Charge pump circuit with bypass transistor
AssigneeFujitsu Limited
InventorsISAMU KOBAYASHI, YOSHIHARU KATO
Life of this patent
Estimating the term…
Abstract
A two stage charge pump circuit can perform either a two stage boosting operation or a single stage boosting operation. The charge pump circuit includes first, second and third gate transistors connected in series between first and second supply voltages, and a bypass transistor. A first booster stage includes a capacitor connected between the first and second gate transistors and a drive circuit. A second booster stage includes a capacitor connected between second and third gate transistors and the drive circuit. The third gate transistor is connected to an internal bus which provides an output voltage to other circuit elements connected to it. The bypass transistor is connected between the first booster stage and the internal bus.
Claims18
A charge pump circuit comprising:
- a plurality of voltage conversion stages connected between an input supply and a supply output;
- a plurality of gate transistors, each connected between respective voltage conversion stages, between a first stage of said voltage conversion stages and the input supply, or between last stage of said voltage conversion stages and the supply output;
- and
- a bypass transistor connected between one of the input supply and the supply output and one of said voltage conversion stages, the bypass transistor connected in parallel with at least one of said gate transistors.
A charge pump circuit comprising:
- a pair of charge pumps connected in parallel to each other between an input supply and a supply output, wherein each charge pump includes:
- a plurality of voltage conversion stages connected between the input supply and the supply output, a plurality of gate transistors, each connected between respective voltage conversion stages, between a first stage of said the voltage conversion stages and the input supply, or between last stage of said voltage conversion stages and the supply output;
- and
- a bypass transistor connected between one of the input supply and the supply output and one of said voltage conversion stages, the bypass transistor connected in parallel with at least one of said gate transistors.
A method of driving a charge pump circuit having
- a plurality of voltage conversion stages connected between an input supply and a supply output, a plurality of gate transistors, each connected between respective voltage conversion stages, between a first stage of said voltage conversion stages and the input supply, or between last stage of said voltage conversion stages and the supply output, and a bypass transistor connected between one of the input supply and the supply output and one of the voltage conversion stages, the bypass transistor connected in prallel with at least one of said gate transistors, the method comprising the steps of:
- operating all of the voltage conversion stages and the gate transistors in a predetermined sequence while maintaining the bypass transistor off to cause all of the voltage conversion stages to convert the voltage of the input supply to a first voltage for the supply output;
- and
- operating at least one of the voltage conversion stages, at least one of the gate transistors and at least one of the bypass transistors in a predetermined sequence to cause at least one of the voltage conversion stages to convert the voltage of the input supply to a second voltage for the supply output.
A voltage conversion circuit comprising:
- a charge pump circuit including a plurality of voltage conversion stages connected between an input supply and a supply output, a plurality of gate transistors, each connected between respective voltage conversion stages, between a first stage of said voltage conversion stages and the input supply, or between last stage of said voltage conversion stages and the supply output, and a bypass transistor connected between one of the input supply and the supply output and one of said voltage conversion stages, the bypass transistor connected in prallel with at least one of said gate transistors;
- a drive circuit connected to the plurality of voltage conversion stages, the plurality of gate transistors and the bypass transistor for controlling the plurality of voltage conversion stages, the plurality of gate transistors, and the bypass transistor;
- and
- a mode switching circuit connected to the drive circuit for providing a mode signal to the drive circuit.
Dependencies are inferred from the claim text.