A Three-Switch-Based Single-Input Dual-Output Converter With Simultaneous Boost & Buck Voltage Conversion

Abstract

With the increasing demand of applications that have two different output voltages, the single-input dual-output (SIDO) converter with fewer components is becoming the cost-effective option instead of employing two single-input single-output converters. However, the cross-regulation of different outputs is still a challenge in SIDO converters design. To save cost and obtain improved cross-regulation performance, a novel SIDO converter consisting of three active switches is proposed in this article. Owing to the use of a voltage multiplier circuit, a high step-up voltage conversion ratio is achieved with relatively low voltage stress of switches. Thanks to the independent power flow and two control variables, the cross-regulation performance is improved, and simultaneous buck as well as boost output voltages is realized. Additionally, all switches can achieve zero-voltage switching operation, which contributes to a significant switching loss reduction. The operation characteristics, design considerations, and control strategy of the proposed converter are analyzed. To verify the theoretical analysis and measure the power efficiency, a prototype circuit with 48 V input and 24 V/2 A, 200 V/1 A outputs is built.