Injection-Locked Oscillator Calibration for Low Jitter Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electronic circuits face challenges in maintaining stable operation across varying supply voltages and temperatures, leading to changes in electrical characteristics and behavior, which existing technologies struggle to address effectively.
Innovation Solution
The implementation of circuitry that quickly determines settings for an injection-locked oscillator (ILO) to align its natural oscillation frequency with the reference clock frequency, minimizing jitter and enhancing tolerance to voltage and temperature drift by adjusting delay elements within the ILO.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the operating conditions (supply voltage, temperature) change, then the electrical characteristics of circuit elements change, but the circuit behavior becomes unstable and operates outside desired specifications
Solution Approach 1:
The patent implements a feedback mechanism where the ILO's output frequency is continuously monitored and compared against a target frequency. Based on this comparison, control signals adjust the ILO's operating parameters in real-time, creating a closed-loop system that maintains stable operation despite external condition changes.
Solution Approach 2:
The patent dynamically changes the ILO's operating parameters (such as injection signal characteristics, delay element settings) in response to detected frequency deviations. This allows the circuit to adapt its behavior to compensate for variations in supply voltage and temperature, maintaining reliable operation across different conditions.
2Reliability
If existing technologies are used to address operating condition variations, then some level of compensation is provided, but the circuit still struggles to maintain stable operation across the full range of conditions
Solution Approach 1:
The ILO circuit performs self-calibration by automatically detecting its own frequency deviations and generating appropriate correction signals. This self-service capability eliminates the need for complex external compensation circuits, achieving reliable operation across conditions while keeping the overall system relatively simple.
Solution Approach 2:
The patent designs the ILO and its control circuitry to perform multiple functions: frequency generation, frequency monitoring, error detection, and automatic correction. This multi-functionality consolidates what would otherwise require separate compensation circuits into a single integrated system, reducing overall complexity while maintaining reliability.
Data Source
AI summary
Embodiments of an integrated circuit (IC) comprising circuitry to determine settings for an injection-locked oscillator (ILO) are described. In some embodiments, an injection signal is generated based on a first clock edge of a reference clock signal, and is injected into an ILO. Next, one or more output signals of the ILO are sampled based on a second clock edge of the reference clock signal, and settings for the ILO are determined based on the samples. In some embodiments, a sequence of two or more time-to-digital (TDC) codes is generated based on a reference clock signal and a free-running ILO. In some embodiments, the TDC circuitry that is already present in a delay-locked loop is reused for determining the sequence of two or more TDC codes. The ILO settings can then be determined based on the sequence of two or more TDC codes.