Window-Enabled TDC Phase Detection With Dynamic Measurement Window
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Solution Overview
Problem
All-digital phase-locked loops (ADPLLs) face challenges in reducing power consumption and noise while maintaining high resolution in time-to-digital converters (TDCs), as conventional methods to reduce the measurement window often introduce noise and degrade precision.
Innovation Solution
A window-enabled TDC design that utilizes a window generator to enable and disable the TDC circuit based on the reference signal and clock signal edges, defining the measurement window as a single local clock pulse, thereby reducing unnecessary power consumption and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the measurement window is reduced to lower power consumption, then power consumption is reduced, but measurement precision may be degraded
Solution Approach 1:
The patent implements dynamic adjustment of the measurement window size based on the locking state of the PLL. During acquisition mode, a larger window is used to ensure accurate phase detection. During locked mode, a smaller window suffices, reducing power consumption. This dynamic adaptation resolves the contradiction by optimizing the window size according to operational requirements rather than using a fixed size.
Solution Approach 2:
The measurement window parameter is changed based on operational mode. The system switches between two distinct window configurations: a first window size for acquisition mode and a second, smaller window size for locked mode. This parameter change allows the system to maintain precision when needed while minimizing power consumption during normal operation.
2Measurement precision
If additional components are added to improve TDC resolution, then measurement precision is improved, but device complexity and power consumption increase
Solution Approach 1:
The patent extracts only the essential functionality needed for phase detection by using a simplified TDC architecture combined with dynamic window adjustment. Rather than adding complex components like Vernier delay chains, the invention achieves high resolution by precisely controlling when the TDC operates and for how long, extracting the critical measurement function while eliminating unnecessary complexity.
Solution Approach 2:
The system applies partial action by operating the TDC circuit only during the necessary measurement window rather than continuously. This partial operation achieves the required measurement precision without the need for continuously active high-resolution components, thereby reducing overall device complexity while maintaining adequate resolution.
3Reliability
If the TDC operates continuously for the duration of the reference pulse, then measurement coverage is complete, but power consumption increases
Solution Approach 1:
The TDC circuit is enabled periodically based on the detection of reference signal edges rather than operating continuously throughout the entire reference pulse duration. This periodic activation—triggered only when phase measurement is actually needed—maintains detection reliability while significantly reducing power consumption during intervals when measurement is not required.
Solution Approach 2:
The system uses preliminary detection of reference signal edges to trigger TDC operation only when necessary. By detecting the arrival of relevant signal edges in advance, the system can enable the TDC precisely when measurement is needed rather than keeping it continuously active, thus maintaining reliability while reducing power consumption.
Data Source
AI summary
A window-enabled TDC and method of detecting phase of a reference signal. One embodiment of the window-enabled TDC includes: (1) a window generator configured to receive a reference signal and a clock signal, and (2) a TDC circuit coupled to the window generator and configured to be enabled based on the reference signal and disabled based on the clock signal.