Datasheet LTC3883, LTC3883-1 (Analog Devices) - 10

LTC3883/LTC3883-1
TYPICAL PERFORMANCE CHARACTERISTICS Efficiency vs Load Current, Efficiency vs Load Current, Efficiency and Power Loss VOUT = 1.8V (LTC3883) VOUT = 3.3V (LTC3883) vs Input Voltage (LTC3883)
100 100 92 4.0 90 90 80 90 3.5 80 70 POWER LOSS (W) 70 88 3.0 60 60 50 V 50 86 2.5 IN = 12V VIN = 12V 40 VOUT = 1.8V 40 VOUT = 3.3V EFFICIENCY (%) fSW = 350kHz EFFICIENCY (%) fSW = 350kHz EFFICIENCY (%) 30 2.0 L = 0.56µH 84 30 L = 0.56µH DCR = 1.8mΩ DCR = 1.8mΩ 20 CCM 20 CCM 82 1.5 10 DCM 10 DCM BM BM 0 0 80 1.0 0.01 0.1 1 10 100 0.01 0.1 1 10 100 5 10 15 20 25 LOAD CURRENT (A) LOAD CURRENT (A) VIN (V) 3883 G01 3883 G02 3883 G03
Load Step Load Step Load Step (Burst Mode Operation) (Forced Continuous Mode) (Pulse-Skipping Mode)
ILOAD ILOAD ILOAD 5A/DIV 5A/DIV 5A/DIV INDUCTOR INDUCTOR INDUCTOR CURRENT CURRENT CURRENT 5A/DIV 5A/DIV 5A/DIV VOUT VOUT VOUT 100mV/DIV 100mV/DIV 100mV/DIV AC-COUPLED AC-COUPLED AC-COUPLED V 3883 G04 3883 G05 3883 G06 IN = 12V 50µs/DIV VIN = 12V 50µs/DIV VIN = 12V 50µs/DIV VOUT = 1.8V VOUT = 1.8V VOUT = 1.8V 0.3A TO 5A STEP 0.3A TO 5A STEP 0.3A TO 5A STEP
Inductor Current at Light Load Start-Up into a Pre-Biased Load Soft-Start Ramp
FORCED RUN RUN CONTINUOUS 2V/DIV 2V/DIV MODE 2A/DIV V V OUT OUT Burst Mode 1V/DIV 1V/DIV OPERATION 2A/DIV PULSE-SKIPPING MODE t 3883 G08 3883 G09 RISE = 10ms 5ms/DIV tRISE = 10ms 5ms/DIV 2A/DIV tDELAY = 5ms tDELAY = 5ms V 3883 G07 OUT = 2V VIN = 12V 1µs/DIV VOUT = 1.8V ILOAD = 100µA Rev. F 10 For more information www.analog.com 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