DC/DC Buck Converter Soft-Start Methods

A. Borkowski (Warsaw Univ. of Techn., Poland), K. Siwiec (Warsaw Univ. of Techn. and ChipCraft Sp. z o.o., Poland), W. Pleskacz (Warsaw Univ. of Techn., Poland)

Startup issues of DC/DC converters can be problematic, and even cause malfunction of the whole system. In this paper selected problems encountered during the DC/DC converter design process are described and solutions are provided. The first solution uses a modified driver, which limits the loading current during startup. The second solution uses a modified passive switch soft start, which based on linearly charged capacitance and output voltage detector with D flip-flop. The described solutions have been designed and fabricated using CMOS 110 nm technology.