Noise-Shaping Time-to-Digital Converter for Wide-Range Resolution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional time-to-digital converters face limitations in achieving both high time resolution and a wide interval range, often sacrificing one for the other, leading to suboptimal performance in applications such as clocking and sensor measurements.
Innovation Solution
The implementation of noise-shaping time-to-digital conversion techniques, which include a phase detector, loop filter, analog-to-digital converter, digital-to-time converter, and feedback circuit, allowing for precise phase error integration and conversion of digital phase error codes into gating signals to improve time resolution while maintaining a wider interval range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional time-to-digital converters use a narrow interval range configuration, then time resolution is improved, but the conversion range is limited
Solution Approach 1:
The converter is divided into multiple independent modules: phase detector, loop filter, analog-to-digital converter, digital-to-time converter, and feedback circuit. Each module operates independently with specific functions, allowing the system to achieve both high resolution and wide range by coordinating these segmented components rather than using a single monolithic structure.
Solution Approach 2:
A feedback circuit is implemented that takes the digital phase error code, converts it back to time domain through the digital-to-time converter, and feeds it back to the phase detector. This closed-loop feedback mechanism enables the system to maintain high resolution measurements while accommodating a wider conversion range by dynamically adjusting the phase error based on feedback from previous measurements.
2Adaptability or versatility
If conventional time-to-digital converters sacrifice time resolution for wider interval range, then conversion range is improved, but time resolution deteriorates
Solution Approach 1:
The invention introduces a dual-domain approach by implementing both analog integration (in the loop filter) and digital processing (in the ADC and digital-to-time converter). This transition from purely analog to hybrid analog-digital architecture adds a new dimension to the conversion process, enabling the system to achieve wide interval range while maintaining high time resolution through coordinated operation of analog and digital components.
Solution Approach 2:
The system dynamically changes parameters including the integration time constant in the loop filter and the sampling frequency in the digital-to-time converter based on the input signal characteristics. By adjusting these parameters, the converter can adapt to different interval ranges while preserving time resolution, resolving the contradiction between range and precision.
3Measurement precision
If conventional converters increase time resolution, then measurement precision is improved, but quantization noise increases
Solution Approach 1:
The loop filter acts as an intermediary component between the phase detector and the analog-to-digital converter. It integrates the phase error signal over time, effectively filtering out high-frequency quantization noise before the signal reaches the ADC. This intermediary integration process reduces quantization noise while preserving the useful signal components, enabling high time resolution without excessive noise.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces quantization noise below the resolution of the reference clock signal period, enhances gain accuracy, and increases the conversion range, resulting in improved time resolution and reduced manufacturing variation impacts, thereby enhancing system performance in applications like delta-sigma modulator based fractional-N phase-locked loops.
Implementation Method 1
a loop filter configured to integrate the phase error signal and generate an analog integrated phase error signal
Implementation Method 2
Noise-shaping time-to-digital conversion techniques are described
Implementation Method 3
The feedback circuit may gate the reference clock signal with the gating signal to generate the phase-adjusted feedback signal
Data Source
AI summary
A noise-shaping time-to-digital converter has a large range and high resolution. The time-to-digital converter includes a phase detector configured to generate a phase error signal based on a phase-adjusted feedback signal and an input signal. The time-to-digital converter includes a loop filter configured to integrate the phase error signal and generate an analog integrated phase error signal. The time-to-digital converter includes an analog-to-digital converter configured to convert the analog integrated phase error signal to a digital phase error code. The time-to-digital converter includes a digital-to-time converter configured to convert at least a portion of the digital phase error code to a gating signal based on a reference signal and an enable signal. The time-to-digital converter includes a feedback circuit to generate the phase-adjusted feedback signal based on the reference signal and the gating signal.