초록 ▼

The specification relates to a thermal shutdown circuit for an integrated circuit. Two matching thermal sensing resistors are used to develop a voltage representing the relative differential temperature between the two resistors. One resistor is fabricated within the integrated circuit dissipating d

The specification relates to a thermal shutdown circuit for an integrated circuit. Two matching thermal sensing resistors are used to develop a voltage representing the relative differential temperature between the two resistors. One resistor is fabricated within the integrated circuit dissipating device dielectric isolation tub and therefore its temperature closely follows the temperature of the dissipating device. The second thermal sensing resistor reflects the ambient temperature of the integrated circuit. A third thermal sensing device is used to obtain actual absolute temperature at the location of the second thermal sensing resistor. By algebraically adding a voltage representing actual absolute temperature at an ambient temperature location with a voltage representing the relative differential temperature between thermal sensing resistors, a voltage representing the actual absolute temperature of the dissipating device is produced. The resulting voltage is compared to a reference voltage, the reference voltage representing a high temperature setpoint, so that when the temperature of the dissipating device exceeds the high temperature setpoint, a thermal shutdown signal is actuated.

대표청구항 ▼

[ What is claimed is:] [1.] An integrated circuit incorporating a thermal shutdown circuit protecting an integrated circuit component, comprising:a thermal sensing device for determining a first voltage corresponding to an integrated circuit ambient temperature;a first thermal sensing resistor locat

[ What is claimed is:] [1.] An integrated circuit incorporating a thermal shutdown circuit protecting an integrated circuit component, comprising:a thermal sensing device for determining a first voltage corresponding to an integrated circuit ambient temperature;a first thermal sensing resistor located proximate to said integrated circuit component so that said first thermal sensing resistor temperature approximates said integrated circuit component temperature;a second thermal sensing resistor located within said integrated circuit such that said second thermal sensing resistor temperature approximates said integrated circuit ambient temperature, said first and second thermal sensing resistors configured to generate a second voltage corresponding to a temperature differential between said integrated circuit ambient temperature and said integrated circuit component temperature; anda comparator comparing the algebraic sum of said first voltage and said second voltage with a reference voltage, said reference voltage corresponding to a temperature limit for said integrated circuit component, and said comparator providing a system shutdown signal when said temperature limit is exceeded.