Table Of Contents - Analog Devices Linear ADI Power LTM4681 Manual

LTM4681

TABLE OF CONTENTS

Features ..................................................... 1
Applications ................................................ 1
Typical Application ........................................ 1
Description.................................................. 1
Absolute Maximum Ratings .............................. 4
Order Information .......................................... 4
Pin Configuration .......................................... 4
Electrical Characteristics ................................. 5
Typical Performance Characteristics .................. 12
Pin Functions .............................................. 16
Simplified Block Diagram ............................... 24
Decoupling Requirements ............................... 24
Functional Diagram ...................................... 25
Test Circuits ............................................... 26
Operation................................................... 28
Power Module Introduction .................................... 28
Power Module Overview, Major Features ................ 28
EEPROM with ECC ..................................................29
Power-Up and Initialization .....................................30
Soft-Start ................................................................ 31
Time-Based Sequencing ......................................... 31
Voltage-Based Sequencing ..................................... 32
Shutdown ............................................................... 32
Light-Load Current Operation ................................. 32
Switching Frequency and Phase .............................33
PWM Loop Compensation ......................................33
Output Voltage Sensing ..........................................33
INTV /V Power ...............................................33
CC BIAS
Output Current Sensing and Sub Milliohm DCR
Current Sensing ......................................................34
Input Current Sensing .............................................34
PolyPhase Load Sharing .........................................34
Internal Temperature Sense ....................................35
RCONFIG (Resistor Configuration) Pins ..................35
Table 1. VOUTn _CFG Pin Strapping Look-Up
Table for the LTM4681's Output Voltage, Coarse
Setting (Not Applicable if MFR_CONFIG_ALL[6] =
1b) Top Resistor = 14.3k .....................................36
Table 2. VTRIMn_CFG Pin Strapping Look-Up
Table for the LTM4681's Output Voltage, Fine
Adjustment Setting (Not Applicable if MFR_
CONFIG_ALL[6] = 1b) Top Resistor = 14.3k........36
2
Table 3. FSWPH_nn_CFG Pin Strapping Look-Up
Table to Set the LTM4681's Switching Frequency
and Channel Phase-Interleaving Angle (Not
Applicable if MFR_CONFIG_ALL[6] = 1b), nn = 0,1
or 2,3 Channels, set top resistor to 14.3k. .......... 37
Table 4. ASEL_nn Pin Strapping Look-Up
Table to Set the LTM4681's Slave Address
(Applicable Regardless of
MFR_CONFIG_ALL[6] Setting) ...........................38
Table 5. LTM4681 MFR_ADDRESS Command
Examples Expressed in 7- and 8-Bit Addressing .. 38
Fault Detection and Handling ..................................38
Status Registers and ALERT Masking ................... 39
Figure 5. LTM4681 Status Register Summary per
Controller ............................................................40
Mapping Faults to FAULTn Pins ............................. 41
Power Good Pins .................................................. 41
CRC Protection ..................................................... 41
Serial Interface ....................................................... 41
Communication Protection ................................... 41
Device Addressing .................................................. 41
Responses to V
Output Overvoltage Fault Response ..................... 42
Output Undervoltage Response ............................43
Peak Output Overcurrent Fault Response .............43
Responses to Timing Faults ....................................43
Responses to V
Responses to OT/UT Faults .....................................43
Internal Overtemperature Fault Response.............43
Overtemperature and Undertemperature
Fault Response ...................................................44
Responses to Input Overcurrent and Output
Undercurrent Faults ................................................44
Responses to External Faults ..................................44
Fault Logging ..........................................................44
Bus Timeout Protection ..........................................44
Similarity Between PMBus, SMBus and I
Interface .................................................................45
PMBus Serial Digital Interface ................................45
Table 6. Abbreviations of Supported Data Formats ... 46
Figure 6. PMBus Timing Diagram .........................46
Figure 7 to Figure 24 PMBus Protocols .................. 47
PMBus Command Summary ............................ 50
PMBus Commands .................................................50
For more information www.analog.com
and I /I Faults ................... 42
OUT IN OUT
OV Faults ....................................43
IN
2
C 2-Wire
Rev. A