Temperature detector circuit and method thereof
AssigneeRichtek Technology Corporation
InventorChung-Lung Pai
Life of this patent
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Abstract
To generate a signal when a target temperature is reached, a temperature detector circuit comprises a first and second current sources connected in series, of which the first current source generates a PTAT current and the second current source is supplied with a temperature-independent reference voltage to generate a second current proportional to the reference voltage. The first and second currents are a first and second referenced currents, respectively, at a reference temperature, and the first and second current sources are configured such that the ratio of the second reference current to the first reference current is proportional to the ratio of the target temperature to the reference temperature.
Claims22
A temperature detector circuit for generating an output when a target temperature is reached, the temperature detector circuit comprising:
- a first current source for generating a PTAT current which is a first reference current at a reference temperature;
- and
- a second current source connected in series to the first current source through a node and supplied with a temperature-independent reference voltage for generating a second current proportional to the reference voltage, which is a second reference current at the reference temperature;
- wherein the first and second current sources are configured such that a ratio of the second reference current to the first reference current is proportional to a ratio of the target temperature to the reference temperature.
A method for generating an output when a target temperature is reached, the method comprising the steps of:
- connecting a first and second current sources in series through a node;
- generating a PTAT current by the first current source;
- supplying a temperature-independent reference voltage to the second current source for generating a second current proportional to the reference voltage;
- selecting a reference temperature for the first and second current to be a first and second reference currents, respectively, at the reference temperature and with a ratio of the second reference current to the first reference current proportional to a ratio of the target temperature to the reference temperature;
- and
- generating the output when the target temperature is reached.
Dependencies are inferred from the claim text.