ADC Range Compression via Dynamic Sampling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Analog-to-Digital Converters (ADCs) face issues with quantization noise near the internal input range endpoints, stability limitations due to high modulator order, and calibration challenges when external reference signals result in out-of-range conversions, requiring a solution that maintains transparency and efficiency while expanding the internal input range without over-designing the conversion engine.
Innovation Solution
The method involves compressing the operational range of an ADC by sampling an analog input signal N times and an additional range compression signal N1 times, using a compression factor based on N1/(N+N1), allowing for precise control of margins at the internal input range endpoints and enabling equal or unequal margins at both ends, thus avoiding the need for over-designing the ADC engine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the internal input range of the ADC is extended beyond the external input range to provide margins at the endpoints, then quantization noise is reduced and stability is improved, but the device complexity increases and the conversion engine must be over-designed
Solution Approach 1:
The patent changes the operational parameters of the ADC by dynamically adjusting the input range mapping. Instead of fixing the internal range to be larger than the external range, the system dynamically compresses or expands the external input range to match the internal processing range, allowing the same conversion engine to operate efficiently without over-design.
Solution Approach 2:
The patent introduces dynamic range adjustment capability where the ADC can adapt its input range mapping based on operating conditions. The system dynamically selects between different range compression modes (equal margin, unequal margin, minimum margin) to optimize performance for different signal conditions, eliminating the need for a permanently oversized conversion engine.
2Productivity
If the ADC operates near the internal input range endpoints to maximize utilization of the conversion engine, then productivity is improved, but quantization noise increases and stability deteriorates
Solution Approach 1:
The patent employs asymmetric range mapping where the external input range is not symmetrically centered on the internal range. By allowing unequal margins at the lower and upper endpoints, the system can optimize the distribution of operating points away from the problematic endpoint regions while maintaining high conversion efficiency.
Solution Approach 2:
The patent applies different margin requirements to different ends of the input range. Instead of requiring equal margins at both endpoints, the system can allocate different safety margins to the lower and upper limits based on the specific characteristics of the signal and application, allowing optimal utilization of the conversion engine in each region.
3Ease of operation
If external reference signals are used for ADC calibration, then ease of operation is improved, but measurement precision deteriorates when the combined equivalent value falls outside the internal input range
Solution Approach 1:
The patent performs preliminary range verification before calibration operations. The system checks whether the external reference signals combined with offset and gain errors will fall within the valid internal input range, and only proceeds with calibration when the conditions are satisfied, preventing out-of-range errors.
Solution Approach 2:
The patent implements feedback mechanisms that monitor the actual input range utilization during calibration. The system uses this feedback to adjust the mapping parameters dynamically, ensuring that calibration signals remain within the valid operating range while maintaining ease of operation.
Data Source
AI summary
An analog-to-digital converter according to the invention is provided. The analog-to-digital converter preferably includes an analog input signal, a first reference signal, a second reference signal, and a range compression signal. The range compression signal is preferably characterized by a magnitude greater than the first reference signal and smaller than the second reference signal. In addition, when the analog input signal is sampled N times and the range compression signal is sampled N1 times, a compression factor that is based at least in part on N1/(N+N1) is obtained.