Temperature protection circuit, power supply, and electronic device
First Claim
1. A temperature protection circuit comprising:
- circuitry to compare a monitored temperature with each of a plurality of threshold temperatures to find the monitored temperature to have reached a threshold temperature when the monitored temperature has been maintained at the threshold temperature or higher over a predetermined confirmation period;
circuitry to set the confirmation period such that the lower a threshold temperature is, compared with the monitored temperature, the longer the confirmation period is;
circuitry to generate a temperature protection signal corresponding to a threshold temperature that the monitored temperature is found to have reached;
heating detector to generate a heating detecting voltage a level of which varies according to the monitored temperature;
alarm signal generator to generate an alarm signal for informing that the monitored temperature has reached a first threshold temperature on finding, based on the heating detecting voltage, the monitored temperature to have reached the first threshold temperature;
suppressing signal generator to generate a suppressing signal for suppressing operation of a protected circuit continuously or in stages according to the monitored temperature after the monitored temperature is found based on the alarm signal to have reached the first threshold temperature;
first cut-off signal generator to generate a first cut-off signal for shutting down operation of the protected circuit when the monitored temperature is found based on the heating detecting voltage to have reached a second threshold temperature that is higher than the first threshold temperature; and
second cut-off signal generator for generating a second cut-off signal for shutting down operation of all circuits including the protected circuit but excluding the temperature protection circuit when the monitored temperature is found based on the heating detecting voltage to have reached a third threshold temperature that is higher than the second threshold temperature.
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Accused Products
Abstract
A temperature protection circuit comprises means adapted to compare the temperature being monitored with each of threshold temperatures and judging that the temperature being monitored reaches a threshold temperature when the temperature being monitored is maintained at the threshold temperature or more for a predetermined confirmation period, means adapted to set a longer confirmation period as the threshold temperature compared with the temperature being monitored is lower, means adapted to generate one of corresponding temperature protection signals (Sarm, Slmt, Stsd1, Stsd2) according to the judgment of which threshold temperature the temperature being monitored reaches. With this constitution, temperature protection operation can be preformed with high accuracy and high safety without unnecessarily narrowing the range of the operating temperature of an IC to be protected.
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Citations
10 Claims
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1. A temperature protection circuit comprising:
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circuitry to compare a monitored temperature with each of a plurality of threshold temperatures to find the monitored temperature to have reached a threshold temperature when the monitored temperature has been maintained at the threshold temperature or higher over a predetermined confirmation period; circuitry to set the confirmation period such that the lower a threshold temperature is, compared with the monitored temperature, the longer the confirmation period is; circuitry to generate a temperature protection signal corresponding to a threshold temperature that the monitored temperature is found to have reached; heating detector to generate a heating detecting voltage a level of which varies according to the monitored temperature; alarm signal generator to generate an alarm signal for informing that the monitored temperature has reached a first threshold temperature on finding, based on the heating detecting voltage, the monitored temperature to have reached the first threshold temperature; suppressing signal generator to generate a suppressing signal for suppressing operation of a protected circuit continuously or in stages according to the monitored temperature after the monitored temperature is found based on the alarm signal to have reached the first threshold temperature; first cut-off signal generator to generate a first cut-off signal for shutting down operation of the protected circuit when the monitored temperature is found based on the heating detecting voltage to have reached a second threshold temperature that is higher than the first threshold temperature; and second cut-off signal generator for generating a second cut-off signal for shutting down operation of all circuits including the protected circuit but excluding the temperature protection circuit when the monitored temperature is found based on the heating detecting voltage to have reached a third threshold temperature that is higher than the second threshold temperature. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A temperature protection circuit comprising:
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circuitry to compare a monitored temperature with each of a plurality of threshold temperatures to find the monitored temperature to have reached a threshold temperature when the monitored temperature has been maintained at the threshold temperature or higher over a predetermined confirmation period; circuitry to set the confirmation period such that the lower a threshold temperature is, compared with the monitored temperature, the longer the confirmation period is; circuitry to generate a temperature protection signal corresponding to a threshold temperature that the monitored temperature is found to have reached; heating detector to generate a heating detecting voltage a level of which varies according to the monitored temperature; alarm signal generator to generate an alarm signal for informing that the monitored temperature has reached a first threshold temperature on finding, based on the heating detecting voltage, the monitored temperature to have reached the first threshold temperature; suppressing signal generator to generate a suppressing signal for suppressing operation of a protected circuit continuously or in stages according to the monitored temperature after the monitored temperature is found based on the alarm signal to have reached the first threshold temperature; and cut-off signal generator to generate a cut-off signal for shutting down operation of the protected circuit when the monitored temperature is found based on the heating detecting voltage to have reached a second threshold temperature that is higher than the first threshold temperature. - View Dependent Claims (8, 9, 10)
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Specification