Improving of efficient control scheme in Switched-Capacitor DC-DC Converters for ultra-low power applications
Subject Areas :
Hamid Tavana
1
,
Abdolrasool Ghasemi
2
,
Najmeh Cheraghi Shirazi
3
1 - Islamic Azad University Boushehr Branch, Boushehr, Iran
2 - گروه مهندسی برق، دانشکده فنی و مهندسی، دانشگاه آزاد اسلامی، بوشهر، ایران
3 - Electrical Engineering, Islamic Azad University Bushehr Branch, Bushehr, Iran
Keywords:
Abstract :
Portable bio-electronic products, such as implantable biosensors, have drawn more and more attentions recently. These portable electronic products are typically supplied by time-varying batteries, which need a DC-DC converter to provide a stable output voltage. Therefore, how to effectively extend battery life and standby time becomes a critical issue in the design of dc-dc converters used in portable bioelectronics. There are three types of DC-DC converters—linear regulators, switching regulators, and switched-capacitor (SC) converters. The linear regulators only can be operated in the step-down mode, while the other two types of dc-dc converters has potential to be operated in either the step-down or the step-up mode. Hence, from the viewpoint of extending battery life and standby time, linear regulators would not be chosen. As to switching regulators, their power conversion and transfer are performed by using inductors or bulky transformers. Therefore, the SC converter is chosen in this work. Use appropriate compensation to zero steadystate error and improve transient response is essential part in the design of Switch Capacitor DC-DC Converter. The design of the op amp PID compensator used in the feedback circuit. The efficiency of this circuit with use of active ingredients is top 98%. The simulation of this cicuits done in the 0.18µmComs Cadence.the input voltage of this circuits is 1.8V and the range of output voltage is 250mV to 900mV in 2t01 topology.Change in the load current is 0 to 40mA.