Temperature sensor, chip and electronic equipment

Abstract

The invention relates to the technical field of semiconductors, in particular to a temperature sensor, a chip and electronic equipment. The temperature sensor comprises a current generation module; the current generation module comprises a current generation circuit and a chopping operational amplifier unit, and the current generation circuit is electrically connected with the chopping operational amplifier unit; the chopping operational amplifier unit is used for receiving a first chopping signal and a second chopping signal, and the current generating circuit is used for outputting a first current signal under the condition that the chopping operational amplifier unit receives the first chopping signal and outputting a second current signal under the condition that the chopping operational amplifier unit receives the second chopping signal. The first current signal and the second current signal are used for determining the detection temperature, and the first chopping signal and the second chopping signal are opposite in phase. According to the scheme, the influence of operational amplifier imbalance on the detection precision of the temperature sensor can be eliminated, and the output precision of the temperature sensor is improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and particularly to a temperature sensor, a chip, and an electronic device. Background Art

[0002] Temperature sensors are widely used in various fields, such as agricultural production, industrial control, Internet of Things, food industry, logistics, medical treatment, etc. Traditional temperature sensors usually adopt an off-chip structure, such as a thermocouple sensor, which can achieve high-precision temperature detection. However, this method occupies a large area and has a high cost. Moreover, since it is off-chip, it is impossible to accurately obtain the temperature of the chip itself, and there is a certain error in chip temperature detection, which is difficult to meet the application requirements in some applications that require detecting the chip temperature to adjust the chip working mode. Therefore, in the trend of increasing integration, the on-chip temperature sensor technology has developed rapidly. Compared with off-chip temperature sensors, on-chip temperature sensors have the advantages of small size and low power consumption.

[0003] On-chip temperature sensors usually use a current generation circuit to generate a current proportional to absolute temperature (PTAT), and then the detected temperature can be obtained by processing the PTAT current. However, in the process of generating the PTAT current by the current generation circuit, it needs to cooperate with an operational amplifier. Affected by the offset of the operational amplifier, an error will be introduced into the PTAT current, resulting in low detection accuracy of the on-chip temperature sensor. Summary of the Invention

[0004] To solve the above problems, embodiments of this application provide a temperature sensor, a chip, and an electronic device.

[0005] In a first aspect, an embodiment of this application provides a temperature sensor, including: a current generation module;

[0006] The current generation module includes a current generation circuit and a chopper op-amp unit, and the current generation circuit is electrically connected to the chopper op-amp unit;

[0007] The chopper op-amp unit is configured to receive a first chopping signal and a second chopping signal, the current generation circuit is configured to output a first current signal when the chopper op-amp unit receives the first chopping signal, and output a second current signal when the chopper op-amp unit receives the second chopping signal. The first current signal and the second current signal are used to determine the detected temperature, and the phases of the first chopping signal and the second chopping signal are opposite.

[0008] In some possible implementation manners, the temperature sensor further includes a current mirror;

[0009] The current generation module includes a first transistor, a second transistor, a first resistor, a second resistor, a third resistor, and a fourth resistor;

[0010] A first end of the first transistor is connected to a first end of the second resistor, a second end of the second resistor is connected to a first end of the third resistor, a second end of the third resistor is connected to a first end of the first resistor, a second end of the first resistor is connected to a first end of the second transistor, and a second end, a third end of the first transistor, a second end, and a third end of the second transistor are all grounded;

[0011] A first end of the fourth resistor is connected to the second end of the second resistor, and a second end of the fourth resistor is connected to a current mirror, which is configured to copy a first current signal and a second current signal according to a preset ratio.

[0012] In some possible implementation manners, the first transistor is a unit bipolar transistor, and the second transistor includes M unit bipolar transistors connected in parallel, where M is a positive integer greater than 1.

[0013] In some possible implementation manners, the chopper operational amplifier unit includes a first chopper operational amplifier circuit and a first chopper switch;

[0014] The first chopper operational amplifier circuit includes a first positive input terminal, a first negative input terminal, and a first output terminal;

[0015] The first chopper switch includes a first connection terminal, a second connection terminal, a third connection terminal, and a fourth connection terminal. The first connection terminal is connected to the second end of the third resistor, the second connection terminal is connected to the first end of the second resistor, the third connection terminal is connected to the first negative input terminal, and the fourth connection terminal is connected to the first positive input terminal;

[0016] The first output terminal is connected to the current mirror.

[0017] In some possible implementation manners, the first chopper operational amplifier circuit includes a first operational amplifier and a second chopper switch; where the second chopper switch includes a first switch, a second switch, a third switch, and a fourth switch, and the first operational amplifier includes a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, a fifth resistor, and a first capacitor;

[0018] A first end of the fifth transistor is used to be connected to a power supply, a second end of the fifth transistor is connected to a first end of the sixth transistor, a second end of the sixth transistor is connected to a second end of the third transistor, a first end of the third transistor and a first end of the fourth transistor are grounded, a second end of the fourth transistor is connected to a second end of the seventh transistor, a first end of the seventh transistor is connected to the second end of the fifth transistor, a third end of the fifth transistor is connected to the current mirror, a third end of the sixth transistor is configured as the first positive input terminal, and a third end of the seventh transistor is configured as the first negative input terminal;

[0019] The third terminal of the third transistor is connected to the third terminal of the fourth transistor, and the third terminal of the third transistor is connected to the second terminal of the third transistor through a first switch, and the third terminal of the fourth transistor is connected to the second terminal of the fourth transistor through a second switch;

[0020] One end of the fifth resistor is configured as the first output terminal, the other end of the fifth resistor is connected to one end of the first capacitor, and the other end of the first capacitor is grounded;

[0021] The second terminal of the sixth transistor is connected to the first output terminal through a fourth switch, and the second terminal of the fourth transistor is connected to the first output terminal through a third switch.

[0022] In some possible implementation manners, the first chopper switch includes a fifth switch, a sixth switch, a seventh switch, and an eighth switch;

[0023] The first connection terminal and the third connection terminal are connected through the fifth switch;

[0024] The second connection terminal and the third connection terminal are connected through the sixth switch;

[0025] The first connection terminal and the fourth connection terminal are connected through the seventh switch;

[0026] The second connection terminal and the fourth connection terminal are connected through the eighth switch.

[0027] In some possible implementation manners, the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, and the eighth switch all have signal input terminals, and the signal input terminals are used to control the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, and / or the eighth switch to turn on according to the first chopping signal and the second chopping signal.

[0028] In some possible implementation manners, the temperature sensor further includes a sampling signal generation module, the sampling signal generation module is connected to the current mirror, and the sampling signal generation module is used to generate a first temperature detection signal according to the first current signal replicated by the current mirror, and generate a second temperature detection signal according to the second current signal replicated by the current mirror.

[0029] In some possible implementation manners, the current mirror includes an eighth transistor, a ninth transistor, a tenth transistor, an eleventh transistor, a twelfth transistor, a thirteenth transistor, a fourteenth transistor, a fifteenth transistor, and a sixteenth transistor;

[0030] The first terminal of the eighth transistor is used to connect to a power supply. The second terminal of the eighth transistor is connected to the second terminal of the fifteenth transistor. The second terminal of the ninth transistor is connected to the second terminal of the sixteenth transistor. The first terminal of the ninth transistor is connected to the second terminal of the tenth transistor. The first terminal of the tenth transistor is used to connect to a power supply;

[0031] The second terminal of the eleventh transistor is connected to the second terminal of the fourth resistor. The first terminal of the eleventh transistor is connected to the second terminal of the twelfth transistor. The first terminal of the twelfth transistor is used to connect to a power supply;

[0032] The second terminal of the thirteenth transistor is connected to the sampling signal generation module. The first terminal of the thirteenth transistor is connected to the second terminal of the fourteenth transistor. The first terminal of the fourteenth transistor is used to connect to a power supply;

[0033] The third terminals of the eighth transistor, the ninth transistor, the eleventh transistor, and the thirteenth transistor are connected together. The third terminals of the tenth transistor, the twelfth transistor, and the fourteenth transistor are connected together;

[0034] The third terminal of the eighth transistor is connected to the second terminal of the eighth transistor. The second terminal of the ninth transistor is connected to the third terminal of the tenth transistor;

[0035] The third terminals of the fifteenth transistor and the sixteenth transistor are both connected to the first output terminal in the first chopper operational amplifier circuit. The first terminals of the fifteenth transistor and the sixteenth transistor are both grounded. The second terminal of the sixteenth transistor is connected to the second terminal of the ninth transistor.

[0036] In some possible implementation manners, the sampling signal generation module includes a resistance trimming circuit and a sampling resistor;

[0037] The resistance trimming circuit is connected to a current mirror. The resistance trimming circuit is used to generate a calibration resistor with a preset resistance value according to a calibration signal;

[0038] One end of the sampling resistor is connected to the resistance trimming circuit, and the other end is grounded.

[0039] In some possible implementation manners, the resistance trimming circuit includes Y trimming resistors, where Y is a positive integer;

[0040] The Y trimming resistors are connected in series, and each trimming resistor is connected in series with a trimming switch. One end of the first trimming resistor among the Y trimming resistors is connected to the current mirror. The end of each trimming resistor far from the current mirror is connected to the first end of the trimming switch in series. The other end of the trimming switch is connected to the output terminal of the resistance trimming circuit. The end of the last trimming resistor among the Y trimming resistors far from the current mirror is also connected to one end of the sampling resistor.

[0041] In some possible implementation manners, the sampling signal generation module further includes a microcontroller, which is configured to control each trimming switch to be turned on or off according to a calibration signal.

[0042] In some possible implementation manners, the temperature sensor further includes a signal processing module, and the signal processing module includes an analog-to-digital conversion unit and a digital filter;

[0043] The analog-to-digital conversion unit is electrically connected to the sampling signal generation module, and is configured to convert a first temperature detection signal into a first digital signal and convert a second temperature detection signal into a second digital signal;

[0044] The digital filter is connected to the analog-to-digital conversion unit and is configured to perform filtering processing based on the first digital signal and the second digital signal to obtain a detected temperature.

[0045] In some possible implementation manners, the temperature sensor further includes a signal processing module and a buffer module;

[0046] The signal processing module includes an analog-to-digital conversion unit and a digital filter, and the digital filter is electrically connected to the analog-to-digital conversion unit;

[0047] One end of the buffer module is connected to the sampling signal generation module, and the other end is connected to the analog-to-digital conversion unit;

[0048] The buffer module is configured to output a first output signal to the analog-to-digital conversion unit when receiving a third chopping signal, and output a second output signal to the analog-to-digital conversion unit when receiving a fourth chopping signal; wherein, the first output signal is obtained by operating on the first temperature detection signal and the second temperature detection signal within a first period, and the second output signal is obtained by operating on the first temperature detection signal and the second temperature detection signal within a second period;

[0049] The analog-to-digital conversion unit is configured to convert the first output signal into a third digital signal and convert the second output signal into a fourth digital signal;

[0050] The digital filter is configured to perform filtering processing on the third digital signal and the fourth digital signal to obtain a detected temperature.

[0051] In some possible implementation manners, the buffer module includes a second chopping operational amplifier circuit and a third chopping switch;

[0052] The second chopping operational amplifier circuit includes a second positive input terminal, a second negative input terminal, and a second output terminal, and the third chopping switch includes a fifth connection terminal, a sixth connection terminal, a seventh connection terminal, and an eighth connection terminal;

[0053] The sampling signal generation module is connected to the sixth connection terminal, the fifth connection terminal is connected to the second output terminal, the seventh connection terminal is connected to the second negative input terminal, the eighth connection terminal is connected to the second positive input terminal, and the second output terminal is connected to the analog-to-digital conversion unit.

[0054] In some possible implementation manners, the second chopper operational amplifier circuit includes a second operational amplifier and a fourth chopper switch; wherein, the fourth chopper switch includes a ninth switch, a tenth switch, an eleventh switch, and a twelfth switch, and the second operational amplifier includes a seventeenth transistor, an eighteenth transistor, a nineteenth transistor, a twentieth transistor, a twenty-first transistor, a sixth resistor, and a second capacitor;

[0055] The first end of the nineteenth transistor is used to be connected to a power supply, the second end of the nineteenth transistor is connected to the first end of the twentieth transistor, the second end of the twentieth transistor is connected to the second end of the seventeenth transistor, the first ends of the seventeenth transistor and the eighteenth transistor are grounded, the second end of the eighteenth transistor is connected to the second end of the twenty-first transistor, the first end of the twenty-first transistor is connected to the second end of the nineteenth transistor, the third end of the nineteenth transistor is connected to a current mirror, the third end of the twentieth transistor is configured as the second positive input terminal, and the third end of the twenty-first transistor is configured as the second negative input terminal;

[0056] The third ends of the seventeenth transistor and the eighteenth transistor are connected, and the third end of the seventeenth transistor is connected to the second end of the seventeenth transistor through the ninth switch, and the third end of the eighteenth transistor is connected to the second end of the eighteenth transistor through the tenth switch;

[0057] One end of the sixth resistor is configured as the second output terminal, the other end of the sixth resistor is connected to one end of the second capacitor, and the other end of the second capacitor is grounded;

[0058] The second end of the twentieth transistor is connected to the second output terminal through the twelfth switch, and the second end of the eighteenth transistor is connected to the second output terminal through the eleventh switch.

[0059] In some possible implementation manners, the signal processing module further includes a bandgap reference circuit;

[0060] The bandgap reference circuit is connected to the analog-to-digital conversion unit, and the bandgap reference circuit is used to supply power to the analog-to-digital conversion unit.

[0061] In a second aspect, an embodiment of the present application provides a chip, and the chip includes a temperature sensor according to any one of the implementation manners provided in the first aspect or the first aspect.

[0062] In a third aspect, an embodiment of the present application provides an electronic device, and the electronic device includes the chip provided in the second aspect.

[0063] The technical solution of the embodiment of the present application has the following beneficial effects:

[0064] The temperature sensor provided by the embodiment of the present application includes a current generation module. The current generation module includes a current generation circuit and a chopper operational amplifier unit. The current generation circuit is electrically connected to the chopper operational amplifier unit. The chopper operational amplifier unit is configured to receive a first chopping signal and a second chopping signal. The current generation circuit is configured to output a first current signal when the chopper operational amplifier unit receives the first chopping signal, and output a second current signal when the chopper operational amplifier unit receives the second chopping signal. The first current signal and the second current signal are used to determine the detected temperature, and the phases of the first chopping signal and the second chopping signal are opposite. Since the phases of the first chopping signal and the second chopping signal are opposite, the first current signal and the second current signal contain opposite offset errors. Determining the detected temperature based on the first current signal and the second current signal can eliminate the offset error, thereby improving the output accuracy of the temperature sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 Schematic diagram of the structure of a temperature sensor provided by an embodiment of the present application Figure 1 ;

[0066] Figure 2 Schematic diagram of the structure of a current generation module provided by an embodiment of the present application;

[0067] Figure 3 Schematic diagram of the structure of a first chopper operational amplifier circuit provided by an embodiment of the present application;

[0068] Figure 4 Schematic diagram of the structure of a first chopper switch provided by an embodiment of the present application;

[0069] Figure 5 Schematic diagram of the structure of a chopping signal controller provided by an embodiment of the present application;

[0070] Figure 6 Schematic diagram of the structure of a temperature sensor provided by an embodiment of the present application Figure 2 ;

[0071] Figure 7 Schematic diagram of the structure of a resistance trimming circuit provided by an embodiment of the present application;

[0072] Figure 8 Schematic diagram of the structure of a microcontroller provided by an embodiment of the present application;

[0073] Figure 9A Schematic diagram of the temperature characteristic curve of the temperature sensor before single-point calibration provided by an embodiment of the present application;

[0074] Figure 9BSchematic diagram of the temperature characteristic curve of a temperature sensor after single-point calibration provided by an embodiment of the present application;

[0075] Figure 10 Schematic structure of a temperature sensor provided by an embodiment of the present application Figure 3 ;

[0076] Figure 11 Schematic diagram of the structure of a second chopper operational amplifier circuit provided by an embodiment of the present application;

[0077] Figure 12 Schematic diagram of the structure of a third chopper switch provided by an embodiment of the present application;

[0078] Figure 13 Switch signal timing diagram of a first chopper switch and a third chopper switch provided by an embodiment of the present application. Detailed implementation manners

[0079] In order to make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions provided by the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings of the specification and specific implementation manners.

[0080] When an electronic device is operating, chips in the electronic device, such as processor chips, etc., will generate heat, and the accumulation of heat will seriously reduce the performance of the chips. Therefore, among many high-performance chips, temperature sensors are equipped to detect the temperature of the chips to ensure the working performance of the chips.

[0081] The temperature detection circuit of the on-chip temperature sensor usually includes several field-effect transistors, bipolar transistors, operational amplifiers, and resistors and other devices. Its detection principle is to utilize the temperature characteristic of the base-emitter voltage (V BE ) of the bipolar transistor to achieve temperature detection. However, the V BE characteristic of the bipolar transistor is significantly affected by process fluctuations, and there is a large difference in accuracy between on-chip temperature sensors in different chips. At the same time, due to certain mismatches between field-effect transistors, bipolar transistors, resistors and other devices, the mismatch between these devices will cause differences in the outputs of on-chip temperature sensors in different chips. In addition, operational amplifier offset, operational amplifier gain change, noise, etc. of the operational amplifier will also affect the temperature characteristic of the on-chip temperature sensor. Therefore, to improve the accuracy of the on-chip temperature sensor, it is necessary to reduce or eliminate the influence of device mismatch, voltage offset, and noise on the accuracy of the on-chip temperature sensor. At the same time, since the on-chip sensor is integrated on the chip, when eliminating the above influences, it is also necessary to ensure that the area of the on-chip temperature sensor cannot be too large so as not to affect the integration of the chip.

[0082] In view of this, embodiments of the present application provide a temperature sensor, a chip, and an electronic device. The temperature sensor includes a current generation module, and the current generation module includes a current generation circuit and a chopper amplifier unit, and the current generation circuit is electrically connected to the chopper amplifier unit. The chopper amplifier unit is configured to receive a first chopping signal and a second chopping signal, and the current generation circuit is configured to output a first current signal when the chopper amplifier unit receives the first chopping signal, and output a second current signal when the chopper amplifier unit receives the second chopping signal. The first current signal and the second current signal contain opposite offset errors, and the first current signal and the second current signal are used to determine the detected temperature. Since the first current signal and the second current signal contain opposite offset errors, determining the detected temperature based on the first current signal and the second current signal can eliminate the offset error, thereby improving the output accuracy of the temperature sensor.

[0083] The following provides a specific introduction to the temperature sensor provided by the embodiments of the present application.

[0084] Figure 1 is a schematic structure of a temperature sensor provided by an embodiment of the present application Figure 1 , referring to Figure 1 shown, the temperature sensor may include a current generation module. The current generation module is configured to generate a current signal proportional to absolute temperature (PTAT), that is, a first current signal and a second current signal.

[0085] Specifically, the current generation module may include a current generation circuit and a chopper amplifier unit, and the current generation circuit is electrically connected to the chopper amplifier unit. The chopper amplifier unit is configured to receive a first chopping signal and a second chopping signal, wherein the first chopping signal and the second chopping signal have opposite phases. The current generation circuit is configured to output a first current signal when the chopper amplifier unit receives the first chopping signal, and output a second current signal when the chopper amplifier unit receives the second chopping signal. The first current signal and the second current signal contain opposite offset errors, and the first current signal and the second current signal are used to determine the detected temperature.

[0086] In the embodiments of the present application, the current generation circuit may include a first transistor, a second transistor, a first resistor, a second resistor, a third resistor, and a fourth resistor. A first end of the first transistor is connected to a first end of the second resistor, a second end of the second resistor is connected to a first end of the third resistor, a second end of the third resistor is connected to a first end of the first resistor, a second end of the first resistor is connected to a first end of the second transistor, and a second end, a third end of the first transistor, a second end, and a third end of the second transistor are all grounded. A first end of the fourth resistor is connected to the second end of the second resistor, and a second end of the fourth resistor is connected to a current mirror, and the current mirror is used to copy a first current signal and a second current signal according to a preset ratio (detailed introduction will be given later Figure 6 ).

[0087] In the embodiments of the present application, the chopper operational amplifier unit may include a first chopper operational amplifier circuit and a first chopper switch. The first chopper operational amplifier circuit includes a first positive input terminal, a first negative input terminal, and a first output terminal. The first chopper switch includes a first connection terminal, a second connection terminal, a third connection terminal, and a fourth connection terminal. The first connection terminal is connected to the second end of the third resistor, the second connection terminal is connected to the first end of the second resistor, the third connection terminal is connected to the first negative input terminal, and the fourth connection terminal is connected to the first positive input terminal. The first output terminal is used to be connected to the current mirror.

[0088] Exemplarily, Figure 2 is a schematic structural diagram of a current generation module provided by the embodiments of the present application. Refer to Figure 2 as shown, the current generation circuit may include a first transistor Q1, a second transistor Q2, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4. Among them, both the first transistor Q1 and the second transistor Q2 are bipolar transistors.

[0089] Taking the emitter of the bipolar transistor as the first end, the collector of the bipolar transistor as the second end, and the base of the bipolar transistor as the third end as an example, the emitter of the first transistor Q1 is connected to the first end of the second resistor R2, the second end of the second resistor R2 is connected to the first end of the third resistor R3, the second end of the third resistor R3 is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the emitter of the second transistor Q2, and the collector, the base of the first transistor Q1, the collector, and the base of the second transistor Q2 are all grounded. The first end of the fourth resistor R4 is connected to the second end of the second resistor R2, and the second end of the fourth resistor R4 is used to be connected to the drain of the eleventh transistor MP4 in the current mirror.

[0090] The chopper operational amplifier unit may include a first chopper switch SW10 and a first chopper operational amplifier circuit. Among them, the first chopper operational amplifier circuit may include a first operational amplifier OP1 and a second chopper switch SW20. The first operational amplifier OP1 has a positive input terminal VIP, a negative input terminal VIN, and an output terminal. Among them, the positive input terminal VIP may serve as the first positive input terminal of the first chopper operational amplifier circuit, the negative input terminal VIN may serve as the first negative input terminal of the first chopper operational amplifier circuit, and the output terminal may serve as the first output terminal of the first chopper operational amplifier circuit. The second chopper switch SW20 is connected inside the first operational amplifier OP1 (detailed introduction will be given below Figure 3 ).

[0091] Refer to Figure 2 As shown, the first end of the second resistor R2 and the second end of the third resistor R3 are electrically connected to the first operational amplifier OP1 through the first chopper switch SW10, so that the voltage at the first end of the second resistor R2 can be made to be the same as the voltage at the second end of the third resistor R3 by using the "virtual short" characteristic of the operational amplifier, and thus the temperature detection can be realized by using the temperature characteristics of the base-emitter voltages of the first transistor Q1 and the second transistor Q2.

[0092] Specifically, the first transistor Q1 and the second transistor Q2 may be PNP-type transistors or NPN-type transistors. The first transistor Q1 and the second transistor Q2 have different areas. Optionally, the first transistor Q1 and the second transistor Q2 may be two bipolar transistors with different areas, or may be formed by connecting different numbers of unit bipolar transistors with the same area. As an example, both the first transistor Q1 and the second transistor Q2 are formed by connecting unit bipolar transistors with the same structural area. Among them, the first transistor Q1 may be a single unit bipolar transistor, and the second transistor Q2 may be formed by connecting M (M is a positive integer greater than 1) unit bipolar transistors in parallel. Since the areas of the first transistor Q1 and the second transistor Q2 are different, when the same magnitude of current flows through the first transistor Q1 and the second transistor Q2, different currents will be generated, and thus there is a base-emitter voltage difference between the first transistor Q1 and the second transistor Q2.

[0093] As an example, when the ratio I1:I2 of the current I1 in the first transistor Q1 to the current I2 in the second transistor Q2 is N:1 (N is a positive integer greater than or equal to 1), the V BE difference between the first transistor Q1 and the second transistor Q2 can be expressed as:

[0094]

[0095] Among them, V BE1 is the base-emitter voltage of the first transistor Q1, and V BE2is the base-emitter voltage of the second transistor Q2, k is the Boltzmann constant, q is the electric charge of a single electron, T is the temperature, M is the area ratio of the second transistor Q2 to the first transistor Q1, N is the current ratio of the first transistor Q1 to the second transistor Q2, and Vos is the sum of the systematic offset and the random offset caused by the non-ideal factors of the operational amplifier.

[0096] As can be seen from formula (1), △V BE has a positive temperature coefficient and a linear relationship with temperature. The current generation circuit converts this voltage-temperature curve with a positive temperature coefficient into a PTAT current, and then the circuit scales and shifts the PTAT current by a certain ratio to obtain a temperature detection signal, and then the temperature detection signal can be processed to convert it into temperature data.

[0097] The first resistor R1 is used to convert △V BE into current, that is, the first resistor R1 is used to generate a PTAT current. The PTAT current can be expressed as:

[0098]

[0099] The second resistor R2 and the third resistor R3 are used to reduce the influence of offset and ensure the normal convergence of the circuit. The second end of the fourth resistor R4 is connected to the drain of the eleventh transistor MP4 in the current mirror, and the PTAT current can be output to the current mirror through the second end of the fourth resistor R4. The fourth resistor R4 is also used to generate a suitable drain voltage of the eleventh transistor MP4 (reference voltage V REF ), so that the difference between the drain voltage of the eleventh transistor MP4 and the drain voltage of the thirteenth transistor MP6 in the current mirror is less than the threshold value, thereby ensuring the accuracy of the current mirror in replicating the PTAT current.

[0100] In the embodiments of the present application, the selection of the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 can be based on the current in the branches where the first resistor R1 and the second resistor R2 are located, the current density ratio of the first transistor Q1 to the second transistor Q2, and the reference voltage V REF for selection. As an example, the current value in the branches where the first resistor R1 and the second resistor R2 are located is 2 μA. Considering the layout area and symmetry during semiconductor processing, the area ratio M of the second transistor Q2 to the first transistor Q1 is taken as 8, and the current ratio N of the first transistor Q1 to the second transistor Q2 is usually 1. Then the first resistor R1 can be 27 kΩ, the second resistor R2 and the third resistor R3 can be 120 kΩ, and the fourth resistor R4 can be 73.8 kΩ. The specific calculation process of the values of the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 is as follows:

[0101] The voltage at the upper end of the fourth resistor R4 is the reference voltage V REF , due to the virtual short characteristic of the operational amplifier, the voltage on the first resistor R1 is the difference in V of the first transistor Q1 and the second transistor Q2 BE . At a temperature of 300K, ΔV is calculated according to formula (1) BE to be approximately 54mV

[0102] The reference voltage V REF can satisfy the following formula

[0103]

[0104] According to the physical characteristics of the PN junction voltage, V in the above formula (3) BE2 has a negative temperature characteristic, while ΔV BE has a positive temperature characteristic. Combining these two quantities in proportion can obtain a voltage V with zero temperature characteristic REF , V REF Taking the derivative with respect to temperature gives

[0105]

[0106] It is required that So there is

[0107]

[0108] Set the current flowing through the twelfth transistor MP5 to be 4μA, and the current flowing through the first resistor R1 to be 2μA. Then the value of the first resistor R1 is: First resistor R1 = ΔV[[ID=4)) BE / I = 54mV / 2μA = 27kΩ, which can be slightly adjusted in actual applications

[0109] At the same time, through simulation, it can be obtained that Therefore, R1 + R3 + 2R4 = 304kΩ. The actual value may have a slight error from the theoretical calculation. Finally, the second resistor R2 and the third resistor R3 are taken as 120kΩ (a larger value is taken to reduce the error at the input end of the operational amplifier), and the fourth resistor R4 is taken as 73.8kΩ

[0110] For the chopper operational amplifier unit, the first operational amplifier OP1 in the chopper operational amplifier unit is used to cooperate with the current generation circuit so that the current generation circuit generates a PTAT current. However, due to the existence of operational amplifier offset, an offset error will be introduced into the PTAT current. To eliminate the offset error, the embodiment of the present application adopts adding a first chopper switch and a second chopper switch in the chopper operational amplifier unit, and controlling the opening and closing of the first chopper switch and the second chopper switch through a first chopper signal and a second chopper signal to generate a PTAT current containing opposite offset errors, that is, a first current signal and a second current signal. By processing the first current signal and the second current signal, the influence of the offset error on the accuracy of the temperature sensor can be eliminated.

[0111] Specifically, the first chopper switch is used to exchange the polarities of the input terminals of the first operational amplifier OP1 according to the first chopper signal and the second chopper signal, that is, to exchange the negative input terminal VIN and the positive input terminal VIP of the first operational amplifier OP1 according to the first chopper signal and the second chopper signal. The second chopper switch is used to connect the actual non-inverting output terminal of the first operational amplifier OP1 to the gate of the fifteen-transistor MN1 in the current mirror to form a feedback loop.

[0112] The first chopper operational amplifier circuit may include a second chopper switch and a first operational amplifier. Among them, the second chopper switch may include a first switch, a second switch, a third switch, and a fourth switch. The first operational amplifier may include a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, a fifth resistor, and a first capacitor. The first end of the fifth transistor is used to connect to the power supply. The second end of the fifth transistor is connected to the first end of the sixth transistor. The second end of the sixth transistor is connected to the second end of the third transistor. The first ends of the third transistor and the fourth transistor are grounded. The second end of the fourth transistor is connected to the second end of the seventh transistor. The first end of the seventh transistor is connected to the second end of the fifth transistor. The third end of the fifth transistor is connected to the current mirror. The third end of the sixth transistor is configured as the first positive input terminal. The third end of the seventh transistor is configured as the first negative input terminal. The third ends of the third transistor and the fourth transistor are connected, and the third end of the third transistor is connected to the second end of the third transistor through the first switch. The third end of the fourth transistor is connected to the second end of the fourth transistor through the second switch. One end of the fifth resistor is configured as the first output terminal. The other end of the fifth resistor is connected to one end of the first capacitor. The other end of the first capacitor is grounded. The second end of the sixth transistor is connected to the first output terminal through the fourth switch. The second end of the fourth transistor is connected to the first output terminal through the third switch.

[0113] Exemplarily, Figure 3 is a schematic structural diagram of a first chopper operational amplifier circuit provided by the embodiment of the present application. Refer to Figure 3As shown, the second chopper switch SW20 may include a first switch SW21, a second switch SW22, a third switch SW23, and a fourth switch SW24. The first operational amplifier OP1 may include a third transistor MN5, a fourth transistor MN6, a fifth transistor MP8, a sixth transistor MP9, a seventh transistor MP10, a fifth resistor R01, and a first capacitor C01. Among them, the third transistor MN5 and the fourth transistor MN6 may be N-type field-effect transistors, and the fifth transistor MP8, the sixth transistor MP9, and the seventh transistor MP10 may be P-type field-effect transistors.

[0114] Taking the source of the field-effect transistor as the first terminal, the drain of the field-effect transistor as the second terminal, and the third terminal of the field-effect transistor as the third terminal as an example, the source of the fifth transistor MP8 is connected to the power supply (VDD), the drain of the fifth transistor MP8 is connected to the source of the sixth transistor MP9, the drain of the sixth transistor MP9 is connected to the drain of the third transistor MN5, the sources of the third transistor MN5 and the fourth transistor MN6 are grounded, the drain of the fourth transistor MN6 is connected to the drain of the seventh transistor MP10, and the source of the seventh transistor MP10 is connected to the drain of the fifth transistor MP8. The gate of the fifth transistor MP8 is connected to the gate of the twelfth transistor MP5 in the current mirror (introduced in detail below), the gate of the sixth transistor MP9 is configured as the positive input terminal (VIP) of the operational amplifier, and the gate of the seventh transistor MP10 is configured as the negative input terminal (VIN) of the operational amplifier. The gates of the third transistor MN5 and the fourth transistor MN6 are connected, and the gate of the third transistor MN5 is connected to the drain of the third transistor MN5 through the first switch SW21, and the gate of the fourth transistor MN6 is connected to the drain of the fourth transistor MN6 through the second switch SW22. One end of the fifth resistor R01 is configured as the output terminal of the operational amplifier, and the other end is connected to one end of the first capacitor C01, and the other end of the first capacitor C01 is grounded. The drain of the sixth transistor MP9 is connected to the output terminal of the operational amplifier through the fourth switch SW24, and the drain of the fourth transistor MN6 is connected to the output terminal of the operational amplifier through the third switch SW23.

[0115] The functions of the fifth resistor R01 and the first capacitor C01 are to provide zero compensation in the feedback loop where the operational amplifier is located and improve the loop stability. The magnitudes of the fifth resistor R01 and the first capacitor C01 can be selected as needed. For example, the fifth resistor R01 can be 40 - 60 kΩ, and the first capacitor C01 can be 600 - 1000 fF.

[0116] In the embodiment of the present application, the first chopper switch may include a fifth switch, a sixth switch, a seventh switch, and an eighth switch.

[0117] The first connection terminal and the third connection terminal are connected through a fifth switch. The second connection terminal and the third connection terminal are connected through a sixth switch.

[0118] The first connection terminal and the fourth connection terminal are connected through a seventh switch. The second connection terminal and the fourth connection terminal are connected through an eighth switch.

[0119] Exemplarily, Figure 4 FIG. is a schematic structural diagram of a first chopper switch provided in an embodiment of the present application. Refer to Figure 4 As shown, the first chopper switch SW10 may include a fifth switch SW11, a sixth switch SW12, a seventh switch SW13, and an eighth switch SW14. Among them, one end of the fifth switch SW11 is configured as the first connection terminal (FB_N) of the first chopper switch SW10, and the other end is configured as the third connection terminal of the first chopper switch SW10. One end of the eighth switch SW14 is configured as the second connection terminal (FB_P) of the first chopper switch SW10, and the other end is configured as the fourth connection terminal of the first chopper switch SW10. The sixth switch SW12 is respectively connected to the second connection terminal and the third connection terminal. The seventh switch SW13 is respectively connected to the first connection terminal and the fourth connection terminal. The first connection terminal (FB_N) of the first chopper switch SW10 is connected to the second end of the third resistor R3, the second connection terminal (FB_P) of the first chopper switch SW10 is connected to the first end of the second resistor R2, the third connection terminal of the first chopper switch SW10 is connected to the negative input terminal VIN of the first operational amplifier OP1, and the second connection terminal of the first chopper switch SW10 is connected to the positive input terminal VIP of the first operational amplifier OP1.

[0120] In the embodiment of the present application, the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, and the eighth switch all have a first signal input terminal and a second signal input terminal, and the first signal input terminal and the second signal input terminal can control the corresponding switch to be turned on or off according to the first chopping signal and the second chopping signal.

[0121] Exemplarily, refer to Figure 3 and Figure 4 As shown, the fifth switch SW11, the sixth switch SW12, the seventh switch SW13, the eighth switch SW14, the first switch SW21, the second switch SW22, the third switch SW23, and the fourth switch SW24 all have two signal input terminals, namely SN and SP. The signal input terminal SN is used to receive the first chopping signal, and the signal input terminal SP is used to receive the second chopping signal.

[0122] The first chopping signal and the second chopping signal can control the opening and closing of the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, and the eighth switch. Optionally, the second chopping signal can be the inverted signal of the first chopping signal. As an example, the first chopping signal is 1 and the second chopping signal is 0. The first chopping signal can control the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, and the eighth switch to open, and the second chopping signal can control the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, and the eighth switch to close.

[0123] The first chopping signal and the second chopping signal can control the opening and closing of the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, and the eighth switch through a chopping signal controller.

[0124] Exemplarily, Figure 5 FIG. [ID] is a schematic structural diagram of a chopping signal controller provided by an embodiment of the present application. Refer to Figure 5 As shown, the chopping signal controller may include two serially connected inverters. Among them, the input terminal of the first inverter is configured as the input terminal of the chopping signal controller for receiving the first chopping signal and the second chopping signal. The output terminal of the first inverter is the SN signal output terminal, and the output terminal of the first inverter is connected to the input terminal of the second inverter. The output terminal of the second inverter is the SP signal output terminal. The SN signal output terminal is used to be connected to the signal input terminal SN of the fifth switch SW11, the sixth switch SW12, the seventh switch SW13, the eighth switch SW14, the first switch SW21, the second switch SW22, the third switch SW23, and the fourth switch SW24 in the operational amplifier. The SP signal output terminal is used to be connected to the signal input terminal SP of the fifth switch SW11, the sixth switch SW12, the seventh switch SW13, the eighth switch SW14, the first switch SW21, the second switch SW22, the third switch SW23, and the fourth switch SW24 in the operational amplifier.

[0125] Taking CHOP_ON1 = 0 as the first chopping signal and CHOP_ON1 = 1 as the second chopping signal as an example, when CHOP_ON1 = 0, the fifth switch SW11 and the eighth switch SW14 are turned on. The first chopping switch SW10 connects the positive input terminal VIP of the first operational amplifier OP1 to the first terminal of the second resistor R2, and at the same time connects the negative input terminal VIN of the first operational amplifier OP1 to the second terminal of the third resistor R3. The first switch SW21 and the third switch SW23 are turned on, and the OP_OUT0 node is connected to the gate of the fifteen-transistor MN1 in the current mirror. At this time, the current generation circuit can output a first current signal. When CHOP_ON1 = 1, the sixth switch SW12 and the seventh switch SW13 are turned on. The first chopping switch SW10 connects the negative input terminal VIN of the first operational amplifier OP1 to the first terminal of the second resistor R2, and at the same time connects the positive input terminal VIP of the first operational amplifier OP1 to the second terminal of the third resistor R3. The second switch SW22 and the fourth switch SW24 are turned on, and the OP_OUT1 node is connected to the gate of the fifteen-transistor MN1 in the current mirror. At this time, the current generation circuit can output a second current signal.

[0126] Generally, a traditional chopping operational amplifier needs to continuously input a chopping signal to eliminate the offset effect of the operational amplifier. It can be understood that different from the traditional chopping operational amplifier, the function of the chopping operational amplifier unit in the embodiment of the present application is to receive the first chopping signal and the second chopping signal, so that the current generation circuit outputs a first current signal when the chopping operational amplifier unit receives the first chopping signal, and outputs a second current signal when the chopping operational amplifier unit receives the second chopping signal, so that the first current signal and the second current signal contain opposite offset errors. That is to say, the chopping signal controller in the embodiment of the present application can generate two-phase chopping signals (i.e., the first chopping signal and the second chopping signal) to meet the detection needs. That is, the chopping signal controller does not need to continuously work to generate a chopping signal. In the embodiment of the present application, by using the characteristic of "exchanging input polarities" of the chopping operational amplifier, the detected temperature can be obtained by sampling PTAT currents of two phases, without the need for the chopping signal clock to keep flipping, thereby reducing the power consumption and noise of the temperature sensor.

[0127] In the embodiment of the present application, the current mirror is connected to the current generation module, and is used to copy the first current signal and the second current signal output by the current generation circuit according to a preset ratio. The preset ratio can be 1:1 - 1:4, such as 1:2, etc. The current mirror can input the copied first current signal and second current signal into the sampling signal generation module, so as to obtain a temperature detection signal.

[0128] As an alternative embodiment, the current mirror may include an eighth transistor, a ninth transistor, a tenth transistor, an eleventh transistor, a twelfth transistor, a thirteenth transistor, a fourteenth transistor, a fifteenth transistor, and a sixteenth transistor. The first end of the eighth transistor is used to connect to a power supply. The second end of the eighth transistor is connected to the second end of the fifteenth transistor. The second end of the ninth transistor is connected to the second end of the sixteenth transistor. The first end of the ninth transistor is connected to the second end of the tenth transistor. The first end of the tenth transistor is used to connect to a power supply. The second end of the eleventh transistor is connected to the second end of the fourth resistor. The first end of the eleventh transistor is connected to the second end of the twelfth transistor. The first end of the twelfth transistor is used to connect to a power supply. The second end of the thirteenth transistor is connected to the sampling signal generation module. The first end of the thirteenth transistor is connected to the second end of the fourteenth transistor. The first end of the fourteenth transistor is used to connect to a power supply. The third ends of the eighth transistor, the ninth transistor, the eleventh transistor, and the thirteenth transistor are connected together. The third ends of the tenth transistor, the twelfth transistor, and the fourteenth transistor are connected together. The third end of the eighth transistor is connected to the second end of the eighth transistor. The second end of the ninth transistor is connected to the third end of the tenth transistor. The third ends of the fifteenth transistor and the sixteenth transistor are both connected to the first output end in the first chopper operational amplifier circuit. The first ends of the fifteenth transistor and the sixteenth transistor are both grounded. The second end of the fifteenth transistor is connected to the drain of the eighth transistor. The second end of the sixteenth transistor is connected to the second end of the ninth transistor.

[0129] Exemplarily, Figure 6 is a schematic structural diagram of a temperature sensor provided by an embodiment of the present application Figure 2 , refer to Figure 6As shown, the current mirror may include an eighth transistor MP1, a ninth transistor MP2, a tenth transistor MP3, an eleventh transistor MP4, a twelfth transistor MP5, a thirteenth transistor MP6, a fourteenth transistor MP7, a fifteenth transistor MN1, and a sixteenth transistor MN2. The eighth transistor MP1, the ninth transistor MP2, the tenth transistor MP3, the eleventh transistor MP4, the twelfth transistor MP5, the thirteenth transistor MP6, and the fourteenth transistor MP7 may all be P-type field effect transistors. The fifteenth transistor MN1 and the sixteenth transistor MN2 may be N-type field effect transistors. The source of the eighth transistor MP1 is connected to the power supply (VDD), and the drain of the eighth transistor MP1 is connected to the drain of the fifteenth transistor MN1 in the current generation module. The drain of the ninth transistor MP2 is connected to the drain of the sixteenth transistor MN2 in the current generation module, the source of the ninth transistor MP2 is connected to the drain of the tenth transistor MP3, and the source of the tenth transistor MP3 is connected to the power supply (VDD). The drain of the eleventh transistor MP4 is connected to one end of the fourth resistor R4 in the current generation module, the source of the eleventh transistor MP4 is connected to the drain of the twelfth transistor MP5, and the source of the twelfth transistor MP5 is connected to the power supply (VDD). The drain of the thirteenth transistor MP6 is connected to the sampling signal generation module, the source of the thirteenth transistor MP6 is connected to the drain of the fourteenth transistor MP7, and the source of the fourteenth transistor MP7 is connected to the power supply (VDD). The gates of the eighth transistor MP1, the ninth transistor MP2, the eleventh transistor MP4, and the thirteenth transistor MP6 are connected together, and the gates of the tenth transistor MP3, the twelfth transistor MP5, and the fourteenth transistor MP7 are connected together. The gate of the eighth transistor MP1 is connected to its drain. The drain of the ninth transistor MP2 is connected to the gate of the tenth transistor MP3. The gates of the fifteenth transistor MN1 and the sixteenth transistor MN2 are both connected to the output terminal (i.e., the first output terminal) of the first operational amplifier, the sources of the fifteenth transistor MN1 and the sixteenth transistor MN2 are both grounded, the drain of the fifteenth transistor MN1 is connected to the drain of the eighth transistor MP1, and the drain of the sixteenth transistor MN2 is connected to the drain of the ninth transistor MP2 in the current mirror.

[0130] The current mirror may form a negative feedback loop with the first operational amplifier OP1, such that the voltages of the positive input terminal VIP and the negative input terminal VIN of the first operational amplifier are equal, so as to maintain the "virtual short" state at the input terminal of the operational amplifier and ensure the accuracy of the current signal replicated by the current mirror.

[0131] In an embodiment of the present application, the temperature sensor further includes a sampling signal generation module, and the sampling signal generation module is connected to the current mirror. The sampling signal generation module is configured to generate a first temperature detection signal according to the first current signal copied by the current mirror, and generate a second temperature detection signal according to the second current signal copied by the current mirror.

[0132] Reference Figure 6 As shown, the sampling signal generation module may include a resistance trimming circuit and a sampling resistor RT1. The resistance trimming circuit is connected to the current mirror, and the resistance trimming circuit is configured to generate a calibration resistor RT0 with a preset resistance according to a calibration signal. One end of the sampling resistor is connected to the resistance trimming circuit, and the other end is grounded.

[0133] The current mirror can copy the current signal output by the current generation module according to a preset ratio k cm so that the copied current signal flows through the sampling signal generation module, thereby generating a positive temperature coefficient temperature detection signal V TEMP (i.e., PTAT voltage). V TEMP can be expressed as:

[0134]

[0135] wherein, I PTAT is the current signal output by the current generation module.

[0136] It can be understood that the current signal output by the current generation module includes a first current signal and a second current signal. After the first current signal passes through the sampling signal generation module, a first temperature detection signal can be obtained. After the second current signal passes through the sampling signal generation module, a second temperature detection signal can be obtained.

[0137] Specifically, when the first chopper switch and the second chopper switch receive a second chopping signal (for example, receive CHOP_ON1 = 1), the current generation module outputs a first current signal. After the first current signal is copied by the current mirror according to the ratio kcm, the copied first current signal passes through the sampling signal generation module, and the sampling signal generation module can output a first temperature detection signal V TEMP1 , V TEMP1 can be expressed as:

[0138]

[0139] When the first chopper switch and the second chopper switch receive a first chopping signal (for example, receive CHOP_ON1 = 0), the current generation module outputs a second current signal. After the second current signal is copied by the current mirror according to the ratio kcm, the copied second current signal passes through the sampling signal generation module, and the sampling signal generation module can output a second temperature detection signal V TEMP0 , V TEMP0It can be expressed as:

[0140]

[0141] As can be seen from Equation (7) and Equation (8), within a chopping period, that is, when the first chopping switch and the second chopping switch receive a first chopping signal and a second chopping signal once, the first temperature detection signal V TEMP1 output by the sampling signal generation module and the second temperature detection signal V TEMP0 The average value of can be expressed as V TEMPM :

[0142]

[0143] It can be seen from Equation (9) that by connecting the first chopping switch and the second chopping switch to the first operational amplifier respectively and controlling the operation of the first chopping switch and the second chopping switch, temperature detection signals containing opposite operational amplifier offset voltages can be obtained. Thus, in the subsequent signal processing process, by averaging the temperature detection signals output by the sampling signal generation module within a chopping period, the error caused by the operational amplifier offset of the first operational amplifier can be eliminated, thereby improving the output accuracy of the temperature sensor.

[0144] In the embodiment of the present application, the resistance trimming circuit may include Y trimming resistors (Y is a positive integer). The Y trimming resistors are connected in series, and each trimming resistor is connected in series with a trimming switch. One end of the first trimming resistor among the Y trimming resistors is connected to the current mirror. One end of each trimming resistor far from the current mirror is connected in series to the first end of the trimming switch. The other end of the trimming switch is connected to the output end of the resistance trimming circuit. One end of the last trimming resistor among the Y trimming resistors far from the current mirror is also connected to one end of the sampling resistor. The resistance trimming circuit is used to generate a calibration resistor RT0 with a determined resistance value according to the calibration signal. The sampling signal generation module may further include a microcontroller, and the microcontroller is used to control each trimming switch to be turned on or off according to the calibration signal.

[0145] Exemplarily, Figure 7 is a schematic structural diagram of a resistance trimming circuit provided by an embodiment of the present application. Refer to Figure 7As shown, the resistance trimming circuit includes 64 trimming resistors Rt0, Rt1... Rt63, and these 64 resistors are connected in series. Among them, one end of Rt0 that is not connected to other trimming resistors forms a connection terminal VA of the resistance trimming circuit, and VA is used to connect to the current mirror. One end of Rt63 that is not connected to other trimming resistors forms another connection terminal VB of the resistance trimming circuit. The connection terminal VA can be connected to the drain of the thirteenth transistor MP6 in the current mirror, and the connection terminal VB can be connected to one end of the sampling resistor RT1, and the other end of the sampling resistor RT1 is grounded. In addition, each trimming resistor is connected to the output terminal (VOUT) of the sampling signal generation module through a trimming switch. That is, Rt0 is connected to the output terminal of the sampling signal generation module through the trimming switch Kt0, Rt1 is connected to the output terminal of the sampling signal generation module through the trimming switch Kt1,..., and Rt63 is connected to the output terminal of the sampling signal generation module through the trimming switch Kt63.

[0146] The trimming switches Kt0, Kt1... Kt63 all have two signal input terminals, namely SN and SP. The signal input terminal SN and the signal input terminal SP are used to connect to the output terminal of the microcontroller. Specifically, Figure 8 is a schematic structural diagram of a microcontroller provided by an embodiment of the present application. Refer to Figure 8 As shown, the microcontroller can be a 6-bit controller and has 64 pairs of output control pins. Each pair of output pins includes an SP output pin and an SN output pin. The SP output pin is connected to the signal input terminal SP of the trimming switch in the resistance trimming circuit, and the SN output pin is connected to the signal input terminal SN of the trimming switch in the resistance trimming circuit. That is to say, the output pins of the microcontroller can include SP0, SP1... SP63, and SN0, SN1... SN63. The SP0 output pin is connected to the signal input terminal SP0 in the trimming switch Kt0 in the resistance trimming circuit, the SN0 output pin is connected to the signal input terminal SN0 in the trimming switch Kt0 in the resistance trimming circuit, the SP1 output pin is connected to the signal input terminal SP1 in the trimming switch Kt1 in the resistance trimming circuit, the SN1 output pin is connected to the signal input terminal SN1 in the trimming switch Kt1 in the resistance trimming circuit,..., the SP63 output pin is connected to the signal input terminal SP63 in the trimming switch Kt63 in the resistance trimming circuit, and the SN63 output pin is connected to the signal input terminal SN63 in the trimming switch Kt63 in the resistance trimming circuit.

[0147] It should be noted that the number of trimming resistors in the resistance trimming circuit can be more or less, such as 32, 128, 256, etc. Similarly, the microcontroller is not limited to a 6-bit controller (i.e., having 64 control bits), and can also be a 5-bit controller (i.e., having 32 control bits), a 7-bit controller (i.e., having 128 control bits), an 8-bit controller (i.e., having 256 control bits), etc. The number of control bits of the microcontroller can be selected according to the number of trimming resistors.

[0148] In the embodiments of the present application, the values of the sampling resistor RT1, the trimming resistors Rt0, Rt1... Rtn depend on the temperature detection signal V that is ultimately desired to be designed. TEMP The slope of the curve that changes with temperature. In order to make more full use of the input range of the analog-to-digital conversion unit, the value of the sampling resistor RT1 is appropriately larger. As an example, the value of the sampling resistor RT1 is 200 - 400 kΩ. Among the trimming resistors Rt0, Rt1... Rtn, the value of each resistor can be the same or different. Among the trimming resistors Rt0, Rt1... Rtn, the value of each resistor depends on the calibration accuracy. As an example, among the trimming resistors Rt0, Rt1... Rtn, the value of each resistor is the same, with a value of 1 - 3 kΩ. In some embodiments, the resistor types of the sampling resistor RT1 and the trimming resistors Rt0, Rt1... Rtn can be the same as the type of the first resistor R1, so as to offset the errors caused by process deviations and temperature changes.

[0149] In the embodiments of the present application, according to formula (9), it can be known that V TEMPM can be regarded as a straight line passing through the origin. This characteristic enables low-cost single-temperature-point calibration during production testing to ensure accuracy. That is, for each temperature sensor, it can be calibrated to reach the designed detection accuracy. Specifically, by adjusting the resistance value of the calibration RT0, the final V TEMPM slope can be adjusted to make the V TEMPM slope reach the designed value, thereby realizing the single-point calibration of the temperature sensor, and further ensuring that the accuracy among the temperature sensors in different chips can be kept consistent.

[0150] In the embodiments of the present application, when trimming the resistance trimming circuit, the microcontroller can be used to select and output a control signal to control the opening or closing of the trimming switch in the resistance trimming circuit, so as to adjust the resistance value of RT0, and further adjust the V TEMPM slope.

[0151] When performing single-point calibration on the temperature sensor, the current test environment temperature can be obtained first, and the difference between the environment temperature and the chip temperature is preferably kept within the threshold range. Subsequently, record the environment temperature as Ta, and the V when the first chopping signal is input for testing is TEMP , recorded as V TEMP0_TEST . Subsequently, switch to input the second chopping signal, and record the V voltage at this time as V TEMP . Calculate the average value of the above two voltages as V TEMP1_TEST . And calculate the value of the calibration resistor RT0, then trim the voltage to the target value V TEMPM_TEST , V TARGET , V TARGET is determined by the set V TEMPM slope k, and V TARGET satisfies the following relationship:

[0152] V TARGET = k·Ta,

[0153] Formula (10).

[0154] In the embodiments of the present application, a resistance trimming circuit is used to generate a tunable positive temperature coefficient voltage V TEMP . By performing single-point calibration on the temperature sensor at room temperature, an accurate temperature characteristic curve can be obtained. Figure 9A FIG. is a schematic diagram of the temperature characteristic curve of the temperature sensor before single-point calibration provided by the embodiments of the present application. Figure 9B FIG. is a schematic diagram of the temperature characteristic curve of the temperature sensor after single-point calibration provided by the embodiments of the present application. Referring to Figure 9A and Figure 9B as shown, by performing single-point calibration on the temperature sensor, the final V TEMP slope can be adjusted to the target value, so as to eliminate the influence of device mismatch on the accuracy of the temperature sensor and make the accuracy of the temperature sensors on different chips consistent.

[0155] Continue to refer to Figure 6 as shown, the temperature sensor further includes a signal processing module, and the signal processing module may include an analog-to-digital conversion unit and a digital filter. Among them, the analog-to-digital conversion unit is connected to, and is used to convert the first temperature detection signal into a first digital signal and convert the second temperature detection signal into a second digital signal. Optionally, the analog-to-digital conversion unit may be an analog-to-digital converter (ADC), such as a successive approximation register ADC (SAR ADC), a dual slope integrating ADC, an ADC based on voltage-to-frequency conversion, etc.

[0156] In the embodiment of the present application, the digital filter is connected to the analog-to-digital conversion unit and is used to filter the first digital signal and the second digital signal to obtain the detected temperature. The digital filter provided in the embodiment of the present application has the characteristics of a moving average filter, and its output is the average value of 2N temperature detection signals V measured under N (N is an integer) chopping periods. TEMP That is to say, for one chopping period, two temperature detection signals can be output, namely the first temperature detection signal and the second temperature detection signal. After the analog-to-digital conversion unit performs analog-to-digital conversion on the first temperature detection signal and the second temperature detection signal, a pair of digital signals (i.e., the first digital signal and the second digital signal) can be obtained. N chopping periods can obtain N pairs of digital signals. The digital filter can obtain the final output temperature detection signal by averaging these N pairs of digital signals, and then convert the output temperature detection signal into temperature data according to the temperature characteristic curve for output. Optionally, the digital filter can be a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA), a Programmable Logic Controller (PLC), etc.

[0157] The digital filter can avoid the problems of component mismatch and temperature drift commonly found in analog filters, thereby achieving a high-precision filtering effect and improving the accuracy of the finally output temperature data. In addition, the working mode of the digital filter can be adjusted by programming, thereby improving the flexibility of the design.

[0158] In the embodiment of the present application, since the chopping method adopted in the chopping operational amplifier unit is a chopping switch with low-frequency switching, that is, the switching frequency of the first chopping signal and the second chopping signal is relatively low, and the temperature information is obtained by averaging a limited number of samplings, the zero temperature coefficient voltage (reference voltage) output by the temperature detection circuit cannot be directly provided to the analog-to-digital conversion unit. In this case, it is necessary to additionally provide a reference voltage to the analog-to-digital conversion unit to prevent the change of the Least Significant Bit (LSB) of the analog-to-digital conversion unit from bringing errors to the measured temperature data.

[0159] Specifically, as shown in Figure 6 the signal processing module further includes a bandgap reference circuit, and the bandgap reference circuit is connected to the analog-to-digital conversion unit and is used to supply power to the analog-to-digital conversion unit. Since the reference voltage adopted by the analog-to-digital conversion unit comes from an additional bandgap reference, the change of the reference voltage corresponding to the analog-to-digital conversion unit following the opening and closing of the chopping switch can be avoided.

[0160] The temperature sensor described in the embodiments of the present application eliminates the influence of device mismatch on the temperature sensor by setting a resistance trimming circuit in the temperature sensor, enabling the accuracy to be consistent among the on-chip temperature sensors of different chips and reducing the production and test costs of the temperature sensor. By setting chopper switches (the first chopper switch and the second chopper switch) in the temperature sensor, the influence of operational amplifier offset on the temperature sensor is eliminated. At the same time, an analog-to-digital conversion unit and a digital filter are used to perform signal conversion and filtering processing on the temperature detection signal. While eliminating the influence of noise on the temperature sensor, the area of the temperature sensor is reduced, thereby not only improving the accuracy of the temperature sensor and the consistency of the outputs of the on-chip temperature sensors in different chips, but also reducing the circuit area of the temperature sensor and improving the integration degree of the chip.

[0161] Generally speaking, the output temperature detection signal is usually weak, with poor driving ability and easy to be lost, resulting in inaccurate temperature data output by the temperature sensor. To avoid this situation, in some embodiments, a buffer module can also be added to the temperature sensor to enhance the driving ability of the temperature detection signal, thereby reducing the loss of the first temperature detection signal and the second temperature detection signal.

[0162] Specifically, Figure 10 is a structural schematic diagram of a temperature sensor provided by the embodiments of the present application Figure 3 , as shown in reference to Figure 10 . Different from the temperature sensor shown in Figure 6 , the temperature sensor shown in Figure 10 further includes a buffer module. The input end of the buffer module is connected to the sampling signal generation module, and the output end is connected to the signal processing module. The buffer module is used to improve the driving ability of the temperature detection signal, reduce the loss of the first temperature detection signal and the second temperature detection signal, and can also isolate the sampling signal generation module and the signal processing module.

[0163] In some embodiments, to avoid additional operational amplifier offset brought by the buffer module, the buffer module can adopt a unity-gain buffer composed of a DC chopper operational amplifier as the buffer module, which can improve the driving ability of the temperature detection signal without bringing additional operational amplifier offset.

[0164] As an optional implementation manner, the unity-gain buffer can include a second chopper operational amplifier circuit and a third chopper switch. The second operational amplifier circuit includes a second positive input terminal, a second negative input terminal, and a second output terminal. The third chopper switch includes a fifth connection terminal, a sixth connection terminal, a seventh connection terminal, and an eighth connection terminal. The sampling signal generation module is connected to the sixth connection terminal, the fifth connection terminal is connected to the second output terminal, the seventh connection terminal is connected to the second negative input terminal, the eighth connection terminal is connected to the second positive input terminal, and the second output terminal is connected to the analog-to-digital conversion unit.

[0165] Exemplarily, referring to Figure 10 as shown, the buffer module may include a third chopper switch SW30 and a second chopper operational amplifier circuit. Among them, the second chopper operational amplifier circuit may include a second operational amplifier OP2 and a fourth chopper switch SW40.

[0166] The second chopper operational amplifier circuit includes a second operational amplifier and a fourth chopper switch. Among them, the fourth chopper switch includes a ninth switch, a tenth switch, an eleventh switch, and a twelfth switch. The second operational amplifier includes a seventeenth transistor, an eighteenth transistor, a nineteenth transistor, a twentieth transistor, a twenty-first transistor, a sixth resistor, and a second capacitor. The first end of the nineteenth transistor is used to connect to the power supply. The second end of the nineteenth transistor is connected to the first end of the twentieth transistor. The second end of the twentieth transistor is connected to the second end of the seventeenth transistor. The first ends of the seventeenth transistor and the eighteenth transistor are grounded. The second end of the eighteenth transistor is connected to the second end of the twenty-first transistor. The first end of the twenty-first transistor is connected to the second end of the nineteenth transistor. The third end of the nineteenth transistor is connected to a current mirror. The third end of the twentieth transistor is configured as a second positive input terminal. The third end of the twenty-first transistor is configured as a second negative input terminal. The third ends of the seventeenth transistor and the eighteenth transistor are connected, and the third end of the seventeenth transistor is connected to the second end of the seventeenth transistor through the ninth switch. The third end of the eighteenth transistor is connected to the second end of the eighteenth transistor through the tenth switch. One end of the sixth resistor is configured as a second output terminal. The other end of the sixth resistor is connected to one end of the second capacitor. The other end of the second capacitor is grounded. The second end of the twentieth transistor is connected to the second output terminal through the twelfth switch. The second end of the eighteenth transistor is connected to the second output terminal through the eleventh switch.

[0167] Exemplarily, Figure 11 is a schematic structural diagram of a second chopper operational amplifier circuit provided by an embodiment of the present application. Referring to Figure 11 as shown, the fourth chopper switch SW40 may include a ninth switch SW41, a tenth switch SW42, an eleventh switch SW43, and a twelfth switch SW44. The second operational amplifier OP2 may include a seventeenth transistor MN7, an eighteenth transistor MN8, a nineteenth transistor MP11, a twentieth transistor MP12, a twenty-first transistor MP13, a sixth resistor R02, and a second capacitor C02. Among them, the seventeenth transistor MN7 and the eighteenth transistor MN8 may be N-type field effect transistors. The nineteenth transistor MP11, the twentieth transistor MP12, and the twenty-first transistor MP13 may be P-type field effect transistors.

[0168] Taking the source of the field-effect transistor as the first terminal, the drain of the field-effect transistor as the second terminal, and the third terminal of the field-effect transistor as the third terminal as an example, the source of the nineteenth transistor MP11 is connected to the power supply (VDD), the drain of the nineteenth transistor MP11 is connected to the source of the twentieth transistor MP12, the drain of the twentieth transistor MP12 is connected to the drain of the seventeenth transistor MN7, the sources of the seventeenth transistor MN7 and the eighteenth transistor MN8 are grounded, the drain of the eighteenth transistor MN8 is connected to the drain of the twenty-first transistor MP13, and the source of the twenty-first transistor MP13 is connected to the drain of the nineteenth transistor MP11. The gate of the nineteenth transistor MP11 is connected to the reference voltage terminal. For example, it is connected to the gate of the twelfth transistor MP5 in the current mirror. The gate of the twentieth transistor MP12 is configured as the positive input terminal (VIP) of the operational amplifier, and the gate of the twenty-first transistor MP13 is configured as the negative input terminal (VIN) of the operational amplifier. The gates of the seventeenth transistor MN7 and the eighteenth transistor MN8 are connected, and the gate of the seventeenth transistor MN7 is connected to the drain of the seventeenth transistor MN7 through the ninth switch SW41, and the gate of the eighteenth transistor MN8 is connected to the drain of the eighteenth transistor MN8 through the tenth switch SW42. One end of the sixth resistor R02 is configured as the output terminal of the operational amplifier, and the other end is connected to one end of the second capacitor C02. The other end of the second capacitor C02 is grounded. The drain of the twentieth transistor MP12 is connected to the output terminal of the operational amplifier through the twelfth switch SW44, and the drain of the eighteenth transistor MN8 is connected to the output terminal of the operational amplifier through the eleventh switch SW43.

[0169] The functions of the sixth resistor R02 and the second capacitor C02 are to provide zero-point compensation in the feedback loop where the operational amplifier is located and improve the loop stability. The magnitudes of the sixth resistor R02 and the second capacitor C02 can be selected as needed. For example, the sixth resistor R02 can be 40 - 60 kΩ, and the second capacitor C02 can be 600 - 1000 fF.

[0170] In the embodiment of the present application, the third chopper switch may include a thirteenth switch, a fourteenth switch, a fifteenth switch, and a sixteenth switch. The fifth connection terminal and the seventh connection terminal are connected through the thirteenth switch. The sixth connection terminal and the seventh connection terminal are connected through the fourteenth switch. The fifth connection terminal and the eighth connection terminal are connected through the fifteenth switch. The sixth connection terminal and the eighth connection terminal are connected through the sixteenth switch.

[0171] Exemplarily, Figure 12 is a schematic structural diagram of a third chopper switch provided by the embodiment of the present application. Refer to Figure 12As shown, the third chopper switch SW30 may include a thirteenth switch SW31, a fourteenth switch SW32, a fifteenth switch SW33, and a sixteenth switch SW34. One end of the thirteenth switch SW31 is configured as the fifth connection end of the third chopper switch SW30, and the other end is configured as the seventh connection end of the third chopper switch SW30. One end of the sixteenth switch SW34 is configured as the sixth connection end of the third chopper switch SW30, and the other end is configured as the eighth connection end of the third chopper switch SW30. The fourteenth switch SW32 is respectively connected to the sixth connection end and the seventh connection end. The fifteenth switch SW33 is respectively connected to the fifth connection end and the eighth connection end. The fifth connection end of the third chopper switch SW30 is connected to the second output end of the second operational amplifier OP2. The sixth connection end of the third chopper switch SW30 is connected to the sampling signal generation module. The seventh connection end of the third chopper switch SW30 is connected to the negative input terminal VIN of the second operational amplifier OP2. The sixth connection end of the third chopper switch SW30 is connected to the positive input terminal VIP of the second operational amplifier OP2.

[0172] In the embodiments of the present application, the ninth switch, the tenth switch, the eleventh switch, the twelfth switch, the thirteenth switch, the fourteenth switch, the fifteenth switch, and the sixteenth switch all have a first signal input terminal and a second signal input terminal, and the first signal input terminal and the second signal input terminal can control the corresponding switch to be turned on or off according to the third chopping signal and the fourth chopping signal.

[0173] Exemplarily, referring to Figure 11 and Figure 12 As shown, the thirteenth switch SW31, the fourteenth switch SW32, the fifteenth switch SW33, the sixteenth switch SW34, the ninth switch SW41, the tenth switch SW42, the eleventh switch SW43, and the twelfth switch SW44 all have two signal input terminals, namely SN and SP. The signal input terminal SN is used to receive the third chopping signal, and the signal input terminal SP is used to receive the fourth chopping signal.

[0174] The third chopping signal and the fourth chopping signal can control the turning on and off of the ninth switch, the tenth switch, the eleventh switch, the twelfth switch, the thirteenth switch, the fourteenth switch, the fifteenth switch, and the sixteenth switch. Optionally, the fourth chopping signal may be an inverted signal of the third chopping signal. As an example, the third chopping signal is 1 and the fourth chopping signal is 0. The third chopping signal can control the ninth switch, the tenth switch, the eleventh switch, the twelfth switch, the thirteenth switch, the fourteenth switch, the fifteenth switch, and the sixteenth switch to be turned on, and the fourth chopping signal can control the ninth switch, the tenth switch, the eleventh switch, the twelfth switch, the thirteenth switch, the fourteenth switch, the fifteenth switch, and the sixteenth switch to be turned off.

[0175] The third chopping signal and the fourth chopping signal can control the turning on and off of the ninth switch, tenth switch, eleventh switch, twelfth switch, thirteenth switch, fourteenth switch, fifteenth switch, and sixteenth switch through a chopping signal controller. For the specific implementation of the chopping signal controller, reference can be made to Figure 5 the corresponding introduction, which will not be elaborated here.

[0176] Unit gain buffering can be used to output a first output signal to the analog-to-digital conversion unit when the third chopping signal is received, and to output a second output signal to the analog-to-digital conversion unit when the fourth chopping signal is received. Among them, the first output signal is obtained by operating on the first temperature detection signal and the second temperature detection signal within the first period, and the second output signal is obtained by operating on the first temperature detection signal and the second temperature detection signal within the second period. The analog-to-digital conversion unit is used to convert the first output signal into a third digital signal and the second output signal into a fourth digital signal. The digital filter is used to filter the third digital signal and the fourth digital signal to obtain the detected temperature.

[0177] Specifically, the third chopping switch and the fourth chopping switch can receive the third chopping signal and the fourth chopping signal. The second output terminal of OP2 outputs the first output signal when the third chopping switch and the fourth chopping switch receive the third chopping signal, and outputs the second output signal when the third chopping switch and the fourth chopping switch receive the fourth chopping signal. As an example, taking CHOP_ON2 = 0 as the third chopping signal and CHOP_ON2 = 1 as the fourth chopping signal, when CHOP_ON2 = 0, the second output terminal outputs the first output signal, and when CHOP_ON2 = 1, the second output terminal outputs the second output signal.

[0178] The analog-to-digital conversion unit in the signal processing module can perform analog-to-digital conversion on the first output signal and the second output signal, and then input the converted first output signal and second output signal into the digital filter for processing, so as to obtain the detected temperature. For the specific process, please refer to the processing process of the first temperature detection signal and the second temperature detection signal by the signal processing module, which will not be elaborated here.

[0179] By adding a second operational amplifier OP2 between the signal generation module and the signal processing module, and controlling the output of the second operational amplifier based on the third chopping switch and the fourth chopping switch, the driving ability of the temperature detection signal can be improved, and at the same time, the influence of the leakage of the sampling switch of the analog-to-digital conversion unit on the temperature detection signal can be eliminated. In addition, in order to eliminate the influence of op-amp offset, during test calibration and normal application, it is necessary to measure V respectively when the third chopping signal and the fourth chopping signal are applied. TEMPM, and then the influence of the offset is eliminated by taking the average. Since this averaging operation is equivalent to digital low-pass filtering, this method saves a large amount of area required for analog filtering.

[0180] Figure 13 It is a corresponding relationship diagram of a chopping signal timing, a temperature detection signal, and temperature data provided by an embodiment of the present application. Refer to Figure 13 As shown, in practical applications, since the temperature generally changes slowly, a low-frequency clock signal can be used as the control signal for the third chopping switch and the fourth chopping switch. Therefore, the non-ideal factors caused by clock switching are also relatively small. Optionally, the change period of the control signals of the third chopping switch and the fourth chopping switch can be several times that of the control signals of the first chopping switch and the second chopping switch, such as 1 time, 2 times, 3 times, 4 times, etc. Through the control signals of the third chopping switch and the fourth chopping switch, the signal acquisition module is controlled to acquire the temperature detection signals V TEMP sampled in several sampling periods. After analog-to-digital conversion processing and filtering processing (averaging multiple samples), the interference introduced by the chopping switch clock can be filtered out, thereby improving the output accuracy of the temperature sensor.

[0181] The temperature sensor described in the embodiment of the present application can eliminate the influence of device mismatch, voltage offset, and noise on the accuracy of the on-chip temperature sensor by adopting a current generation module including a first chopping switch, a second chopping switch, and a first operational amplifier, a sampling signal generation module including a resistance trimming circuit, a buffer module including a third chopping switch, a fourth chopping switch, and a second operational amplifier, and a signal processing module including an analog-to-digital conversion unit and a digital filter, meeting the high-precision application requirements and taking into account the area index at the same time. At the same time, the combination of the chopping switch and the trimming resistor adopted in the embodiment of the present application can achieve an accurate temperature characteristic curve only by single-point calibration through a specific calibration method, reducing the cost of production testing. In addition, the digital filter adopted in the embodiment of the present application reduces the influence of on-chip interference by means of digital moving average, and uses a unity-gain buffer circuit composed of a DC chopping operational amplifier to achieve the function of offset-free buffering and enhance the driving ability, finally realizing a temperature sensor with high-precision output.

[0182] In summary, the embodiment of the present application provides an effective way to improve the accuracy of the temperature sensor. By adopting low-frequency chopping operational amplifiers, resistance trimming circuits, chopping buffer output, and digital filtering technologies in the circuit, the accuracy of the temperature sensor is effectively improved.

[0183] The embodiment of the present application also provides a chip, and the chip includes the temperature sensor as described above.

[0184] The temperature sensor provided by the embodiments of the present application can be integrated inside an integrated circuit (such as a microprocessor or a system-on-chip) to monitor the temperature of the chip, ensure its operation within a safe working range, and prevent damage caused by overheating, thereby ensuring the stability and reliability of the system.

[0185] The chip described in the embodiments of the present application includes the above temperature sensor. For the specific implementation manner of the temperature sensor, please refer to the above description and will not be elaborated here.

[0186] The embodiments of the present application also provide an electronic device, and the electronic device includes the chip as described above.

[0187] The electronic device described in the embodiments of the present application can be any electronic product or device such as a smart phone, a desktop computer, a tablet computer, a laptop computer, a digital assistant, an augmented reality (AR) / virtual reality (VR) device, a smart voice interaction device, a smart home appliance, a smart wearable device, a vehicle-mounted terminal device, etc., or can also be any intermediate product including the above chip. The above-described chip is provided in the electronic device.

[0188] The electronic device described in the embodiments of the present application includes the above chip, and the chip includes the above temperature sensor. For the specific implementation manner of the temperature sensor, please refer to the above description and will not be elaborated here.

[0189] It should be noted that the "one embodiment" or "embodiment" referred to in the specification of the embodiments of the present application means specific features, structures or characteristics that can be included in at least one implementation manner of the present application. It should be understood that in the specification of the embodiments of the present application and the above-mentioned drawings, the orientation or positional relationship indicated by terms such as "upper", "lower", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present application. The terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Moreover, the terms "first", "second", etc. are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here. In addition, in the description of this embodiment, unless otherwise specified, the meaning of "a plurality" is two or more. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system or product that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0190] It should be noted that each unit / module mentioned in the device embodiments of the present application is a logical unit / module. Physically, a logical unit / module can be a physical unit / module, a part of a physical unit / module, or can also be implemented as a combination of multiple physical units / module. The physical implementation manner of these logical units / module themselves is not the most important. The combination of the functions implemented by these logical units / module is the key to solving the technical problems proposed by the present application. In addition, in order to highlight the innovative part of the present application, the above-mentioned device embodiments of the present application do not introduce units / modules that are not closely related to solving the technical problems proposed by the present application, which does not mean that there are no other units / modules in the above-mentioned device embodiments.

[0191] Although the present application has been illustrated and described by referring to certain embodiments of the present application, those of ordinary skill in the art should understand that various changes can be made in form and detail without departing from the spirit and scope of the present application.

Claims

1. A temperature sensor, characterized in that, Comprising: A current generation module; The current generation module includes a current generation circuit and a chopper operational amplifier unit, and the current generation circuit is electrically connected to the chopper operational amplifier unit; The chopper operational amplifier unit is used to receive a first chopping signal and a second chopping signal. The current generation circuit is configured to output a first current signal when the chopper operational amplifier unit receives the first chopping signal, and output a second current signal when the chopper operational amplifier unit receives the second chopping signal. The first current signal and the second current signal are used to determine the detected temperature, and the phases of the first chopping signal and the second chopping signal are opposite.

2. The temperature sensor according to claim 1, characterized in that, The temperature sensor further includes a current mirror; The current generation module further includes a first transistor, a second transistor, a first resistor, a second resistor, a third resistor, and a fourth resistor; A first end of the first transistor is connected to a first end of the second resistor, a second end of the second resistor is connected to a first end of the third resistor, a second end of the third resistor is connected to a first end of the first resistor, a second end of the first resistor is connected to a first end of the second transistor, and a second end, a third end of the first transistor, a second end, and a third end of the second transistor are all grounded; A first end of the fourth resistor is connected to a second end of the second resistor, a second end of the fourth resistor is connected to the current mirror, and the current mirror is configured to copy the first current signal and the second current signal according to a preset ratio.

3. The temperature sensor according to claim 2, characterized in that, The first transistor is a unit bipolar transistor, and the second transistor includes M unit bipolar transistors connected in parallel, where M is a positive integer greater than 1.

4. The temperature sensor according to claim 2 or 3, characterized in that, The chopper operational amplifier unit includes a first chopper operational amplifier circuit and a first chopper switch; The first chopper operational amplifier circuit includes a first positive input terminal, a first negative input terminal, and a first output terminal; The first chopper switch includes a first connection end, a second connection end, a third connection end, and a fourth connection end. The first connection end is connected to a second end of the third resistor, the second connection end is connected to a first end of the second resistor, the third connection end is connected to the first negative input terminal, and the fourth connection end is connected to the first positive input terminal; The first output terminal is connected to the current mirror.

5. The temperature sensor according to claim 4, wherein The first chopper operational amplifier circuit includes a first operational amplifier and a second chopper switch; wherein, the second chopper switch includes a first switch, a second switch, a third switch, and a fourth switch, and the first operational amplifier includes a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, a fifth resistor, and a first capacitor; The first end of the fifth transistor is used to connect to a power supply. The second end of the fifth transistor is connected to the first end of the sixth transistor. The second end of the sixth transistor is connected to the second end of the third transistor. The first ends of the third transistor and the fourth transistor are grounded. The second end of the fourth transistor is connected to the second end of the seventh transistor. The first end of the seventh transistor is connected to the second end of the fifth transistor. The third end of the fifth transistor is connected to the current mirror. The third end of the sixth transistor is configured as the first positive input terminal. The third end of the seventh transistor is configured as the first negative input terminal; The third end of the third transistor and the third end of the fourth transistor are connected, and the third end of the third transistor is connected to the second end of the third transistor through the first switch. The third end of the fourth transistor is connected to the second end of the fourth transistor through the second switch; One end of the fifth resistor is configured as the first output terminal. The other end of the fifth resistor is connected to one end of the first capacitor. The other end of the first capacitor is grounded; The second end of the sixth transistor is connected to the first output terminal through the fourth switch. The second end of the fourth transistor is connected to the first output terminal through the third switch.

6. The temperature sensor according to claim 5, characterized in that The first chopper switch includes a fifth switch, a sixth switch, a seventh switch, and an eighth switch; The first connection terminal and the third connection terminal are connected through the fifth switch; The second connection terminal and the third connection terminal are connected through the sixth switch; The first connection terminal and the fourth connection terminal are connected through the seventh switch; The second connection terminal and the fourth connection terminal are connected through the eighth switch.

7. The temperature sensor according to claim 6, characterized in that, The first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, and the eighth switch all have signal input terminals. The signal input terminals are used to control the opening of the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, and / or the eighth switch according to the first chopping signal and the second chopping signal.

8. The temperature sensor according to any one of claims 2-7, characterized in that, The temperature sensor further includes a sampling signal generation module. The sampling signal generation module is connected to the current mirror. The sampling signal generation module is used to generate a first temperature detection signal according to the first current signal copied by the current mirror, and generate a second temperature detection signal according to the second current signal copied by the current mirror.

9. The temperature sensor according to claim 8, wherein The current mirror includes an eighth transistor, a ninth transistor, a tenth transistor, an eleventh transistor, a twelfth transistor, a thirteenth transistor, a fourteenth transistor, a fifteenth transistor, and a sixteenth transistor; The first end of the eighth transistor is used to connect to a power supply. The second end of the eighth transistor is connected to the second end of the fifteenth transistor. The second end of the ninth transistor is connected to the second end of the sixteenth transistor. The first end of the ninth transistor is connected to the second end of the tenth transistor. The first end of the tenth transistor is used to connect to the power supply; The second end of the eleventh transistor is connected to the second end of the fourth resistor. The first end of the eleventh transistor is connected to the second end of the twelfth transistor. The first end of the twelfth transistor is used to connect to the power supply; The second end of the thirteenth transistor is connected to the sampling signal generation module. The first end of the thirteenth transistor is connected to the second end of the fourteenth transistor. The first end of the fourteenth transistor is used to connect to the power supply; The third ends of the eighth transistor, the ninth transistor, the eleventh transistor, and the thirteenth transistor are connected together. The third ends of the tenth transistor, the twelfth transistor, and the fourteenth transistor are connected together; The third end of the eighth transistor is connected to the second end of the eighth transistor. The second end of the ninth transistor is connected to the third end of the tenth transistor; The third ends of the fifteenth transistor and the sixteenth transistor are both connected to the first output end in the first chopper operational amplifier circuit. The first ends of the fifteenth transistor and the sixteenth transistor are both grounded. The second end of the sixteenth transistor is connected to the second end of the ninth transistor.

10. The temperature sensor according to claim 8, characterized in that, The sampling signal generation module includes a resistance trimming circuit and a sampling resistor; The resistance trimming circuit is connected to the current mirror and is used to generate a calibration resistor with a preset resistance value according to a calibration signal; One end of the sampling resistor is connected to the resistance trimming circuit, and the other end is grounded.

11. The temperature sensor according to claim 10, characterized in that, The resistance trimming circuit includes Y trimming resistors, where Y is a positive integer; The Y trimming resistors are connected in series, and each trimming resistor is connected in series with a trimming switch. One end of the first trimming resistor among the Y trimming resistors is connected to the current mirror. One end of each trimming resistor away from the current mirror is connected to the first end of the trimming switch. The other end of the trimming switch is connected to the output end of the resistance trimming circuit. One end of the last trimming resistor among the Y trimming resistors away from the current mirror is also connected to one end of the sampling resistor.

12. The temperature sensor according to claim 11, characterized in that, The sampling signal generation module further includes a microcontroller, and the microcontroller is used to control the opening or closing of each trimming switch according to the calibration signal.

13. The temperature sensor according to claim 8, characterized in that, The temperature sensor further includes a signal processing module, and the signal processing module includes an analog-to-digital conversion unit and a digital filter; The analog-to-digital conversion unit is electrically connected to the sampling signal generation module and is used to convert the first temperature detection signal into a first digital signal and convert the second temperature detection signal into a second digital signal; The digital filter is connected to the analog-to-digital conversion unit and is configured to perform filtering processing based on the first digital signal and the second digital signal to obtain a detected temperature.

14. The temperature sensor according to claim 8, characterized in that, The temperature sensor further includes a signal processing module and a buffer module; The signal processing module includes an analog-to-digital conversion unit and a digital filter, and the digital filter is electrically connected to the analog-to-digital conversion unit; One end of the buffer module is connected to the sampling signal generation module, and the other end is connected to the analog-to-digital conversion unit; The buffer module is configured to output a first output signal to the analog-to-digital conversion unit when receiving a third chopping signal, and output a second output signal to the analog-to-digital conversion unit when receiving a fourth chopping signal; wherein, the first output signal is obtained by operating on the first temperature detection signal and the second temperature detection signal within a first period, and the second output signal is obtained by operating on the first temperature detection signal and the second temperature detection signal within a second period; The analog-to-digital conversion unit is configured to convert the first output signal into a third digital signal and convert the second output signal into a fourth digital signal; The digital filter is configured to perform filtering processing on the third digital signal and the fourth digital signal to obtain a detected temperature.

15. The temperature sensor according to claim 14, characterized in that, The buffer module includes a second chopping operational amplifier circuit and a third chopping switch; The second chopping operational amplifier circuit includes a second positive input terminal, a second negative input terminal, and a second output terminal; The third chopping switch includes a fifth connection terminal, a sixth connection terminal, a seventh connection terminal, and an eighth connection terminal; The sampling signal generation module is connected to the sixth connection terminal, the fifth connection terminal is connected to the second output terminal, the seventh connection terminal is connected to the second negative input terminal, the eighth connection terminal is connected to the second positive input terminal, and the second output terminal is connected to the analog-to-digital conversion unit.

16. The temperature sensor according to claim 15, characterized in that, The second chopping operational amplifier circuit includes a second operational amplifier and a fourth chopping switch; wherein, the fourth chopping switch includes a ninth switch, a tenth switch, an eleventh switch, and a twelfth switch, and the second operational amplifier includes a seventeenth transistor, an eighteenth transistor, a nineteenth transistor, a twentieth transistor, a twenty-first transistor, a sixth resistor, and a second capacitor; The first end of the nineteenth transistor is configured to be connected to a power supply, the second end of the nineteenth transistor is connected to the first end of the twentieth transistor, the second end of the twentieth transistor is connected to the second end of the seventeenth transistor, the first ends of the seventeenth transistor and the eighteenth transistor are grounded, the second end of the eighteenth transistor is connected to the second end of the twenty-first transistor, the first end of the twenty-first transistor is connected to the second end of the nineteenth transistor, the third end of the nineteenth transistor is connected to the current mirror, the third end of the twentieth transistor is configured to be the second positive input terminal, and the third end of the twenty-first transistor is configured to be the second negative input terminal; The third terminal of the seventeenth transistor and the third terminal of the eighteenth transistor are connected, and the third terminal of the seventeenth transistor is connected to the second terminal of the seventeenth transistor through the ninth switch, and the third terminal of the eighteenth transistor is connected to the second terminal of the eighteenth transistor through the tenth switch; One end of the sixth resistor is configured as the second output terminal, the other end of the sixth resistor is connected to one end of the second capacitor, and the other end of the second capacitor is grounded; The second terminal of the twentieth transistor is connected to the second output terminal through the twelfth switch, and the second terminal of the eighteenth transistor is connected to the second output terminal through the eleventh switch.

17. The temperature sensor according to claim 13 or 14, characterized in that, The signal processing module further includes a bandgap reference circuit; The bandgap reference circuit is connected to the analog-to-digital conversion unit, and the bandgap reference circuit is used to supply power to the analog-to-digital conversion unit.

18. A chip, characterized in that, The chip includes the temperature sensor according to any one of claims 1 to 17.

19. An electronic device, characterized in that, The electronic device includes the chip according to claim 18.

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