Method for measuring temperature with an integrated circuit device
First Claim
1. A method of measuring temperature utilizing an integrated circuit (IC) chip, the method comprising:
- flowing a current through a resistor (Rext), the resistance value of which is substantially independent of temperature, said current being a function of an absolute temperature of a transistor (Q1) resident on the IC chip, said transistor being of a type which exhibits a predictable change in its base-emitter voltage over a temperature range;
mirroring the current flowing through the resistor to a circuit on the IC chip, said circuit providing an output signal which is proportional to the current flowing through the resistor, thereby making the output signal temperature-dependent as a function of the absolute temperature of the transistor;
including at least one internal capacitor in the circuit and an external capacitor outside the circuit; and
selectively switching the external capacitor across the at least one internal capacitor to alter a characteristic of the output signal.
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Accused Products
Abstract
A temperature-sensor is implemented with a temperature-sensitive component of an IC chip which functions as a radio frequency transponder capable of measuring parameters associated with an object and transmitting data to an external reader/interrogator. In use with a pneumatic tire, the transponder measures temperature and pressure within the tire. The transponder includes circuitry for controlling windows of time during which real-time temperature and pressure measurements are made, and for storing calibration data, transponder ID number and the like, and for transmitting this information in a data stream to the reader/interrogator. An excessive temperature condition may also be sensed and included in the data stream.
132 Citations
2 Claims
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1. A method of measuring temperature utilizing an integrated circuit (IC) chip, the method comprising:
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flowing a current through a resistor (Rext), the resistance value of which is substantially independent of temperature, said current being a function of an absolute temperature of a transistor (Q1) resident on the IC chip, said transistor being of a type which exhibits a predictable change in its base-emitter voltage over a temperature range;
mirroring the current flowing through the resistor to a circuit on the IC chip, said circuit providing an output signal which is proportional to the current flowing through the resistor, thereby making the output signal temperature-dependent as a function of the absolute temperature of the transistor;
including at least one internal capacitor in the circuit and an external capacitor outside the circuit; and
selectively switching the external capacitor across the at least one internal capacitor to alter a characteristic of the output signal. - View Dependent Claims (2)
the circuit is a relaxation oscillator, and the output of the circuit is a temperature-dependent frequency.
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Specification
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- Resources
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Current AssigneeGoodyear Tire & Rubber Company
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Original AssigneeGoodyear Tire & Rubber Company
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InventorsPollack, Richard Stephen, Yones, Dale Lee, Brown, Robert Walter, Black, Donald Lee
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Primary Examiner(s)Gutierrez, Diego
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Assistant Examiner(s)VERBITSKY, GAIL KAPLAN
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Application NumberUS09/622,680Time in Patent Office683 DaysField of Search374/141, 374/153, 374/178, 327/538, 327/543, 327/539, 327/512, 323/315US Class Current374/178CPC Class CodesG01K 1/024 for remote indicationG01K 7/01 using semiconducting elemen...
