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LT3957A - Boost, Flyback, SEPIC and Inverting Converter with 5A, 40V Switch

The LT®3957A is a wide input range, current mode DC/DC converter which is capable of generating either positive or negative output voltages. It can be configured as either a boost, flyback, SEPIC or inverting converter. It features an internal low side N-channel power MOSFET rated for 40V at 5A and driven from an internal regulated 5.2V supply. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages.

The operating frequency of LT3957A can be set with an external resistor over a 100kHz to 1MHz range, and can be synchronized to an external clock using the SYNC pin. A minimum operating supply voltage of 3V, and a low shutdown quiescent current of less than 1μA, make the LT3957A ideally suited for battery-powered systems.

The LT3957A features soft-start and frequency foldback functions to limit inductor current during start-up. The LT3957A has improved load transient performance compared to the LT3957.

Features Wide Input Voltage Range: 3V to 40V Single Feedback Pin for Positive or Negative Output Voltage Internal 5A/40V Power Switch Current Mode Control Provides Excellent Transient Response Programmable Operating Frequency (100kHz to 1MHz) with One External Resistor Synchronizable to an External Clock Low Shutdown Current < 1μA Internal 5.2V Low Dropout Voltage Regulator Programmable Input Undervoltage Lockout with Hysteresis Programmable Soft-Start Thermally Enhanced QFN (5mm × 6mm) Package Typical Application

Applications Automotive Telecom Industrial Packaging

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