Micrel's MIC2800 is an efficient, flexible power management IC that provides three output voltages and a power-on reset in a 3- by 3-mm MLF-16 package. The part features a 2.7- to 5.5-V input range. Of its three voltage outputs, output 1 is a high-frequency, high-efficiency dc-to-dc switching regulator for up to 600 mA, while outputs 2 and 3 are low-dropout linear regulators (LDOs). One of the linear regulators works from a low input voltage, allowing it to post-regulate the switching regulator for best efficiency. For example, the dc-to-dc converter can step down the Li-Ion battery input to 1.8 V and the LDO can provide 1.6 V by post-regulating the 1.8-V rail with greater than 80% efficiency. An additional low-noise linear output can provide a third voltage, such as 2.8 V for an analog rail.
The MIC2800 operates with small ceramic output capacitors for stability and reducing solution footprint and cost. The dc-to-dc converter provides virtually no noise in light-load mode and just 75 μVrms output noise in LOWQ mode. This lets designers avoid higher noisy light-load modes that can interfere with sensitive RF circuitry. Independent enables for the switching and two linear regulators enhance design flexibility. The MIC2800 is currently available in volume and pricing starts at $2.25 for lots of 1000. More information is available at www.micrel.com.