Datasheet LTC3889 (Analog Devices) - 2
| Manufacturer | Analog Devices |
| Description | 60V Dual Output Step-Down Controller with Digital Power System Management |
| Pages / Page | 120 / 2 — TABLE OF CONTENTS Features ... 1. Applications .. 1. Typical Application … |
| File Format / Size | PDF / 2.5 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 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 ...28
Table of Contents .. 2
Responses to Timing Faults ..28
Absolute Maximum Ratings .. 4
Responses to VIN OV Faults ..28
Order Information .. 4
Responses to OT/UT Faults ...28
Pin Configuration .. 4
Internal Overtemperature Fault/Warn Response 28
Electrical Characteristics ... 5
External Overtemperature and
Typical Performance Characteristics ..10
Undertemperature Fault Response ..29
Pin Functions ..13
Responses to External Faults ...29
Block Diagram ...15
Fault Logging ..29
Operation...16
Bus Timeout Protection ..29 Overview ... 16 Similarity Between PMBus, SMBus and I2C Main Control Loop .. 16 2-Wire Interface ..30 EEPROM ... 17 PMBus Serial Digital Interface ..30 CRC Protection .. 17
PMBus Command Summary ..35
Power-Up and Initialization ... 18 PMBus Commands ...35 Soft-Start .. 18
Applications Information ..40
Time-Based Sequencing ... 19 Current Limit Programming ..40 Event-Based Sequencing .. 19 I + – SENSE and ISENSE Pins ...40 Shutdown ... 19 Low Value Resistor Current Sensing ... 41 Light-Load Current Operation ...20 Inductor DCR Current Sensing ..42 PWM Loop Compensation ..20 Slope Compensation and Inductor Peak Current ..43 Switching Frequency and Phase ...20 Inductor Value Calculation ..43 Output Voltage Sensing ..21 Inductor Core Selection ..44 Output Current Sensing ..21 Power MOSFET and Optional Schottky Diode Input Current Sensing ...21 Selection ...44 PolyPhase Load Sharing ...22 CIN and COUT Selection ...45 External/Internal Temperature Sense ..22 Variable Delay Time, Soft-Start and Output Voltage RCONFIG (Resistor Configuration) Pins ..23 Ramping ...45 Fault Handling ...23 Digital Servo Mode ...46 Status Registers and
ALERT
Masking ... 24 Soft Off (Sequenced Off) ..47 Mapping Faults to
FAULT
Pins ..26 DRVCC Regulator ..48 Power Good Pins ..26 Topside MOSFET Driver Supply (CB, DB) ..48 Serial Interface ...26 Undervoltage Lockout ...49 Communication Protection ..26 Fault Indications ...49 Device Addressing ..26 Open-Drain Pins ...50 Rev. 0 2 For more information www.analog.com Document Outline Table of Contents 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 CRC Protection Power-Up and Initialization Soft-Start Time-Based Sequencing Event-Based Sequencing Shutdown Light-Load Current Operation PWM Loop Compensation Switching Frequency and Phase Output Voltage Sensing Output Current Sensing Input Current Sensing PolyPhase Load Sharing External/Internal Temperature Sense RCONFIG (Resistor Configuration) Pins Fault Handling Status Registers and ALERT Masking Mapping Faults to FAULT Pins Power Good Pins 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 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 Optional Schottky Diode Selection CIN and COUT Selection Variable Delay Time, Soft-Start and Output Voltage Ramping Digital Servo Mode Soft Off (Sequenced Off) DRVCC Regulator Topside MOSFET Driver Supply (CB, DB) Undervoltage Lockout Fault Indications Open-Drain Pins Phase-Locked Loop and Frequency Synchronization Minimum On-Time Considerations External Temperature Sense Derating EEPROM Retention at Temperature Input Current Sense Amplifier External Resistor Configuration Pins (RCONFIG) Voltage Selection Frequency Selection Phase Selection Address Selection Using RCONFIG Efficiency 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 Adapter to the LTC3889 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 EEPROM Memory Commands Store/Restore Fault Logging Fault Log Operation Block Memory Write/Read Typical Applications Package Description Typical Application Related Parts
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 ...28
Table of Contents .. 2
Responses to Timing Faults ..28
Absolute Maximum Ratings .. 4
Responses to VIN OV Faults ..28
Order Information .. 4
Responses to OT/UT Faults ...28
Pin Configuration .. 4
Internal Overtemperature Fault/Warn Response 28
Electrical Characteristics ... 5
External Overtemperature and
Typical Performance Characteristics ..10
Undertemperature Fault Response ..29
Pin Functions ..13
Responses to External Faults ...29
Block Diagram ...15
Fault Logging ..29
Operation...16
Bus Timeout Protection ..29 Overview ... 16 Similarity Between PMBus, SMBus and I2C Main Control Loop .. 16 2-Wire Interface ..30 EEPROM ... 17 PMBus Serial Digital Interface ..30 CRC Protection .. 17
PMBus Command Summary ..35
Power-Up and Initialization ... 18 PMBus Commands ...35 Soft-Start .. 18
Applications Information ..40
Time-Based Sequencing ... 19 Current Limit Programming ..40 Event-Based Sequencing .. 19 I + – SENSE and ISENSE Pins ...40 Shutdown ... 19 Low Value Resistor Current Sensing ... 41 Light-Load Current Operation ...20 Inductor DCR Current Sensing ..42 PWM Loop Compensation ..20 Slope Compensation and Inductor Peak Current ..43 Switching Frequency and Phase ...20 Inductor Value Calculation ..43 Output Voltage Sensing ..21 Inductor Core Selection ..44 Output Current Sensing ..21 Power MOSFET and Optional Schottky Diode Input Current Sensing ...21 Selection ...44 PolyPhase Load Sharing ...22 CIN and COUT Selection ...45 External/Internal Temperature Sense ..22 Variable Delay Time, Soft-Start and Output Voltage RCONFIG (Resistor Configuration) Pins ..23 Ramping ...45 Fault Handling ...23 Digital Servo Mode ...46 Status Registers and
ALERT
Masking ... 24 Soft Off (Sequenced Off) ..47 Mapping Faults to
FAULT
Pins ..26 DRVCC Regulator ..48 Power Good Pins ..26 Topside MOSFET Driver Supply (CB, DB) ..48 Serial Interface ...26 Undervoltage Lockout ...49 Communication Protection ..26 Fault Indications ...49 Device Addressing ..26 Open-Drain Pins ...50 Rev. 0 2 For more information www.analog.com Document Outline Table of Contents 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 CRC Protection Power-Up and Initialization Soft-Start Time-Based Sequencing Event-Based Sequencing Shutdown Light-Load Current Operation PWM Loop Compensation Switching Frequency and Phase Output Voltage Sensing Output Current Sensing Input Current Sensing PolyPhase Load Sharing External/Internal Temperature Sense RCONFIG (Resistor Configuration) Pins Fault Handling Status Registers and ALERT Masking Mapping Faults to FAULT Pins Power Good Pins 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 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 Optional Schottky Diode Selection CIN and COUT Selection Variable Delay Time, Soft-Start and Output Voltage Ramping Digital Servo Mode Soft Off (Sequenced Off) DRVCC Regulator Topside MOSFET Driver Supply (CB, DB) Undervoltage Lockout Fault Indications Open-Drain Pins Phase-Locked Loop and Frequency Synchronization Minimum On-Time Considerations External Temperature Sense Derating EEPROM Retention at Temperature Input Current Sense Amplifier External Resistor Configuration Pins (RCONFIG) Voltage Selection Frequency Selection Phase Selection Address Selection Using RCONFIG Efficiency 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 Adapter to the LTC3889 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 EEPROM Memory Commands Store/Restore Fault Logging Fault Log Operation Block Memory Write/Read Typical Applications Package Description Typical Application Related Parts
