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US 6,476,666 B1Granted
Bootstrapped charge pump
AssigneeAlliance Semiconductor Corporation
InventorsChaitanya Palusa, Abhijit Ray
Life of this patent
Estimating the term…
Abstract
The diode drops associated with the output voltage from a conventional charge pump are eliminated in the present invention with a dual-chain charge pump that utilizes the pumped voltages from each charge pump chain to drive the gates of the other charge pump chain. As a result, the voltages on the gates of the transistors are pumped up to a level such that there is no threshold voltage drop across the transistor, and thus, making it behave like an ideal switch.
Claims17
A charge pump comprising:
- a plurality of stages connected together in series, each stage having:
- a bottom transistor having a first node, a gate, and a second node;
- a top transistor having a first node, a gate connected to the second node of the bottom transistor, and a second node connected to the gate of the bottom transistor;
- a bottom capacitor connected between the second node of the bottom transistor and either a first clock signal or a second clock signal, the first clock signal being connected when a stage is an odd-numbered stage, the second clock signal being connected when a stage is an even-numbered stage;
- and
- a top capacitor connected between the second node of the top transistor and either the first clock signal or the second clock signal, the first clock signal being connected when a stage is an even-numbered stage, the second clock signal being connected when a stage is an odd-numbered stage, the second clock signal being out-of-phase and non-overlapping with the first clock signal,
- the plurality of stages being connected together so that, excluding a last stage, the second nodes of the bottom and top transistors in each stage are connected to the first nodes of the bottom and top transistors, respectively, in an adjacent stage, and so that, excluding a first stage, the first nodes of the bottom and top transistors in each stage are connected to the second nodes of the bottom and top transistors, respectively, in an adjacent stage.
4 more elements
A method for operating a charge pump, the charge pump comprising:
- a plurality of stages connected together in series, each stage having:
- a bottom transistor having a first node, a gate, and a second node;
- a top transistor having a first node, a gate connected to the second node of the bottom transistor, and a second node connected to the gate of the bottom transistor;
- a bottom capacitor having a first plate and a second plate, the first plate being connected to the second node of the bottom transistor;
- and
- a top capacitor having a first plate and a second plate, the first plate being connected to the second node of the top transistor,
- the plurality of stages being connected together so that, excluding a last stage, the second nodes of the bottom and top transistors in each stage are connected to the first nodes of the bottom and top transistors, respectively, in an adjacent stage, and so that, excluding a first stage, the first nodes of the bottom and top transistors in each stage are connected to the second nodes of the bottom and top transistors, respectively, in an adjacent stage;
- the method comprising the steps of:
- applying a first clock signal to the second plate of each odd numbered bottom transistor;
- applying a second clock signal to the second plate of each even numbered bottom transistor;
- applying the first clock signal to the second plate of each even numbered top transistor;
- and
- applying the second clock signal to the second plate of each odd numbered top transistor, the second clock signal being out-of-phase and non-overlapping with the first clock signal, the second clock signal being out-of-phase and non-overlapping with the first clock signal.
10 more elements
Dependencies are inferred from the claim text.