LT8613 42V, 6A Synchronous Step-Down Regulator with Current Sense and 3µA Quiescent Current FeaTuresDescripTion n Rail-to-Rail Current Sense Amplifier with Monitor The LT®8613 is a compact, high efficiency, high speed n Wide Input Voltage Range: 3.4V to 42V synchronous monolithic step-down switching regulator n Ultralow Quiescent Current Burst Mode® Operation: that consumes only 3µA of quiescent current. Top and 3μA IQ Regulating 12VIN to 3.3VOUT bottom power switches are included with all necessary Output Ripple < 10mVP-P circuitry to minimize the need for external components. n High Efficiency Synchronous Operation: The built-in current sense amplifier with monitor and 95%Efficiency at 3A, 5VOUT from 12VIN control pins allows accurate input or output current 94%Efficiency at 3A, 3.3VOUT from 12VIN regulation and limiting. Low ripple Burst Mode operation n Fast Minimum Switch-On Time: 40ns enables high efficiency down to very low output currents n Low Dropout Under All Conditions: 250mV at 3A while keeping the output ripple below 10mVP-P. A SYNC n Allows Use Of Small Inductors pin allows synchronization to an external clock. Internal n Low EMI compensation with peak current mode topology allows n Adjustable and Synchronizable: 200kHz to 2.2MHz the use of small inductors and results in fast transient n Current Mode Operation response and good loop stability. The EN/UV pin has an n Accurate 1V Enable Pin Threshold accurate 1V threshold and can be used to program VIN n Internal Compensation undervoltage lockout or to shut down the LT8613 reduc- n Output Soft-Start and Tracking ing the input supply current to 1µA. A capacitor on the n Small Thermally Enhanced 3mm × 6mm 28-Lead TR/SS pin programs the output voltage ramp rate during QFN Package start-up. The PG flag signals when VOUT is within ±9% of the programmed output voltage as wel as fault conditions. applicaTions The LT8613 is available in a small 28-lead 3mm × 6mm n QFN package with exposed pad for low thermal resistance. Automotive and Industrial Supplies n General Purpose Step-Down L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective n CCCV Power Supplies owners. Typical applicaTionEfficiency at 5V5V Step-Down Converter with 6A Output Current LimitOUT 100 VIN V V IN = 12V IN BST 5.8V TO 42V 10µF 95 ON OFF EN/UV 0.1µF V 3.9µH 8mΩ V 90 IN = 24V SYNC OUT SW LT8613 5V IMON 1µF 6A 85 ICTRL ISP 80 ISN BIAS EFFICIENCY (%) 75 PG 10pF INTVCC 70 TR/SS 10µF 1M 65 fSW = 700kHz RT FB L = 3.9µH PGND GND 60 1µF 60.4k 243k 100µF 0 1 2 3 4 5 6 LOAD CURRENT (A) 8613 TA01a fSW = 700kHz 8613 TA01b L: EPCOS B82559 8613f 1 For more information www.linear.com/LT8613 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts
