A Low Power and Low Current-Mismatch Charge Pump with Dynamic Current Compensation*

摘要

A novel low power charge pump (CP) that minimizes the mismatch between the charging and the discharging currents is proposed in this paper. The switching circuit with dynamic current compensation is used to reduce the power consumption of the proposed CP. In addition, precise current replication which makes use of the resistors and the low offset operational ampliers (OTA) can enable a reduction in current mismatch caused by process mismatch. Meanwhile, the high output impedance can reduce the current mismatch caused by the channel length modulation effect. Based on the 0.18 mu m deep-Nwell CMOS process, the proposed CP can reduce the overall power consumption by 56% compared with the CP without current compensation, reduce the current mismatch caused by process mismatch to less than 0.9% and reduce the current mismatch caused by the channel length modulation effect to less than 0.01% over the output voltage ranging from 0.3 to 1.5V with 1.8V supply.