AnalogicTech has introduced the AAT2504, an adjustable 3-channel regulator that combines a step-down converter with two low dropout linear regulators (LDOs). By offering a switching regulator and two LDOs on a single IC, the AAT2504 sub-PMU allows designers to add functionality to established platforms, such as Bluetooth capability to a Personal Navigation Device (PND) or HD radio capability to an MP3 player, and still take advantage of the cost, footprint and power savings of an integrated approach. 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 minimise the size of external components. Efficiency exceeds 95%.

By tying the MODE/SYNC pin high, designers can enable an optional PWM-only operation that maintains constant frequency and low output ripple across all load conditions. Also the converter can 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 ideal 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 (POK) function provides an open drain output signal when LDOA is within regulation. The AAT2504 features a low 80microA typical no-load quiescent current when all three regulators are on. The device also features under-voltage lockout and over-temperature protection. Qualified across the -40 C to +85 C temperature range, the AAT2504 is available in a Pb-free, 20-pin, QFN34 package.