Charge pump circuit having an improved charge pumping efficiency
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorYasuhiko Tsukikawa
Life of this patent
Estimating the term…
Abstract
A charge pump circuit includes a P channel field effect transistor, a diode-connected N channel field effect transistor between a first node and a second node. The P channel field effect transistor operates in response to a first clock signal applied through a first capacitor to discharge the first node to a ground potential. The first node receives a second clock signal through a second capacitor. Negative electric charges are pumped out to the second node. A negative bias voltage is generated from the second node with an improved efficiency and reliability.
Claims20
A charge pump circuit for generating a predetermined voltage, comprising:
- a first transistor element responsive to a first clock signal applied through first capacitance means for transferring a first reference voltage to a first node, said first node receiving a second clock signal through capacitive coupling of second capacitance means;
- and
- a rectifying element connected between the first node and a second node such that electric charges required for generating said predetermined voltage are unidirectionally transferred, said rectifying element comprising a diode-connected transistor element different in conductivity type from said first transistor element.
A charge pump circuit for generating a predetermined voltage comprising:
- a first gate type field effect transistor of a first conductivity type responsive to a first clock signal applied through first capacitance means for transferring a first reference voltage to a first node, said first node receiving a second clock signal through capacitive coupling of second capacitance means;
- and
- a rectifying element connected between the first node and a second node such that electric charges required for generating said predetermined voltage are unidirectionally transferred, said rectifying element comprising:
- a junction diode and,
- wherein said junction diode is formed in a well region of the first conductivity type surrounded by a semiconductor layer of a second conductivity type and separated from any other region forming an element.
Dependencies are inferred from the claim text.