Single-Oscillator Sensor Interface for Drift-Free Multiplexing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing closed-loop oscillator-based sensor interfaces face challenges with oscillator drift and mismatch between Voltage Controlled Oscillators (VCOs), leading to artefacts in digital output and difficulty in multiplexing between different sensor readouts.
Innovation Solution
A closed-loop oscillator-based sensor interface circuit utilizing a single oscillator with switching means, a counter, and control logic to manage oscillator cycles, eliminating oscillator drift by applying the same impact to all inputs and allowing for multiplexing between different sensor signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple Voltage Controlled Oscillators (VCOs) are used in closed-loop oscillator-based sensor interfaces, then the system can process multiple sensor signals, but oscillator drift and mismatch between VCOs lead to artefacts in digital output
Solution Approach 1:
The patent merges multiple VCO functions into a single VCO by using switching means that connects the VCO input to different sensor signals at different times. This eliminates oscillator drift and mismatch between multiple VCOs while maintaining the ability to process multiple sensor signals through time-multiplexed operation.
Solution Approach 2:
The single VCO is designed to be universal by accepting multiple sensor signals through switching means. The same VCO processes different sensor inputs sequentially, making one oscillator capable of performing the function previously requiring multiple oscillators, thereby eliminating drift-related artefacts.
2Adaptability or versatility
If multiple VCOs are used to handle different sensor readouts, then multiple sensor signals can be converted, but it creates difficulty in multiplexing between different sensor readouts
Solution Approach 1:
The patent combines multiple sensor signal processing paths into a single VCO processing path using switching means. Instead of managing multiple VCOs and their synchronization, the system uses one VCO with switching inputs, significantly reducing multiplexing complexity while maintaining multi-sensor capability.
Solution Approach 2:
The patent segments the signal processing into time-multiplexed phases where the switching means connects different sensor signals to the single VCO at different times. This temporal segmentation simplifies the overall system architecture compared to spatial segmentation using multiple parallel VCOs.
3Use of energy by moving object
If a single oscillator is used, then power consumption is reduced and drift issues are avoided, but the system must handle multiple sensor signals through switching
Solution Approach 1:
The patent merges multiple sensor signal processing functions into a single oscillator system with switching inputs. This consolidation reduces power consumption compared to running multiple oscillators while the switching means manages the temporal multiplexing of different sensor signals to the single oscillator.
Data Source
AI summary
An oscillator-based sensor interface circuit includes an oscillator and a switching means is arranged for switching between at least two signals to be applied to the oscillator via that input. At least one of the signals is an electrical signal representative of an electrical quantity. A counter is arranged to count a number of cycles produced by the oscillator. A control logic is arranged to control the switching means and to derive a control output signal from a first number of counted oscillator cycles. A feedback element is arranged for converting a representation of the control output signal into a feedback signal used directly or indirectly to maintain a given relation between the first number of counted oscillator cycles.