TDC-Based Synchronization Circuit for Accurate Sampling Phase Alignment
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Solution Overview
Problem
Synchronizing sampling devices and setting specific output sample rates is challenging due to significant board design overhead and reduced accuracy caused by delays between the applied output data rate signal and clock signal, leading to phase errors and reduced synchronization accuracy.
Innovation Solution
Implementing a time-to-digital converter (TDC) to measure and account for timing errors between the output data rate signal and the clock signal, allowing for improved synchronization by adjusting phase delays and applying fractional time delays without complex circuitry, thereby enhancing synchronization accuracy and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If clock signal routing is carefully matched to synchronize sampling at multiple devices, then synchronization accuracy is improved, but board design overhead and device complexity increase significantly
Solution Approach 1:
A TDC-based timing error measurement circuit is introduced as an intermediary component between the clock signal source and the sampling devices. This circuit measures the timing error between the ODR signal and the clock signal, and provides compensation information to the synchronization logic, thereby achieving accurate synchronization without requiring complex clock signal routing matching across the entire system.
2Device complexity
If one device is used as master to provide clock to other devices, then device count is reduced, but clock signal routing complexity and sampling edge compensation requirements increase
Solution Approach 1:
Each sampling device is equipped with its own TDC-based timing error measurement circuit that autonomously measures the timing error between its local ODR signal and clock signal. This self-service approach allows each device to independently compensate for its own timing errors without requiring complex centralized clock distribution or manual sampling edge compensation, thereby simplifying the overall system architecture.
3Device complexity
If ODR signal frequency is adjusted to match clock signal frequency, then synchronization is simplified, but ability to set specific output sample rates is lost
Solution Approach 1:
The TDC circuit continuously measures the timing error between the ODR signal and the clock signal, and this measurement is fed back to the synchronization logic. The synchronization logic uses this feedback information to generate a compensated clock signal that maintains the correct frequency relationship while allowing the ODR signal to operate at the desired output sample rate, thus preserving both synchronization simplicity and rate flexibility.
4Measurement precision
If timing error measurement is implemented, then synchronization accuracy is improved, but power consumption increases
Solution Approach 1:
The TDC circuit is activated periodically only during the brief intervals when timing error measurement is needed, rather than operating continuously. The circuit measures the timing error between the ODR signal and clock signal edges, then enters a low-power state until the next measurement cycle, thereby achieving accurate timing error measurement while minimizing power consumption.
Data Source
AI summary
This disclosure relates to providing an improved synchronization circuit for a sampling device. In particular, it relates to providing a time-to-digital converter for improving the accuracy of a synchronization circuit for a data sampling device.