link to page 55 link to page 55 link to page 56 link to page 56 link to page 56 link to page 57 link to page 58 link to page 58 link to page 59 link to page 59 link to page 60 link to page 60 link to page 61 link to page 62 link to page 63 link to page 64 link to page 64 link to page 67 link to page 67 link to page 68 link to page 69 link to page 69 link to page 69 link to page 70 link to page 70 link to page 73 link to page 73 link to page 75 link to page 76 link to page 78 link to page 81 link to page 81 link to page 82 link to page 85 link to page 87 link to page 88 link to page 88 link to page 89 link to page 89 link to page 90 link to page 91 link to page 91 link to page 91 link to page 92 link to page 92 link to page 95 link to page 96 link to page 97 link to page 98 link to page 98 link to page 100 link to page 100 link to page 101 link to page 102 link to page 109 link to page 113 link to page 113 link to page 114 link to page 114 link to page 118 link to page 119 link to page 125 link to page 127 link to page 128 link to page 128 LTC3884/LTC3884-1 TABLE OF CONTENTS Fault Indication ...55 Output Current and Limits ..85 Open-Drain Pins ...55 Input Current and Limits ..87 Phase-Locked Loop and Frequency Temperature ..88 Synchronization ...56 External Temperature Calibration..88 Minimum On-Time Considerations..56 Timing ..89 External Temperature Sense ...57 Timing—On Sequence/Ramp ...89 Input Current Sense Amplifier ...58 Timing—Off Sequence/Ramp ..90 External Resistor Configuration Pins (RCONFIG) ..58 Precondition for Restart ...91 Voltage Selection ..59 Fault Response ...91 Frequency Selection ...59 Fault Responses Al Faults ..91 Phase Selection ..60 Fault Responses Input Voltage ...92 Address Selection Using RCONFIG ...60 Fault Responses Output Voltage ...92 Efficiency Considerations ...61 Fault Responses Output Current ...95 Programmable Loop Compensation ...62 Fault Responses IC Temperature ..96 Checking Transient Response ...63 Fault Responses External Temperature ...97 PolyPhase Configuration ..64 Fault Sharing ...98 Master Slave Operation ..64 Fault Sharing Propagation ..98 PC Board Layout Checklist ...67 Fault Sharing Response .. 100 PC Board Layout Debugging ...67 Scratchpad ... 100 Design Example ..68 Identification ... 101 Additional Design Checks ...69 Fault Warning and Status .. 102 Connecting the USB to I2C/SMBus/PMBus Control er Telemetry .. 109 to the LTC3884 in System ..69 NVM Memory Commands .. 113 LTpowerPlay: An Interactive GUI for Digital Power .70 Store/Restore ... 113 PMBus Communication and Command Processing 70 Fault Log Operation .. 114 PMBus Command Details ...73 Fault Logging .. 114 Addressing and Write Protect ...73 Block Memory Write/Read.. 118 General Configuration Commands ..75 Typical Applications .. 119 On/Off/Margin ..76 Package Description ... 125 PWM Configuration ..78 Revision History .. 127 Voltage ..81 Typical Application ... 128 Input Voltage and Limits ...81 Related Parts .. 128 Output Voltage and Limits ..82 Rev. F For more information www.analog.com 3 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 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 and ECC Serial Interface Communication Protection Device Addressing Responses to VOUT, IIN 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 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 Power MOSFET and Optional Schottky Diode Selection 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 Programmable Loop Compensation Checking Transient Response PolyPhase Configuration Master Slave Operation PC Board Layout Checklist PC Board Layout Debugging Design Example Additional Design Checks Connecting the USB to I2C/SMBus/PMBus Controller to the LTC3884 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 Log Operation Fault Logging Block Memory Write/Read Typical Applications Package Description Revision History Typical Application Related Parts