دانلود رایگان مقاله انگلیسی مبدل DC-DC خازن سوئیچ دوگانه با مدولاسیون عریض سوئیچ تطبیقی - الزویر 2018

ABSTRACT

This paper proposes a step-down switched-capacitor (SC) DC-DC converter with pulse frequency modulation (PFM) and burst mode. This design proposes a novel dual mode control strategy to achieve high performance over a wide load range. PFM is adopted at heavy load to achieve the small output voltage ripple while burst mode is adopted at light load to improve transient response and power efficiency. To further improve the efficiency, an adaptive switch width modulation (ASWM) is proposed to reduce switching losses. The measured results show that the proposed four conversion ratios converter can operate with a 2.0–3.6 V input voltage range, load current from 0 to 2 mA at the output voltage of 1.2 V. The peak power efficiency is up to 84.2% from a 2.7 V input voltage supply at a load current of 2 mA. At a load of 60 μA, the burst mode achieves an 11% maximum efficiency improvement, and the average efficiency improvement of 6% is achieved with ASWM.

5. Conclusion

This paper presented the detailed design, the circuit implementation and the measured results for a step-down SC DC-DC converter. Firstly, a reconfigurable SC array has four conversion ratios for a 2.0–3.6 V input voltage range. Secondly, a dual mode control strategy is proposed for output regulation, PFM is adopted to complete small output voltage ripple at heavy load while burst mode is adopted to improve load transient and power efficiency at light load. Thirdly, ASWM is proposed to further improve power efficiency over the entire load range. The peak efficiency of the proposed SC DC-DC converter is 84.2% from a 2.7 V input voltage supply at a load current of 2 mA. In conclusion, this paper proposed a high performance SC DC-DC converter for ultra-low power portable devices.