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US 7,612,816 B2Granted
Low power comparator
AssigneeMicron Technology, Inc.
InventorPhilip Neaves
Life of this patent
Estimating the term…
Abstract
A comparator with an input stage that selectively powers up an output stage provides an electronic device with a comparator that operates at low power. In an embodiment, an input stage produces a near decision and a true decision, where the near decision is provided to power up an output stage for the comparator to provide an output representative of the true decision.
Claims74
An electronic device comprising:
- an input stage of a comparator to produce a near decision and a true decision, the near decision to power up a switching output stage for the comparator to provide an output representative of the true decision, wherein the input stage includes an offset voltage circuit to provide an offset voltage such that the near decision is produced prior to producing the true decision relative to a ramping reference voltage.
An electronic device comprising:
- an input stage of a comparator to produce a near decision and a true decision, the near decision to power up a switching output stage for the comparator to provide an output representative of the true decision, the switching output stage configured to be powered up for a time period set at a fraction of a total ramp time of a ramping reference voltage.
An electronic device comprising:
- a first differential pair of an input stage, the first differential pair having a first input section responsive to an input signal and a reference section responsive to a reference signal, the first input section balanced with respect to the reference section;
- and
- a second differential pair of the input stage, the second differential pair including the reference section of the first differential pair and a second input section responsive to the input signal, the second input section unbalanced with respect to the reference section, wherein the second differential pair provides a near decision and the first differential pair provides a true decision, the near decision to power up a switching output stage to provide an output representative of the true decision.
An integrated circuit comprising:
- a switching output stage;
- an input stage of a comparator to provide a near decision and a true decision to the switching output stage, the near decision to power up the switching output stage to provide an output representative of the true decision, wherein the input stage includes an offset voltage circuit to provide an offset voltage such that the near decision is produced prior to producing the true decision relative to a ramping reference voltage.
An integrated circuit comprising:
- a switching output stage;
- an input stage of a comparator to provide a near decision and a true decision to the switching output stage, the near decision to power up the switching output stage to provide an output representative of the true decision, the switching output stage configured to be powered up for a time period set at a fraction of a total ramp time of a ramping reference voltage.
An integrated circuit comprising:
- a switching output stage;
- an input stage of a comparator to provide a near decision and a true decision to the switching output stage, the near decision to power up the switching output stage to provide an output representative of the true decision;
- a plurality of switching output stages;
- and
- a plurality of input stages for comparators, each input stage to produce a near decision and a true decision, the near decision to power up one of the switching output stages to provide an output representative of the true decision, wherein the input stage includes a first differential transistor pair to produce the near decision and a second differential transistor pair to produce the true decision, the first differential transistor pair offset from the second differential pair to provide the near decision before the second differential pair provides the true decision in response to a ramping reference signal becoming substantially equal to an input signal to the first and second differential pairs.
2 more elements
An imaging device comprising:
- a pixel array having multiple rows and multiple columns;
- a number of sample and hold units, each sample and hold unit coupled to a separate column of the pixel array;
- a number of comparators, each comparator coupled to a separate sample and hold unit, each comparator including an input stage and an output stage, the input stage to produce a near decision and a true decision, the near decision to power up the output stage to provide an output representative of the true decision, wherein each input stage includes an offset voltage circuit to provide an offset voltage such that the near decision is produced prior to producing the true decision relative to a ramping reference voltage.
An imaging device comprising:
- a pixel array having multiple rows and multiple columns;
- a number of sample and hold units, each sample and hold unit coupled to a separate column of the pixel array;
- a number of comparators, each comparator coupled to a separate sample and hold unit, each comparator including an in put stage and an output stage, the input stage to produce a near decision and a true decision, the near decision to power up the output stage to provide an output representative of the true decision, wherein each comparator includes a first differential pair having a first input section to receive an input signal from a sample and hold unit at a first transistor group and a reference section to receive a reference input and a second differential pair having the reference section to receive the reference input and a second input section to receive the input signal from the sample and hold unit at a second transistor group, the first transistor group having an effective aspect ratio larger than that of the second transistor group.
An imaging device comprising:
- a pixel array having multiple rows and multiple columns;
- a number of sample and hold units, each sample and hold unit coupled to a separate column of the pixel array;
- a number of comparators, each comparator coupled to a separate sample and hold unit, each comparator including an input stage and an output stage, the input stage to produce a near decision and a true decision, the near decision to power up the output stage to provide an output representative of the true decision, wherein the output stage is configured to be powered up for a time period set at a fraction of a total ramp time of a ramping reference voltage.
A system comprising:
- a processor;
- and
- an imaging device coupled to the processor, the imaging device including:
- a pixel array having a number of rows and a number of columns;
- a number of sample and hold units, the number equal to the number of columns of the pixel array, each sample and hold unit coupled to a separate column of the pixel array;
- a number of comparators, each comparator coupled to a separate sample and hold unit of the number of sample and hold units;
- each comparator including an input stage to produce a near decision and a true decision, the near decision to power up a switching output stage to provide an output representative of the true decision, wherein the input stage includes an offset voltage circuit to provide an offset voltage such that the near decision is produced prior to producing the true decision relative to a ramping reference voltage.
4 more elements
A system comprising:
- a processor;
- and
- an imaging device coupled to the processor, the imaging device including:
- a pixel array having a number of rows and a number of columns;
- a number of sample and hold units, the number equal to the number of columns of the pixel array, each sample and hold unit coupled to a separate column of the pixel array;
- a number of comparators, each comparator coupled to a separate sample and hold unit of the number of sample and hold units;
- each comparator including an input stage to produce a near decision and a true decision, the near decision to power up a switching output stage to provide an output representative of the true decision, wherein each comparator includes a first differential pair having a first input section to receive an input signal from a sample and hold unit at a first transistor group and a reference section to receive a reference input and a second differential pair having the reference section to receive the reference input and a second input section to receive the input signal from the sample and hold unit at a second transistor group, the first transistor group larger in effective size than the second transistor group.
4 more elements
A method for forming an electronic device comprising:
- providing an input stage of a comparator configured to produce a near decision and a true decision, and
- coupling the input stage to a switching output stage such that the near decision operatively powers up the switching output stage to provide an output representative of the true decision, wherein providing an input stage includes providing the input stage with a circuit to provide an offset voltage such that the near decision is produced prior to producing the true decision relative to a ramping reference voltage.
A method for forming an electronic device comprising:
- providing an input stage of a comparator configured to produce a near decision and a true decision,
- coupling the input stage to a switching output stage such that the near decision operatively powers up the switching output stage to provide an output representative of the true decision;
- and
- coupling a ramp generator to each input stage and configuring the switching output stage with logic circuitry such that the switching output stage is powered up for a time period set at a fraction of a total ramp time of a ramping reference voltage.
1 more element
A method for forming an imaging device comprising:
- providing a pixel array, the pixel array having a number of rows and a number of columns;
- coupling a number of sample and hold units to the pixel array;
- coupling a number of comparators to the number of sample and hold units, each comparator coupled to a different one of the number of sample and hold units, each comparator provided by
- providing an input stage configured to produce a near decision and a true decision, and
- coupling the input stage to a switching output stage such that the near decision operatively powers up the switching output stage to provide an output representative of the true decision, wherein providing an input stage includes providing the input stage with a circuit to provide an offset voltage such that the near decision is produced prior to producing the true decision relative to a ramping reference voltage.
2 more elements
A method for forming an imaging device comprising:
- providing a pixel array, the pixel array having a number of rows and a number of columns;
- coupling a number of sample and hold units to the pixel array;
- coupling a number of comparators to the number of sample and hold units, each comparator coupled to a different one of the number of sample and hold units, each comparator provided by
- providing an input stage configured to produce a near decision and a true decision, and
- coupling the input stage to a switching output stage such that the near decision operatively powers up the switching output stage to provide an output representative of the true decision, wherein providing an input stage configured to produce a near decision and a true decision includes:
- providing a first differential pair having a first input section to receive an input signal from a sample and hold unit at a first transistor group and a reference section to receive a reference input;
- and
- providing a second differential pair having the reference section to receive the reference input and a second input section to receive the input signal from the sample and hold unit at a second transistor group, the first transistor group larger in effective size than the second transistor group.
5 more elements
A method for forming an imaging device comprising:
- providing a pixel array, the pixel array having a number of rows and a number of columns;
- coupling a number of sample and hold units to the pixel array;
- coupling a number of comparators to the number of sample and hold units, each comparator coupled to a different one of the number of sample and hold units, each comparator provided by
- providing an input stage configured to produce a near decision and a true decision, and
- coupling the input stage to a switching output stage such that the near decision operatively powers up the switching output stage to provide an output representative of the true decision, wherein the method further includes coupling a ramp generator to each input stage and configuring the switching output stage with logic circuitry such that the switching output stage is powered up for a time period set at a fraction of a total ramp time of a ramping reference voltage.
2 more elements
A method for forming an electronic system comprising:
- providing a processor;
- coupling a pixel array to the processor;
- and
- coupling the pixel array to a number of comparators, each comparator having an input stage configured to produce a near decision and a true decision such that the near decision operatively powers up an output stage to provide an output representative of the true decision, wherein coupling the pixel array to a number of comparators includes coupling the pixel array to a number of comparators with each comparator having an input stage including a circuit to provide an offset voltage such that the near decision is produced prior to producing the true decision relative to a ramping reference voltage.
1 more element
A method for forming an electronic system comprising:
- providing a processor;
- coupling a pixel array to the processor;
- and
- coupling the pixel array to a number of comparators, each comparator having an input stage configured to produce a near decision and a true decision such that the near decision operatively powers up an output stage to provide an output representative of the true decision;
- for each comparator, coupling the input stage to an output stage having logic circuitry to reset the input stage once a voltage representing the true decision has been processed by the switching output stage;
- and
- coupling a ramp generator to the input stage of each comparator and configuring the logic circuitry of the output stage such that the output stage is powered up for a time period set at a fraction of a total ramp time of a ramping reference voltage.
4 more elements
A method of operating an electronic device comprising:
- comparing an input voltage with a reference voltage in an input stage;
- generating a near voltage from the input stage prior to the reference voltage being equal to the input voltage, the near voltage defining a near decision;
- powering up an output stage in response to generating the near voltage;
- generating a true voltage from the input stage in response to the reference voltage being substantially equal to the input voltage, the true voltage defining a true decision;
- and
- providing an output from the output stage representative of the true decision.
3 more elements
A method of operating an imaging device comprising:
- selecting a row of pixels of a pixel array of the imaging device;
- sampling a voltage at a column of the pixel array for the selected row to provide an input voltage;
- comparing the input voltage with a reference voltage in the input stage;
- generating a near voltage from the input stage prior to the reference voltage being equal to the input voltage, the near voltage defining a near decision;
- powering up an output stage in response to generating the near voltage;
- and
- generating a true voltage from the input stage in response to the reference voltage being substantially equal to the input voltage, the true voltage defining a true decision.
4 more elements
A method of operating an electronic system comprising:
- addressing a column of a pixel array;
- selecting a row of the pixel array;
- comparing an input voltage provided from the addressed column of the selected row of pixels with a reference voltage in an input stage;
- generating a near voltage from the input stage prior to the reference voltage being equal to the input voltage, the near voltage defining a near decision;
- and
- powering up an output stage in response to generating the near voltage;
- generating a true voltage from the input stage in response to the reference voltage being substantially equal to the input voltage, the true voltage defining a true decision;
- and
- latching a word representing the true voltage;
- and
- providing the word to a system unit external to the pixel array.
8 more elements
Dependencies are inferred from the claim text.