LTM4676A elecTrical characTerisTicsThe l denotes the specifications which apply over the specified internaloperating temperature range (Note 2). Specified as each individual output channel (Note 4). TA = 25°C, VIN = 12V, RUNn= 5V,FREQUENCY_SWITCH = 500kHz and VOUTncommanded to 1.000V unless otherwise noted. Configured with factory-default EEPROMsettings and per Test Circuit 1, unless otherwise noted.SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS tCONVERT-VO-RB Output Voltage Readback MFR_ADC_CONTROL = 0x00 (Notes 9, 15) 90 ms Update Rate MFR_ADC_CONTROL = 0x0D (Notes 9, 15) 27 ms MFR_ADC_CONTROL = 0x05 or 0x09 (Notes 9, 15) 8 ms Input Voltage (SVIN) Readback (READ_VIN) NSVIN-RB Input Voltage Readback (Notes 10, 15) 10 Bits Resolution and LSB Step 15.625 mV Size SVIN-F/S Input Voltage Full-Scale (Notes 11, 15) 38.91 V Digitizable Range SVIN-RB-ACC Input Voltage Readback READ_VIN, 4.5V ≤ SVIN ≤ 26.5V l Within ±2% of Reading Accuracy tCONVERT-SVIN-RB Input Voltage Readback MFR_ADC_CONTROL = 0x00 (Notes 9, 15) 90 ms Update Rate MFR_ADC_CONTROL = 0x01 (Notes 9, 15) 8 ms Channels 0 and 1 Output Current (READ_IOUTn), Duty Cycle (READ_DUTY_CYCLEn), and Computed Input Current (MFR_READ_IINn) Readback NIO-RB Output Current Readback (Notes 10, 12) 10 Bits Resolution and LSB Step 15.6 mA Size IO-F/S, II-F/S Output Current Full-Scale (Note 12) ±40 A Digitizable Range and Input Current Range of Calculation IO-RB-ACC Output Current, Readback READ_IOUTn, Channels 0 and 1, 0 ≤ IOUTn ≤ 10A, l Within 250mA of Reading Accuracy Forced-Continuous Mode, MFR_PWM_MODEn[1:0] = 10b IO-RB(13A) Full Load Output Current IOUTn = 13A (Note 12). See Histograms in Typical Performance 13.1 A Readback Characteristics NII-RB Computed Input Current, (Notes 10, 12) 10 Bits Readback Resolution and 1.95 mA LSB Step Size II-RB-ACC Computed Input Current, MFR_READ_IINn, Channels 0 and 1, 0 ≤ IOUTn ≤ 10A, l Within 150mA of Reading Readback Accuracy, Forced-Continuous Mode, MFR_PWM_MODEn[1:0] = 10b, Neglecting ISVIN MFR_IIN_OFFSETn = 0mA tCONVERT-IO-RB Output Current Readback MFR_ADC_CONTROL = 0x00 (Notes 9, 15) 90 ms Update Rate MFR_ADC_CONTROL = 0x0D (Notes 9, 15) 27 ms MFR_ADC_CONTROL = 0x06 or 0x0A (Notes 9, 15) 8 ms tCONVERT-II-RB Computed Input Current, MFR_ADC_CONTROL = 0x00 (Notes 9, 15) 90 ms Readback Update Rate NDUTY-RB Resolution, Duty Cycle (Notes 10, 15) 10 Bits Readback DRB-ACC Duty Cycle TUE READ_DUTY_CYCLEn, 16.3% Duty Cycle (Note 15) ±3 % tCONVERT-DUTY-RB Duty Cycle Readback MFR_ADC_CONTROL = 0x00 (Notes 9, 15) 90 ms Update Rate Temperature Readback for Channel 0, Channel 1, and Controller (Respectively: READ_TEMPERATURE_10, READ_TEMPERATURE_11,and READ_TEMPERATURE_2) TRES-RB Temperature Readback Channel 0, Channel 1, and Controller (Note 15) 0.0625 °C Resolution TRB-CH-ACC(72mV) Channel Temperature Channels 0 and 1, PWM Inactive, RUNn = 0V, l Within ±3°C of Reading TUE, Switching Action Off ∆VTSNSna = 72mV 4676afa For more information www.linear.com/LTM4676A 7 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 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 LTM4676A 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