Background calibration of non-linearity of samplers and amplifiers in adcs
AssigneeAnalog Devices, Inc.
InventorsAhmed Mohamed Abdelatty ALI, Paridhi GULATI
Life of this patent
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Abstract
Analog circuits are often non-linear, and the non-linearities can hurt performance. Designers would trade off power consumption to achieve better linearity. An efficient and effective calibration technique can address the non-linearities and reduce the overall power consumption. A dither signal injected to the analog circuit can be used to expose the non-linear behavior in the digital domain. To detect the non-linearities, a counting approach is applied to isolate non-linearities independent of the input distribution. The approach is superior to and different from other approaches in many ways.
Claims20
A calibration system with efficient error estimation, comprising:
- dither circuitry to inject a dither at an input of a circuit and to remove the dither at an output of the circuit;
- counting circuitry to accumulate counts of an output within ranges defined by one or more inspection points of the output;
- error circuitry to compare counts associated with different values of the dither and determining an error estimate;
- and
- calibration circuitry to drive the error estimate towards zero.
A method for efficient error estimation and calibration of a circuit, comprising:
- adding a dither at an input of the circuit;
- removing the dither at an output of the circuit;
- accumulating counts of an output within ranges defined by one or more inspection points of the output;
- comparing counts associated with different values of the dither;
- determining an error estimate based on the comparing of counts;
- and
- driving the error estimate towards zero.
An apparatus for estimating errors and calibrating a circuit, comprising:
- means injecting a dither at an input of a circuit and removing the dither at an output of the circuit;
- means for evaluating counts of the output of the circuit associated with different values of the dither within ranges defined by one or more inspection points;
- means for combining the counts associated with different values of the dither to expose an error associated with a component of the circuit;
- and
- means for updating an estimate of the component of the circuit based on the error.
Dependencies are inferred from the claim text.