Abstract: To keep even current distribution among DC/DC converters in a paralleled power system,an automatic master-slave control (AMSC) current sharing scheme is presented,which was implemented by a current share control IC.A current feedback loop for output voltage adjustment is proposed for low signal distortion.Moreover,a special startup control logic is designed to improve startup timing and to speed up the initial current sharing.It was completed in 1.5μm bipolar-CMOS-DMOS (BCD) technology with an area of 3.6mm2.Using it,a paralleled power system of two DC/DC converters capable of outputting 12V/3A was built.Experimental results show that the current sharing error at full load is kept within 1%.

Key words: current sharing, IC, paralleled power system, automatic master-slave control