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 40ľA 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.