[1998]MOS charge pumps for low-voltage operation

—New MOS charge pumps utilizing the charge trans-
fer switches (CTS’s) to direct charge flow and generate boosted
output voltage are described. Using the internal boosted voltage
to backward control the CTS of a previous stage yields charge
pumps that are suitable for low-voltage operation. Applying
dynamic control to the CTS’s can eliminate the reverse charge
sharing phenomenon and further improve the voltage pumping
gain. The limitation imposed by the diode-configured output stage
can be mitigated by pumping it with a clock of enhanced voltage
amplitude. Using the new circuit techniques, a 1.2-V-to-3.5-V
charge pump and a 2-V-to-16-V charge pump are demonstrated
592 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 33, NO. 4, APRIL 1998




MOS Charge Pumps for Low-Voltage Operation
Jieh-Tsorng Wu, Member, IEEE, and Kuen-Long Chang



Abstract―New MOS charge pumps utilizing the charge trans- voltage at node 2 is settled to , where and are
fer switches (CTS’s) to direct charge ow and generate boosted dened as the steady-state lower voltage at node 1 and node
output voltage are described. Using the internal boosted voltage 2, respectively. Both MD1 and MD3 are reverse biased, and
to backward control the CTS of a previous stage yields charge
pumps that are suitable