LTC3858IUFD-1#PBF

The LTC3858IUFD-1#PBF is a low quiescent current, high performance, adjustable frequency synchronous step-down DC/DC switching controller. It is part of a family of application specific DC/DC switching controllers that provide superior efficiency performance from switch mode regulators. The LTC3858IUFD-1#PBF is specifically designed for high current applications that require fast transient response and high efficiency. It is intended for use in voltage regulators, DC/DC converters and similar power regulation applications.

Features

• High current capability: up to 6A
• Wide input voltage range: 4.5V to 36V
• High switching frequency: up to 1MHz
• Low quiescent current: only 10mA
• Precise current limit with accuracy of ±5%
• Internal soft-start/hiccup andfoldback/over temperature protection
• Complete solutions available with external components

Application Field

The LTC3858IUFD-1#PBF is ideal for applications requiring high current, low quiescent current, low parts count and efficient operation. It can be used for low voltage, fixed and adjustable output solutions. It is suitable for a wide range of applications including on-board point-of-load voltage conversion, microprocessor/digital system power supplies, and distributed power architectures. It is particularly suited for high-current applications such as 12V to 1V conversion and 24V to 1V conversion.

Working Principle

The LTC3858IUFD-1#PBF is a low voltage, high current synchronous step-down switching regulator that utilizes a synchronous rectification topology. The controller regulates the output voltage by manipulating the two power MOSFETs alternately switching them on and off. The output voltage is determined by the gradual change in duty cycle of the power MOSFETs and the output inductor ripple current. The duty cycle of the power MOSFETs is changed according to the output voltage and the output inductor current.

The LTC3858IUFD-1#PBF also operates in pulse frequency modulation (PFM) mode at light loads to reduce noise and improve efficiency. In addition, the LTC3858IUFD-1#PBF provides accurate current limit. This current limiting, coupled with a stable output voltage and a low quiescent current, make the LTC3858IUFD-1#PBF ideal for energy sensitive applications.