Common-mode charge control in a pipelined charge-domain signal-processing circuit
AssigneeKenet, Inc.
InventorMichael P. Anthony
Life of this patent
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Abstract
In a differential bucket-brigade device (BBD) pipeline it is necessary for proper circuit function to maintain the common-mode charge within an acceptable range at each pipeline stage. Embodiments of the present invention provide for reducing common-mode charge variations in a differential charge-domain pipeline. Common mode charge at a given stage of the pipeline is adjusted according to one or more measured characteristics, thereby controlling common mode charge variation throughout the differential charge-domain pipeline.
Claims33
A method of adjusting common-mode charge in a Bucket-Brigade Device (BBD) differential charge-domain pipeline having at least a first stage propagating charge toward a second stage, comprising:
- comparing a reference voltage against an output voltage, the output voltage corresponding to a common-mode charge at the second stage of the charge-domain pipeline;
- and
- based on the comparison, controlling a common-mode charge output at the first stage such that the common-mode charge at the second stage is adjusted.
A method of adjusting common-mode charge in a Bucket-Brigade Device (BBD) differential charge-domain pipeline having at least a first stage propagating charge toward a second stage, comprising:
- replicating operation of a charge-transfer circuit;
- generating a replica control signal to control an output voltage resulting from the replicating toward a replica reference voltage;
- and
- applying the replica control signal to control a common-mode charge output at the first stage.
A method of adjusting common-mode charge in a Bucket-Brigade Device (BBD) differential charge-domain pipeline having at least a first stage propagating charge toward a second stage, comprising:
- sampling a voltage corresponding to common-mode charge at the first stage;
- comparing the voltage against a reference voltage;
- and
- based on the comparison, controlling charge transfer circuits to adjust the common-mode charge output of the first stage.
An apparatus for adjusting common-mode charge in a charge-domain pipeline having at least a first stage propagating charge toward a second stage, comprising:
- a comparison circuit to compare a reference voltage against an output voltage, the output voltage corresponding to a common-mode charge at the second stage of the charge-domain pipeline;
- and
- a control circuit to control a common-mode charge output at the first stage, based on the comparison, such that common-mode charge at the second stage is adjusted.
An apparatus for adjusting common-mode charge in a charge-domain pipeline having at least a first stage propagating charge toward a second stage, comprising:
- a replica circuit replicating operation of a charge-transfer circuit;
- a replica control circuit to generate a replica control signal to control an output of the replica circuit toward a replica reference voltage, the replica control signal being applied to control a common-mode charge output at the first stage.
An apparatus for adjusting common-mode charge in a charge-domain pipeline having at least a first stage propagating charge toward a second stage, comprising:
- a sampler to sample a voltage corresponding to common-mode charge;
- a comparator to compare the voltage against a reference voltage;
- and
- a sampler control circuit that, based on the comparison, controls charge transfer circuits to adjust the common-mode charge output of the stage.
Dependencies are inferred from the claim text.