How low can you go?

Power management has grown to account for about 50% of the analogue market. The prime market driver is of course the cell phone, for which ever more complex ics are required to control the use of power around the system in order to maximise battery run time. Whilst huge technical leaps and bounds have been made, the emergence of features like cellular TV, extremely high resolution phone cameras and white LED backlights, means that power ic refinement is still very much on the agenda. The demands made by most portable applications have meant that the days of simply integrating a few linear regulators to step up and step down voltage are long gone. Indeed, whilst linear regulators have become more sophisticated – National Semiconductor, for example, has a linear regulator coming out with an output noise of just 10microvolt rms – the abiding trend is towards switch mode conversion. Recounts Patrick Heyer, product marketing manager for Texas Instruments’ portable power management group: “Switch mode is inherently more efficient. Whereas the typical efficiency for a linear regulator might be 30%, dc/dc converters can now achieve up to 95%.” Click here to request the complete article by email