Microprocessor ADC Calibration for Flexible Error Correction
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Solution Overview
Problem
Existing analog-to-digital converters (ADCs) face challenges in achieving accurate and reliable conversion performance due to errors and artifacts arising from fabrication limitations and environmental changes, which are often addressed with fixed, specialized circuitry that lacks flexibility and configurability.
Innovation Solution
Incorporating an on-chip microprocessor (uP) within ADCs to perform calibration and digital functions, enabling flexible and adaptive correction of errors through programmable algorithms and digital processing, which can be configured for various applications without silicon changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If fixed specialized circuitry is used to correct ADC errors, then manufacturing precision is improved, but adaptability deteriorates
Solution Approach 1:
The patent replaces fixed specialized analog circuitry with a digital microprocessor-based calibration system. The microprocessor executes calibration algorithms to measure and correct ADC errors, substituting rigid hardware correction mechanisms with flexible software-based solutions that can be reconfigured for different applications without physical changes.
Solution Approach 2:
The calibration system dynamically adjusts correction parameters through executable instructions stored in memory. By changing the calibration parameters and correction algorithms via software rather than fixed hardware, the system maintains high manufacturing precision while enabling adaptability across different application requirements.
2Measurement precision
If specialized calibration circuitry is added to ADCs, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent merges the calibration functionality into the existing ADC structure by utilizing the microprocessor and memory already present in modern ADC designs. Rather than adding separate specialized calibration circuitry, the system combines error measurement and correction functions with the digital processing resources already available in the converter, thereby improving measurement precision without proportionally increasing device complexity.
Solution Approach 2:
The ADC system performs self-calibration using its own internal resources. The microprocessor executes calibration algorithms that utilize the ADC's existing digital output and control capabilities to measure and correct its own errors, eliminating the need for external specialized calibration equipment and reducing overall system complexity.
3Adaptability or versatility
If on-chip microprocessor is integrated in ADC, then adaptability is improved, but manufacturing precision deteriorates
Solution Approach 1:
The microprocessor implements feedback-based calibration by measuring the ADC's actual performance characteristics and automatically adjusting correction parameters to compensate for manufacturing variations. This closed-loop approach ensures that conversion accuracy is maintained despite the added complexity of the microprocessor, as the system continuously optimizes its operation based on measured performance.
Solution Approach 2:
The calibration system performs preliminary error measurement and correction parameter determination before actual conversion operations. By pre-characterizing the ADC's errors and storing correction lookup tables in memory, the system compensates for manufacturing imprecisions while maintaining the adaptability benefits of the microprocessor across different operating conditions.
Data Source
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AI summary
Analog-to-digital converters (ADCs) can have errors which can affect their performance. To improve the performance, many techniques have been used to compensate or correct for the errors. When the ADCs are being implemented with sub-micron technology, ADCs can be readily and easily equipped with an on-chip microprocessor for performing a variety of digital functions. The on-chip microprocessor and any suitable digital circuitry can implement functions for reducing those errors, enabling certain undesirable artifacts to be reduced, and providing a flexible platform for a highly configurable ADC. The on-chip microprocessor is particularly useful for a randomized time-interleaved ADC. Moreover, a randomly sampling ADC can be added in parallel to a main ADC for calibration purposes. Furthermore, the overall system can include an efficient implementation for correcting errors in an ADC.