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US 8,013,664 B2Granted
Charge pump controller and method therefor
AssigneeSemiconductor Components Industries, LLC
InventorRemi Gerber
Life of this patent
Estimating the term…
Abstract
A charge pump controller (20) comprises a configurable pump capacitor (15, 16). A charge pump controller (20) controls the charge supplied to a load (12) to be less than the charge stored on the pump capacitor (15, 16).
Claims18
A charge pump controller comprising:
- a configurable pump capacitor;
- a control circuit configured to couple the configurable pump capacitor in a charging configuration for a first time interval and to couple the configurable pump capacitor in a discharge configuration for a second time interval;
- a current source configured to provide a reference current;
- a charging circuit configured to form a charging current that is proportional to the reference current and to couple the charging current to the configurable pump capacitor to store a charge of a first value on the configurable pump capacitor responsively to the first time interval;
- and
- a discharge circuit configured to operate in a first state or a second state responsively to a first value of the reference current, the discharge circuit configured to limit charge coupled from the configurable pump capacitor to a load during the second time interval to approximately the first value responsively to the first state and to limit charge coupled from the configurable pump capacitor to the load during the second time interval to less than the first value responsively to the second state, the discharge circuit including a first current mirror configured to form a first current that is proportional to the reference current, a first transistor coupled to receive the first current responsively to the second time interval, and a second transistor that controls charge coupled from the configurable pump capacitor to the load to no greater than approximately the first value.
3 more elements
A method of forming a charge pump controller comprising:
- configuring the charge pump controller to supply a first charge to a pump capacitor during a charging configuration of the charge pump controller;
- configuring the charge pump controller to supply a second charge from the pump capacitor to a load that is external to the charge pump controller during a discharge configuration of the charge pump controller wherein the second charge is less than the first charge, including configuring a reference circuit to form a reference current that varies responsively to an output voltage formed by the charge pump controller;
- and
- configuring a discharge circuit to form the second charge responsively to a first value of the output voltage.
1 more element
A charge pump method comprising:
- charging a pump capacitor of a charge pump controller to a first charge with a first current value during a charging configuration of the charge pump controller;
- coupling a second charge from the pump capacitor to a load of the charge pump controller during a discharge configuration of the charge pump controller;
- configuring a discharge circuit to form a reference current responsively to a value of an output voltage;
- and
- controlling the second charge to be less than the first charge responsively to a first value of the output voltage that is formed by the charge pump controller by varying an impedance of a first transistor responsively to the reference current.
2 more elements
Dependencies are inferred from the claim text.