Current Context and Research Trends in Linear DC–DC Converters

Abstract

With the introduction of switch-mode power supplies (SMPS) in the mid-1970s, the efficiency of DC–DC conversion rose from 60 to 80% and SMPS became a popular power supply solution. However, linear regulators have not become obsolete. The modern power management system in portable devices supports a complex mix of DC–DC converters, combining switch-mode power supplies (SMPS), switched capacitor converters (SCCs), and linear regulators in the form of low-dropout regulators (LDOs). LDOs are used to supply low-voltage DC power rails with very low noise and high current slew rate capability, which are usually fed by the output rail of SMPS. This paper provides a comprehensive review of the evolution of the application scope of linear-type DC–DC converters in the power supply context and the present research trends. First, we review the context of linear DC–DC converters in detail, particularly in portable device power supplies. Then, the details of LDO regulators and their recent industry development and research trends are discussed. Then, the discussion focuses on supercapacitor-assisted low-dropout (SCALDO) regulator design and its scope in the portable device power management together with SCALDO-based dual output and reduced switch designs, and finally, the conclusions follow.

Dynamic Voltage and Frequency Scaling as a Method for Reducing Energy Consumption in Ultra-Low-Power Embedded Systems

“…The efficiency of DC-DC converters, especially in the context of linear converters, has evolved significantly with technological advancements. Initially, with the introduction of switch-mode power supplies in the mid-1970s, DC-DC conversion efficiency improved significantly, from 60% to 80%, making them a popular solution in power supply systems [44]. With the goal of high efficiency across a range of voltages, modern DC-DC converters utilize adaptive control mechanisms.…”