Datasheet LTM4675 (Analog Devices) - 125

link to page 124 LTM4675
APPENDIX C: PMBUS COMMAND DETAILS Table 31. Explanation of Position_Fault Values POSITION_FAULT VALUE SOURCE OF FAULT LOG
0xFF MFR_FAULT_LOG_STORE 0x00 TON_MAX_FAULT Channel 0 0x01 VOUT_OV_FAULT Channel 0 0x02 VOUT_UV_FAULT Channel 0 0x03 IOUT_OC_FAULT Channel 0 0x05 OT_FAULT Channel 0 0x06 UT_FAULT Channel 0 0x07 VIN_OV_FAULT Channel 0 0x0A MFR_OT_FAULT Channel 0 0x10 TON_MAX_FAULT Channel 1 0x11 VOUT_OV_FAULT Channel 1 0x12 VOUT_UV_FAULT Channel 1 0x13 IOUT_OC_FAULT Channel 1 0x15 OT_FAULT Channel 1 0x16 UT_FAULT Channel 1 0x17 VIN_OV_FAULT Channel 1 0x1A MFR_OT_FAULT Channel 1
Fault Logging CMD DATA DEFAULT COMMAND NAME CODE DESCRIPTION TYPE PAGED FORMAT UNITS NVM VALUE
MFR_FAULT_LOG 0xEE Fault log data bytes. This sequentially retrieved data is R Block N CF Y NA used to assemble a complete fault log. MFR_FAULT_LOG_ STORE 0xEA Command a transfer of the fault log from RAM to Send Byte N NA EEPROM. MFR_FAULT_LOG_CLEAR 0xEC Initialize the EEPROM block reserved for fault logging. Send Byte N NA
MFR_FAULT_LOG
The MFR_FAULT_LOG command allows the user to read the contents of the FAULT_LOG after the first fault occurrence since the last MFR_FAULT_LOG_CLEAR command was last written. The contents of this command are stored in non-volatile memory, and are cleared by the MFR_FAULT_LOG_CLEAR command. The length and content of this command are listed in Table 30. If the user accesses the MFR_FAULT_LOG command and no fault log is present, the command will return a data length of 0. If a fault log is present, the MFR_FAULT_LOG will always return a block of data 147 bytes long. If a fault occurs within the first second of applying power, some of the earlier pages in the fault log may not contain valid data. NOTE: The approximate transfer time for this command is 3.4ms using a 400kHz clock. This read-only command is in block format. Rev. C For more information www.analog.com 125 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Simplified Block Diagram Decoupling Requirements Functional Diagram Test Circuits Operation Power Module Introduction Power Module Configurability and Readback Data Time-Averaged and Peak Readback Data Power Module Overview EEPROM Serial Interface Device Addressing Fault Detection and Handling Responses to VOUT and IOUT Faults Responses to Timing Faults Responses to SVIN OV Faults Responses to OT/UT Faults Responses to External Faults Fault Logging Bus Timeout Protection PMBus Command Summary PMBus Commands Applications Information VIN to VOUT Step-Down Ratios Input Capacitors Output Capacitors Light Load Current Operation Switching Frequency and Phase Minimum On-Time Considerations Variable Delay Time, Soft-Start and Output Voltage Ramping Digital Servo Mode Soft Off (Sequenced Off) Undervoltage Lockout Fault Detection and Handling Open-Drain Pins Phase-Locked Loop and Frequency Synchronization RCONFIG Pin-Straps (External Resistor Configuration Pins) Voltage Selection Connecting the USB to the I2C/SMBus/PMBus Controller to the LTM4675 In System LTpowerPlay: An Interactive GUI for Digital Power System Management PMBus Communication and Command Processing Thermal Considerations and Output Current Derating EMI Performance Safety Considerations Layout Checklist/Example Typical Applications Appendix A Similarity Between PMBus, SMBus and I2C 2-Wire Interface Appendix B PMBus Serial Digital Interface Appendix C: PMBus Command Details Addressing and Write Protect General Configuration Registers On/Off/Margin PWM Config Voltage Current Temperature Timing Fault Response Fault Sharing Scratchpad Identification Fault Warning and Status Telemetry NVM (EEPROM) Memory Commands Package Description Package Photograph Package Description Revision History Typical Application Design Resources Related Parts