Multi-Shot Time-to-Digital Converter for Higher Resolution Timing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing time-to-digital converters (TDCs) face limitations in resolution and nonlinearity due to manufacturing technology, which results in mismatched time delay cells and quantization errors.
Innovation Solution
A multi-shot time-to-digital converter that sends a start signal multiple times, utilizing different clock phases to measure time intervals and reduce nonlinearity and quantization errors by rolling across fine phase times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple time delay cells are used to achieve fine time resolution, then the resolution of TDC is improved, but manufacturing mismatch causes nonlinearity and quantization error to worsen
Solution Approach 1:
The patent employs periodic action by sending the start signal multiple times (multi-shot approach) and using multiple clock signals with different phases to periodically sample the time interval. This allows the system to accumulate multiple measurements and average out the random errors caused by manufacturing mismatch, thereby improving measurement accuracy while maintaining fine time resolution
Solution Approach 2:
The patent implements feedback through digital processing of multiple time-to-digital codes obtained from different clock phases. The system measures the time interval multiple times with different phase references, processes these measurements digitally to calculate statistical parameters, and uses this feedback information to improve the overall measurement accuracy and compensate for nonlinearity effects
2Measurement precision
If the minimum time delay of delay cells is reduced to improve resolution, then quantization step size decreases, but technology node limitations prevent further reduction
Solution Approach 1:
The patent transitions from a single-dimensional approach (reducing time delay in one direction) to a multi-dimensional approach by introducing multiple clock signals with different phases. Instead of relying solely on reducing the minimum time delay of individual cells, the system uses phase diversity to achieve finer effective resolution, overcoming the limitations of technology node constraints
3Length of stationary object
If more time delay cells are added to improve measurement range, then the time measurement capability is enhanced, but nonlinearity increases due to cell mismatch
Solution Approach 1:
By using multiple clock signals with different phases to periodically measure the same time interval from different phase references, the system can cover a larger measurement range while maintaining linearity. The periodic sampling at different phases allows digital processing to reconstruct the linear relationship across the extended range
Data Source
AI summary
The present invention relates a multi-shot time-to-digital converter and a time-measurement device. The multi-shot time-to-digital converter includes a time-to-digital conversion circuit and a timing control circuit. The timing control circuit is coupled to the time-to-digital conversion circuit and sending a start signal to the time-to-digital conversion circuit multiple times for measuring a time interval corresponding to the start signal. The time-to-digital conversion circuit obtains a fine phase time based on a plurality of clock signals to measure the time interval and provides a plurality of time-to-digital codes for digital processing. The clock signals have different phases. The time-to-digital codes are further processed to obtain the time-to-digital codes with better resolution.