An Output Capacitorless Low-Dropout Regulator Design Based on Cross-Coupled Technique with Extract Power Supply Ripple Technique

Abstract

With the rapid change in technology, portable electronic products are designed to extend battery life through low power consumption and small size. The low-dropout regulator (LDO) is a crucial power management block and it is widely used in electronic products. Although the conventional LDO has the ability of voltage regulation, it cannot achieve low power consumption and fast transient response at the same time. In this paper, an output capacitor-less LDO with a fast transient response was proposed based on the extract power supply ripple technique. By adding a proposed voltage buffer and low-pass filter, was further applied to improve the transient response. Moreover, a cross-coupled technique was enhanced the power supply rejection ratio (PSRR) compared with the conventional LDO. The proposed regulator was fabricated using TSMC 0.18 μm CMOS process technology and subjected to simulations using a 1.8V power supply. From the results, the proposed LDO achieved a fast transient response of 0.27 μs and low PSRR of .-76 dB at 1 kHz .