LT3757 DC/DC controller

Linear Technology has announced the LT3757, a wide input range DC/DC controller for boost, flyback, SEPIC and inverting power supply applications, capable of generating either positive or negative regulated output voltages.

The device has two voltage feedback error amplifiers and reference voltages. One set is for positive output voltages, with a 1.60 V reference, the other for negative output voltages, with a -0.80 V reference, both off a single feedback pin.

The controller operates with an input voltage range from 2.9 to 40, achieves efficiencies up to 96% and is suitable for industrial, motor vehicle, medical and telecom applications. With a programmable fixed or synchronisable operating frequency from 100 kHz to 1 MHz, designers can choose a range of inductors and capacitors to optimise size, performance and cost.

The fixed frequency, current-mode control results in stable operation over a wide range of supply and output voltages, along with all ceramic capacitor designs.

It drives an external N-channel MOSFET from an internally regulated 7.2 V supply. Programmable soft-start allows control of the output voltage turn-on time. In addition, the device features a programmable input undervoltage lockout with hysteresis, along with output overvoltage and overcurrent protection.