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LT8611 - 42V, 2.5A Synchronous Step-Down Regulator with Current Sense and 2.5μA Quiescent Current

The LT®8611 is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that consumes only 2.5μA of quiescent current. Top and bottom power switches are included with all necessary circuitry to minimize the need for external components. The built-in current sense amplifier with monitor and control pins allows accurate input or output current regulation and limiting. Low ripple Burst Mode operation enables high efficiency down to very low output currents while keeping the output ripple below 10mVP-P. A SYNC pin allows synchronization to an external clock. Internal compensation with peak current mode topology allows the use of small inductors and results in fast transient response and good loop stability. The EN/UV pin has an accurate 1V threshold and can be used to program VIN undervoltage lockout or to shut down the LT8611 reducing the input supply current to 1μA. A capacitor on the TR/SS pin programs the output voltage ramp rate during start-up. The PG flag signals when VOUT is within ±9% of the programmed output voltage as well as fault conditions. The LT8611 is available in a small 24-lead 3mm × 5mm QFN package with exposed pad for low thermal resistance.

Features Rail-to-Rail Current Sense Amplifier with Monitor Wide Input Voltage Range: 3.4V to 42V Ultralow Quiescent Current Burst Mode® Operation: 2.5μA IQ Regulating 12VIN to 3.3VOUT Output Ripple < 10mVP-P High Efficiency Synchronous Operation: 96% Efficiency at 1A, 5VOUT from 12VIN 94% Efficiency at 1A, 3.3VOUT from 12VIN Fast Minimum Switch-On Time: 50ns Low Dropout Under All Conditions: 200mV at 1A Allows Use Of Small Inductors Low EMI Adjustable and Synchronizable: 200kHz to 2.2MHz Current Mode Operation Accurate 1V Enable Pin Threshold Internal Compensation Output Soft-Start and Tracking Small Thermally Enhanced 3mm × 5mm 24-Lead QFN Package Typical Application

Applications Automotive and Industrial Supplies General Purpose Step-Down CCCV Power Supplies Packaging

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