A dynamic-biasing 4× charge pump based on exponential topology

A 4× charge pump using exponential topology is proposed and implemented. Comparing to the conventional implementations, the proposed circuit suppresses the reverse current effectively without using different threshold‐voltage transistors and additional capacitors. Also, the body effect found in the charge transfer switches is eliminated. The proposed charge pump is analyzed with the state‐space method and fabricated using 0.35 µm complementary metal–oxide–semiconductor process. Results show that the output voltages close to the ideal one, and a maximum power efficiency of 95% was recorded. Copyright © 2013 John Wiley & Sons, Ltd. This figure shows the measured power efficiency of the proposed 4× exponential charge pump with different loading currents at 25, 50, 100, and 200 kHz operation frequencies. A maximum power efficiency of 95% was found, which suggests that the proposed circuit can realize the voltage conversion effectively.