A Single-Stage Low-Dropout Regulator With a Wide Dynamic Range for Generic Applications

Abstract

Single-stage regulator topologies are often preferred in embedded applications due to their low power consumption with a single-pole behavior, resulting in easy frequency compensation. Since the achievable differential gain from a single stage is low, the dc load regulation is poor over a wide dynamic range. This paper presents a single-stage, adaptively biased, low-dropout regulator to achieve a comparable dc load regulation similar to multistage topologies. This is achieved mainly by modifying the adaptive bias loop which amplifies both the common-mode and differential-mode signals. In addition, as the proposed regulator is stable for a wide range of output capacitors, including the capacitor-less (on-chip) and with-capacitor (off-chip) conditions, it is suitable for more generic applications. The proposed regulator is implemented in a standard 0.18-μm CMOS technology. The experimental results show that the regulator is capable of delivering up to 100 mA with a dc load regulation of 0.140 mV/mA and is stable with C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sub> ≤3.3 nF (capacitor-less) and C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sub> ≥1 μF (with-capacitor).