LTC7813 Low IQ, 60V Synchronous Boost+Buck Controller FeaTuresDescripTion n Synchronous Boost and Buck Controllers The LTC®7813 is a high performance synchronous n When Cascaded, Allows VIN Above, Below, or Equal Boost+Buck DC/DC switching regulator controller that to Regulated VOUT of Up to 60V drives all N-channel power MOSFET stages. It contains n Wide Bias Input Voltage Range: 4.5V to 60V independent step-up (boost) and step-down (buck) n Output Remains in Regulation Through Input Dips controllers that can regulate two separate outputs or be (e.g. Cold Crank) Down to 2.2V cascaded to regulate an output voltage from an input n Adjustable Gate Drive Level 5V to 10V (OPTI-DRIVE) voltage that can be above, below, or equal to the output n Low EMI with Low Input and Output Ripple voltage. The LTC7813 operates from a wide 4.5V to 60V n Fast Output Transient Response input supply range. When biased from the output of the n No External Bootstrap Diodes Required boost regulator, the LTC7813 can operate from an input n High Light Load Efficiency supply as low as 2.2V after start-up. The 34μA no-load n Low Operating IQ: 29µA (One Channel On) quiescent current (both channels on) extends operating n Low Operating IQ: 34µA (Both Channels On) runtime in battery-powered systems. n RSENSE or Lossless DCR Current Sensing Unlike conventional buck-boost regulators, the LTC7813’s n Buck Output Voltage Range: 0.8V ≤ VOUT ≤ 60V cascaded Boost+Buck solution has continuous, non- n Boost Output Voltage Up 60V pulsating, input and output currents, substantially reducing n Phase-Lockable Frequency (75kHz to 850kHz) voltage ripple and EMI. The LTC7813 has independent n Small 32-Pin 5mm × 5mm QFN Package feedback and compensation points for the boost and buck regulation loops, enabling a fast output transient response applicaTions that can be externally optimized. n Automotive and Industrial Power Systems L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective n High Power Battery Operated Systems owners. Typical applicaTionWide Input Range to 10V/10A Low IQ Cascaded Boost+Buck Regulator VIN 8V TO 60V 2.2µH 10µH VMID, 12V** VOUT DOWN TO 10V 2.2V AFTER 22µF 6.8µF 10A* START-UP 47µF 22µF ×3 ×4 47µF 47µF ×3 1.62k 2.32k 15k R 33pF B1 332k 0.1µF 1µF 0.1µF 0.1µF RA1 11.5k SENSE2+ SENSE2– BG2 SW2 BOOST2 TG2 VFB2 VBIAS TG1 BOOST1 SW1 BG1 SENSE1+ SENSE1– VFB1 LTC7813 EXTVCC RUN1 RUN2 ITH1 ITH2 TRACK/SS1 SS2 FREQ PLLIN/MODE GND DRVCC INTVCC VPRG2 ILIM DRVUVDRVSET 7813 TA01 VIN 8.87k 6.19k 0.1µF 4.7µF 0.1µF 37.4k 100pF 470pF 0.1µF 3300pF 22nF * WHEN VIN <8V MAXIMUM LOAD CURRENT AVAILABLE IS REDUCED **VMID = 12V WHEN VIN < 12V VMID FOLLOWS VIN WHEN VIN > 12V 7813f For more information www.linear.com/LTC7813 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagrams Operation Applications Information Typical Applications Package Description Typical Application Related Parts