Datasheet LTM4678 (Analog Devices) - 6

link to page 89 link to page 11 LTM4678
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the specified internal operating temperature range (Note 2). n is 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_AVG) Output Current Limit, Time Time-Averaged Output Inductor Current Limit Inception 30A; 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 = 36A, Page 89 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 2.75V, MFR_PWM_MODEn[1] = 1b 2.75 V Range Low (0.5V to 2.75V) (Note 15) % Set Point Accuracy −0.5 −0.5 Bits Resolution 12 mV LSB Step Size 0.688 VOUT-RNGH Full-Scale Command Voltage, VOUTn Commanded to 3.6V, MFR_PWM_MODEn[1] = 0b 3.6 V Range High (0.5V to 3.6V) (Notes 7, 15) Set Point Accuracy −0.5 0.5 % 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 ) 60 ns RCOMP0,1 Resolution MFR_PWM_CONFIG[4:0] = 0 to 31 (See Figure 1, Note 5 Bits Compensation Resistor RTH(MAX) Section) (Note 15) 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) (Note 15) 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 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 ≤ V + – VOSNSn – VVOSNSn ≤ 3.6V, MFR_PWM_MODE[1] = 0b l ±1.5 % VUV-RNG Output UV Comparator Threshold (Note 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 Rev. A 6 For more information www.analog.com Document Outline 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 VOUTn _CFG Pin Strapping Look-Up Table for the LTM4678’s Output Voltage, Coarse Setting (Not Applicable if MFR_CONFIG_ALL[6] = 1b) VTRIMn_CFG Pin Strapping Look-Up Table for the LTM4678’s Output Voltage, Fine Adjustment Setting (Not Applicable if MFR_CONFIG_ALL[6] = 1b) 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) ASEL Pin Strapping Look-Up Table to Set the LTM4678’s Slave Address (Applicable Regardless of MFR_CONFIG_ALL[6] Setting) LTM4678 MFR_ADDRESS Command Examples Expressed in 7- and 8-Bit Addressing Fault Detection and Handling Status Registers and ALERT Masking 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 Abbreviations of Supported Data Formats Figure 7 to Figure 24 PMBus Protocols PMBus Command Summary PMBus Commands PMBus Commands Summary (Note: The Data Format Abbreviations are Detailed in 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 Recommended Switching Frequency for Various VIN-to-VOUT Step-Down Scenarios 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 Table 10 thru Table 11: Output Current Derating 0.9V Output 1.8V Output Channel Output Voltage vs Component Selection, 0A to 12.5A/μs Load Step Output Capacitor-GRM32ER60G337ME05L, 330μF, 4V, X5R, Murata Low VOUT Range for VOUT ≤ 2.5V High VOUT Range for 2.5V ≤ VOUT ILIMIT Range = High Channel Output Voltage vs Component Selection, 0A to 12.5A/μs Load Step Low VOUT Range for VOUT ≤ 2.5V High VOUT Range for 2.5V ≤ VOUT ILIMIT Range = High Dual Phase Single Output – Ceramic and Poscap Output Capacitors 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 VOUT_OV_FAULT_RESPONSE Data Byte Contents VOUT_UV_FAULT_RESPONSE Data Byte Contents Fault Responses Output Current OUT_OC_FAULT_RESPONSE Data Byte Contents Fault Responses IC Temperature Data Byte Contents MFR_OT_FAULT_RESPONSE Fault Responses External Temperature Fault Sharing Fault Sharing Propagation FAULTn Propagate Fault Configuration Fault Sharing Response Scratchpad Identification Fault Warning and Status Telemetry NVM Memory Commands Store/Restore Fault Logging Fault Logging Explanation of Position_Fault Values Block Memory Write/Read Package Description LTM4678 BGA Pinout Revision History Package Photograph Design Resources Related Parts