Differential charge pump with open loop common mode
AssigneeHoneywell International Inc.
InventorsMark Dvorak, James Hiller, James Seefeldt
Life of this patent
Estimating the term…
Abstract
A differential charge pump with common mode and active regulators is presented. Either type of regulator may be used to improve the performance characteristics of the differential charge pump. The active regulator increases the output range of the differential amplifier. The common mode regulator establishes the common mode voltage of the differential charge pump. The common mode voltage is established independently from external circuitry and does not use a feedback path. The common mode regulator may also be used to establish a mid-rail voltage, which may be used to further improve the output range of the differential amplifier.
Claims20
A differential charge pump, comprising:
- a current steerer comprising:
- first and second output terminals for outputting a differential current;
- first and second input terminals, the first input terminal receiving a source current, the second input terminal receiving a sink current;
- a differential control for steering the source and sink currents to the first and second output terminals;
- and
- a common mode regulator having first and second input terminals respectively coupled to the first and second output terminals of the current steerer, the common mode regulator driving the first and second output terminals of the current steerer to a common mode voltage.
A differential charge pump, comprising:
- a current steerer comprising:
- first and second output terminals for outputting a differential current;
- first and second input terminals, the first terminal receiving a source current, the second terminal receiving a sink current;
- a differential control for steering the source and sink current to the first and second output terminals;
- and
- a first active regulator having first and second reference terminals, the first reference terminal coupled to the first input terminal of the current steerer, the second reference terminal coupled to a first reference source, the first active regulator, in operation, minimizing a first voltage difference between a first supply voltage and the first input terminal of the current steerer.
A method of operating a differential charge pump comprising a current steerer and a common mode regulator, the current steerer including a differential input, first and second input terminals, and first and second output terminals, the first and second output terminals coupled to the common mode regulator, the method comprising:
- receiving a source current at the first input terminal and a sink current at the second input terminal;
- receiving a differential signal at the differential input;
- steering the source and sink currents to the first and second output terminals, the steering of the source and sink currents being determined by the differential input;
- and
- regulating deviations in a common mode voltage by the common mode regulator, the common mode regulator establishing the common voltage at the first and second output terminals.
Dependencies are inferred from the claim text.