Generation of positive or negative regulated voltage

October 6, 2011 – Linear Technology Korea (Country Manager Hong Sa-kwak, www.linear.com ) announced the development of a DC/DC controller (product name: LT3759) for boost, SEPIC, and inverting power supply applications with a wide input range. The LT3759 can generate positive or negative regulated output voltages. It also features two voltage feedback error amplifiers and a reference voltage. One set is for the positive output voltage and the other is for the negative output voltage; with both having a single feedback pin, the LT3759 is an ideal multi-functional DC/DC controller for various types of power supply designs.

The LT3759 operates over an input voltage range of 1.6V to 42V and is suitable for industrial, automotive, medical, and telecom applications. The operating frequency range of 100kHz to 1MHz is programmable and synchronizable, allowing designers to select inductors and capacitors based on size, performance, and cost. The fixed-frequency, current-mode control architecture provides stable operation over a wide supply and output voltage range, and the use of all-ceramic capacitors further reduces the solution size.

The LT3759 drives an external N-channel MOSFET from an internally regulated 4.75V supply. Other features include a programmable soft start, a precision 50mV current sensing threshold, a programmable hysteresis undervoltage lockout (UVLO), and a power good signal for output overvoltage and overcurrent protection.

The LT3759 is available in a thermally enhanced MSOP-12 package, with an extended operating temperature range of -40°C to 125°C for industrial use. The H-class version has a temperature range of -40°C to 150°C. Pricing starts at $2.35 per unit for orders of 1,000. For more information, please visit www.linear.com/product/LT3759 .

Photo caption: Boost, SEPIC, and inverting controllers

Product Features: LT3759

• Boost, SEPIC, and Inverting Applications
• Wide input operating voltage range: 1.6V ~ 42V
• Set positive or negative output voltage using a single feedback pin
• Selectable fixed operating frequency from 100kHz to 1MHz
• Synchronization with an external clock possible
• Programmable soft start function
• True current mode control function
• Internal 4.75V low dropout voltage regulator
• Input UVLO for programmable hysteresis