Zero-Crossing Phase Detection Using Interpolated ADC Sampling
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Solution Overview
Problem
The phase difference between zero-crossing points of analog signals and sampling clock edges, known as jitter, affects the quality of digital signals during analog-to-digital conversion, necessitating a phase detection device to accurately determine zero-crossing points for signal adjustment.
Innovation Solution
A phase detection device comprising an analog-to-digital converter, an interpolator, and a determining unit that calculates interpolation points and generates selection signals to determine the phase of zero-crossing points, potentially using XOR operations or lookup tables, and can include a phase-locked loop circuit to synchronize the sampling clock, enabling jitter detection and calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If analog-to-digital conversion is performed using simple sampling at clock edges, then the conversion process is simple and fast, but phase difference (jitter) between zero-crossing points and sampling edges degrades signal quality
Solution Approach 1:
The patent segments the sampling process into multiple stages: initial sampling at clock edges, interpolation to generate intermediate points, and determination of zero-crossing phase. This segmentation allows the system to maintain fast initial sampling while adding precision through subsequent interpolation and phase determination steps.
Solution Approach 2:
The patent performs preliminary sampling at clock edges before performing the more complex interpolation and phase determination. This preliminary action captures the basic signal information quickly, allowing subsequent processing to focus only on refining the phase measurement without re-sampling the entire signal.
2Measurement precision
If interpolation points are calculated between digital sampling points to improve zero-crossing detection accuracy, then phase detection precision is improved, but computational complexity increases
Solution Approach 1:
The patent extracts only the essential information needed for phase detection from the interpolated points - specifically the signs of consecutive interpolation points to determine zero-crossing occurrence. This extraction approach avoids the need to perform full-precision calculations on all interpolated values, significantly reducing computational complexity while maintaining detection accuracy.
Solution Approach 2:
The patent performs interpolation to generate intermediate points, but only processes enough of these points to determine the sign changes that indicate zero-crossings. This partial action approach generates more interpolation points than strictly necessary for basic interpolation, but processes them efficiently by focusing only on the sign information needed for phase detection.
3Reliability
If a phase detection device is added to detect jitter and adjust digital signals, then signal quality is improved, but device complexity increases
Solution Approach 1:
The patent merges the phase detection functionality with the existing analog-to-digital conversion process by integrating interpolation and zero-crossing determination into the conversion pipeline. This merging allows phase detection to be performed using the same hardware resources already allocated for signal conversion, adding reliability without proportionally increasing overall system complexity.
Solution Approach 2:
The patent designs the phase detection device to serve multiple functions: detecting zero-crossing phases, measuring jitter, and providing information for signal adjustment. This multi-functionality allows a single added device to improve signal quality through multiple mechanisms rather than requiring separate dedicated components for each function.
Data Source
AI summary
A phase detection device comprising an analog-digital converter, an interpolator, and a determining unit. The analog-digital converter receives an analog signal and converts the analog signal to a digital signal according to a plurality of digital sampling points. The interpolator generates a plurality of interpolation points according to a predetermined amount of digital sampling points. The determining unit obtains a phase of the ZC point according to the interpolation points or the digital sampling points.