link to page 1 link to page 1 link to page 1 link to page 1 link to page 4 link to page 4 link to page 4 link to page 5 link to page 14 link to page 15 link to page 15 link to page 15 link to page 15 link to page 16 link to page 18 link to page 19 link to page 19 link to page 19 link to page 19 link to page 19 link to page 20 link to page 20 link to page 20 link to page 20 link to page 21 link to page 21 link to page 21 link to page 21 link to page 22 link to page 22 link to page 22 link to page 23 link to page 23 link to page 23 link to page 23 link to page 24 link to page 24 link to page 24 link to page 24 link to page 25 link to page 25 link to page 25 link to page 27 link to page 27 link to page 27 link to page 30 link to page 31 link to page 31 link to page 35 link to page 35 link to page 36 link to page 36 link to page 36 link to page 41 link to page 41 link to page 41 link to page 42 link to page 43 link to page 43 link to page 44 link to page 45 link to page 45 link to page 47 link to page 48 link to page 50 link to page 50 link to page 51 link to page 52 link to page 53 link to page 53 link to page 55 link to page 55 link to page 58 link to page 59 link to page 60 link to page 61 link to page 61 link to page 61 link to page 62 link to page 63 link to page 64 link to page 64 link to page 65 link to page 67 link to page 67 link to page 67 link to page 67 link to page 68 link to page 68 link to page 69 link to page 69 link to page 69 link to page 69 link to page 69 link to page 70 link to page 70 link to page 70 link to page 71 link to page 71 link to page 72 link to page 72 LTC3882 TABLE OF CONTENTSFeatures ...1PMBus Command Summary ... 36Applications ..1 PMBus Commands ..36 Typical Application ..1 Data Formats ...36 Description..1Applications Information ... 41Absolute Maximum Ratings ..4 Efficiency Considerations ..41 Order Information ..4 PWM Frequency and Inductor Selection ...41 Pin Configuration ..4 Power MOSFET Selection ..42 Electrical Characteristics ...5 MOSFET Driver Selection ..43 Block Diagram .. 14 Using PWM Protocols ...43 Test Circuit .. 15 CIN Selection ...44 Timing Diagram .. 15 COUT Selection ...45 Operation.. 15 Feedback Loop Compensation ..45 Overview ...15 PCB Layout Considerations ...47 Main Control Loop ...16 Output Current Sensing ...48 Power-Up and Initialization..18 Output Voltage Sensing ...50 Soft-Start ..19 Soft-Start and Stop ...50 Time-Based Output Sequencing ..19 Time-Based Output Sequencing and Ramping ..51 Output Ramping Control ...19 Voltage-Based Output Sequencing ..52 Voltage-Based Output Sequencing ..19 Using Output Voltage Servo ..53 Output Disable ...19 Using AVP ...53 Minimum Output Disable Times ..20 PWM Frequency Synchronization ...55 Output Short Cycle ..20 PolyPhase Operation and Load Sharing ..55 Light Load Current Operation ..20 External Temperature Sense ...58 Switching Frequency and Phase ...20 Resistor Configuration Pins ..59 PolyPhase Load Sharing ...21 Internal Regulator Outputs ..60 Active Voltage Positioning ...21 IC Junction Temperature ...61 Input Supply Monitoring ...21 Derating EEPROM Retention at Temperature ..61 Output Voltage Sensing and Monitoring ...21 Configuring Open-Drain Pins ..61 Output Current Sensing and Monitoring ...22 PMBus Communication and Command Processing ..62 External and Internal Temperature Sense..22 Status and Fault Log Management ..63 Resistor Configuration Pins ..22 LTpowerPlay – An Interactive Digital Power GUI ...64 Internal EEPROM with ECC and CRC ...23 Interfacing to the DC1613 ..64 Fault Detection ..23 Design Example ...65 Input Supply Faults ...23 PMBus COMMAND DETAILS .. 67 Hardwired PWM Response to VOUT Faults ..23 Addressing and Write Protect ..67 Power Good Indication ..24 PAGE ...67 Hardwired PWM Response to IOUT Faults ...24 PAGE_PLUS_WRITE ...67 Hardwired PWM Response to Temperature Faults ..24 PAGE_PLUS_READ ...68 Hardwired PWM Response to Timing Faults ...24 WRITE_PROTECT ...68 External Faults ...25 MFR_ADDRESS ..69 Fault Handling ...25 MFR_RAIL_ADDRESS ..69 Status Registers and ALERT Masking ...25 General Device Configuration ..69 Mapping Faults to GPIO Pins ...27 PMBUS_REVISION ..69 Other GPIO Uses ...27 CAPABILITY ..69 Fault Logging ...27 On, Off and Margin Control ..70 Factory Default Operation ...30 ON_OFF_CONFIG ...70 Serial Interface ..31 MFR_CONFIG_ALL_LTC3882 ...70 Serial Bus Addressing ...31 OPERATION ...71 Serial Bus Timeout ..35 MFR_RESET ..71 Serial Communication Errors ..35 PWM Configuration ...72 FREQUENCY_SWITCH ...72 Rev. C 2 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Block Diagram Test Circuit Timing Diagram Operation Overview Main Control Loop Power-Up and Initialization Soft-Start Time-Based Output Sequencing Output Ramping Control Voltage-Based Output Sequencing Output Disable Minimum Output Disable Times Output Short Cycle Light Load Current Operation Switching Frequency and Phase PolyPhase Load Sharing Active Voltage Positioning Input Supply Monitoring Output Voltage Sensing and Monitoring Output Current Sensing and Monitoring External and Internal Temperature Sense Resistor Configuration Pins Internal EEPROM with ECC and CRC Fault Detection Input Supply Faults Hardwired PWM Response to VOUT Faults Power Good Indication Hardwired PWM Response to IOUT Faults Hardwired PWM Response to Temperature Faults Hardwired PWM Response to Timing Faults External Faults Fault Handling Status Registers and ALERT Masking Mapping Faults to GPIO Pins Other GPIO Uses Fault Logging Factory Default Operation Serial Interface Serial Bus Addressing Serial Bus Timeout Serial Communication Errors PMBus Command Summary PMBus Commands Data Formats Applications Information Efficiency Considerations PWM Frequency and Inductor Selection Power MOSFET Selection MOSFET Driver Selection Using PWM Protocols CIN Selection COUT Selection Feedback Loop Compensation PCB Layout Considerations Output Current Sensing Output Voltage Sensing Soft-Start and Stop Time-Based Output Sequencing and Ramping Voltage-Based Output Sequencing Using Output Voltage Servo Using AVP PWM Frequency Synchronization PolyPhase Operation and Load Sharing External Temperature Sense Resistor Configuration Pins Internal Regulator Outputs IC Junction Temperature Derating EEPROM Retention at Temperature Configuring Open-Drain Pins PMBus Communication and Command Processing Status and Fault Log Management LTpowerPlay – An Interactive Digital Power GUI Interfacing to the DC1613 Design Example PMBus COMMAND DETAILS Addressing and Write Protect PAGE PAGE_PLUS_WRITE PAGE_PLUS_READ WRITE_PROTECT MFR_ADDRESS MFR_RAIL_ADDRESS General Device Configuration PMBUS_REVISION CAPABILITY On, Off and Margin Control ON_OFF_CONFIG MFR_CONFIG_ALL_LTC3882 OPERATION MFR_RESET PWM Configuration FREQUENCY_SWITCH MFR_PWM_CONFIG_LTC3882 MFR_CHAN_CONFIG_LTC3882 MFR_PWM_MODE_LTC3882 Input Voltage and Limits VIN_ON VIN_OFF VIN_OV_FAULT_LIMIT VIN_UV_WARN_LIMIT Output Voltage and Limits VOUT_MODE VOUT_COMMAND MFR_VOUT_MAX VOUT_MAX MFR_VOUT_AVP VOUT_MARGIN_HIGH VOUT_MARGIN_LOW VOUT_OV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT VOUT_UV_FAULT_LIMIT Output Current and Limits IOUT_CAL_GAIN MFR_IOUT_CAL_GAIN_TC IOUT_OC_FAULT_LIMIT IOUT_OC_WARN_LIMIT Output Timing, Delays, and Ramping MFR_RESTART_DELAY TON_DELAY TON_RISE TON_MAX_FAULT_LIMIT VOUT_TRANSITION_RATE TOFF_DELAY TOFF_FALL TOFF_MAX_WARN_LIMIT External Temperature and Limits MFR_TEMP_1_GAIN MFR_TEMP_1_OFFSET OT_FAULT_LIMIT OT_WARN_LIMIT Status Reporting STATUS_BYTE UT_FAULT_LIMIT STATUS_WORD STATUS_VOUT STATUS_IOUT STATUS_INPUT STATUS_TEMPERATURE STATUS_CML STATUS_MFR_SPECIFIC MFR_PADS_LTC3882 MFR_COMMON MFR_INFO CLEAR_FAULTS Telemetry READ_VIN MFR_VIN_PEAK READ_VOUT MFR_VOUT_PEAK READ_IOUT MFR_IOUT_PEAK READ_POUT READ_TEMPERATURE_1 MFR_TEMPERATURE_1_PEAK READ_TEMPERATURE_2 MFR_TEMPERATURE_2_PEAK READ_DUTY_CYCLE READ_FREQUENCY MFR_CLEAR_PEAKS Fault Response and Communication VIN_OV_FAULT_RESPONSE VOUT_OV_FAULT_RESPONSE VOUT_UV_FAULT_RESPONSE IOUT_OC_FAULT_RESPONSE OT_FAULT_RESPONSE UT_FAULT_RESPONSE MFR_OT_FAULT_RESPONSE TON_MAX_FAULT_RESPONSE MFR_RETRY_DELAY SMBALERT_MASK MFR_GPIO_PROPAGATE_LTC3882 MFR_GPIO_RESPONSE MFR_FAULT_LOG Fault Log Operation MFR_FAULT_LOG_CLEAR EEPROM User Access STORE_USER_ALL RESTORE_USER_ALL MFR_COMPARE_USER_ALL MFR_FAULT_LOG_STORE MFR_EE_xxxx USER_DATA_0x Unit Identification MFR_ID MFR_MODEL MFR_SERIAL MFR_SPECIAL_ID Typical Applications Package Description Revision History Typical Application Related Parts