Design, MA TLAB Simulation, and Implementation of a Single Inductor Double Output DC-to-DC Converter with Digital Control

Abstract

A single-inductor multiple-output (SIMO) converter with constant frequency auto-buck-boost feature is presented in this paper. This converter can supply more than one output. Some applications of this converter include their use in mobile phones and medical devices that require different voltages. This paper deals with a single-inductor dual-output (SIDO) converter for simplicity, which can be generalized to multiple outputs. Here, according to the mode in which the converter works and the maximum load current, which is about 1 rnA, the outputs work completely independent, which means changing the load in one output does not affect the other output. The converter operates in discontinuous conduction mode (DCM), and the time-multiplexing control (TMC) method and pulse width modulation (PWM) are used in its controller. An analog to digital converter (ADC) is used to monitor the output voltage. The switching frequency in this converter is 5 kHz, and due to the possibility of changing the load at the output, the optimal duty cycle value for each output channel is set by the measured voltage. In this paper, the goal is to generate stable voltage and reduce cross regulations to the minimum possible value or even to zero and consider regular timing for switches by the controller.