POWER LOSS (W) LTC3883/LTC3883-1 Single Phase Step-Down DC/DC Controller with Digital Power System Management FEATURES DESCRIPTION 2 n PMBus/I C Compliant Serial Interface The LTC 3883/LTC3883-1 are PolyPhase capable DC/DC n Telemetry Read-Back Includes V , I , V , synchronous step-down switching regulator controllers IN IN OUT I , Temperature and Faults with a PMBus compliant serial interface. The controllers OUT n Programmable Voltage, Current Limit, Digital use a constant frequency, current mode architecture that Soft-Start/Stop, Sequencing, Margining, OV/UV/OC is supported by the LTPowerPlay software development and Frequency Synchronization (250kHz to 1MHz) tool with graphical user interface (GUI). n 0.5% Output Voltage Accuracy over Temperature Switching frequency, output voltage, and device address n Integrated 16-Bit ADC and 12-Bit DAC can be programmed using external configuration resistors. n Integrated High Side Current Sense Amplifier Additionally, parameters can be set via the digital interface n Internal EEPROM with ECC and Fault Logging or stored in on-chip EEPROM. n Integrated N-Channel MOSFET Gate Drivers The LTC3883/LTC3883-1 can be configured for Burst Power Conversion n Mode operation, discontinuous (pulse-skipping) mode or Wide V Range: 4.5V to 24V IN n continuous inductor current mode. The LTC3883 incorpo- V Range: 0.5V to 5.4V OUT n Analog Current Mode Control Loop rates an internal 5V linear regulator while the LTC3883-1 n Accurate PolyPhase Current Sharing for Up to 6 Phases uses an external 5V supply for minimum power loss. n Auto Calibration of Inductor DCR The LTC3883/LTC3883-1 are available in a 32-lead 5mm n Minimum On Time 45ns 5mm QFN package. n Available in a 32-Lead (5mm 5mm) QFN Package All registered trademarks and trademarks are the property of their respective owners. Protected n AEC-Q100 Qualified for Automotive Applications by U.S. Patents including 5481178, 5705919, 5929620, 6100678, 6144194, 6177787, 5408150, 6580258, 6304066, 7420359. Licensed under U.S. Patent 7000125 and other related patents worldwide. APPLICATIONS n High Current Distributed Power Systems n Telecom Systems n Intelligent Energy Efficient Power Regulation TYPICAL APPLICATION 5m V IN Efficiency and Power Loss 6V TO 24V 10F 1F 10F vs Load Current D1 INTV CC 100 100 100 8 TG M1 V = 12V IN 1F 0.1F 90 V = 1.8V OUT 7 I BOOST f = 350kHz IN SNS SW 0.56H V OUT 80 6 V SW 1.8V IN SNS 70 20A M2 1.4k V BG IN 5 60 0.22F 22F LTC3883* 50 4 + I SDA SENSE 40 SCL I PMBus SENSE 3 ALERT INTERFACE V SENSE 30 RUN 2 TSNS C OUT 20 10nF 530F MMBT3906 2200pF 1 10 FAULT 4.99k GPIO I MANAGEMENT PGOOD TH 0 0 0.01 0.1 1 10 100 V DD33 V LOAD CURRENT (A) DD25 TO/FROM *SOME DETAILS OMITTED SHARE CLK 1F 1F 3883 TA01b OTHER LTC DEVICES FOR CLARITY WRITE PROTECT WP SGND 3883 TA01a Rev. F 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LTC3883/LTC3883-1 TABLE OF CONTENTS Features ..................................................... 1 Responses to V and I Faults ........................27 OUT OUT Applications ................................................ 1 Output Overvoltage Fault Response ...................27 Typical Application ........................................ 1 Output Undervoltage Response .........................27 Description.................................................. 1 Peak Output Overcurrent Fault Response ...........27 Table of Contents .......................................... 2 Responses to Timing Faults ....................................28 Absolute Maximum Ratings .............................. 4 Responses to V OV Faults ....................................28 IN Pin Configuration .......................................... 4 Responses to OT/UT Faults .....................................28 Order Information .......................................... 4 Overtemperature Fault ResponseInternal ......28 Electrical Characteristics ................................. 5 Overtemperature and Undertemperature Typical Performance Characteristics .................. 10 Fault ResponseExternals ...............................28 Pin Functions .............................................. 14 Responses To Input Overcurrent And Output Block Diagram ............................................. 16 Undercurrent Faults ................................................29 Operation................................................... 17 Responses to External Faults .................................29 Overview ................................................................. 17 Fault Logging ..........................................................29 Main Control Loop .................................................. 17 Bus Timeout Failure ................................................29 2 EEPROM ................................................................. 18 Similarity Between PMBus, SMBus and I C Power Up and Initialization ..................................... 18 2-Wire Interface ......................................................29 Soft-Start ................................................................ 19 PMBus Serial Digital Interface ................................30 Sequencing ............................................................. 19 PMBus Command Summary ............................ 33 Voltage-Based Sequencing .....................................20 PMBus Commands .................................................33 Shutdown ...............................................................20 *Data Format ..........................................................38 Light Load Current Operation .................................21 Applications Information ................................ 39 Switching Frequency and Phase .............................21 Current Limit Programming ....................................39 + Output Voltage Sensing ..........................................22 I and I Pins .........................................39 SENSE SENSE Output Current Sensing ..........................................22 Low Value Resistor Current Sensing .......................40 Auto Calibration .....................................................22 Inductor DCR Current Sensing ................................ 41 Accurate DCR Temperature Compensation ............22 Slope Compensation and Inductor Peak Current ....42 Input Current Sensing .............................................22 Inductor Value Calculation ......................................42 Load Sharing ..........................................................23 Inductor Core Selection ..........................................43 External/Internal Temperature Sense ......................23 Power MOSFET and Schottky Diode (Optional) RCONFIG (Resistor Configuration) Pins .................. 24 Selection .................................................................43 Fault Detection and Handling ..................................25 Variable Delay Time, Soft-Start and Output Voltage Internal Memory with CRC and ECC ..................26 Ramping .................................................................44 Serial Interface .......................................................26 Digital Servo Mode .................................................45 Communication Failure ......................................26 Soft Off (Sequenced Off) ........................................45 Device Addressing ..................................................26 INTV Regulator ....................................................46 CC Rev. F 2 For more information www.analog.com