Oscillator based sensors
AssigneeCirrus Logic International Semiconductor Ltd.
InventorsJohn P. LESSO, James T. DEAS
Life of this patent
Estimating the term…
Abstract
This application relates to methods and apparatus for sensing using controlled oscillators. A sensor apparatus has a first ring oscillator formed a plurality of delay elements which generates a first oscillator signal. At least one of the delay elements is a sensing delay element which includes a sensor component with an electrical property that varies with a measurand of interest to vary a propagation delay of the sensing delay element, and hence an oscillation frequency of the first oscillator signal.
Claims20
A sensor apparatus comprising:
- a first ring oscillator comprising a plurality of delay elements configured to generate a first oscillator signal;
- wherein at least one of the delay elements comprises a sensing delay element which comprises a sensor component with an electrical property that varies with a measurand of interest to vary a propagation delay of the sensing delay element and hence an oscillation frequency of the first oscillator signal.
A sensor apparatus comprising:
- a first ring oscillator comprising a plurality of delay elements configured to generate a first oscillator signal;
- wherein at least one delay element comprises a sensor component connected between a first voltage and a delay element output node and a switching device connected between the delay element output node and a second voltage;
- wherein the sensor component provides at least one of a variable resistance and a variable current that varies with a measurand of interest.
A sensor apparatus comprising:
- a first ring oscillator comprising a plurality of delay elements configured to generate a first oscillator signal, wherein at least one of the delay elements is configured to provide a propagation delay which varies with a measurand of interest so as to vary a frequency of the first oscillator signal;
- and
- decode circuitry configured to receive and decode the first oscillator signal so as to provide a measurement signal indicative of the measurand of interest.
Dependencies are inferred from the claim text.