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

HerstellerAnalog Devices
BeschreibungDual Output PolyPhase Step-Down DC/DC Controller with Digital Power System Management
Seiten / Seite116 / 2 — TABLE OF CONTENTS Features ... 1. Applications .. 1. Typical Application …
RevisionF
Dateiformat / GrößePDF / 3.7 Mb
DokumentenspracheEnglisch

TABLE OF CONTENTS Features ... 1. Applications .. 1. Typical Application .. 1. Description.. 1. Table of Contents .. 2

TABLE OF CONTENTS Features .. 1 Applications . 1 Typical Application . 1 Description. 1 Table of Contents . 2

Modelllinie für dieses Datenblatt

Textversion des Dokuments

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 5 link to page 6 link to page 10 link to page 13 link to page 15 link to page 16 link to page 16 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 21 link to page 22 link to page 22 link to page 23 link to page 24 link to page 25 link to page 25 link to page 25 link to page 25 link to page 25 link to page 26 link to page 26 link to page 26 link to page 27 link to page 27 link to page 27 link to page 27 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 29 link to page 34 link to page 34 link to page 39 link to page 40 link to page 40 link to page 40 link to page 41 link to page 42 link to page 43 link to page 43 link to page 44 link to page 44 link to page 44 link to page 45 link to page 45 link to page 46 link to page 46 link to page 47 link to page 47 link to page 47 link to page 48 link to page 48 link to page 49 link to page 49 link to page 50 link to page 51 LTC3887/LTC3887-1/ LTC3887-2
TABLE OF CONTENTS Features ... 1
Responses to OT/UT Faults ...27
Applications .. 1
Internal Overtemperature Fault/Warn
Typical Application .. 1
Response ...27
Description.. 1
External Overtemperature and Undertemperature
Table of Contents .. 2
Fault Response ...27
Absolute Maximum Ratings .. 4
Responses to External Faults ...28
Pin Configuration .. 4
Fault Logging ..28
Order Information .. 5
Bus Timeout Protection ..28
Electrical Characteristics ... 6
Similarity Between PMBus, SMBus and I2C
Typical Performance Characteristics ..10
2-Wire Interface ..28
Pin Functions ..13
PMBus Serial Digital Interface ..29
Block Diagram ...15 PMBus Command Summary ..34 Operation...16
PMBus Commands ...34 Overview ... 16 *Data Format ..39 Main Control Loop .. 17
Applications Information ..40
EEPROM (NVM) .. 17 Current Limit Programming ..40 Power Up and Initialization ... 18 I + – SENSE and ISENSE Pins ...40 Soft-Start .. 18 Low Value Resistor Current Sensing ... 41 Sequencing ... 19 Inductor DCR Current Sensing ..42 EVENT-Based Sequencing .. 19 Slope Compensation and Inductor Peak Current ..43 Shutdown ...20 Inductor Value Calculation ..43 Light Load Current Operation ...20 Inductor Core Selection ..44 Switching Frequency and Phase ...21 Power MOSFET and Schottky Diode (Optional) Output Voltage Sensing ..21 Selection ...44 Current Sensing ..21 Variable Delay Time, Soft-Start and Output Voltage PolyPhase Load Sharing ...22 Ramping ...45 External/Internal Temperature Sense ..22 Digital Servo Mode ...46 RCONFIG (Resistor Configuration) Pins ..23 Soft Off (Sequenced Off) ..46 Fault Detection and Handling .. 24 INTVCC Regulator ..47 Internal EEPROM with CRC Protection Topside MOSFET Driver Supply (CB, DB) (LTC3887, and ECC ..25 LTC3887-2) ...47 Serial Interface ...25 Undervoltage Lockout ...48 Communication Protection ..25 CIN and COUT Selection ...48 Device Addressing ..25 Fault Conditions ..49 Responses to VOUT and IOUT Faults ..26 Open-Drain Pins ...49 Output Overvoltage Fault Response ...26 Phase-Locked Loop and Frequency Synchronization 50 Output Undervoltage Response ...26 Minimum On-Time Considerations.. 51 Peak Output Overcurrent Fault Response ...27 Responses to Timing Faults ..27 Responses to VIN OV Faults ..27 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 (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