METHOD FOR SENSING INTEGRATED CIRCUIT TEMPERATURE INCLUDING ADJUSTABLE GAIN AND OFFSET
First Claim
1. A method for sensing the temperature of an integrated circuit, comprising the steps of:
- generating a proportional to absolute temperature (PTAT) current IPTAT that is proportional to absolute temperature (T);
scaling the PTAT current IPTAT by a factor of N to generate an N-scaled PTAT current;
diverting with an offset circuit an offset portion of current IOFF from the N-scaled PTAT current, the offset circuit having a bandgap voltage VBG across an offset resistor ROFF;
sourcing the remaining, non-diverted portion of the N-scaled PTAT current through a temperature sensor resistor RTS as a temperature sensor current ITS;
generating an output voltage VTS by the flow of the temperature sensor current ITS through the temperature sensor resistor RTS, the output voltage VTS being a function of the absolute temperature T and a function of the bandgap voltage VBG; and
offsetting the voltage across the temperature sensor resistor RTS by a voltage offset VOFF, wherein the voltage offset VOFF is the bandgap voltage VBG multiplied by a scaling factor P and multiplied by the ratio of the temperature sensor resistor RTS to an offset resistor ROFF.
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Accused Products
Abstract
Embodiments of the invention include a temperature sensor method for providing an output voltage response that is linear to the temperature of the integrated circuit to which the temperature sensor belongs and/or the integrated circuit die on which the temperature sensor resides. The output voltage of the temperature sensor has an adjustable gain component and an adjustable voltage offset component that both are adjustable independently based on circuit parameters. The inventive temperature sensor includes an offset circuit that diverts a portion of current from the scaled PTAT current before the current is sourced through the output resistor. The offset circuit includes a bandgap circuit arrangement, a voltage to current converter arrangement, and a current mirror arrangement that are configured to provide a voltage offset adjustable based on independent circuit parameters such as resistor value ratios and transistor device scaling ratios. The gain of the temperature sensor also is based on similar independent circuit parameters.
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Citations
13 Claims
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1. A method for sensing the temperature of an integrated circuit, comprising the steps of:
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generating a proportional to absolute temperature (PTAT) current IPTAT that is proportional to absolute temperature (T); scaling the PTAT current IPTAT by a factor of N to generate an N-scaled PTAT current; diverting with an offset circuit an offset portion of current IOFF from the N-scaled PTAT current, the offset circuit having a bandgap voltage VBG across an offset resistor ROFF; sourcing the remaining, non-diverted portion of the N-scaled PTAT current through a temperature sensor resistor RTS as a temperature sensor current ITS; generating an output voltage VTS by the flow of the temperature sensor current ITS through the temperature sensor resistor RTS, the output voltage VTS being a function of the absolute temperature T and a function of the bandgap voltage VBG; and offsetting the voltage across the temperature sensor resistor RTS by a voltage offset VOFF, wherein the voltage offset VOFF is the bandgap voltage VBG multiplied by a scaling factor P and multiplied by the ratio of the temperature sensor resistor RTS to an offset resistor ROFF. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for detecting the temperature of one or more integrated circuits chips on an integrated circuit die, the method comprising the steps of:
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generating with a current source a PTAT current IPTAT that is proportional to absolute temperature T, the current source including a resistor RPTAT; scaling with a current mirror having a scaling factor of N the PTAT current IPTAT to generate an N-scaled PTAT current; diverting with an offset circuit an offset portion of current IOFF from the N-scaled PTAT current generated by the current mirror, the offset circuit having a bandgap voltage VBG across an offset resistor ROFF; sourcing the remaining, non-diverted portion of the N-scaled PTAT current through a temperature sensor resistor RTS as a temperature sensor current IOUT, generating an output voltage VTS by the flow of the temperature sensor current ITS through the temperature sensor resistor RTS, the output voltage VTS being a function of the absolute temperature T and a function of the bandgap voltage VBG, wherein the temperature sensor has a gain that is based on the ratio of the temperature sensor resistor RTS to the current source resistor RPTAT, and wherein the temperature sensor has a voltage offset that is based on the ratio of the temperature sensor resistor RTS to the offset resistor ROFF. - View Dependent Claims (9, 10, 11, 12, 13)
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Specification