Semiconductor Current Control with Dynamic Gain Offset Correction
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Solution Overview
Problem
Incorporating a current detection circuit in an IC chip faces challenges due to changes in the gain and offset values caused by temperature and reference voltage fluctuations, leading to increased current detection errors.
Innovation Solution
A current control semiconductor element with a transistor, current-to-voltage conversion circuit, AD converter, reference current generator, gain/offset corrector, and current digital value calculator, which dynamically corrects gain and offset values to ensure accurate current detection within a single IC chip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a current detection circuit is incorporated in an IC chip, then the number of externally attached parts is reduced and device size is downsized, but the gain and offset values change due to temperature and reference voltage fluctuations, leading to increased current detection errors
Solution Approach 1:
The patent applies preliminary action by measuring the gain and offset values at the factory under controlled temperature conditions and storing these calibrated values in a ROM. This pre-calibration allows the system to compensate for temperature-induced variations during operation without requiring real-time external calibration equipment, thus maintaining measurement precision while keeping the device compact.
Solution Approach 2:
The patent implements feedback by using a temperature sensor to detect the current operating temperature and comparing it with the reference temperature stored in the ROM. Based on this temperature difference feedback, the system automatically adjusts the gain and offset values to compensate for thermal drift, thereby maintaining accurate current detection despite temperature fluctuations.
2Volume of moving object
If a current detection circuit is incorporated in an IC chip, then the number of externally attached parts is reduced and device size is downsized, but the gain and offset values change due to reference voltage fluctuations, leading to increased current detection errors
Solution Approach 1:
The patent applies preliminary action by measuring and storing the gain and offset values at the factory under controlled reference voltage conditions. These pre-calibrated values are stored in a ROM and used as reference data to compensate for reference voltage fluctuations during operation, maintaining measurement precision without requiring external calibration components.
Solution Approach 2:
The patent implements feedback by monitoring the reference voltage and using the pre-stored calibration data to adjust the gain and offset values dynamically. This feedback mechanism compensates for reference voltage variations, ensuring accurate current detection while keeping the device compact and integrated.
3Measurement precision
If gain and offset values are dynamically corrected in an IC chip, then current detection accuracy is improved, but the device complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing correction values in a ROM during manufacturing. This approach eliminates the need for complex real-time calculation circuits, as the correction values are simply retrieved from memory based on temperature sensing, thereby improving accuracy while minimizing the increase in device complexity.
Solution Approach 2:
The patent uses a temperature sensor and ROM as intermediaries to bridge the gap between temperature detection and gain/offset correction. Instead of implementing complex real-time mathematical calculations, the system uses the temperature sensor to index into pre-computed correction tables stored in the ROM, simplifying the overall circuit architecture while maintaining high measurement precision.
Data Source
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AI summary
This invention provides a current control semiconductor element that can detect a current with high accuracy in a single IC chip by dynamically correcting changes in a gain a and an offset b, and a control device that uses the current control semiconductor element. The current control semiconductor element has a transistor 4, a current-to-voltage conversion circuit 22 and an AD converter 23 on the same semiconductor chip. A reference current generation circuit 6 superimposes a current pulse Ic on a current of a load 2 and changes a voltage digital value to be output from the AD converter. A gain/offset corrector 8 executes signal processing on change in the voltage digital value caused by the reference current generation circuit 6 to dynamically acquire the gain a and the offset b that are used in an equation that indicates a linear relationship between the voltage digital value output from the AD converter 23 and the current digital value of the load. A current digital value , calculator 12 uses the gain and the offset acquired by the gain/offset corrector 8 to correct the voltage value output from the AD converter.