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link to page 44 link to page 45 link to page 46 link to page 46 link to page 46 link to page 47 link to page 48 link to page 48 link to page 48 link to page 49 link to page 49 link to page 50 link to page 50 link to page 51 link to page 51 LTC7132 TABLE OF CONTENTS Features ... 1 Device Addressing ..30 Applications .. 1 Responses to VOUT and IIN/IOUT Faults ...30 Typical Application .. 1 Output Overvoltage Fault Response ...31 Description.. 1 Output Undervoltage Response ..31 Table of Contents .. 2 Peak Output Overcurrent Fault Response ...31 Absolute Maximum Ratings .. 4 Responses to Timing Faults ..31 Order Information .. 4 Responses to VIN OV Faults ..32 Pin Configuration .. 4 Responses to OT/UT Faults ...32 Electrical Characteristics ... 5 Internal Overtemperature Fault Response ..32 Typical Performance Characteristics ..11 External Overtemperature and Undertemperature Pin Functions ..15 Fault Response ...32 Block Diagram ...17 Responses to Input Overcurrent and Output Operation...18 Undercurrent Faults ..32 Overview ... 18 Responses to External Faults ..32 Main Control Loop .. 19 Fault Logging ..32 EEPROM ... 19 Bus Timeout Protection ..33 Power-Up and Initialization ...20 Similarity Between PMBus, SMBus and I2C 2-Wire Soft-Start ..20 Interface ...33 Time-Based Sequencing ...21 PMBus Serial Digital Interface ..33 Voltage-Based Sequencing ...21 PMBus Command Summary ..38 Shutdown ...22 PMBus Commands ...38 Light-Load Current Operation ...22 *Data Format ..43 Switching Frequency and Phase ...22 Applications Information ..44 PWM Loop Compensation ..23 Current Limit Programming ..44 Output Voltage Sensing ..23 I ± ± SENSE0 and ISENSE1 Pins ..44 INTVCC/EXTVCC Power ...23 Inductor DCR Sensing ..45 Output Current Sensing and Sub-Mil iohm DCR Inductor Value Calculation ..46 Current Sensing .. 24 Inductor Core Selection ..46 Input Current Sensing ...25 Low Value Resistor Current Sensing ...46 PolyPhase Load Sharing ...25 Slope Compensation and Inductor Peak Current ..47 External/Internal Temperature Sense ..25 Variable Delay Time, Soft-Start and Output Voltage RCONFIG (Resistor Configuration) Pins ..26 Ramping ...48 Fault Detection and Handling ..27 Digital Servo Mode ...48 Status Registers and ALERT Masking ...27 Soft Off (Sequenced Off) ..49 Mapping Faults to FAULT Pins ..29 INTVCC/EXTVCC Power ...49 Power Good Pins ..29 Topside MOSFET Driver Supply (CB, DB) ..50 CRC Protection ...29 Undervoltage Lockout ...50 Serial Interface ...29 CIN and COUT Selection ...51 Communication Protection ...30 Fault INDICATION .. 51 Rev 0 2 For more information www.analog.com Document Outline Features Applications Typical Application Description Table of Contents Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Overview Main Control Loop EEPROM Power-Up and Initialization Soft-Start Time-Based Sequencing Voltage-Based Sequencing Shutdown Light-Load Current Operation Switching Frequency and Phase PWM Loop Compensation Output Voltage Sensing INTVCC/EXTVCC Power Output Current Sensing and Sub-Milliohm DCR Current Sensing Input Current Sensing PolyPhase Load Sharing External/Internal Temperature Sense RCONFIG (Resistor Configuration) Pins Fault Detection and Handling Status Registers and ALERT Masking Mapping Faults to FAULT Pins Power Good Pins CRC Protection Serial Interface Communication Protection Device Addressing Responses to VOUT and IIN/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 Response External Overtemperature and Undertemperature Fault Response Responses to Input Overcurrent and Output Undercurrent Faults 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 ISENSE0± and ISENSE1± Pins Inductor DCR Sensing Inductor Value Calculation Inductor Core Selection Low Value Resistor Current Sensing Slope Compensation and Inductor Peak Current Variable Delay Time, Soft-Start and Output Voltage Ramping Digital Servo Mode Soft Off (Sequenced Off) INTVCC/EXTVCC Power Topside MOSFET Driver Supply (CB, DB) Undervoltage Lockout CIN and COUT Selection Fault INDICATION Open-Drain Pins Phase-Locked Loop and Frequency Synchronization Minimum On-Time Considerations External Temperature Sense Input Current Sense Amplifier External Resistor Configuration Pins (RCONFIG) Voltage Selection Frequency Selection Phase Selection Address Selection Using RCONFIG Efficiency Considerations Thermal Considerations Programmable Loop Compensation Checking Transient Response PolyPhase Configuration PC Board Layout Checklist PC Board Layout Debugging Design Example Additional Design Checks Connecting the USB to I2C/SMBus/PMBus Controller to the LTC7132 in System 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 Output Current and Limits Input Current and Limits Temperature External Temperature Calibration 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 Memory Commands Store/Restore Fault Logging Block Memory Write/Read Typical Applications Package Description Typical Application Related Parts