Design and Analysis of a Capacitive Charge Pump

This work focuses on studying and designing a capacitive charge pump DC-DC converter for voltage elevation in radio frequency energy harvesting (RFEH) systems. The study aims to design a Dickson charge pump circuit that meets certain constraints and performance targets using components from the GPDK45. The article begins with a brief overview of RFEH systems, discussing their advantages and challenges. It then explores the operational principles of the Dickson charge pump, detailing its functionality and the key design considerations. The design process includes selecting and sizing MOSFETs and capacitors to optimize voltage gain and efficiency while accounting for the limitations imposed by the manufacturing process. Through simulations conducted, the performance of different transistor types and component dimensions is analyzed, allowing for an optimal balance between output voltage, efficiency, and power capability. Results indicate that the designed charge pump can achieve, for a constant input voltage of 0.5 V, an output voltage of approximately 1.48V with an efficiency of 34.8% for low-power applications around <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1\text{pW}$</tex> The peak efficiency of 42.3 % is attained at an output power of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2.2\mu \mathrm{W}$</tex> and an output voltage of 1.24 V.