Datasheet LTC3884, LTC3884-1 (Analog Devices) - 10

LTC3884/LTC3884-1
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C (Notes 2, 3). VIN = 12V, EXTVCC = 0V, VRUN0,1 = 3.3V, fSYNC = 500kHz (externally driven) and all programmable parameters at factory default, unless otherwise specified. SYMBOL PARAMETER CONDITION MIN TYP MAX UNITS Open-Drain Outputs SCL, SDA, FAULTn , ALERT, RUNn , SHARE_CLK, PGOODn
VOL Output Low Voltage ISINK = 3mA 0.4 V
Digital Inputs SHARE_CLK, WP
VIH Input High Threshold Voltage l 1.5 1.8 V VIL Input Low Threshold Voltage l 0.6 1 V
Digital Filtering of FAULTn
IFLTG Input Digital Filtering FAULTn 3 µs
Digital Filtering of PGOODn
IFLTG Output Digital Filtering PGOODn 60 µs
Digital Filtering of RUNn
IFLTG Input Digital Filtering RUN 10 µs
PMBus Interface Timing Characteristics
fSCL Serial Bus Operating Frequency l 10 400 kHz tBUF Bus Free Time Between Stop and l 1.3 µs Start tHD(STA) Hold Time After Repeated Start l 0.6 µs Condition After This Period, the First Clock is Generated tSU(STA) Repeated Start Condition Setup Time l 0.6 10000 µs tSU(ST0) Stop Condition Setup Time l 0.6 µs tHD(DAT) Date Hold Time Receiving Data l 0 µs Transmitting Data l 0.3 0.9 µs tSU(DAT) Data Setup Time Receiving Data l 0.1 µs tTIMEOUT_SMB Stuck PMBus Timer Non-Block Reads Measured from the Last PMBus Start Event 32 ms Stuck PMBus Timer Block Reads 255 tLOW Serial Clock Low Period l 1.3 10000 µs tHIGH Serial Clock High Period l 0.6 µs
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 3:
All currents into device pins are positive; all currents out of device pins may cause permanent damage to the device. Exposure to any Absolute are negative. All voltages are referenced to ground unless otherwise specified Maximum Rating condition for extended periods may affect device
Note 4:
Rise and fall times are measured using 10% and 90% levels. Delay reliability and lifetime. times are measured using 50% levels. CLOAD = 3500pF is guaranteed by
Note 2:
The LTC3884/LTC3884-1 is tested under pulsed load conditions design. such that TJ ≈ TA. The LTC3884E/LTC3884E-1 is guaranteed to meet
Note 5:
The data format in PMBus is 5 bits exponent (signed) and 11 bits performance specifications from 0°C to 85°C. Specifications over the –40°C mantissa (signed). This limits the output resolution to 10 bits though the to 125°C operating junction temperature range are assured by design, internal ADC is 16 bits and the calculations use 32-bit words. characterization and correlation with statistical process controls. The
Note 6:
The data conversion is done by default in round robin fashion. All LTC3884I/LTC3884I-1 is guaranteed over the full –40°C to 125°C operating inputs signals are continuously converted for a typical latency of 90ms. junction temperature range. TJ is calculated from the ambient temperature Setting MFR_ADC_CONTRL value to be 0 to 12, LTC3884 can do fast data TA and power dissipation PD according to the following formula: conversion with only 8ms to 10ms. See section PMBus Command for TJ
=
TA + (PD
•
θJA) details. The maximum ambient temperature consistent with these specifications is
Note 7:
The IOUT_CAL_GAIN = 1.0mΩ and MFR_IOUT_TC = 0.0. Value as determined by specific operating conditions in conjunction with board layout, read from READ_IOUT in Amperes. the rated package thermal impedance and other environmental factors. 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 Time-Based Sequencing Voltage-Based Sequencing Shutdown Light-Load Current Operation Switching Frequency and Phase PWM Loop Compensation Output Voltage Sensing INTVCC/EXTVCC Power Output Current Sensing and Sub Milliohm DCR Current Sensing Input Current Sensing PolyPhase Load Sharing External/Internal Temperature Sense RCONFIG (Resistor Configuration) Pins Fault Detection and Handling Status Registers and ALERT Masking Mapping Faults to FAULT Pins Power Good Pins CRC Protection and ECC Serial Interface Communication Protection Device Addressing Responses to VOUT, IIN 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 Internal Overtemperature Fault Response External Overtemperature and Undertemperature Fault Response Responses to Input Overcurrent and Output Undercurrent Faults Responses to External Faults Fault Logging Bus Timeout Protection 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 ISENSE0± and ISENSE1± Pins Inductor DCR Sensing Inductor Value Calculation Inductor Core Selection Low Value Resistor Current Sensing Slope Compensation and Inductor Peak Current Power MOSFET and Optional Schottky Diode Selection Variable Delay Time, Soft-Start and Output Voltage Ramping Digital Servo Mode Soft Off (Sequenced Off) INTVCC/EXTVCC Power Topside MOSFET Driver Supply (CB, DB) Undervoltage Lockout CIN and COUT Selection Fault Indication Open-Drain Pins Phase-Locked Loop and Frequency Synchronization Minimum On-Time Considerations External Temperature Sense Input Current Sense Amplifier External Resistor Configuration Pins (RCONFIG) Voltage Selection Frequency Selection Phase Selection Address Selection Using RCONFIG Efficiency Considerations Programmable Loop Compensation Checking Transient Response PolyPhase Configuration Master Slave Operation PC Board Layout Checklist PC Board Layout Debugging Design Example Additional Design Checks Connecting the USB to I2C/SMBus/PMBus Controller to the LTC3884 in System 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 Output Current and Limits Input Current and Limits Temperature External Temperature Calibration 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 Fault Warning and Status Telemetry NVM Memory Commands Store/Restore Fault Log Operation Fault Logging Block Memory Write/Read Typical Applications Package Description Revision History Typical Application Related Parts