A PWM-free DC-DC Boost Converter with 0.43 V Input for Extended Battery Use in IoT Applications

Abstract

A new single stage dc-dc converter is presented in order to fully exploit the energy of a battery cell that aims to bridge the gap between low-voltage, low-current and high-voltage, high-current converters. A theoretical analysis is presented along with expressions that describe the operation and DC gain of the converter. Classic dc-dc converters include a digital block for pulse width modulation (PWM) that controls the output voltage as a function of the duty cycle. The proposed converter utilizes only a current mirror connected to a transformer in order to boost output voltage, thereby lowering the dissipated power by up to 28.86% as a PWM block is not required. The simplicity of the presented topology is traded off with a small decrease in peak power efficiency, which drops to about 80%. Nevertheless, measurements show that the proposed converter operates at input voltages as low as 0.43 V, appropriate for commercial battery cells, and provides tens of mA. In this way, the energy of a battery source is fully exploitable almost doubling the practical battery lifetime (1.83×) as shown through real-world scenarios and experimental results.