Design and implementation of a digitally controlled single-inductor dual-output (SIDO) buck converter

This paper describes design and implementation of a digitally controlled single-inductor dual-output (SIDO) buck converter operating in discontinuous conduction mode. This converter adopts time-multiplexing control in providing two independent output voltages using only an inductor. The design issues of the digital controller are discussed, including static and dynamic characteristics. Implementation of the controller, a modified hybrid digital pulse width modulator and a single look-up table are developed. The digital controller was implemented on a field-programmable gate array-based control board. Experimental results demonstrating system validity are presented for a SIDO buck converter with nominal 3.6 V input voltage, and the outputs are regulated at 1.8 and 2.2 V.