LT3757 Inverting Controller

By Analog Devices Inc 46

LT3757 Inverting Controller

Linear Technology's LT3757 is a wide input range, current mode, DC / DC controller that is capable of generating either positive or negative output voltages. It can be configured as a boost, flyback, SEPIC or inverting converter. The LT3757 drives a low side external N-channel power MOSFET from an internal regulated 7.2 V supply. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages.

The operating frequency of LT3757 can be set with an external resistor over a 100 kHz to 1 MHz range and can be synchronized to an external clock using the SYNC pin. A low minimum operating supply voltage of 2.9 V and a low shutdown quiescent current of less than 1 µA make the LT3757 ideally suited for battery-operated systems.

The LT3757 features soft-start and frequency foldback functions to limit inductor current during start-up and output short-circuit. The device is available in a small 10-lead DFN (3 mm × 3 mm) or MSOP package.

  • Wide input voltage range: 2.9 V to 40 V
  • Positive or negative output voltage programming with a single feedback pin
  • Current mode control provides excellent transient response
  • Programmable operating frequency (100 kHz to 1 MHz) with one external resistor
  • Synchronizeable to an external clock
  • Output overvoltage protection
  • Low shutdown current < 1 µA
  • Internal 7.2 V low dropout voltage regulator
  • Programmable input undervoltage lockout with hysteresis
  • Programmable soft-start
  • Small 10-lead DFN (3 mm × 3 mm) and thermally enhanced 10-pin MSOP packages
  • Automotive and industrial boost, flyback, SEPIC and inverting converters
  • Telecom power supplies
  • Portable electronic equipment