Features

• 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

Typical Application

Description

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.