Ring Oscillator Phase Shifting Without Added Chip Area
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Solution Overview
Problem
Conventional ring oscillators in semiconductor devices face challenges in efficiently shifting the phases of periodic waves while maintaining the same frequency, which requires increased chip area and complexity.
Innovation Solution
An integrated circuit with a ring oscillator and a phase controller that adjusts the delay value of delay cells to generate and shift periodic waves by changing the frequency momentarily, then restoring it to maintain the original frequency, thereby shifting phases without increasing chip area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional methods are used to shift phases of periodic waves while maintaining the same frequency, then phase shifting capability is achieved, but chip area and circuit complexity increase
Solution Approach 1:
The patent changes the delay parameter of delay cells dynamically by controlling the number of active delay cells. By adjusting the delay value parameter rather than adding dedicated phase shifters for each phase, the circuit achieves phase shifting capability while minimizing chip area usage.
Solution Approach 2:
The same delay cells are used for multiple purposes: generating the original periodic waves and generating phase-shifted periodic waves. By universally utilizing the delay cells for both functions through selective activation, the patent eliminates the need for separate dedicated phase shifting circuits, thereby reducing chip area.
2Adaptability or versatility
If conventional methods are used to shift phases of periodic waves while maintaining the same frequency, then phase shifting capability is achieved, but circuit complexity increases
Solution Approach 1:
The patent controls circuit complexity by dynamically changing the delay parameter through selective activation of delay cells rather than implementing complex dedicated phase shifting circuits. This parameter-based approach simplifies the overall circuit architecture.
Solution Approach 2:
The delay cells serve dual functions as both original wave generators and phase-shifted wave generators. This multi-functionality reduces circuit complexity by eliminating redundant components and simplifying the overall circuit structure.
3Adaptability or versatility
If delay value of delay cells is changed to shift phases, then phase shifting is achieved, but frequency changes occur
Solution Approach 1:
The patent employs periodic switching between different delay cell configurations to achieve phase shifting. By periodically activating different sets of delay cells in a controlled manner, the system shifts phases while maintaining frequency stability through the periodic nature of the switching operation.
Solution Approach 2:
The patent carefully controls parameter changes in delay cells by selectively activating specific delay cells rather than uniformly changing all delay values. This selective parameter adjustment allows phase shifting while minimizing frequency deviations, as the overall delay characteristic remains controlled.
Data Source
AI summary
An integrated circuit includes a ring oscillator including delay cells having a delay value and configured to generate two or more periodic waves, a first phase controller configured to compare the phase of a first selected periodic wave to the phase of a reference wave and change the delay value of the delay cells from a first delay value to a second delay value based on a first comparison signal corresponding to a phase difference between the first selected periodic wave and the reference wave, and a second phase controller configured to compare the phase of a second selected periodic wave to the phase of the reference wave and restore the delay value of the delay cells from the second delay value to the first delay value based on a second comparison signal corresponding to a phase difference between the second selected periodic wave and the reference wave.