Datasheet LTC3887, LTC3887-1, LTC3887-2 (Analog Devices) - 35

link to page 79 link to page 70 link to page 71 link to page 71 link to page 75 link to page 72 link to page 74 link to page 73 link to page 72 link to page 72 link to page 82 link to page 76 link to page 85 link to page 76 link to page 77 link to page 87 link to page 78 link to page 78 link to page 87 link to page 71 link to page 81 link to page 71 link to page 75 LTC3887/LTC3887-1/ LTC3887-2
PMBus COMMAND SUMMARY CMD DATA DEFAULT COMMAND NAME CODE DESCRIPTION TYPE PAGED FORMAT UNITS NVM VALUE PAGE
VOUT_TRANSITION_RATE 0X27 Rate the output changes when VOUT R/W Word Y L11 V/ms Y 0.25 79 commanded to a new value. AA00 FREQUENCY_SWITCH 0x33 Switching frequency of the controller. R/W Word N L11 kHz Y 350 70 0xFABC VIN_ON 0x35 Input voltage at which the unit should start R/W Word N L11 V Y 6.5 71 power conversion. 0xCB40 VIN_OFF 0x36 Input voltage at which the unit should stop R/W Word N L11 V Y 6.0 71 power conversion. 0xCB00 IOUT_CAL_GAIN 0x38 The ratio of the voltage at the current sense pins R/W Word Y L11 mΩ Y 1.8 75 to the sensed current. For devices using a fixed 0xBB9A current sense resistor, it is the resistance value in mΩ. VOUT_OV_FAULT_LIMIT 0x40 Output overvoltage fault limit. R/W Word Y L16 V Y 1.1 72 0x119A VOUT_OV_FAULT_ 0x41 Action to be taken by the device when an output R/W Byte Y Reg Y 0xB8 74 RESPONSE overvoltage fault is detected. VOUT_OV_WARN_LIMIT 0x42 Output overvoltage warning limit. R/W Word Y L16 V Y 1.075 73 0x1133 VOUT_UV_WARN_LIMIT 0x43 Output undervoltage warning limit. R/W Word Y L16 V Y 0.925 72 0x0ECD VOUT_UV_FAULT_LIMIT 0x44 Output undervoltage fault limit. R/W Word Y L16 V Y 0.9 72 0x0E66 VOUT_UV_FAULT_ 0x45 Action to be taken by the device when an output R/W Byte Y Reg Y 0xB8 82 RESPONSE undervoltage fault is detected. IOUT_OC_FAULT_LIMIT 0x46 Output overcurrent fault limit. R/W Word Y L11 A Y 29.75 76 0xDBB8 IOUT_OC_FAULT_ 0x47 Action to be taken by the device when an output R/W Byte Y Reg Y 0x00 85 RESPONSE overcurrent fault is detected. IOUT_OC_WARN_LIMIT 0x4A Output overcurrent warning limit. R/W Word Y L11 A Y 20.0 76 0xDA80 OT_FAULT_LIMIT 0x4F External overtemperature fault limit. R/W Word Y L11 C Y 100.0 77 0xEB20 OT_FAULT_RESPONSE 0x50 Action to be taken by the device when an R/W Byte Y Reg Y 0xB8 87 external overtemperature fault is detected, OT_WARN_LIMIT 0x51 External overtemperature warning limit. R/W Word Y L11 C Y 85.0 78 0xEAA8 UT_FAULT_LIMIT 0x53 External undertemperature fault limit. R/W Word Y L11 C Y –40.0 78 0xE580 UT_FAULT_RESPONSE 0x54 Action to be taken by the device when an R/W Byte Y Reg Y 0xB8 87 external undertemperature fault is detected. VIN_OV_FAULT_LIMIT 0x55 Input supply overvoltage fault limit. R/W Word N L11 V Y 15.5 71 0xD3E0 VIN_OV_FAULT_ 0x56 Action to be taken by the device when an input R/W Byte Y Reg Y 0x80 81 RESPONSE overvoltage fault is detected. VIN_UV_WARN_LIMIT 0x58 Input supply undervoltage warning limit. R/W Word N L11 V Y 6.3 71 0xCB26 IIN_OC_WARN_LIMIT 0x5D Input supply overcurrent warning limit. R/W Word N L11 A Y 10.0 75 0xD280 Rev. F For more information www.analog.com 35 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