Micrel has a synchronous buck controller IC which incorporates a frequency dithering feature that will minimise EMI.

The MIC21301/1 operates over an input voltage range of 8 to 40V and offers adjustable output voltages down to 0.7V. 

There is also a 150kHz frequency option. It offers internal drivers for output currents up to 15A and an adaptive gate drive allows efficiencies of more than 95 per cent.

The converter is designed to provide better than 2 per cent output voltage accuracy over -40 to +125 deg.

The MIC2131 has advanced current limit protection which allows for increased current when powering highly capacitive loads quickly.  The ICs are available in a 150kHz, 16-pin e-pad TSSOP option today. 

The 400kHz frequency option and the MLF-16 4x4mm package option will both be available in the first quarter of 2008.