Datasheet LTM4678 (Analog Devices) - 6

link to page 90 link to page 90 link to page 11 LTM4678
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the specified internal operating temperature range (Note 2). Specified as each individual output channel (Note 4). TA = 25°C, VIN = 12V, RUNn = 3.3V, EXTVCC = 0, FREQUENCY_SWITCH = 350kHz and VOUTn commanded to 1.000V unless otherwise noted. Configured with factory-default EEPROM settings and per Test Circuit 1, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
tSETTLE Settling Time for Dynamic Load Load: 0A to 12.5A and 12.5A to 0A at 12.5A/µs, 25 µs Step VOUTn = 1V, VIN = 12V (Note 12) See Load Transient Graphs IOUTn(OCL_PK) Output Current Limit, Peak High Cycle-by-Cycle Inductor Peak Current Limit Inception, 40 A Range Utilizing MFR_PWM_MODE[7] = 1, Using ~IOUT = 34A for IOUT_OC_FAULT_LIMIT, Page 90 IOUTn(OCL_AVG) Output Current Limit, Time Time-Averaged Output Inductor Current Limit Inception 35A; See IO-RB-ACC Averaged Threshold, Commanded by IOUT_OC_FAULT_LIMITn (Note 12) Specification (Output Current Utilizing MFR_PWM_MODE[7] = 1, Using ~IOUT = 34A, Page 90 Readback Accuracy)
Control Section
V – FBCM0 Channel 0 Feedback Input Common VOSNS0 Valid Input Range (Referred to SGND) l –0.1 0.3 V Mode Range V + OSNS0 Valid Input Range (Referred to SGND) l 3.6 V V – FBCM1 Channel 1 Feedback Input Common VOSNS1 Valid Input Range (Referred to SGND) l –0.1 0.3 V Mode Range V + OSNS1 Valid Input Range (Referred to SGND) l 3.6 V VOUT-RNGL Full-Scale Command Voltage, VOUTn Commanded to 2.750V, MFR_PWM_MODEn[1] = 1b 2.7 2.8 V Range Low (0.6V to 2.75V, Set Point Accuracy −0.5 −0.5 % Notes 7, 15) Resolution 12 Bits LSB Step Size 0.688 mV VOUT-RNGH Full-Scale Command Voltage, VOUTn Commanded to 3.6V, MFR_PWM_MODEn[0] = 1b Range High (0.6V to 3.6V, Note 8) Limit Design to 1.5V Operating for Module Set Point Accuracy 3.5 3.7 V Resolution 12 Bits LSB Step Size 1.375 mV R + + + VSNS0 VOSNS0 Impedance to SGND 0.05V ≤ VVOSNS0 – VSGND ≤ 3.3V 50 kΩ R + VSNS1 VOSNS1 Impedance to SGND 0.05V ≤ VVOSNS1 – VSGND ≤ 3.3V 50 kΩ tON(MIN) Minimum On-Time (Note 8 ) 50 ns RCOMP0,1 Resolution MFR_PWM_CONFIG[4:0] = 0 to 31 (See Figure 1, Note 5 Bits Compensation Resistor RTH(MAX) Section) 62 kΩ Compensation Resistor RTH(MIN) 0 kΩ gm0,1 Resolution COMP0,1 = 1.35V, MFR_PWM_CONFIG[7:5] = 0 to 7 3 Bits Error Amplifier gm(MAX) 5.76 mmho Error Amplifier gm(MIN) 1 mmho LSB Step Size 0.68 mmho
Analog OV/UV (Overvoltage/Undervoltage) Output Voltage Supervisor Comparators (VOUT_OV/UV_FAULT_LIMIT and VOUT_OV/UV_WARN_LIMIT Monitors)
NOV/UV_COMP Resolution, Output Voltage (Notes 14, 15) 9 Bits Supervisors VOV-RNG Output OV Comparator Threshold (Notes 14, 15) Detection Range High Range Scale, MFR_PWM_MODEn[1] = 0b 1 3.6 V Low Range Scale, MFR_PWM_MODEn[1] = 1b 0.5 2.7 V VOUSTP Output OV and UV Comparator (Note 15) Threshold Programming LSB Step High Range Scale, MFR_PWM_MODEn[1] = 0b 11.2 mV Size Low Range Scale, MFR_PWM_MODEn[1] = 1b 5.6 mV VOUT-RNGH Full-Scale Command Voltage, VOUTn Commanded to 3.6V, MFR_PWM_MODEn[0] = 1b 3.5 3.7 V Range High (0.6V to 3.6V, Set Point Accuracy –0.5 –0.5 % Notes 7, 15) Resolution 12 Bits LSB Step Size 1.375 mV VOV-ACC-0,1 Output OV Comparator Threshold (See Note 14) Accuracy Channel 0 and 1 1V ≤ V + – VOSNSn – VVOSNSn ≤ 2.7V, MFR_PWM_MODE[1] = 1b l ±1.5 % 0.5V ≤ V + – VOSNSn – VVOSNSn ≤ 1V, MFR_PWM_MODE[1] = 1b l ±40 mV 2.0V ≤ VVSNS – VSNG ≤ 3.6V, MFR_PWM_MODE[0] = 0b l ±1.5 % Rev 0 6 For more information www.analog.com Document Outline Functional Diagram Features Applications Typical Application Description Table of Contents 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 Overview, Major Features EEPROM with ECC Power-Up and Initialization Soft-Start Time-Based Sequencing Voltage-Based Sequencing Shutdown Light-Load Current Operation Switching Frequency and Phase PWM Loop Compensation Output Voltage Sensing INTVCC/EXTVCC Power Output Current Sensing and Sub Milliohm DCR Current Sensing Input Current Sensing PolyPhase Load Sharing External/Internal Temperature Sense RCONFIG (Resistor Configuration) Pins Table 1. VOUTn _CFG Pin Strapping Look-Up Table for the LTM4678’s Output Voltage, Coarse Setting (Not Applicable if MFR_CONFIG_ALL[6] = 1b) Table 2. VTRIMn_CFG Pin Strapping Look-Up Table for the LTM4678’s Output Voltage, Fine Adjustment Setting (Not Applicable if MFR_CONFIG_ALL[6] = 1b) Table 3. FSWPH_CFG Pin Strapping Look-Up Table to Set the LTM4678’s Switching Frequency and Channel Phase-Interleaving Angle (Not Applicable if MFR_CONFIG_ALL[6] = 1b) Table 4. ASEL Pin Strapping Look-Up Table to Set the LTM4678’s Slave Address (Applicable Regardless of MFR_CONFIG_ALL[6] Setting) Table 5. LTM4678 MFR_ADDRESS Command Examples Expressed in 7- and 8-Bit Addressing Fault Detection and Handling Status Registers and ALERT Masking Figure 5. LTM4678 Status Register Summary Mapping Faults to FAULT Pins Power Good Pins CRC Protection Serial Interface Communication Protection Device Addressing Responses to VOUT and IIN/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 Response External Overtemperature and Undertemperature Fault Response Responses to Input Overcurrent and Output Undercurrent Faults Responses to External Faults Fault Logging Bus Timeout Protection Similarity Between PMBus, SMBus and I2C 2-Wire Interface PMBus Serial Digital Interface Table 6. Abbreviations of Supported Data Formats Figure 6. PMBus Timing Diagram Figures 7 to 24 PMBus Protocols PMBus Command Summary PMBus Commands Table 7. PMBus Commands Summary (Note: The Data Format Abbreviations are Detailed in Table 8) Table 8. Data Format Abbreviations Applications Information VIN to VOUT Step-Down Ratios Input Capacitors Output Capacitors Light Load Current Operation Switching Frequency and Phase Output Current Limit Programming 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 Input Current Sense Amplifier Programmable Loop Compensation Checking Transient Response PolyPhase Configuration Connecting The USB to I2C/SMBus/PMBus Controller to the LTM4678 In System LTpowerPlay: An Interactive GUI for Digital Power PMBus Communication and Command Processing Thermal Considerations and Output Current Derating Tables 10 thru 11: Output Current Derating Table 12. Channel Output Voltage vs Component Selection, 0A to 12.5A/μs Load Step Output Capacitor-GRM32ER60G337ME05L, 330μF, 4V, X5R, Murata Table 13. Channel Output Voltage vs Component Selection, 0A to 12.5A/μs Load Step Dual Phase Single Output Voltage vs Component Selection, 25A to 50A/μs Load Step Applications Information-Derating Curves EMI Performance Safety Considerations Layout Checklist/Example Typical Applications PMBus Command Details Addressing and Write Protect General Configuration Commands On/Off/Margin PWM Configuration Voltage Input Voltage and Limits Output Voltage and Limits Output Current and Limits Input Current and Limits Temperature Power Stage DCR Temperature Calibration 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 MFR_INFO Data Contents: Telemetry NVM Memory Commands Store/Restore Fault Logging Block Memory Write/Read Package Description Table 22. LTM4678 BGA Pinout Typical Applications Design Resources Related Parts