INTEGRATED CIRCUIT INCLUDING A TEMPERATURE SENSOR

Abstract

According to one aspect, an integrated circuit is proposed comprising a temperature sensor (TSENS) including: - two transistors mounted as diodes and having different sizes, - a buffer circuit (TAMPC), - a switching circuit (M1, M2) configured to selectively apply to the input of the buffer circuit the voltages generated through the two transistors, - a control unit (CU) configured to control the switching circuit (M1, M2) so as to successively apply to the input of the buffer circuit the voltages generated through the two transistors, - an analog-to-digital converter (ADC) having an input connected to the output of the buffer circuit (TAMPC), the analog-to-digital converter (ADC) being configured to calculate a digital value (BNW) corresponding to a difference (ΔVBE) between the voltages generated through the two transistors, this voltage difference being proportional to the absolute temperature.Figure for the abbreviation: Figure 1.

Description

Description Title of the invention: INTEGRATED CIRCUIT COMPRISING A TEMPERATURE SENSOR Embodiments relate to integrated circuits, in particular those comprising a temperature sensor. An integrated circuit may include a temperature sensor to meet various applications. A temperature sensor may be used to know a temperature of the silicon of the integrated circuit in order to prevent an increase in the temperature of the silicon beyond a temperature suitable for normal operation of the integrated circuit. In particular, an integrated circuit may be configured to reduce an operating frequency of this integrated circuit or to stop electrically supplying this integrated circuit when the temperature reaches a given temperature threshold. A temperature sensor can also be used to measure ambient temperature when the silicon of the integrated circuit is at this same temperature, particularly when the integrated circuit includes a package that effectively dissipates the heat generated during operation of the integrated circuit. A temperature sensor can also be used to counter malicious attacks on the integrated circuit. Indeed, certain malicious attacks can be carried out by subjecting the integrated circuit to extreme conditions. In particular, it is possible to subject the integrated circuit to extreme temperatures in order to modify its operation. Measuring the temperature of the integrated circuit can therefore be used to counter a malicious attack when the measured temperature is outside a predefined temperature range.In particular, when such a temperature outside the predefined range is measured, the integrated circuit can be configured to erase security keys or to stop its power supply. Known temperature sensors typically include a large number of electronic components that may exhibit nonlinearities. These nonlinearities can accumulate and thus impact the accuracy of the temperature sensor. To improve the accuracy of such a temperature sensor, it is important to calibrate the temperature sensor. Calibration requires performing multiple temperature measurements at different temperatures. This calibration can be time-consuming and complex, and therefore costly. There is therefore a need to propose an integrated circuit comprising a temperature sensor having a reduced number of electronic elements capable of introducing non-linearities so as to improve the accuracy of the temperature sensor. According to one aspect, there is provided an integrated circuit comprising a temperature sensor comprising: - two transistors mounted as diodes and having different sizes, - a buffer circuit, - a switching circuit configured to be able to selectively apply to the input of the buffer circuit voltages generated across the two transistors, - a control unit configured to control the switching circuit so as to successively apply to the input of the buffer circuit the voltages generated across the two transistors, - an analog-to-digital converter having an input connected to the output of the buffer circuit, the analog-to-digital converter being configured to successively convert the voltages delivered by the buffer circuit into digital voltage values ​​and to calculate a digital value corresponding to a difference between the digital values ​​of the voltages generated across the two transistors, this voltage difference being proportional to the absolute temperature and independent of the offset voltages of the analog-to-digital converter and the buffer circuit. Such a temperature sensor is therefore configured to successively measure the two voltages generated by the diode-connected transistors to calculate a voltage difference. Such a voltage difference has the advantage of depending solely on temperature. More specifically, the buffer circuit and the analog-to-digital converter may each have an offset voltage that adds up to each voltage measurement. However, the voltages generated across the transistors are acquired by the same buffer circuit and the same analog-to-digital converter. Thus, the voltage difference calculated by the analog-to-digital converter eliminates the offset voltage of the buffer circuit and the offset voltage of the digital-to-analog converter. Advantageously, the temperature sensor further comprises: - an analog-to-digital converter having an input connected to the output of the buffer circuit, this analog-to-digital converter being configured to convert the voltage corresponding to a difference between these two voltages proportional to the temperature into a digital value, - a processing unit configured to determine a temperature from the digital value calculated by the analog-to-digital converter. In an advantageous embodiment, the processing unit is configured to determine a temperature from the digital value calculated by the analog-to-digital converter using a conversion table. Such a temperature sensor has the advantage of being able to simply determine a temperature of the integrated circuit from a voltage difference that depends solely on the absolute temperature of the integrated circuit. Such a temperature sensor can thus be calibrated simply and can therefore be manufactured at reduced cost. Preferably, the buffer circuit comprises an operational amplifier mounted as a follower and having an input connected to the switching circuit, the switching circuit being configured to be able to selectively apply to this input of this operational amplifier the voltages proportional to the temperature generated by the two diode-mounted transistors. Advantageously, the two diode-connected transistors are bipolar transistors, each transistor having an emitter, a base, and a collector electrically connected to ground. Alternatively, these two transistors may be insulated-gate field-effect transistors. Advantageously, the integrated circuit comprises a circuit for generating current proportional to an absolute temperature configured to generate a current proportional to the absolute temperature. In an advantageous embodiment, the circuit for generating current proportional to the absolute temperature comprises: - a first bipolar transistor and a second bipolar transistor connected as a diode, - an operational amplifier having an inverting input connected to an emitter of the first bipolar transistor and a non-inverting input connected to an emitter of the second bipolar transistor via a resistor, - two PMOS type transistors each having a gate connected to an output of the operational amplifier and a source configured to receive a supply voltage, a first PMOS type transistor having a drain connected to the inverting input of the operational amplifier and to the emitter of the first bipolar transistor, and a second PMOS type transistor having a drain connected to the non-inverting input of the operational amplifier and to the emitter of the second bipolar transistor. In one embodiment, the temperature sensor further comprises an absolute temperature sensitive circuit comprising a third PMOS type transistor and a third diode-connected bipolar transistor, the third PMOS type transistor having a gate connected to the output of the operational amplifier of the circuit for generating current proportional to the absolute temperature, a configured source to receive the supply voltage and a drain connected to an emitter of the third bipolar transistor. In one embodiment, the absolute temperature sensitive circuit also comprises a fourth PMOS type transistor and a fourth diode-connected bipolar transistor, the fourth PMOS type transistor having a gate connected to the output of the operational amplifier of the absolute temperature proportional current generation circuit, a source configured to receive the supply voltage and a source drain connected to an emitter of the fourth bipolar transistor. In one embodiment, the switching circuit is configured to apply to the input of the buffer circuit either a base-emitter voltage of the third bipolar transistor or a base-emitter voltage of the fourth bipolar transistor. Alternatively, the switching circuit is configured to apply to the input of the buffer circuit either a base-emitter voltage of the first bipolar transistor or a base-emitter voltage of the third bipolar transistor. Alternatively, the switching circuit is configured to apply to the input of the buffer circuit either a base-emitter voltage of the first bipolar transistor or a base-emitter voltage of the second bipolar transistor. Other advantages and characteristics of the invention will appear on examining the detailed description of embodiments, which are in no way limiting, and the appended drawings in which: [Fig.1] [Fig.2] [Fig.3] illustrate embodiments and implementations of the invention. [Fig.1] illustrates a first embodiment of an integrated circuit IC comprising a TSENS temperature sensor. The TSENS temperature sensor includes a current generator circuit proportional to the absolute temperature BDGP (also referred to by the English expression “bandgap”). The BDGP generator circuit consists of two bipolar transistors BPL1, BPL2. Each bipolar transistor BPL1, BPL2 is connected as a diode. Each transistor BPL1, BPL2 has an emitter, a collector and a base, the base being electrically connected to the collector and to a ground GND. Bipolar transistors BPL1, BPL2 have different sizes. The size of a bipolar transistor BPLI1, BPL2 corresponds to the area of ​​the emitter of this bipolar transistor. In particular, a ratio between the sizes of bipolar transistors BPL1, BPL2 is equal to N, where N can be between 4 and 32. The generator circuit BDGP also includes an operational amplifier AOPI. The operational amplifier AOP1 has an inverting input electrically connected to the emitter of the first bipolar transistor BPL1. The operational amplifier AOP1 also has a non-inverting input electrically connected to the emitter of the second bipolar transistor BPL2 via a resistive element R1. The resistive value of the resistive element R1 is chosen to adjust the value of the current flowing through the resistive element R1 so that it is proportional to the absolute temperature. The generator circuit BDGP also comprises two PMOS1, PMOS2 transistors of PMOS type (i.e. P-type channel metal-oxide gate field effect transistors). A first PMOS1 transistor has a gate connected to an output of the operational amplifier AOP1, a source configured to receive a voltage VDD and a drain connected to the inverting input of the operational amplifier AOP1 and to the emitter of the first bipolar transistor BPL1. A second PMOS2 transistor has a gate connected to the output of the operational amplifier AOP1, a source configured to receive a voltage VDD and a drain connected to the non-inverting input of the operational amplifier AOPI and to the emitter of the second bipolar transistor BPL2. The operational amplifier AOP1 equalizes the voltages of the signals it receives at its non-inverting input and its inverting input. Thus, the base-collector voltage of the first transistor BPLI is the same as the voltage across resistor R1 connected to the non-inverting input of the operational amplifier AOPI. This allows a current to be generated through the resistor R1. The TSENS temperature sensor also includes a temperature-sensitive circuit SENSC. This temperature-sensitive circuit includes two branches BRCHI, BRCH2, each comprising a bipolar transistor BPL3 and BPL4. Each bipolar transistor BPL3, BPL4 is connected as a diode. Each BPL3, BPLA bipolar transistor has an emitter, a collector, and a base, with the base being electrically connected to the collector and a GND ground. BPL3, BPL4 bipolar transistors have different sizes. In particular, a ratio between the sizes of BPL3, BPLA bipolar transistors is equal to M, where M can be between 4 and 32. Each branch BRCHI, BRCH2 also has a PMOS type transistor (i.e. P-type channel metal-oxide gate field effect transistors). In particular, the first BRCHI branch comprises a third PMOS3 transistor which has a gate connected to an output of the operational amplifier AOP1, a source configured to receive a voltage VDD and a drain connected to the emitter of the third bipolar transistor BPL3. The second branch BRCH2 includes a fourth PMOS4 transistor which has a gate connected to the output of the operational amplifier AOP1, a source configured to receive a voltage VDD and a drain connected to the emitter of the fourth bipolar transistor BPLA4. The third transistor PMOS3 and the fourth transistor PMOS4 are configured to copy the current flowing through resistor R1 to the first branch BRCHI and to the second branch BRCH2, these branches BRCHI and BRCH2 then being crossed by a current IPTAT proportional to the absolute temperature. The current flowing through resistor R1 can in particular be copied by the transistors PMOS3 and PMOS4 with a copying factor f between the transistors PMOS3 and PMOS4, where B is greater than or equal to 1. The third transistor PMOS3 and the fourth transistor PMOS4 are identical. Alternatively, the PMOS3 and PMOS4 transistors have different sizes. In particular, a ratio between the sizes of the PMOS3 and PMOS4 transistors can be equal to M, where M can be between 4 and 32. In the latter case, the BPL3 and BPL4 transistors are identical. This creates a base-emitter voltage VBES3 on the third bipolar transistor BPL3 and a base-emitter voltage VBE4 on the fourth bipolar transistor. The difference between the base-emitter voltage VBEA and the base-emitter voltage VBE3 is then proportional to the absolute temperature (designated by the acronym "PTAT" from the English "proportional to absolute temperature"). The TSENS temperature sensor also includes a TAMPC buffer circuit. This TAMPC buffer circuit includes an operational amplifier AOP2 connected as a follower. The operational amplifier AOP2 has a non-inverting input electrically connected to the emitter of the third bipolar transistor via a switch M1 and to the emitter of the fourth bipolar transistor via a switch M2. The operational amplifier AOP2 also has an inverting input connected to an output of this operational amplifier AOP2. The temperature sensor also includes a control unit UC configured to control switches M1 and M2. In particular, the control unit UC is configured to open and close switches M1 and M2 alternately. Thus, when switch M1 is closed, then switch M2 is open. When switch M1 is open, then switch M2 is closed. In this way, the base-emitter voltage VBE3 and the base-emitter voltage VBE4 are applied alternately to the non-inverting input of the operational amplifier AOP2. The TSENS temperature sensor also includes an ADC analog-to-digital converter. The ADC analog-to-digital converter has a first input connected to the output of the AOP2 operational amplifier. The analog-to-digital converter ADC also has a second input configured to receive a VREF voltage. This VREF voltage is a temperature-independent voltage. In particular, the integrated circuit IC comprises a circuit for generating a reference voltage (not shown) for generating this VREF voltage. For example, the circuit for generating the VREF voltage can be obtained from a reference voltage generation circuit (in English "Bandgap voltage reference") for generating the VREF voltage and a buffer circuit for maintaining the reference voltage VREF constant at the output of this buffer circuit. Switches M1 and M2 are controlled so as to successively obtain the base-emitter voltage VBE3 and the base-emitter voltage VBEA at the output of the buffer circuit TAMPC. The analog-to-digital converter ADC is configured to receive the voltages VBE3, VBE4 delivered one after the other by the buffer circuit, then to convert these two voltages VBE3, VBEA into a digital value before calculating a difference between these digital voltage values ​​in order to obtain the value AVBE. The value AVBE is then delivered at the output of the analog-to-digital converter ADC in the form of a digital word BNW. The VBE3 and VBE4 voltages are acquired by the same operational amplifier AOP2 and by the same analog-to-digital converter ADC. This eliminates an offset voltage of the operational amplifier AOP2 in the output signal of the latter as well as an offset voltage of the digital-to-analog converter ADC. Thus, the output voltage of the assembly comprising operational amplifier AOP2 and the analog-to-digital converter ADC depends only on the temperature and constants. In particular, the difference in voltages AVBE is equal to AEn(M xB) where k is the Boltzmann constant, q is the charge of an electron, T is the temperature, and M corresponds to the ratio between the sizes of bipolar transistors BPL3 and BPL4, and B corresponds to the current ratio between transistors PMOS3 and PMOS4. Since the BDGP generator circuit and the SENSC temperature-sensitive circuit have few electronic components, the AVBE voltage difference is only weakly affected by the nonlinearities of the electronic components. In particular, the PMOS1, PMOS2, PMOS3 and PMOS4 transistors can introduce non-linearities low enough not to impact the AVBE voltage difference. The integrated circuit IC also comprises a processing unit U'T. This processing unit UT is configured to determine a temperature value TEMP from the digital word BNW generated by the analog-to-digital converter ADC corresponding to the voltage difference AVBE. This temperature value TEMP can be obtained from a conversion table obtained during a calibration step of the integrated circuit IC and stored in a memory of the integrated circuit (not shown). The performance of the TSENS temperature sensor can be adjusted with the ratio M between the sizes of the bipolar transistors BPL3 and BPLA and also with the ratio fB of the current copies made by the transistors PMOS3 and PMOS4. Such a temperature sensor has the advantage of determining the temperature of the integrated circuit from an AVBE voltage difference that depends solely on temperature. Thus, such a temperature sensor is accurate and can be calibrated quickly. Such a temperature sensor can therefore be manufactured at low cost. [Fig.2] illustrates a second embodiment of an integrated circuit IC comprising a TSENS temperature sensor. The integrated circuit IC comprises a current generator circuit proportional to an absolute temperature BDGP identical to that described previously. The generator circuit BDGP therefore comprises two bipolar transistors BPLI, BPL2, an operational amplifier AOP1, a resistor R1 and two PMOS type transistors PMOS1, PMOS2, as described previously. The TSENS temperature sensor also includes a SENSC temperature-sensitive circuit. This temperature-sensitive circuit includes a single BRCHI branch containing a BPL3 bipolar transistor. This BPL3 bipolar transistor is connected as a diode. This BPL3 bipolar transistor has an emitter, a collector, and a base, with the base electrically connected to the collector and a GND ground. The BPL3 bipolar transistor has different sizes than the BPL1 transistor. In particular, a ratio between the sizes of the BPL3 and BPLI bipolar transistors is equal to M, where M can be between 4 and 32. The BRCHI1 branch also includes a third PMOS3 transistor of PMOS type (i.e. P-type channel metal-oxide gate field effect transistors). This third PMOS3 transistor has a gate connected to an output of the operational amplifier AOP1, a source configured to receive a voltage VDD and a drain connected to the emitter of the third bipolar transistor BPL3. The third transistor PMOS3 is configured to copy the current flowing through resistor Rl to the first branch BRCHI with a copy factor 1 / B, where B is greater than or equal to 1. This creates a base-emitter voltage VBES3 on the third bipolar transistor BPL3. This base-emitter voltage VBE3 is then dependent on the absolute temperature. The TSENS temperature sensor also includes a buffer circuit TAMPC. This buffer circuit TAMPC includes an operational amplifier AOP2 connected as a follower. In particular, the operational amplifier AOP2 has a non-inverting input electrically connected to the emitter of the first bipolar transistor BPL1 via a switch M1 and to the emitter of the third bipolar transistor BPL3 via a switch M2. The operational amplifier AOP2 also has an inverting input connected to an output of this operational amplifier AOP2. The TSENS temperature sensor also includes a control unit UC configured to control switches M1 and M2. In particular, the control unit UC is configured to open and close switches M1 and M2 alternately. Thus, when switch M1 is closed, then switch M2 is open. When switch MI is open, then switch M2 is closed. In this way, the base-emitter voltage VBE1 of the first bipolar transistor BLP1 and the base-emitter voltage VBE3 of the third bipolar transistor BLP3 are applied alternately to the non-inverting input of the operational amplifier AOP2. The TSENS temperature sensor also includes an ADC analog-to-digital converter. The ADC analog-to-digital converter has a first input connected to the output of the AOP2 operational amplifier. The analog-to-digital converter ADC also has a second input configured to receive a VREF voltage. This VREF voltage is a temperature-independent voltage. In particular, the integrated circuit IC comprises a circuit for generating a reference voltage (not shown) for generating this VREF voltage. For example, the circuit for generating the VREF voltage can be obtained from a reference voltage generation circuit (in English "Bandgap voltage reference") for generating the VREF voltage and a buffer circuit for maintaining the reference voltage VREF constant at the output of this buffer circuit. Switches M1 and M2 are controlled so as to successively obtain the base-emitter voltage VBE1 and the base-emitter voltage VBE3 at the output of the buffer circuit TAMPC. The analog-to-digital converter ADC is configured to receive the voltages VBEI, VBE3 delivered one after the other by the buffer circuit, then to convert these two voltages VBE1, VBE3 into a digital value before calculating a difference between these digital voltage values ​​in order to obtain the AVBE value. The AVBE value is then delivered at the output of the analog-to-digital converter ADC in the form of a digital word BNW. The VBE and VBE3 voltages are acquired by the same operational amplifier AOP2 and by the same analog-to-digital converter. This eliminates an offset voltage of the operational amplifier AOP2 in the signal at the output of the latter, but also an offset voltage of the analog-to-digital converter ADC. Thus, the difference in voltages AVBE at the output of the analog-to-digital converter depends only on the temperature and constants. In particular, the difference in voltages AVBE is equal to nm xf) where k is the Boltzmann constant, q is the charge of an electron, T is the temperature, M corresponds to the ratio between the sizes of the bipolar transistors BPLI1 and BPL3, and 1 / corresponds to the current ratio between the transistors PMOSI and PMOS3. The integrated circuit IC also includes a processing unit UT. This processing unit UT is configured to determine a temperature value TEMP from the digital value BNW generated by the analog-to-digital converter ADC with respect to the voltage VREF. The performance of the TSENS temperature sensor can be adjusted with the ratio M between the sizes of the bipolar transistors BLP1 and BLP3 and also with the ratio 1 / B of the current copies made by the transistors PMOS1 and PMOS3. Such a temperature sensor also has the advantage of determining the temperature from an AVBE voltage difference that depends solely on the temperature. As a result, such a temperature sensor is accurate and can be calibrated quickly. Such a temperature sensor can therefore be manufactured at low cost. [Fig.3] illustrates a third embodiment of an integrated circuit IC. The integrated circuit IC comprises a current generator circuit proportional to an absolute temperature BDGP identical to that described previously. The generator circuit BDGP therefore comprises two bipolar transistors BPL1, BPL2, an operational amplifier AOP1, a resistor R1 and two PMOS transistors 1, PMOS2 of PMOS type, as described previously. The integrated circuit IC also includes a buffer circuit TAMPC. This buffer circuit TAMPC includes an operational amplifier AOP2 connected as a follower. In particular, the operational amplifier AOP2 has a non-inverting input electrically connected to the emitter of the first bipolar transistor BLP1 via a switch MI and to the emitter of the second bipolar transistor BLP2 via a switch M2. The operational amplifier AOP2 also has an inverting input connected to an output of this operational amplifier AOP2. The TSENS temperature sensor also includes a control unit UC configured to control switches M1 and M2. In particular, the control unit UC is configured to open and close switches M1 and M2 alternately. Thus, when switch M1 is closed, then switch M2 is open. When switch MI is open, then switch M2 is closed. In this way, the base-emitter voltage VBE1 of the first bipolar transistor BPL1 and the base-emitter voltage VBE2 of the second bipolar transistor BPL2 are applied alternately to the non-inverting input of the operational amplifier AOP2. The TSENS temperature sensor also includes an ADC analog-to-digital converter. The ADC analog-to-digital converter has a first input connected to the output of the AOP2 operational amplifier. The analog-to-digital converter ADC also has a second input configured to receive a VREF voltage. This VREF voltage is a temperature-independent voltage. In particular, the integrated circuit IC comprises a circuit for generating a reference voltage (not shown) for generating this VREF voltage. For example, the circuit for generating the VREF voltage can be obtained from a reference voltage generation circuit (in English "Bandgap voltage reference") for generating the VREF voltage and a buffer circuit for maintaining the reference voltage VREF constant at the output of this buffer circuit. Switches M1 and M2 are controlled so as to successively obtain the base-emitter voltage VBE1 and the base-emitter voltage VBE2 at the output of the buffer circuit TAMPC. The analog-to-digital converter ADC is configured to receive the voltages VBE1, VBE2 delivered one after the other by the buffer circuit, then to convert these two voltages VBE1, VBE2 into a digital value before calculating a difference between these digital voltage values ​​in order to obtain the value AVBE. The value AVBE is then delivered at the output of the analog-to-digital converter ADC in the form of a digital word BNW. The voltages VBE1 and VBE2 are acquired by the same operational amplifier AOP2 and by the same analog-to-digital converter ADC. This makes it possible to eliminate an offset voltage from the operational amplifier AOP2 in the signal at the output of the latter and also a voltage from offset of the analog-to-digital converter ADC. Thus, the difference in AVBE voltages at the output of the analog-to-digital converter ADC depends only on temperature and constants. In particular, the difference in AVBE voltages is equal to {nn (M) where k is the Boltzmann constant, q is the charge of an electron, T is the temperature, and M corresponds to the ratio between the sizes of the bipolar transistors BPL1 and BPL2. Since the BDGP generator circuit has few electronic components, the AVBE voltage difference is only slightly impacted by the non-linearities of the electronic components. In particular, the PMOS1, PMOS2 transistors can introduce non-linearities that are small enough to slightly impact or not impact the AVBE voltage difference. The integrated circuit IC also includes a processing unit UT. This processing unit UT is configured to determine a temperature value TEMP from the digital value BNW generated by the analog-to-digital converter ADC. Such a temperature sensor has the advantage of determining the temperature from an AVBE voltage difference that depends solely on the temperature. As a result, such a temperature sensor is accurate and can be calibrated quickly. Such a temperature sensor can therefore be manufactured at low cost. The integrated circuit IC may include several TSENS temperature sensors such as those described above, so as to determine the temperature at different locations of the integrated circuit.

Claims

Claims

1. Integrated circuit comprising a temperature sensor (TSENS) comprising: - two diode-mounted transistors having different sizes, - a buffer circuit (TAMPC), - a switching circuit (Ml, M2) configured to be able to selectively apply to the input of the buffer circuit voltages generated across the two transistors, - a control unit (UC) configured to control the switching circuit (Ml, M2) so as to successively apply to the input of the buffer circuit the voltages generated across the two transistors, - an analog-to-digital converter (ADC) having an input connected to the output of the buffer circuit (TAMPC),the analog-to-digital converter (ADC) being configured to successively convert the voltages delivered by the buffer circuit into digital voltage values and to calculate a digital value (BNW) corresponding to a difference (AVBE) between the digital values of the voltages generated across the two transistors, this voltage difference being proportional to the absolute temperature and independent of the offset voltages of the analog-to-digital converter (ADC) and the buffer circuit (TAMPC), and - a circuit for generating current proportional to an absolute temperature (BDGP) configured to generate a current proportional to the absolute temperature.,

2. Integrated circuit according to claim 1, wherein the temperature sensor comprises a processing unit (UT) configured to determine a temperature (TEMP) from the digital value (BNW) calculated by the analog-to-digital converter (ADC).

3. Integrated circuit according to claim 2, wherein the processing unit is configured to determine a temperature (TEMP) from the digital value (BNW) calculated by the analog-to-digital converter (ADC) using a conversion table.

4. Integrated circuit according to one of claims 1 to 3, in which the buffer circuit (TAMPC) comprises an operational amplifier (A0P2) mounted as a follower and having an input connected to the switching circuit (Ml, M2), the switching circuit (Ml, M2) being configured to be able to selectively apply to this input of this operational amplifier (AOP2) the voltages proportional to the temperature generated by the two diode-mounted transistors.

5. Integrated circuit according to one of claims 1 to 4, in which the two diode-mounted transistors are bipolar transistors, each transistor having an emitter as well as a base and a collector electrically connected to a ground.

6. Integrated circuit according to claim 5, wherein the absolute temperature proportional current generation circuit (BDGP) comprises: - a first bipolar transistor (BPL1) and a second bipolar transistor (BPL2) connected as a diode, - an operational amplifier (A0P1) having an inverting input connected to an emitter of the first bipolar transistor (BPLI) and a non-inverting input connected to an emitter of the second bipolar transistor (BPL2) via a resistor (RI), - two PMOS type transistors (PM0S1, PM0S2) each having a gate connected to an output of the operational amplifier (A0P1) and a source configured to receive a supply voltage (VDD), a first PMOS type transistor (PM0S1) having a drain connected to the inverting input of the operational amplifier (A0P1) and to the emitter of the first bipolar transistor (BPL1),and a second PMOS type transistor (PM0S2) having a drain connected to the non-inverting input of the operational amplifier (A0P1) and to the emitter of the second bipolar transistor (BPL2).,

7. Integrated circuit according to claim 6, wherein the temperature sensor (TSENS) further comprises an absolute temperature sensitive circuit (SENSC) comprising a third PMOS type transistor (PM0S3) and a third diode-mounted bipolar transistor (BPL3), the third PMOS type transistor (PM0S3) having a gate connected to the output of the operational amplifier (A0P1) of the circuit for generating current proportional to an absolute temperature, a source configured to receive the supply voltage and a drain connected to an emitter of the third bipolar transistor (BPL3).

8. Integrated circuit according to claim 7, in which the absolute temperature sensitive circuit (SENSC) also comprises a fourth PMOS type transistor (PMOS4) and a fourth bipolar transistor (BPL4) connected as a diode, the fourth PMOS type transistor (PMOS4) having a gate connected to the output of the operational amplifier (AOP1) of the circuit for generating current proportional to the absolute temperature, a source configured to receive the supply voltage and a drain connected to an emitter of the fourth bipolar transistor (BPL4).

9. Integrated circuit according to claim 8, in which the switching circuit (Ml, M2) is configured to apply to the input of the buffer circuit (TAMPC) either a base-emitter voltage of the third bipolar transistor (BPL3) or a base-emitter voltage of the fourth bipolar transistor (BPL4).

10. Integrated circuit according to claim 7, in which the switching circuit (Ml, M2) is configured to apply to the input of the buffer circuit (TAMPC) either a base-emitter voltage of the first bipolar transistor (BPL1) or a base-emitter voltage of the third bipolar transistor (BPL3).

11. Integrated circuit according to claim 6, in which the switching circuit (Ml, M2) is configured to apply to the input of the buffer circuit (TAMPC) either a base-emitter voltage of the first bipolar transistor (BPL1) or a base-emitter voltage of the second bipolar transistor (BPL2).

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