A low load- and cross-regulation SIDO converter using an adaptive current sensor and LDO regulator with a selectable charge pump for mobile devices

Abstract

In this paper, a single-inductor dual-output (SIDO) converter is proposed to generate stable output voltages with low load- and cross-regulations for mobile applications. The proposed converter, which operates in the buck-boost or boost mode, employs an adaptive current sensor and a low-dropout regulator with a selectable charge pump to achieve low load- and cross-regulations. In addition, an error amplifier and comparators are implemented to provide stable dual output voltages of 1.8 and 3.3 V at an input voltage range of between 1.0 and 3.2 V. The proposed SIDO converter was fabricated using a 0.18-mu m CMOS process technology and occupies a chip area of 1568 mu m x 728 mu m. The measurement results show that the maximum power efficiency, load-regulation, and cross-regulation are 89.2%, 0.120 and 0.088 mV/mA, respectively, when the load current changes from 10 to 50 mA.