Datasheet LTC3882-1 (Analog Devices)

LTC3882-1 Dual Output PolyPhase Step-Down DC/DC Voltage Mode Controller with Digital Power System Management
FEATURES DESCRIPTION
n
PMBus/I2C Compliant Serial Interface
The LTC®3882-1 is a dual, PolyPhase DC/DC synchronous
– Monitor Voltage, Current, Temperature and Faults
step-down switching regulator controller with PMBus
– Program Voltage, Soft-Start/Stop, Sequencing,
compliant serial interface. It uses a constant frequency,
Margining, AVP and UV/OV/OC Limits
leading-edge modulation, voltage mode architecture for n
3V ≤ VINSNS ≤ 38V, 0.5V ≤ VOUT ≤ 5.25V
excellent transient response and output regulation. Each n
±0.5% Output Voltage Error
PWM channel can produce output voltages from 0.5V to n
Programmable PWM Frequency or External Clock
5.25V using a wide range of 3.3V compatible power stages,
Synchronization from 250kHz to 1.25MHz
including power blocks, DrMOS or discrete FET drivers. n
Accurate PolyPhase® Current Sharing
Up to four LTC3882-1 devices can operate in parallel for n
Internal EEPROM with Fault Logging and ECC
2-, 3-, 4-, 6- or 8-phase operation. n IC Supply Range: 3V to 13.2V n System configuration and monitoring is supported by the Resistor or Inductor DCR Current Sensing n LTpowerPlay™ software tool. The LTC3882-1 serial interface Power Good Output Voltage Monitor n can read back input voltage, output voltage and current, Optional Resistor Programming for Key Parameters n temperature and fault status. Most operating parameters can 40-Pin (6mm × 6mm) QFN Package n be set via the digital interface or stored in internal EEPROM AEC-Q100 Qualified for Automotive Applications for use at power up. Switching frequency and phase, output voltage and device address can also be set using external
APPLICATIONS
configuration resistors. n High Current Distributed Power Systems All registered trademarks and trademarks are the property of their respective owners. Protected n by U.S. Patents, including 5396245, 5859606, 6144194, 6937178, 7420359 and 7000125. Servers, Network and Storage Equipment n Intelligent Energy Efficient Power Regulation
TYPICAL APPLICATION PWM ENABLE TG/BG HW WRITE DEDICATED DIFFERENTIAL OUTPUT CONTROL PROTECT PGOOD OUTPUT VOUT SENSE
LTC3882 • • •
VOUT0 Only
LTC3882-1 •
V
V
OUT0
&
VOUT1
IN 7V TO 13.2V VCC VINSNS V + SENSE0 FB0 FDMF5820DC VIN LTC3882-1 SDA
Load Step Transient Current Sharing
PWM V SW OUT SCL 1V COMP0
(Using FDMF5820DC DrMOS)
TO/FROM 70A MCU ALERT COMP1 RUN0 PWM0 GND RUN1 TSNS0 I PGOOD0 OUT I + SENSE0 10A/DIV FAULT0 I – SENSE0 TO/FROM PGOOD1 V + SENSE1 EXTERNAL DEVICES FAULT1 I – SENSE1 SYNC I + SENSE1 FDMF5820DC VIN SHARE_CLK IAVG0 PWM SW PWM1 IAVG1 IL0, IL1 10A/DIV TSNS1 IAVG_GND V – GND SENSE0 38821 TA01b V – SENSE1 GND 50µs/DIV 38821 TA01a INDUCTORS: COOPER FP1007R1-R22 SOME DETAILS OMITTED FOR CLARITY Rev B Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Test Circuit Timing Diagram Operation Overview Main Control Loop Power-Up and Initialization Soft-Start Time-Based Output Sequencing Output Ramping Control Voltage-Based Output Sequencing Minimum Output Disable Times Output Short Cycle Light Load Current Operation Switching Frequency and Phase PolyPhase Load Sharing Active Voltage Positioning Input Supply Monitoring Output Voltage Sensing and Monitoring Output Current Sensing and Monitoring External and Internal Temperature Sense Resistor Configuration Pins Internal EEPROM with CRC and ECC Fault Detection Input Supply Faults Hardwired PWM Response to VOUT Faults Power Good Indication (Master) Power Good Indication (Slave) Hardwired PWM Response to IOUT Faults Hardwired PWM Response to Temperature Faults Hardwired PWM Response to Timing Faults External Faults Fault Handling Status Registers and ALERT Masking FAULT Pin I/O Fault Logging Factory Default Operation Serial Interface Serial Bus Addressing Serial Bus Timeout Serial Communication Errors PMBus Command Summary PMBus Commands Data Formats Applications Information Efficiency Considerations PWM Frequency and Inductor Selection Power MOSFET Selection MOSFET Driver Selection Using PWM Protocols CIN Selection COUT Selection Feedback Loop Compensation PCB Layout Considerations Output Current Sensing Output Voltage Sensing Soft-Start and Stop Time-Based Output Sequencing and Ramping Voltage-Based Output Sequencing Using Output Voltage Servo Using AVP PWM Frequency Synchronization PolyPhase Operation and Load Sharing External Temperature Sense Resistor Configuration Pins Internal Regulator Outputs IC Junction Temperature Derating EEPROM Retention at Temperature Configuring Open-Drain Pins PMBus Communication and Command Processing Status and Fault Log Management LTpowerPlay – An Interactive Digital Power GUI Interfacing to the DC1613 Design Example PMBus COMMAND DETAILS Addressing and Write Protect PAGE PAGE_PLUS_WRITE PAGE_PLUS_READ WRITE_PROTECT MFR_ADDRESS MFR_RAIL_ADDRESS General Device Configuration PMBUS_REVISION CAPABILITY On, Off and Margin Control ON_OFF_CONFIG MFR_CONFIG_ALL_LTC3882-1 OPERATION MFR_RESET PWM Configuration FREQUENCY_SWITCH MFR_PWM_CONFIG_LTC3882-1 MFR_CHAN_CONFIG_LTC3882-1 MFR_PWM_MODE_LTC3882-1 Input Voltage and Limits VIN_ON VIN_OFF VIN_OV_FAULT_LIMIT VIN_UV_WARN_LIMIT Output Voltage and Limits VOUT_MODE VOUT_COMMAND MFR_VOUT_MAX VOUT_MAX MFR_VOUT_AVP VOUT_MARGIN_HIGH VOUT_MARGIN_LOW VOUT_OV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT VOUT_UV_FAULT_LIMIT Output Current and Limits IOUT_CAL_GAIN MFR_IOUT_CAL_GAIN_TC IOUT_OC_FAULT_LIMIT IOUT_OC_WARN_LIMIT Output Timing, Delays, and Ramping MFR_RESTART_DELAY TON_DELAY TON_RISE TON_MAX_FAULT_LIMIT VOUT_TRANSITION_RATE TOFF_DELAY TOFF_FALL TOFF_MAX_WARN_LIMIT External Temperature and Limits MFR_TEMP_1_GAIN MFR_TEMP_1_OFFSET OT_FAULT_LIMIT OT_WARN_LIMIT Status Reporting STATUS_BYTE UT_FAULT_LIMIT STATUS_WORD STATUS_VOUT STATUS_IOUT STATUS_INPUT STATUS_TEMPERATURE STATUS_CML STATUS_MFR_SPECIFIC MFR_PADS_LTC3882-1 MFR_COMMON MFR_INFO CLEAR_FAULTS Telemetry READ_VIN MFR_VIN_PEAK READ_VOUT MFR_VOUT_PEAK READ_IOUT MFR_IOUT_PEAK READ_POUT READ_TEMPERATURE_1 MFR_TEMPERATURE_1_PEAK READ_TEMPERATURE_2 MFR_TEMPERATURE_2_PEAK READ_DUTY_CYCLE READ_FREQUENCY MFR_CLEAR_PEAKS Fault Response and Communication VIN_OV_FAULT_RESPONSE VOUT_OV_FAULT_RESPONSE VOUT_UV_FAULT_RESPONSE IOUT_OC_FAULT_RESPONSE OT_FAULT_RESPONSE UT_FAULT_RESPONSE MFR_OT_FAULT_RESPONSE TON_MAX_FAULT_RESPONSE MFR_RETRY_DELAY SMBALERT_MASK MFR_FAULT_PROPAGATE_LTC3882-1 MFR_FAULT_RESPONSE MFR_FAULT_LOG Fault Log Operation MFR_FAULT_LOG_CLEAR EEPROM User Access STORE_USER_ALL RESTORE_USER_ALL MFR_COMPARE_USER_ALL MFR_FAULT_LOG_STORE MFR_EE_xxxx USER_DATA_0x Unit Identification MFR_ID MFR_MODEL MFR_SERIAL MFR_SPECIAL_ID Typical Applications Package Description Revision History Typical Application Related Parts