Datasheet LTC3880, LTC3880-1 (Analog Devices) - 2
| Manufacturer | Analog Devices |
| Description | Dual Output PolyPhase Step-Down DC/DC Controller with Digital Power System Management |
| Pages / Page | 118 / 2 — TABLE OF CONTENTS Features ... 1. Applications .. 1. Typical Application … |
| Revision | H |
| File Format / Size | PDF / 1.8 Mb |
| Document Language | English |
TABLE OF CONTENTS Features ... 1. Applications .. 1. Typical Application .. 1. Description.. 1. Table of Contents .. 2
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TABLE OF CONTENTS Features ... 1
Responses to Timing Faults ..29
Applications .. 1
Responses to VIN OV Faults ..29
Typical Application .. 1
Responses to OT/UT Faults ...29
Description.. 1
Overtemperature Fault Response—Internal ..29
Table of Contents .. 2
Overtemperature and Undertemperature
Absolute Maximum Ratings .. 4
Fault Response—Externals ...29
Pin Configuration .. 4
Responses to External Faults ...29
Order Information .. 4
Bus Timeout Failure ..30
Electrical Characteristics ... 5
Similarity Between PMBus, SMBus and I2C
Typical Performance Characteristics ..11
2-Wire Interface ..30
Pin Functions ..15
PMBus Serial Digital Interface ..31
Block Diagram ...17 PMBus Command Summary ..34 Operation...18
PMBus Commands ...34 Overview ... 18 *Data Format ..39 Main Control Loop .. 18
Applications Information ..40
EEPROM ... 19 Current Limit Programming ..40 Power Up and Initialization ...20 I + – SENSE and ISENSE Pins ...40 Soft-Start ..20 Low Value Resistor Current Sensing ... 41 Sequencing ...21 Inductor DCR Current Sensing ..42 Voltage-Based Sequencing ...21 Slope Compensation and Inductor Peak Current ..43 Shutdown ...21 Inductor Value Calculation ..43 Light Load Current Operation ...22 Inductor Core Selection ..44 Switching Frequency and Phase ...22 Power MOSFET and Schottky Diode (Optional) Output Voltage Sensing ..23 Selection ...44 Current Sensing ..23 Variable Delay Time, Soft-Start and Output Voltage Load Sharing .. 24 Ramping ...45 External/Internal Temperature Sense .. 24 Digital Servo Mode ...46 RCONFIG (Resistor Configuration) Pins ..25 Soft Off (Sequenced Off) ..46 Fault Detection and Handling ..25 INTVCC Regulator ..47 Internal Memory with CRC and ECC ...26 Topside MOSFET Driver Supply (CB, DB) ..48 Serial Interface ...27 Undervoltage Lockout ...48 Communication Failure ..27 CIN and COUT Selection ...48 Device Addressing ..27 Fault Conditions ..49 Responses to VOUT and IOUT Faults ..28 Open-Drain Pins ...50 Output Overvoltage Fault Response ...28 Phase-Locked Loop and Frequency Output Undervoltage Response ...28 Synchronization ..50 Peak Output Overcurrent Fault Response ...28 Minimum On-Time Considerations.. 51 Rev. H 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 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 External Faults 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 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 Connecting the USB to the I2C/SMBus/PMBus Controller to the LTC3880 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 Memory Commands Store/Restore Fault Log Operation Fault Logging Block Memory Write/Read Typical Applications Package Description Revision History Typical Application Related Parts
TABLE OF CONTENTS Features ... 1
Responses to Timing Faults ..29
Applications .. 1
Responses to VIN OV Faults ..29
Typical Application .. 1
Responses to OT/UT Faults ...29
Description.. 1
Overtemperature Fault Response—Internal ..29
Table of Contents .. 2
Overtemperature and Undertemperature
Absolute Maximum Ratings .. 4
Fault Response—Externals ...29
Pin Configuration .. 4
Responses to External Faults ...29
Order Information .. 4
Bus Timeout Failure ..30
Electrical Characteristics ... 5
Similarity Between PMBus, SMBus and I2C
Typical Performance Characteristics ..11
2-Wire Interface ..30
Pin Functions ..15
PMBus Serial Digital Interface ..31
Block Diagram ...17 PMBus Command Summary ..34 Operation...18
PMBus Commands ...34 Overview ... 18 *Data Format ..39 Main Control Loop .. 18
Applications Information ..40
EEPROM ... 19 Current Limit Programming ..40 Power Up and Initialization ...20 I + – SENSE and ISENSE Pins ...40 Soft-Start ..20 Low Value Resistor Current Sensing ... 41 Sequencing ...21 Inductor DCR Current Sensing ..42 Voltage-Based Sequencing ...21 Slope Compensation and Inductor Peak Current ..43 Shutdown ...21 Inductor Value Calculation ..43 Light Load Current Operation ...22 Inductor Core Selection ..44 Switching Frequency and Phase ...22 Power MOSFET and Schottky Diode (Optional) Output Voltage Sensing ..23 Selection ...44 Current Sensing ..23 Variable Delay Time, Soft-Start and Output Voltage Load Sharing .. 24 Ramping ...45 External/Internal Temperature Sense .. 24 Digital Servo Mode ...46 RCONFIG (Resistor Configuration) Pins ..25 Soft Off (Sequenced Off) ..46 Fault Detection and Handling ..25 INTVCC Regulator ..47 Internal Memory with CRC and ECC ...26 Topside MOSFET Driver Supply (CB, DB) ..48 Serial Interface ...27 Undervoltage Lockout ...48 Communication Failure ..27 CIN and COUT Selection ...48 Device Addressing ..27 Fault Conditions ..49 Responses to VOUT and IOUT Faults ..28 Open-Drain Pins ...50 Output Overvoltage Fault Response ...28 Phase-Locked Loop and Frequency Output Undervoltage Response ...28 Synchronization ..50 Peak Output Overcurrent Fault Response ...28 Minimum On-Time Considerations.. 51 Rev. H 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 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 External Faults 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 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 Connecting the USB to the I2C/SMBus/PMBus Controller to the LTC3880 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 Memory Commands Store/Restore Fault Log Operation Fault Logging Block Memory Write/Read Typical Applications Package Description Revision History Typical Application Related Parts
