Table Of Contents - Analog Devices Linear LTM 4700 User Manual

LTM4700

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 .............................................. 15
Simplified Block Diagram ............................... 19
Decoupling Requirements ............................... 19
Functional Diagram ...................................... 20
Test Circuits ............................................... 21
Operation................................................... 22
Power Module Introduction ...................................22
Power Module Overview, Major Features ................22
EEPROM with ECC .................................................23
Power-Up and Initialization .................................... 24
Soft-Start ...............................................................25
Time-Based Sequencing ........................................25
Voltage-Based Sequencing ....................................25
Shutdown ..............................................................26
Light-Load Current Operation ................................26
Switching Frequency and Phase ............................. 27
PWM Loop Compensation ..................................... 27
Output Voltage Sensing ......................................... 27
INTV and Build-in 5V Bias Converter ................. 27
CC
Output Current Sensing and Sub Milliohm
DCR Current Sensing ............................................. 28
Input Current Sensing ............................................ 28
PolyPhase Load Sharing ........................................ 28
External/Internal Temperature Sense .....................29
RCONFIG (Resistor Configuration) Pins .................29
Fault Detection and Handling ................................. 32
Status Registers and ALERT Masking ................33
Mapping Faults to FAULT Pins ...........................35
Power Good Pins ...............................................35
CRC Protection ..................................................35
2
Serial Interface ......................................................35
Communication Protection ................................35
Device Addressing .................................................35
Responses to V
Output Overvoltage Fault Response ..................36
Output Undervoltage Response ......................... 37
Peak Output Overcurrent Fault Response .......... 37
Responses to Timing Faults ................................... 37
Responses to V
Responses to OT/UT Faults .................................... 37
Internal Overtemperature Fault Response ......... 37
External Overtemperature and
Undertemperature Fault Response .................38
Responses to Input Overcurrent and Output
Undercurrent Faults ...............................................38
Responses to External Faults .................................38
Fault Logging .........................................................38
Bus Timeout Protection .........................................38
Similarity Between PMBus, SMBus and
2
I C 2-Wire Interface ...............................................39
PMBus Serial Digital Interface ...............................39
Figures 7 to 24 PMBus Protocols ........................... 41
PMBus Command Summary ............................ 44
PMBus Commands ................................................44
Applications Information ................................ 50
V to V
IN
Input Capacitors ....................................................50
Output Capacitors ..................................................50
Light Load Current Operation .................................50
Switching Frequency and Phase ............................ 51
Output Current Limit Programming ....................... 52
Minimum On-Time Considerations .........................53
Variable Delay Time, Soft-Start and
Output Voltage Ramping ........................................53
Digital Servo Mode ................................................53
Soft Off (Sequenced Off) .......................................54
Undervoltage Lockout ............................................55
Fault Detection and Handling .................................55
Open-Drain Pins ....................................................55
Phase-Locked Loop and Frequency
Synchronization .....................................................56
Input Current Sense Amplifier ................................ 57
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and I /I Faults ..................36
OUT IN OUT
OV Faults ................................... 37
IN
Step-Down Ratios ...............................50
OUT
Rev. B