Datasheet LTM4686, LTM4686-1 (Analog Devices) - 86

LTM4686/LTM4686-1
APPENDIX C: PMBUS COMMAND DETAILS MFR_CONFIG_ALL
General purpose configuration command common to multiple ADI products
BIT MEANING
7 Enable Fault Logging 6 Ignore Resistor Configuration Pins 5 Disable CML fault for Quick Command message 4 Disable SYNC out 3 Enable 255ms Time Out 2 A valid PEC required for PMBus writes to be accepted. If this bit is not set, the part will accept commands with invalid PEC. 1 Enable the use of PMBus clock stretching 0 Enables a low to high transition on either RUN pin to issue a CLEAR_FAULTS command This command has one data byte.
ON/OFF/MARGIN CMD DATA DEFAULT COMMAND NAME CODE DESCRIPTION TYPE PAGED FORMAT UNITS NVM VALUE
ON_OFF_CONFIG 0x02 RUN pin and PMBus bus on/off command configuration. R/W Byte Y Reg Y 0x1F OPERATION 0x01 Operating mode control. On/off, margin high and margin R/W Byte Y Reg Y 0x80 low. MFR_RESET 0xFD Commanded reset without requiring a power-down. Send Byte N NA Identical to RESTORE_USER_ALL.
ON_OFF_CONFIG
The ON_OFF_CONFIG command configures the combination of RUNn pin input and serial bus commands needed to turn the unit on and off. This includes how the unit responds when power is applied.
Table 22. Supported Values VALUE MEANING
0x1F OPERATION value and RUNn pin must both command the device to start/run. Device executes immediate off when commanded off. 0x1E OPERATION value and RUNn pin must both command the device to start/run. Device uses TOFF_ command values when commanded off. 0x17 RUNn pin control with immediate off when commanded off. OPERATION on/off control ignored. 0x16 RUNn pin control using TOFF_ command values when commanded off. OPERATION on/off control ignored. Note: A high on the RUNn pin is always required to start power conversion. Power conversion will always stop with a low on RUNn. Programming an unsupported ON_OFF_CONFIG value will generate a CML fault and the command will be ignored. This command has one data byte. Rev. B 86 For more information www.analog.com 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 LTM4686 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 Photographs Package Description Revision History Typical Application Design Resources Related Parts