Faults ..27 Applications .. 1 Output Overvoltage Fault Response ...27 Typical Application .. 1 Output Undervoltage Response ...27 Description.. 1 Peak Output Overcurrent Fault Response ...27 Table of Contents .. 2 Responses to Timing Faults ..28 Absolute Maximum Ratings .. 4 Responses to VIN OV Faults ..28 Pin Configuration .. 4 Responses to OT/UT Faults ...28 Order Information .. 4 Overtemperature Fault Response—Internal ..28 Electrical Characteristics ... 5 Overtemperature and Undertemperature Typical Performance Characteristics ..10 Fault Response—Externals ...28 Pin Functions ..14 Responses To Input Overcurrent And Output Block Diagram ...16 Undercurrent Faults ..29 Operation...17 Responses to External Faults ...29 Overview ... 17 Fault Logging ..29 Main Control Loop .. 17 Bus Timeout Failure ..29 EEPROM ... 18 Similarity Between PMBus, SMBus and I2C Power Up and Initialization ... 18 2-Wire Interface ..29 Soft-Start .. 19 PMBus Serial Digital Interface ..30 Sequencing ... 19 PMBus Command Summary ..33 Voltage-Based Sequencing ...20 PMBus Commands ...33 Shutdown ...20 *Data Format ..38 Light Load Current Operation ...21 Applications Information ..39 Switching Frequency and Phase ...21 Current Limit Programming ..39 Output Voltage Sensing ..22 I + – SENSE and ISENSE Pins ... 39 Output Current Sensing ..22 Low Value Resistor Current Sensing ...40 Auto Calibration ...22 Inductor DCR Current Sensing .. 41 Accurate DCR Temperature Compensation ..22 Slope Compensation and Inductor Peak Current ..42 Input Current Sensing ...22 Inductor Value Calculation ..42 Load Sharing ..23 Inductor Core Selection ..43 External/Internal Temperature Sense ..23 Power MOSFET and Schottky Diode (Optional) RCONFIG (Resistor Configuration) Pins .. 24 Selection ...43 Fault Detection and Handling ..25 Variable Delay Time, Soft-Start and Output Voltage Internal Memory with CRC and ECC ..26 Ramping ...44 Serial Interface ...26 Digital Servo Mode ...45 Communication Failure ..26 Soft Off (Sequenced Off) ..45 Device Addressing ..26 INTVCC Regulator ..46 Rev. F 2 For more information www.analog.com 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 Power Up and Initialization Soft-Start Sequencing Voltage-Based Sequencing Shutdown Light Load Current Operation Switching Frequency and Phase Output Voltage Sensing Output Current Sensing Auto Calibration Accurate DCR Temperature Compensation Input Current Sensing Load Sharing External/Internal Temperature Sense RCONFIG (Resistor Configuration) Pins Fault Detection and Handling Internal Memory with CRC and ECC Serial Interface Communication Failure 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 Overtemperature Fault Response—Internal Overtemperature and Undertemperature Fault Response—Externals Responses To Input Overcurrent And Output Undercurrent Faults Responses to External Faults Fault Logging Bus Timeout Failure 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) Undervoltage Lockout CIN and COUT Selection Fault Conditions Open-Drain Pins Phase-Locked Loop and Frequency Synchronization Minimum On-Time Considerations Input Current Sense Amplifier RCONFIG (External Resistor Configuration Pins) Voltage Selection Frequency and Phase Selection Using RCONFIG Address Selection Using RCONFIG Efficiency Considerations Checking Transient Response PolyPhase Configuration PC Board Layout Checklist PC Board Layout Debugging Design Example Connecting the USB to I2C/SMBus/PMBus Controller to the LTC3883 In System Inductor DCR Auto Calibration Accurate DCR Temperature Compensation LTpowerPlay: An Interactive GUI for Digital Power PMBus Communication and Command Processing PMBus Command Details Addressing and Write Protect General Configuration COMMANDS On/Off/Margin PWM Configuration Voltage Input Voltage and Limits Output Voltage and Limits Current Output Current Calibration Output Current Input Current Calibration Input 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 Telemetry NVM Memory Commands Store/Restore Fault Logging Block Memory Write/Read Typical Applications Package Description Revision History Typical Application Related Parts