Datasheet LTC3883, LTC3883-1 (Analog Devices)

LTC3883/LTC3883-1 Single Phase Step-Down DC/DC Controller with Digital Power System Management
FEATURES DESCRIPTION
n
PMBus/I2C Compliant Serial Interface
The LTC®3883/LTC3883-1 are PolyPhase capable DC/DC n
Telemetry Read-Back Includes VIN, IIN, VOUT,
synchronous step-down switching regulator controllers
IOUT, Temperature and Faults
with a PMBus compliant serial interface. The controllers 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 Power Conversion
The LTC3883/LTC3883-1 can be configured for Burst n Wide VIN Range: 4.5V to 24V Mode® operation, discontinuous (pulse-skipping) mode or n VOUT Range: 0.5V to 5.4V continuous inductor current mode. The LTC3883 incorpo- 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 n AEC-Q100 Qualified for Automotive Applications All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620, 6100678, 6144194, 6177787, 5408150,
APPLICATIONS
6580258, 6304066, 7420359. Licensed under U.S. Patent 7000125 and other related patents worldwide. n High Current Distributed Power Systems n Telecom Systems n Intelligent Energy Efficient Power Regulation
TYPICAL APPLICATION
5mΩ VIN 6V TO 24V
Efficiency and Power Loss
10µF 10µF 1µF
vs Load Current
D1 100Ω 100Ω INTVCC 100 8 TG M1 V 1µF IN = 12V 0.1µF 90 VOUT = 1.8V 7 IIN_SNS BOOST 0.56µH VOUT 80 fSW = 350kHz VIN_SNS SW 1.8V 6 POWER LOSS (W) 20A 70 VIN BG M2 1.4k 0.22µF 60 5 22µF LTC3883* 50 4 SDA I + SENSE– 40 PMBus SCL ISENSE EFFICIENCY (%) 3 INTERFACE ALERT VSENSE 30 RUN 2 TSNS COUT 20 10nF 530µF 2200pF MMBT3906 10 1 FAULT GPIO 4.99k MANAGEMENT PGOOD ITH 0 0 0.01 0.1 1 10 100 VDD33 VDD25 LOAD CURRENT (A) TO/FROM SHARE_CLK *SOME DETAILS OMITTED OTHER LTC DEVICES 1µF 1µF 3883 TA01b FOR CLARITY WRITE PROTECT WP SGND 3883 TA01a Rev. F Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Table of Contents Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Overview Main Control Loop EEPROM Power Up and Initialization Soft-Start Sequencing Voltage-Based Sequencing Shutdown Light Load Current Operation Switching Frequency and Phase Output Voltage Sensing Output Current Sensing Auto Calibration Accurate DCR Temperature Compensation Input Current Sensing Load Sharing External/Internal Temperature Sense RCONFIG (Resistor Configuration) Pins Fault Detection and Handling Internal Memory with CRC and ECC Serial Interface Communication Failure Device Addressing Responses to VOUT and 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 Overtemperature Fault Response—Internal Overtemperature and Undertemperature Fault Response—Externals Responses To Input Overcurrent And Output Undercurrent Faults Responses to External Faults Fault Logging Bus Timeout Failure Similarity Between PMBus, SMBus and I2C 2-Wire Interface PMBus Serial Digital Interface PMBus Command Summary PMBus Commands *Data Format Applications Information Current Limit Programming ISENSE+ and ISENSE– Pins Low Value Resistor Current Sensing Inductor DCR Current Sensing Slope Compensation and Inductor Peak Current Inductor Value Calculation Inductor Core Selection Power MOSFET and Schottky Diode (Optional) Selection Variable Delay Time, Soft-Start and Output Voltage Ramping Digital Servo Mode Soft Off (Sequenced Off) INTVCC Regulator Topside MOSFET Driver Supply (CB, DB) Undervoltage Lockout CIN and COUT Selection Fault Conditions Open-Drain Pins Phase-Locked Loop and Frequency Synchronization Minimum On-Time Considerations Input Current Sense Amplifier RCONFIG (External Resistor Configuration Pins) Voltage Selection Frequency and Phase Selection Using RCONFIG Address Selection Using RCONFIG Efficiency Considerations Checking Transient Response PolyPhase Configuration PC Board Layout Checklist PC Board Layout Debugging Design Example Connecting the USB to I2C/SMBus/PMBus Controller to the LTC3883 In System Inductor DCR Auto Calibration Accurate DCR Temperature Compensation LTpowerPlay: An Interactive GUI for Digital Power PMBus Communication and Command Processing PMBus Command Details Addressing and Write Protect General Configuration COMMANDS On/Off/Margin PWM Configuration Voltage Input Voltage and Limits Output Voltage and Limits Current Output Current Calibration Output Current Input Current Calibration Input Current Temperature External Temperature Calibration External Temperature Limits 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 Fault Responses Output Current Fault Responses IC Temperature Fault Responses External Temperature Fault Sharing Fault Sharing Propagation Fault Sharing Response Scratchpad Identification Telemetry NVM Memory Commands Store/Restore Fault Logging Block Memory Write/Read Typical Applications Package Description Revision History Typical Application Related Parts