A low cross-regulation and high-efficiency SIDO boost converter with near-threshold start-up

摘要

This paper proposes a single-inductor dual-output (SIDO) DC-DC boost converter with Near-threshold Start-up voltage which adopts ordered-power-distributive-control (OPDC) method. A load-dependent feedback loop control is proposed to effectively suppress cross-regulation between the outputs, which is simple and flexible. Meanwhile, a two-step start-up scheme which makes the start-up circuit simpler has been put forward. It makes sure that the SIDO converter can adjust and complete near-threshold start-up depending on different load currents. This SIDO DC-DC converter has been fabricated in 0.18 mu m CMOS process. The minimum starting voltage is 0.5 V, and the simulation results show that the cross-regulation suppression circuit successfully reduce the voltage cross-regulation ratios VCR1 and VCR2 to 0.2 mV/mA and 0.11 mV/mA, respectively. In normal operation, both of the output voltages and its corresponding maximum output currents are 1.2 V/40 mA and 1.8 V/40 mA. A maximum conversion efficiency of 91% can be achieved.