Active Technique for Load Transients Suppression in Capacitor-free LDOs

• Main Authors: Hung-Ming Chen, 陳弘明
• Other Authors: Don-Gey Liu
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/94324269586651882057

碩士 === 逢甲大學 === 電子工程所 === 100 === With the portable battery-operated electronic devices development, there is a growing trend toward low power consumption to extend battery life products has become the subject of the study. The low dropout (LDO) linear regulator is widely used in portable systems because good load transient response, less output noise and ripples and smaller PCB layout area. The traditional linear regulator has to consider the external load capacitance, it constitute for a large area. Therefore, this study proposes is a capacitance-free low-dropout linear regulator to improve transient response and stability of the circuit. First, this study introduces the traditional architecture of low-dropout linear regulator. Then, the study will introduce the definition of basic noun and the design considerations. This study propose a capacitor-free low-dropout linear regulator, removing external capacitor, the original low-frequency dominant pole is removed. This architecture designed to produce a low-frequency dominant pole, and using compensation circuits senses the output current between the light (heavy) loads to heavy (light) load voltage of change, and to provide additional current path. So that, this circuit has a good transient response.