Temperature sensor and method for operating a temperature sensor
AssigneeInfineon Technologies AG
InventorsKarl Schrodinger, Jaro Robert Stimma
Life of this patent
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Abstract
The invention relates to a temperature sensor having a first FET transistor circuit and a second FET transistor circuit and also to a method for operating a temperature sensor. Both FET transistor circuits are operated at an operating point that lies outside the temperature-independent operating point. The difference between the voltages at the first and second FET transistor circuits is evaluated as a measure of the temperature at one of the FET transistor circuits. The invention enables the temperature sensor to provide a relatively large output signal even in the case of only small changes in temperature.
Claims19
A temperature sensor, comprising:
- a first FET transistor circuit and a second FET transistor circuit each having a gate voltage and a temperature-independent operating point at which, for a constant drain-source current, the gate voltage is essentially temperature-independent;
- and
- a circuit for operating said first FET transistor circuit at a first operating point being different from said temperature-independent operating point;
- said circuit also being for operating said second FET transistor circuit at a second operating point being different from said temperature-independent operating point;
- said first FET transistor circuit providing a first voltage;
- said second FET transistor circuit providing a first voltage;
- and
- a difference between the first voltage and the second voltage being evaluated as a measure of a temperature at a transistor circuit selected from a group consisting of said first FET transistor circuit and said second FET transistor circuit.
A method for operating a temperature sensor, which comprises:
- providing the temperature sensor with a first FET transistor circuit, a second FET transistor circuit, and a circuit for operating the first FET transistor circuit and the second FET transistor circuit;
- evaluating a difference between a voltage at the first FET transistor circuit and a voltage at the second FET transistor circuit as a measure of a temperature at a transistor circuit selected from a group consisting of the first FET transistor circuit and the second FET transistor circuit;
- providing the first FET transistor circuit and the second FET transistor circuit with a temperature-independent operating point at which, for a constant drain-source current, a gate voltage is essentially temperature-independent;
- and
- operating the first FET transistor circuit and the second FET transistor circuit at a respective operating point that is different from the temperature-independent operating point.
Dependencies are inferred from the claim text.