A High-Efficiency and Low-Ripple Boost Charge Pump

A high-efficiency and low-ripple charge pump structure is proposed to address the problems of severe voltage losses and high output ripple of conventional charge pumps. The charge pump uses a deep n-well process and a substrate biasing circuit to reduce voltage losses and improve conversion efficiency. And the upper and lower two parallel branches are used to reduce the output ripple, while the pre-charging process is carried out to shorten the start-up time. The charge pump is designed based on the SMIC
$\mathbf{0.11}\boldsymbol{\mu} \mathbf{m}$
CMOS process, and the final simulation results show that the charge pump can achieve an output voltage of 2.85V with a ripple of only about 1mV at an input voltage of 1.5V and a load of
$\mathbf{1}\mathbf{k}\mathbf{\Omega}$
. This charge pump has the advantages of high conversion efficiency and regulated output, and can be widely used in electronic products such as Bluetooth headset and lithium battery.