Microcontroller ADC Sampling Time Adjustment for RC Signal Accuracy
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Solution Overview
Problem
Conventional microcontrollers sample external signals at fixed times, leading to errors due to varying capacitor and resistor parameters in different external peripheral circuits.
Innovation Solution
A microcontroller comprising a selection circuit, sample and hold circuit, analog-to-digital converter circuit, and control circuit that adjusts sampling time based on digital output values, allowing for automatic correction of sampling time to match the parameters of external peripheral circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fixed sampling time is used to sample external signals, then the sampling process is simple and fast, but the sample result is in error due to varying capacitor and resistor parameters in different external peripheral circuits
Solution Approach 1:
The patent implements a feedback mechanism where the digital output from the ADC is fed back to the control circuit. The control circuit compares the digital output with expected values and adjusts the sampling time accordingly. This closed-loop feedback system automatically corrects sampling errors caused by varying external circuit parameters without requiring manual intervention or complex pre-calibration procedures.
Solution Approach 2:
The patent transforms the static fixed sampling time into a dynamic adjustable parameter. The control circuit modifies the sampling time based on the actual digital output values obtained from previous sampling operations. This dynamic adjustment allows the system to adapt to different external peripheral circuits with varying capacitor and resistor parameters, thereby maintaining sampling accuracy across different configurations.
2Measurement precision
If the sampling time is adjusted to match different external peripheral circuit parameters, then the sampling accuracy is improved, but the control process becomes more complex
Solution Approach 1:
The patent performs preliminary sampling operations to determine the appropriate sampling time before actual measurements are taken. The control circuit uses initial sampling results to calculate and set the optimal sampling time for subsequent operations. This preliminary action ensures that when actual measurements are performed, the sampling time is already optimized, minimizing the impact of adjustment time on overall measurement efficiency.
Solution Approach 2:
The control circuit automatically adjusts the sampling time based on feedback from the ADC without requiring external intervention. The system serves itself by using its own output (digital signal) to control its own input parameters (sampling time), eliminating the need for manual calibration or external timing adjustments. This self-service mechanism reduces both control complexity and adjustment time.
Data Source
AI summary
A microcontroller including a selection circuit, a sample and hold circuit, an analog-to-digital converter circuit, and a control circuit is provided. The selection circuit provides a first external voltage or a second external voltage as an output voltage according to a selection signal. The sample and hold circuit samples the output voltage according to a turn-on signal to generate an analog input. The analog-to-digital converter circuit converts the analog input to generate a digital output. The control circuit generates the selection signal according to the digital output, adjusts the sampling time, and then generates a turn-on signal according to the sampling time.