High Input Voltage, Boost, Flyback, SEPIC and Inverting Converter

The LT3958 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 84V at 3.3A and driven from an internal regulated 7.2V supply. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages.

The operating frequency of LT3958 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 5V, and a low shutdown quiescent current of less than 1μA, make the LT3958 ideally suited for battery-powered systems.

The LT3958 features soft-start and frequency foldback functions to limit inductor current during start-up.

Applications

* Automotive

* Telecom

* Industrial

* Wide Input Voltage Range: 5V to 80V

* Single Feedback Pin for Positive or Negative Output Voltage

* Internal 3.3A/84V Power Switch

* Current Mode Control Provides Excellent Transient Response

* Programmable Operating Frequency (100kHz to 1MHz) with One External Resistor

* Synchronizeable to an External Clock

* Low Shutdown Current < 1μA

* Internal 7.2V Low Dropout Voltage Regulator

* Programmable Input Undervoltage Lockout with Hysteresis

* Programmable Soft-Start

* Thermally Enhanced QFN (5mm × 6mm) Package