Comparator Offset Correction Using Repeated Filtered Comparisons
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional comparator offset correction devices inaccurately measure the offset amount due to noise interference, especially when the input voltage differs from the actual input voltage.
Innovation Solution
A comparator offset correction device that includes a comparator, an open switch, a short-circuit switch, a controller, and a filter, which allows multiple comparison operations and generates a threshold value control signal based on a frequency signal obtained by smoothing comparison results, thereby reducing noise influence and accurately correcting the comparator's threshold value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional offset correction methods are used to measure the offset amount, then the correction process can be completed, but noise interference causes erroneous measurement of the offset amount
Solution Approach 1:
The comparator performs comparison operations multiple times periodically, and the filter processes these repeated comparison results to generate a frequency signal. This periodic action allows the system to average out noise interference across multiple measurements, thereby improving the accuracy of offset amount measurement while maintaining correction efficiency.
2Measurement precision
If multiple comparison operations are performed to reduce noise influence, then measurement accuracy improves, but correction time increases
Solution Approach 1:
The filter generates a frequency signal based on multiple comparison results, which is fed back to the controller. The controller uses this frequency signal to determine the offset amount and generate the threshold value control signal. This feedback mechanism enables the system to efficiently process multiple comparisons and convert them into actionable correction data, improving measurement accuracy while managing correction time through intelligent signal processing.
3Productivity
If the threshold value is corrected based on noisy offset measurement, then the correction process is completed quickly, but the A/D conversion accuracy deteriorates
Solution Approach 1:
The filter acts as an intermediary between the multiple comparison operations and the threshold value correction process. It processes the raw comparison results to generate a smoothed frequency signal that accurately represents the offset amount without noise interference. This intermediary processing ensures that the correction is both accurate and efficient, improving A/D conversion accuracy while maintaining correction speed through optimized signal processing.
Data Source
AI summary
A comparator offset correction device opens an open switch 205 and closes a short-circuit switch 204 in offset correction of a comparator 201. In this state, a controller 203 allows the comparator 201 to repeat, more than once, the operation of comparing reference voltages 101 input to two input terminals with each other. The filter 202 outputs a frequency signal obtained by smoothing a plurality of comparison results. Based on the frequency signal from the filter 202, the controller 203 outputs a threshold value control signal to the comparator 201 so that the ratio of a high-level voltage to a low-level voltage in the results of the comparison in the comparator 201 is 50%. Thus, even when a current which will be input may differ from a current which is currently input due to, for example, the influence of noise, the threshold value offset amount is normally corrected.