LTC3886/LTC3886-1
TABLE OF CONTENTS
Features...................................................... 1
Power Conversion.................................................1
Applications................................................. 1
Typical Application ......................................... 1
Description.................................................. 1
Absolute Maximum Ratings............................... 4
Order Information........................................... 4
Pin Configuration........................................... 4
Electrical Characteristics.................................. 5
Typical Performance Characteristics................... 10
Pin Functions............................................... 13
Block Diagram.............................................. 15
Operation................................................... 16
Overview.................................................................. 16
Main Control Loop................................................... 16
EEPROM.................................................................. 17
Power-Up and Initialization...................................... 17
Soft-Start................................................................. 18
Time-Based Sequencing.......................................... 18
Event-Based Sequencing......................................... 19
Shutdown................................................................ 19
Light-Load Current Operation..................................20
PWM Loop Compensation.......................................20
Switching Frequency and Phase..............................20
Output Voltage Sensing........................................... 21
Output Current Sensing........................................... 21
Input Current Sensing.............................................. 21
PolyPhase Load Sharing..........................................22
External/Internal Temperature Sense.......................22
RCONFIG (Resistor Configuration) Pins...................23
Fault Handling..........................................................23
Status Registers and ALERT Masking.................. 24
Mapping Faults to FAULT Pins.............................26
Power Good Pins.................................................26
CRC Protection ...................................................26
Serial Interface........................................................26
Communication Protection ................................. 27
Device Addressing................................................... 27
Responses to VOUT and IOUT Faults/Warnings......... 27
Output Overvoltage Fault Response.................... 27
Output Undervoltage Response .......................... 28
Peak Output Overcurrent Fault Response............ 28
Responses to Timing Faults..................................... 28
Responses to VIN OV Faults..................................... 28
Responses to OT/UT Faults...................................... 28
Internal Overtemperature Fault/Warn
Response............................................................. 28
External Overtemperature and Undertemperature
Fault Response ...................................................29
Responses to External Faults ..................................29
Fault Logging...........................................................29
Bus Timeout Protection...........................................29
Similarity Between PMBus, SMBus and I2C
2-Wire Interface.......................................................30
PMBus Serial Digital Interface.................................30
PMBus Command Summary............................. 35
PMBus Commands..................................................35
*Data Format...........................................................40
Applications Information................................. 41
Current Limit Programming..................................... 41
ISENSE+ and ISENSE– Pins.......................................... 41
Low Value Resistor Current Sensing........................ 42
Inductor DCR Current Sensing.................................43
Slope Compensation and Inductor Peak Current.....44
Inductor Value Calculation.......................................44
Inductor Core Selection...........................................45
Power MOSFET and Optional Schottky Diode
Selection.................................................................. 45
CIN and COUT Selection............................................46
Variable Delay Time, Soft-Start and Output Voltage
Ramping.................................................................. 46
Digital Servo Mode.................................................. 47
Soft Off (Sequenced Off).........................................48
INTVCC Regulator..................................................... 49
Topside MOSFET Driver Supply (CB, DB).................50
Undervoltage Lockout..............................................50
Rev G
2
For more information www.analog.com
