Cross-Regulation Generation Principle in Nonideal Single-Inductor Double-Output Boost Converter With Voltage Mode Control

Cross regulation of single-inductor multiple-output dc-dc converters deteriorates the dynamic and static performance, reduces the energy transfer efficiency, and even destabilizes the converter. To explore the deep reason for cross regulation in the single-inductor dual-output (SIDO) boost converter, the generation principle of the cross regulation in a nonideal SIDO boost converter with voltage mode control is analyzed. The nonlinear mathematical model and small-signal model of the converter are established, and the cross-regulation characteristics with parasitic parameters of circuit components are discussed. The dc voltage gain and transfer functions such as control-to-coupling, control-to-output, and cross-regulation impedance are derived. Furthermore, the characteristics of closed-loop cross regulation based on the voltage-mode control are analyzed by the Bode diagram. Both simulation results and experimental results verify that the cross regulation can be reduced by 14.3% when the parasitic resistor of the inductor increased by 0.1 Omega, and reduced by 14.5% and 14% when the parasitic resistor of the capacitor at output-a increased by 0.1 Omega and the output-b decreases by 0.1 Omega, respectively.