6 MHz buck regulator achieve 88% efficiency

Fairchild Semiconductor has announced the FAN5365, a 6MHz, 800mA/1A, digitally programmable buck regulator. The part provides excellent dynamics, high efficiency, and a small footprint. The chip is used 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 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 0.75V to 1.975V in 12.5mV increments.

Additionally, the FAN5365 supports an extended Li-Ion battery range from 2.3V to 5.5V and offers advanced protection features including short-circuit current limit protection, thermal protection and under voltage lock out. The FAN5365 is available in a 1.27mm by 1.29mm, 9-bump WLCSP package. Price is $0.57 in 1,000 quantity pieces.