Datasheet LTC7132 (Analog Devices)

LTC7132 25A, Dual PolyPhase Regulator with Digital Power System Management
FEATURES DESCRIPTION
n
PMBus/I2C Compliant Serial Interface
The LTC®7132 is a dual output PolyPhase DC/DC synchro-
– Telemetry Read-Back Includes VIN, IIN, VOUT, IOUT,
nous step-down monolithic regulator with an I2C-based
Temperature and Faults
PMBus compliant serial interface. The regulator employs
– Programmable Voltage, Current Limit, Digital Soft-
a constant-frequency current mode architecture, together
Start/Stop, Sequencing, Margining, OV/UV/OC
with a unique scheme to provide excellent performance n
Sub-Milliohm DCR Current Sensing
in sub-milliohm DCR applications. The LTC7132 is sup- n
Digitally Adjustable Loop Compensation Parameters
ported by the LTpowerPlay® software development tool n
±0.5% Output Voltage Accuracy Over Temperature
with graphical user interface (GUI). n
Integrated Input Current Sense Amplifier
Programmable loop compensation allows the regulator to n
Internal EEPROM with ECC and Fault Logging
be compensated digitally. The switching frequency, chan- n
Integrated N-Channel MOSFET Gate Drivers
nel phasing and device address can be programmed both
Power Conversion
by the digital interface as well as the external configura- n Wide VIN Range: 4.5V to 20V tion resistors. Additionally, parameters can be set via the n VOUT Range: 0.5V to 3.5V (with Ultralow DCR Setting); digital interface and stored in EEPROM. Both outputs have 0.5V to 5.5V (Typical DCR Setting) independent power good indicators and FAULT function. n Accurate PolyPhase® Current Sharing for Up to 6 Phases n The LTC7132 can be configured to operate in discontinu- Available in a 140-Lead (9mm × 11.25mm × 2.22mm) ous (pulse-skipping) mode or forced continuous conduc- BGA Package tion mode. Each channel can deliver up to 25A of load current; the total current capability will depend on the
APPLICATIONS
total power dissipations on both channels. n Telecom, Datacom and Storage Systems All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620, 6144194, 6177787, 6580258, 5408150, n Industrial and Point-of-Load Applications 7420359, 8648623, 8786265, 8823352, 7000125. Licensed under U.S. Patent 7000125 and other related patents worldwide.
TYPICAL APPLICATION
1µF 1Ω 2mΩ VIN 4.5V TO 15V
Efficiency and Power Loss
10µF 4.7µF 10µF ×2 C10 D2 INTV + – D4 ×2 SV I I
vs Load Current
CC IN IN IN 270µF PVIN0 PVIN1 ×2 0.1µF 0.1µF 100 6 EXTVCC = 5.5V DCR = 0.29mΩ DCR = 0.29mΩ BOOST0 BOOST1 VIN = 12V L2 0.3µH L1 0.3µH 95 fSW = 425kHz 5 SW0 SW1 LTC7132* CCM SDA FAULT0 POWER LOSS (W) SCL FAULT1 90 4 PMBus FAULT MANAGEMENT ALERT PGOOD0 INTERFACE RUN0 PGOOD1 TO/FROM 85 3 RUN1 SHARE_CLK OTHER LTC DEVICES EXTVCC 931Ω 931Ω EFFICIENCY (%) 2 I + + 80 SENSE0 ISENSE1 0.22µF 0.22µF I – I – V SENSE0 SENSE1 OUT0 V 75 1 V + + OUT1 1.8V, 20A SENSE0 VSENSE1 1V, 20A 330µF 100µF 100µF 330µF ×2 ×2 ×2 V – – ×2 70 0 SENSE0 VSENSE1 0 4 8 12 16 20 TSNS0 TSNS1 I LOAD CURRENT (A) TH0 ITH1 7132 TA01a 150pF 7132 TA01b ITH_R0 ITH_R1 150pF C5 EFFICIENCY POWER LOSS VDD33 PGND SGND V 10nF DD25 1500pF VOUT = 1.8V VOUT = 1.8V 4700pF 1µF 1µF VOUT = 1.0V VOUT = 1.0V *SOME DETAILS OMITTED FOR CLARITY Rev 0 Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Table of Contents Absolute Maximum Ratings Order Information Pin Configuration 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 Serial Interface Communication Protection Device Addressing Responses to VOUT and IIN/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 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 Thermal Considerations Programmable Loop Compensation Checking Transient Response PolyPhase Configuration PC Board Layout Checklist PC Board Layout Debugging Design Example Additional Design Checks Connecting the USB to I2C/SMBus/PMBus Controller to the LTC7132 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 Logging Block Memory Write/Read Typical Applications Package Description Typical Application Related Parts