POWER LOSS (W) LTC3886/LTC3886-1 60V Dual Output Step-Down Controller with Digital Power System Management FEATURES DESCRIPTION 2 n PMBus/I C Compliant Serial Interface The LTC 3886/LTC3886-1 is a dual PolyPhase DC/DC syn- n Telemetry Read-Back Includes V , I , V , I , chronous step-down switching regulator controller with IN IN OUT OUT 2 I C-based PMBus compliant serial interface. This controller Temperature and Faults n employs a constant-frequency, current-mode architecture, Programmable Voltage, Current Limit, Digital with high voltage input and output capability along with Soft-Start/Stop, Sequencing, Margining, OV/UV/OC, programmable loop compensation. The LTC3886 is sup- Frequency, and Control Loop Compensation n ported by the LTpowerPlay software development tool with Output Error Less Than 0.5% Over Temperature n graphical user interface (GUI). Integrated 16-Bit ADC and 12-Bit DAC n Integrated High Side Current Sense Amplifier The EXTV pin supports voltages up to 14V allowing for CC n Internal EEPROM with ECC and Fault Logging optimized circuit efficiency and die temperature, and for n Integrated N-Channel MOSFET Gate Drivers the controller output to supply the chip power. Switching frequency, output voltage, and device address can be Power Conversion n programmed both by digital interface as well as external Wide V Range: 4.5V to 60V IN n configuration resistors. Parameters can be set via the V , V Range: 0.5V to 13.8V OUT0 OUT1 n digital interface or stored in EEPROM. Both outputs have Analog Current Mode Control an independent power good indicator and FAULT function. n Accurate PolyPhase Current Sharing for Up to 6 Phases (100kHz to 750kHz) The LTC3886 can be configured for discontinuous (pulse- n Available in a 52-Lead (7mm 8mm) QFN Package skipping) mode or continuous inductor current mode. The LTC3886-1 also includes a sequencing off feature to APPLICATIONS discharge very large output capacitors. n All registered trademarks and trademarks are the property of their respective owners. Protected Telecom, Datacom, and Storage Systems by U.S. Patents including 5481178, 5705919, 5929620, 6100678, 6144194, 6177787, 5408150, n Industrial and Point of Load Applications 6580258, 6304066, 7420359, 8786268 Patent Pending. Licensed under U.S. Patent 7000125 and other related patents worldwide. TYPICAL APPLICATION 10F 2 5m V IN 18V TO 48V 10F 1F + INTV V I I CC IN IN IN Efficiency and Power Loss TG0 TG1 0.1F 0.1F vs Load Current BOOST0 BOOST1 3.1H 6.82H 100 9 SW0 SW1 V = 48V IN 90 V = 12V 8 OUT BG0 BG1 f = 150kHz LTC3886* 6.81k 7.5k SW 80 7 SDA FAULT0 1F 1F SCL FAULT1 70 PMBus FAULT MANAGEMENT 6 ALERT PGOOD0 INTERFACE 60 RUN0 PGOOD1 5 TO/FROM RUN1 SHARE CLK 50 OTHER ADI DEVICES + + 4 I I SENSE0 SENSE1 40 6.81k 7.5k 0.22F 0.22F 3 I I SENSE0 SENSE1 30 V EXTV V OUT1 OUT0 CC 2 + 20 12V 5V V V SENSE0 SENSE1 15A V 15A EFFICIENCY SENSE0 1 10 TSNS0 TSNS1 POWER LOSS + I I + 0 0 TH0 TH1 1 100 I I 0.01 0.1 10 530F 530F THR0 THR1 10nF 10nF LOAD CURRENT (A) V GND V DD33 DD25 4700pF 2200pF 3883 TA01b 220pF 1F 1F 220pF *SOME DETAILS OMITTED FOR CLARITY 3886 TA01a Rev G 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LTC3886/LTC3886-1 TABLE OF CONTENTS Features ..................................................... 1 Responses to V and I Faults/Warnings ........27 OUT OUT Power Conversion ................................................1 Output Overvoltage Fault Response ...................27 Applications ................................................ 1 Output Undervoltage Response .........................28 Typical Application ........................................ 1 Peak Output Overcurrent Fault Response ...........28 Description.................................................. 1 Responses to Timing Faults ....................................28 Absolute Maximum Ratings .............................. 4 Responses to V OV Faults ....................................28 IN Order Information .......................................... 4 Responses to OT/UT Faults .....................................28 Pin Configuration .......................................... 4 Internal Overtemperature Fault/Warn Electrical Characteristics ................................. 5 Response ............................................................28 Typical Performance Characteristics .................. 10 External Overtemperature and Undertemperature Pin Functions .............................................. 13 Fault Response ..................................................29 Block Diagram ............................................. 15 Responses to External Faults .................................29 Operation................................................... 16 Fault Logging ..........................................................29 Overview ................................................................. 16 Bus Timeout Protection ..........................................29 2 Main Control Loop .................................................. 16 Similarity Between PMBus, SMBus and I C EEPROM ................................................................. 17 2-Wire Interface ......................................................30 Power-Up and Initialization ..................................... 17 PMBus Serial Digital Interface ................................30 Soft-Start ................................................................ 18 PMBus Command Summary ............................ 35 Time-Based Sequencing ......................................... 18 PMBus Commands .................................................35 Event-Based Sequencing ........................................ 19 *Data Format ..........................................................40 Shutdown ............................................................... 19 Applications Information ................................ 41 Light-Load Current Operation .................................20 Current Limit Programming .................................... 41 + PWM Loop Compensation ......................................20 I and I Pins ......................................... 41 SENSE SENSE Switching Frequency and Phase .............................20 Low Value Resistor Current Sensing .......................42 Output Voltage Sensing ..........................................21 Inductor DCR Current Sensing ................................43 Output Current Sensing ..........................................21 Slope Compensation and Inductor Peak Current ....44 Input Current Sensing .............................................21 Inductor Value Calculation ......................................44 PolyPhase Load Sharing .........................................22 Inductor Core Selection ..........................................45 External/Internal Temperature Sense ......................22 Power MOSFET and Optional Schottky Diode RCONFIG (Resistor Configuration) Pins ..................23 Selection .................................................................45 Fault Handling .........................................................23 C and C Selection ...........................................46 IN OUT Status Registers and ALERT Masking ................. 24 Variable Delay Time, Soft-Start and Output Voltage Mapping Faults to FAULT Pins ............................26 Ramping .................................................................46 Power Good Pins ................................................26 Digital Servo Mode ................................................. 47 CRC Protection ..................................................26 Soft Off (Sequenced Off) ........................................48 Serial Interface .......................................................26 INTV Regulator.................................................... 49 CC Communication Protection ................................27 Topside MOSFET Driver Supply (C , D ) ................50 B B Device Addressing ..................................................27 Undervoltage Lockout .............................................50 Rev G 2 For more information www.analog.com