CMOS voltage booster circuits

摘要

This invention is a new CMOS voltage booster (20) having an output which can be used in memories to boost the word line voltage above VDD or other voltage boosting applications. One key idea in this CMOS booster is to use a NMOS FET (MN1) to charge the boosting capacitor (C1) to VDD at the end of each memory access and to use a PMOS FET (MP1, MP2) to keep the voltage at the output at VDD during standby. By using this combination, the word line rise time, the size of the booster, and the power consumption during access are significantly reduced. The gate of the NMOS FET is boosted above VDD+Vthn by a small capacitor (C2) to charge the word line boosting capacitor to VDD at the end of each memory access. The small capacitor (C2) is pre-charged to VDD by a NMOSFET (MN2) whose gate is connected to the word line boosting capacitor. The gate of the PMOS FET is shorted to its source to turn it off during boosting.