Tiny PMU for mobiles touts above 95% efficiency

Advanced Analogic Technologies Inc. has released the AAT2504 adjustable 3-channel regulator that combines a step-down converter with two LDOs and touting 95 percent and above efficiency. Targeted at mobile devices with rapidly changing feature sets, the power-management unit (PMU) allows designers to extend system functionality and still benefit from power management integration.

The step-down converter delivers up to 800mA of output current and supports an input range of 2.7V to 5.5V. A 2MHz switching frequency helps minimize the size of external components. By tying the MODE/SYNC pin high, designers can enable an optional PWM-only operation which maintains constant frequency and low output ripple across all load conditions. The converter can also be synchronized to an external clock via the MODE/SYNC pin.

The two LDOs on the AAT2504 operate across an input range of 1.8V to 5.5V, making them suitable for post-regulating from the step-down converter. Each LDO has an independent input and delivers up to 300mA. Through an external feedback pin, designers can program each LDO's output voltage from 0.6V to 3.6V. A Power OK function provides an open drain output signal when LDOA is within regulation.

In addition, the AAT2504 features low 80 ?A typical no-load quiescent current when all 3 regulators are on. The device also features under-voltage lockout and over-temperature protection.

"As mobile systems continue to evolve and add functions, it is difficult for designers to find a single comprehensive PMU that will serve their system's continually changing power needs," notes Bill Weiss, product line director for AnalogicTech. "By offering a switching regulator and two LDOs on a single IC, this AAT2504 sub-PMU allows designers to add functionality to established platforms, such as Bluetooth capability to a personal navigation device or HD radio capability to an MP3 player, and still take advantage of the cost, footprint and power savings of an integrated approach."

Qualified across the -40?C to 85?C temperature range, the AAT2504 is available in a Pb-free, 20-pin, QFN34 package for $1.75 in 1,000-unit quantities.