Datasheet LTC3888-1 (Analog Devices) - 101

link to page 18 LTC3888-1
PMBus COMMAND DETAILS (Fault Response and Communication) IOUT_OC_FAULT_RESPONSE
The IOUT_OC_FAULT_RESPONSE command instructs the device on what action to take in response to an output overcurrent fault. The device also: • Sets the IOUT_OC Bit in the STATUS_BYTE • Sets the IOUT Bit in the STATUS_WORD • Sets the IOUT Overcurrent Fault Bit in the STATUS_IOUT Command • Notifies the Host by Asserting ALERT, Unless Masked Output overcurrent faults are ignored during turn-on and turn-off output transitions.
Data Byte Contents for IOUT_OC_FAULT_RESPONSE: BITS DESCRIPTION VALUE MEANING
[7:6] For all values of bits [7:6], the LTC3888-1: 00 The LTC3888-1 continues to operate indefinitely with the • Sets the corresponding fault bits in the status commands. normal hardware response described in the Operation • Notifies the host by asserting ALERT, unless masked. section. The fault, once set, is cleared only when one or more of the 01 Not supported. Writing this value will generate a CML fault. following events occurs: 10 The LTC3888-1 continues operating with the normal • The device receives a CLEAR_FAULTS command. hardware response for the delay time specified by bits • The corresponding STATUS_IOUT bit is written to a one. [2:0]. If the fault is continuously present for the entire delay, the unit then disables the output and responds according to • The output is commanded off, then on, by the RUN pin or the retry setting in bits [5:3]. OPERATION command. • The device receives a RESTORE_USER_ALL command. 11 The LTC3888-1 immediately disables the output and • The device receives an MFR_RESET command. responds according to the retry setting in bits [5:3]. • IC supply power is cycled. [5:3] Retry setting. 000-110 The LTC3888-1 does not attempt to restart. The output remains disabled until the fault is cleared, the device is commanded off and then on, or IC supply power is cycled. 111 The LTC3888-1 attempts to restart continuously without limitation with an interval set by MFR_RETRY_DELAY. This response persists until the unit is commanded off, IC supply power is removed, or another fault response forces shutdown without retry. [2:0] Delay time. xxx Response delay time in 16ms increments. This delay time determines how long the fault may have to persist before the controller is disabled, depending on bits [7:6]. These bits always return zero if bits [7:6]. This command has one data byte. Rev. 0 For more information www.analog.com 101 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Test Circuit Operation Overview About This Document Major Product Features Main Control Loop Power-Up and Initialization Testing Integrity of Output Voltage Sense Analog Output Voltage Control PMBus Output Voltage Control Soft-Start Time-Based Output Sequencing Output Ramping Control Voltage-Based Output Sequencing Output Disable Minimum Output Disable Times Output Short Cycle Switching Frequency and Phase PolyPhase Load Sharing Voltage Control Loop Compensation Load Step Emulation Input Supply Monitoring Output Voltage Sensing and Monitoring Output Current Sensing and Monitoring Temperature Sense Resistor Configuration Pins Internal EEPROM with CRC Fault Detection Input Supply Faults Hardwired PWM Response to Power Stage Faults Hardwired PWM Response to Power Stage UV Hardwired PWM Response to VOUT Faults Power Good Indication Hardwired PWM Response to IOUT Faults Hardwired PWM Response to Internal Temperature Faults External Temperature Faults Timing Faults External Faults Higher-Level Fault Handling Status Registers and ALERT Masking FAULT Pin I/O Fault Log Operation Fault Log Details 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 Power Stage Selection and Interface Using The VDR Monitor Unused TSNS Inputs PWM Frequency and Inductor Selection CIN Selection COUT Selection Programmable Loop Compensation PCB Layout Considerations Output Voltage Sensing Classical Analog Output Voltage Control PMBus Output Voltage Control Using Output Voltage Servo Soft-Start and Stop Time-Based Output Sequencing and Ramping Voltage-Based Output Sequencing PWM Frequency Synchronization PolyPhase Operation and Load Sharing 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 MFR_CONFIG_ALL On, Off and Margin Control ON_OFF_CONFIG OPERATION MFR_RESET PWM Configuration FREQUENCY_SWITCH MFR_CHAN_CONFIG MFR_PWM_CONFIG_LTC3888-1 MFR_PWM_MODE_LTC3888-1 MFR_PWM_COMP Input Voltage and Limits VIN_ON VIN_OFF VIN_OV_FAULT_LIMIT VIN_UV_WARN_LIMIT Output Voltage and Limits VOUT_MODE VOUT_COMMAND VOUT_MAX MFR_VOUT_MAX VOUT_MARGIN_HIGH VOUT_MARGIN_LOW VOUT_SCALE_LOOP VOUT_OV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT VOUT_UV_FAULT_LIMIT Output Current and Limits IOUT_CAL_GAIN MFR_LOAD_EMULATION MFR_LOAD_EMULATION IOUT_OC_FAULT_LIMIT IOUT_OC_WARN_LIMIT Output Timing, Delays, and Ramping MFR_RESTART_DELAY TON_DELAY TON_MAX_FAULT_LIMIT VOUT_TRANSITION_RATE TOFF_DELAY 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 STATUS_WORD STATUS_VOUT STATUS_IOUT STATUS_INPUT STATUS_TEMPERATURE STATUS_CML STATUS_MFR_SPECIFIC MFR_PADS_LTC3888-1 MFR_COMMON MFR_INFO CLEAR_FAULTS Telemetry READ_VIN MFR_VIN_PEAK READ_VOUT MFR_VOUT_PEAK READ_IOUT MFR_IOUT_PEAK MFR_TOTAL_IOUT MFR_READ_ALL_IOUT READ_TEMPERATURE_1 MFR_TEMPERATURE_1_PEAK READ_TEMPERATURE_2 MFR_TEMPERATURE_2_PEAK 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 MFR_OT_FAULT_RESPONSE TON_MAX_FAULT_RESPONSE MFR_RETRY_DELAY SMBALERT_MASK MFR_FAULT_PROPAGATE MFR_FAULT_RESPONSE MFR_FAULT_LOG 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 IC_DEVICE_ID MFR_SPECIAL_ID Package Description Typical Applications Related Parts