High-efficiency stepdown/step-up converter for series-connected energy storage system

Area of Science:

• Electrical Engineering
• Power Electronics
• Integrated Circuits

Background:

• Series-connected batteries experience voltage drop with usage, limiting device operational time.
• Conventional power converters struggle to maintain optimal voltage levels for devices with degrading batteries.

Purpose of the Study:

• To develop a novel step-down/step-up converter for optimizing the runtime of series-connected batteries.
• To enhance the performance and longevity of batteries in compact electronic devices.

Main Methods:

• A novel converter design automatically transitions between step-down, step-up, and step-down/step-up modes based on input/output voltage comparison.
• Incorporation of a capacitive coupling level shift circuit to protect power transistors.
• Fabrication using 180 nm BCD technology, resulting in a compact chip size (1.44 mm x 0.73 mm).

Main Results:

• Achieved up to 93% power conversion efficiency, an 11% improvement over conventional models.
• Supports an output current up to 500 mA, a 67% increase.
• Demonstrated effective operation across an input voltage range of 2.5 V to 8 V.

Conclusions:

• The proposed converter significantly enhances battery performance and extends operational life in compact electronic devices.
• The adaptive voltage regulation and high efficiency make it suitable for battery-powered applications.
• The compact design and protective circuitry ensure reliability and miniaturization.