LT8612 42V, 6A Synchronous Step-Down Regulator with 3µA Quiescent Current FEATURESDESCRIPTION n Wide Input Voltage Range: 3.4V to 42V The LT®8612 is a compact, high efficiency, high speed n Ultralow Quiescent Current Burst Mode® Operation: synchronous monolithic step-down switching regulator n 3μA IQ Regulating 12VIN to 3.3VOUT that consumes only 3µA of quiescent current. Top and n Output Ripple < 10mVP-P bottom power switches are included with all necessary n High Efficiency Synchronous Operation: circuitry to minimize the need for external components. n 95% Efficiency at 3A, 5VOUT from 12VIN Low ripple Burst Mode operation enables high efficiency n 94% Efficiency at 3A, 3.3VOUT from 12VIN down to very low output currents while keeping the output n Fast Minimum Switch-On-Time: 40ns ripple below 10mVP-P. A SYNC pin allows synchronization n Low Dropout Under All Conditions: 250mV at 3A to an external clock. Internal compensation with peak cur- n Allows Use of Small Inductors rent mode topology allows the use of small inductors and n Safely Tolerates Inductor Saturation in Overload results in fast transient response and good loop stability. Conditions The EN/UV pin has an accurate 1V threshold and can be n Adjustable and Synchronizable: 200kHz to 2.2MHz used to program VIN undervoltage lockout or to shut down n Current Mode Operation the LT8612 reducing the input supply current to 1µA. A n Accurate 1V Enable Pin Threshold capacitor on the TR/SS pin programs the output voltage n Internal Compensation ramp rate during start-up. The PG flag signals when VOUT n Output Soft-Start and Tracking is within ±9% of the programmed output voltage as well n Small Thermally Enhanced 3mm × 6mm 28-Lead as fault conditions. The LT8612 is available in a small QFN Package 3mm × 6mm 28-lead QFN package with exposed pad for low thermal resistance. APPLICATIONS L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks of Analog Devices, Inc. All other trademarks are the property of their respective owners. n Automotive and Industrial Supplies n General Purpose Step-Down n GSM Power Supplies TYPICAL APPLICATIONEfficiency at 5VOUT5V 6A Step-Down Converter 100 VIN = 12V VIN 95 VIN BST 5.6V TO 42V 0.1µF V 10µF IN = 24V EN/UV 90 3.9µH VOUT PG SW 5V 85 LT8612 6A SYNC BIAS 100µF 10nF 1210 80 1M TR/SS FB 75 1µF EFFICIENCY (%) 10pF INTV 70 CC RT PGND GND 65 fSW = 700kHz L = 3.9µH 60.4k 243k 60 0 1 2 3 4 5 6 f LOAD CURRENT (A) SW = 700kHz 8612 TA01a 8612 TA01b L: EPCOS B82559 8612fa For more information www.linear.com/LT8612 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts