An Energy Efficient Charging Technique for Switched Capacitor Voltage Converters With Low-Duty Ratio

作者：Arslan Saad; Shah Syed Asmat Ali; Lee Jae Jin; Kim Hyungwon^*

来源：IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS, 2018, 65(6): 779-783.

DOI：10.1109/TCSII.2017.2751146

• Step-wise charging
• capacitor charging
• switched capacitor
• DC-DC converter
• low-duty ratio
• on-chip voltage converter

Charging a capacitor array of a switched-capacitor (SC) dc-dc converter, supplying load circuits with a very short active period, can be pivotal to achieve high energy efficiency of its operation. This is because the capacitors may lose most of the stored energy during a long sleep period, and thus every sleep-to-active transition requires full recharging of the capacitors. In this brief, we present an energy efficient capacitor charging technique called split-capacitor charging, which charges a capacitor array in a step-wise fashion. Circuit simulations demonstrate that the proposed technique can reduce the energy wastage during sleep-to-active transition up to 66%. When tested on load circuits with a short active period, a voltage converter employing the proposed charging method shows up to 24% improvement in energy efficiency over conventional SC converters.

• 出版日期2018-6