Fairchild Dynamic Voltage Scaling Buck Regulator Saves Power in Lithium Ion Battery Devices

Consumer demand is driving the need for cell phone designers and chipset reference design firms to offer more multimedia functionality in their devices, resulting in heavy core processor demands, which in turn pushes the need for power reduction techniques such as dynamic voltage scaling (DVS). Fairchild Semiconductor’s FAN5365, a 6MHz, 800mA/1A, digitally programmable Buck regulator, provides excellent dynamics, high efficiency and a small footprint, making it an ideal complimentary piece to the PMIC in a system engineer’s design.

The FAN5365, available in a 1.27 by 1.29mm, 9-bump WLCSP package is said to be the smallest 6MHz DVS buck regulator currently available and is up to 40% smaller than previous solutions, making it well suited for powering core processors in single cell lithium ion (Li-Ion) battery devices such as smartphones, ultra-mobile PCs, tablets and wireless broadband hot spots.

The company says the device offers excellent transient response while consuming low 40µA quiescent current in light-load efficiency enhancing PFM mode. For heavier loads, the regulator will automatically switch to a fixed frequency 6MHz PWM mode, allowing designers to use low cost and compact chip inductors and capacitors. The FAN5365 supports up to 800mA or 1A load currents and also offers a pin-selectable or I2C Bus® interface programmable output voltage, adjustable from 0.75 to 1.975V in 12.5mV increments.

Additionally, the FAN5365 supports an extended Li-Ion battery range from 2.3 to 5.5V and offers advanced protection features including short-circuit current limit protection, thermal protection and under voltage lock out.

The FAN5365 is part of Fairchild’s comprehensive portfolio of DVS Buck converters, which enable engineers to drive innovation in their designs by integrating functionality, improving performance and reducing device size as well as overall component count.

The units are priced at US $.57 in 1,000 quantity pieces with a delivery of 12 weeks ARO.