Datasheet LTC7871 (Analog Devices)

LTC7871 Six-Phase, Synchronous Bidirectional Buck or Boost Controller
FEATURES DESCRIPTION
n
Unique Architecture Allows Dynamic Regulation of
The LTC®7871 is a high performance bidirectional buck or
Input Voltage, Output Voltage or Current
boost switching regulator controller that operates in either n
Operates with External Gate Drivers and MOSFETs
buck or boost mode on demand. It regulates in buck mode n
VHIGH Voltages Up to 100V; VLOW Voltages Up to 60V
from VHIGH-to-VLOW and boost mode from VLOW-to-VHIGH n
Synchronous Rectification: Up to 98% Efficiency
depending on a control signal, making it ideal for 48V/12V n
ADI-Proprietary Advanced Current Mode Control
automotive dual battery systems. An accurate current pro- n
±1% Voltage Regulation Accuracy Overtemperature
gramming loop regulates the maximum current that can n
Accurate, Programmable Inductor Current
be delivered in either direction. The LTC7871 allows both
Monitoring and Bidirectional Regulation
batteries to supply energy to the load simultaneously by n
SPI Compliant Serial Interface
driving energy from either battery to the other. n
Operation Status and Fault Report
Its proprietary constant frequency current mode archi- n
Programmable VHIGH, VLOW Margining
tecture enhances the signal-to-noise ratio enabling low n Phase-Lockable Frequency: 60kHz to 750kHz noise operation and provides excellent current match- n Optional Spread Spectrum Modulation ing between phases. Additional features include an SPI- n Multiphase/Multi-ICs Operation Up to 24 Phases compliant serial interface, discontinuous or continuous n Selectable CCM/DCM/Burst Mode Operation mode of operation, OV/UV monitors, independent loop n Thermally Enhanced 64-Lead LQFP Package compensation for buck and boost operation, accurate n AEC-Q100 Qualification in Progress inductor current monitoring and overcurrent protection.
APPLICATIONS
The LTC7871 is available in a 64 pin 10mm × 10mm LWE package. n Automotive 48V/12V Dual Battery Systems n Backup Power Systems All registered trademarks and trademarks are the property of their respective owners.
TYPICAL APPLICATION High Voltage Bidirectional Controller with Programming and Monitoring Functions Boost-to-Buck Transition Boost–to–Buck Transition
VHIGH 30V TO 2.2µF VFB BUCK LOW 70V ×12 3.01M 2.2Ω OV 5V/DIV LOW 10k 210k EXTVCC V OV LOW 499k HIGH + 10k 2V/DIV 33µF UVHIGH VHIGH ×12 VFBHIGH 90.9k IL V 48.7k HIGH 110k 5A/DIV 6.8µH 1mΩ 12.7k 10k 1µF PWM1 DRIVER VLOW VHIGH 22µF 12V/180A 2V/DIV 47pF 1nF 16.9k 1.5k 0.1µF 0.1µF ×6 LTC7060 + V LTC7871 100µF SW 100V/DIV 0.1µF 0.33µF ×6 499Ω 499Ω 1.69k ITH 7871 TA01b HIGH SNSA1+ 50µs/DIV SNSD1+ ITH PINS NOT USED LOW SNS1– IMON IN THIS CIRCUIT: SS (PHASE 2 TO PHASE 5) CLKOUT SETCUR DRVSET DRVCC VHIGH MODE 45.3k V5 ILIM 100pF 4.7µF 51k RUN PWMEN 6.8µH 1mΩ FAULT PWM6 DRIVER 0.1µF 4.7µF 37.4k PGOOD FREQ 16.9k 1.5k SGND 0.1µF 0.1µF LTC7060 BUCK BOOST BUCK SCLK 1.69k SPI SDI SNSA6+ NOTE: SDO REQUIRES PULL-UP INTERFACE SDO SNSD6+ CSB SNS6– 7871 TA01a Rev. 0 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 Operation Applications Information Serial Port Serial Port Register Details Typical Applications Package Description Typical Application Related Parts