US 2003/0118079 A1Published application

Threshold temperature sensor comprising room temperature test means

AssigneeSTMicroelectronics S.r.l.

InventorsFabrice Marinet, Benjamin Duval

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Abstract

An integrated temperature sensor delivers threshold detection signals when temperature thresholds have been exceeded. The temperature sensor includes a circuit for detecting a first temperature threshold having a first detection threshold, and for detecting a second temperature threshold having a second detection threshold. The circuit also detects a third temperature threshold between the first and second temperature thresholds, and detects a fourth temperature threshold between the first and second temperature thresholds. The third temperature threshold has a third detection threshold linked with the first detection threshold so that a deviation of the first detection threshold causes a corresponding deviation of the third detection threshold. Similarly, the fourth temperature has a fourth detection threshold linked with the second detection threshold so that a deviation of the second detection threshold causes a corresponding deviation of the fourth detection threshold. The third and fourth temperature thresholds define a temperature window to test the temperature sensor for detecting a deviation of the first and second detection thresholds.

Claims22

Dependent claims

An integrated temperature sensor (20, 21, 22, 23, 24, 30, 31, 32) delivering signals (S1, S2) for detecting exceeded temperature thresholds, comprising means (MC1-MC4, CP1, CP1′, CP1″, VT1, Vref, VT, Vref1, MS1-MS5) for detecting a first temperature threshold (T1) exhibiting a first detection threshold, and means (MC1-MC4, CP2, CP2′, CP2″, VT2, Vref, VT, Vref2, MS1-MS5) for detecting a second temperature threshold (T2) exhibiting a second detection threshold, characterized in that it comprises:

means (MC1-MC4, MX1, MX2, CP1, CP1″, CP3′, VT3, Vref, VT, Vref3, MS1-MS5) for detecting a third temperature threshold (T3) comprised between the first (T1) and second (T2) temperature thresholds, exhibiting a third detection threshold linked with the first detection threshold so that a deviation of the first detection threshold causes a corresponding deviation of the third detection threshold,
means (MC1-MC4, MX1, MX2, CP2, CP2″, CP3′, VT4, Vref, VT, Vref4, MS1-MS5) for detecting a fourth temperature threshold (T4) comprised between the first (Ti) and second (T2) temperature thresholds, exhibiting a fourth detection threshold linked with the second detection threshold so that a deviation of the second detection threshold causes a corresponding deviation of the fourth detection threshold,
the third (T3) and fourth (T4) temperature thresholds delineating a temperature window to test the temperature sensor with a view to detect a deviation of the first and second detection thresholds.

A method to test detection thresholds of an integrated temperature sensor delivering signals (S1, S2) for detecting an overshoot of at least two temperature thresholds (T1, T2), the temperature sensor exhibiting a first detection threshold of a first temperature threshold (T1) and a second detection threshold of a second threshold temperature (T2), characterized in that it comprises the phases consisting in:

offsetting the first detection threshold to obtain a third detection threshold of a third temperature threshold (T3) comprised between the first (T1) and the second (T2) temperature thresholds, so that the third detection threshold is linked with the first detection threshold and that a deviation of the first detection threshold causes a corresponding deviation of the third detection threshold,
offsetting the second detection threshold to obtain a fourth detection threshold of a fourth temperature threshold (T4) comprised between the first (T1) and second (T2) temperature thresholds, so that the fourth detection threshold is linked with the second detection threshold and that a deviation of the second detection threshold causes a corresponding deviation of the fourth detection threshold, and
observing threshold detection signals (SiS4) delivered by the temperature sensor, while adhering to a temperature window comprised between the third (T3) and fourth (T4) temperature thresholds.

Dependencies are inferred from the claim text.