Temperature compensation circuit and calibration method thereof

Abstract

The application discloses a temperature compensation circuit, comprising: a first temperature calibration module and a second temperature calibration module; the first temperature calibration module and the second temperature calibration module are connected in sequence, and the second temperature calibration module outputs an output current; the first temperature calibration module comprises a first variable resistance unit, and the second temperature calibration module comprises a second variable resistance unit; the value of the first variable resistance unit is set so that the output current does not change with the value of the second variable resistance unit at a first temperature point; and the value of the second variable resistance unit is set so that the output current is temperature-compensated at a second temperature point. The application provides a temperature calibration circuit, which adjusts the bias current by calibrating the first temperature calibration module and the second temperature calibration module at two different temperature points, so as to compensate the temperature coefficient of the sensitivity of a subsequent sensor element. Such a compensation circuit can be widely used in the temperature compensation of various sensor elements requiring current bias.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a temperature compensation circuit and a calibration method for the temperature compensation circuit. Background Technology

[0002] In today's society, sensors have permeated an extremely wide range of fields, including industrial production, space exploration, ocean exploration, environmental protection, resource surveys, medical diagnosis, bioengineering, and even cultural relic preservation. From the vast expanse of space to the boundless ocean, and to various complex engineering systems, almost every modern project relies on a variety of sensors.

[0003] Because the sensitivity of sensor elements is sensitive to temperature changes, the bias current needs to be adjusted accordingly to compensate for the sensitivity changes caused by temperature variations. For example, by adding an additional high-precision temperature sensor and corresponding compensation circuitry, the sensor's bias current can be adjusted to ensure the accuracy and stability of the sensor's sensitivity within a specific temperature range. However, such compensation techniques place high demands on the temperature sensor and its corresponding reference source, such as a bandgap, thus increasing the difficulty and cost of chip design.

[0004] Introducing additional temperature sensors for compensation increases chip complexity and places higher demands on the corresponding reference source. Therefore, such techniques typically increase the difficulty and cost of chip design. Summary of the Invention

[0005] The purpose of this invention is to provide a temperature compensation circuit and its calibration method, which calibrates the bias current based on temperature changes.

[0006] To address the above problems, a first aspect of the present invention provides a temperature compensation circuit, comprising: a first temperature calibration module and a second temperature calibration module;

[0007] The first temperature calibration module and the second temperature calibration module are connected in sequence, and the second temperature calibration module outputs current.

[0008] The first temperature calibration module includes a first variable resistor unit, and the second temperature calibration module includes a second variable resistor unit;

[0009] The value of the first variable resistor unit is set such that the output current does not change with the value of the second variable resistor unit at the first temperature point; the value of the second variable resistor unit is set such that the output current is temperature compensated at the second temperature point.

[0010] Optionally, the first temperature calibration module further includes a first switch, which connects the first variable resistor unit to the positive power supply or the power supply ground according to the output current direction of the second temperature calibration module.

[0011] The first variable resistor unit includes a first resistor and a second resistor, and the first resistor and the second resistor have different temperature coefficients;

[0012] The connection point where the first resistor and the second resistor are connected in series is connected to the second temperature calibration module.

[0013] Optionally, the first resistor includes a first variable resistor matrix.

[0014] Optionally, the second temperature calibration module further includes a first amplifier;

[0015] The inverting input of the first amplifier is connected to the first temperature calibration module, and the output is connected to the input of the second variable resistor unit.

[0016] The output terminal of the second variable resistor unit outputs current;

[0017] The inverting input terminal and the output terminal of the first amplifier are connected through a third resistor.

[0018] Optionally, the second variable resistor unit includes a second variable resistor matrix.

[0019] Another aspect of the present invention provides a calibration method for a temperature compensation circuit, wherein the temperature compensation circuit described above, the method includes:

[0020] Adjust the value of the first variable resistor unit so that the output current does not change with the value of the second variable resistor unit at the first temperature point, and record the resistance value in the register of the first variable resistor unit.

[0021] Adjust the conduction direction of the first switch and the value of the second variable resistor unit to perform temperature compensation on the output current.

[0022] Optionally, adjusting the value of the first variable resistor unit so that the output current at the first temperature point does not change with the value of the second variable resistor unit includes:

[0023] The resistance value of the second variable resistor unit is controlled to change at a fixed frequency between two different resistance values;

[0024] Adjust the value of the first variable resistor unit so that the output current does not change with the value of the second variable resistor unit at the first temperature point.

[0025] Optionally, adjusting the conduction direction of the first switch and the resistance value of the second variable resistor unit includes:

[0026] Adjust the current ambient temperature;

[0027] If the output current is opposite to the direction of the output current when the value of the first variable resistor unit is adjusted, then the conduction direction of the first switch is adjusted.

[0028] Adjust the resistance value of the second variable resistor unit until the current output current is exactly the same as the output current when the value of the first variable resistor unit was adjusted.

[0029] Another aspect of the present invention provides a bias circuit with temperature compensation, including a temperature compensation circuit and a bias circuit;

[0030] The temperature compensation circuit is the temperature compensation circuit described above.

[0031] The output of the temperature compensation circuit is connected to the bias circuit.

[0032] The output current is compensated for by temperature through a temperature compensation circuit, and the bias current of the bias circuit is also compensated for by temperature.

[0033] Optionally, the bias circuit includes a fourth resistor for generating a bias current and a second field-effect transistor for outputting the bias current.

[0034] The output current of the temperature compensation circuit is output to the high potential end of the fourth resistor.

[0035] The above-described technical solution of the present invention has the following beneficial technical effects:

[0036] This invention provides a temperature calibration circuit for use in a bias current circuit. By performing calibration at two different temperature points using a first temperature calibration module and a second temperature calibration module, the bias current is adjusted to compensate for the temperature coefficient of sensitivity of subsequent sensor components. Introducing this calibration circuit eliminates the need for additional temperature measurement and corresponding compensation circuitry in the current bias circuit, thereby reducing design complexity and chip cost. Furthermore, by calibrating at two different temperature points, this technique can eliminate the first-order temperature coefficient of sensor sensitivity, making this circuit widely applicable to most high-precision measurement applications. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the temperature compensation circuit for bias current provided by the present invention.

[0038] Figure 2 This is a flowchart of a calibration method for a temperature compensation circuit according to an embodiment of the present invention.

[0039] Figure 3This is a schematic diagram of the sensor output voltage waveform during the calibration of the first variable resistor matrix provided in an embodiment of the present invention.

[0040] Figure 4 This is a schematic diagram of the sensor output voltage waveform during calibration based on the second variable resistor matrix. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0042] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0043] In the description of this invention, it should be noted that the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0045] The invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0046] In existing technologies, the calibration of chip temperature drift is mostly achieved by introducing an additional temperature sensor into the chip to measure the chip's temperature change, and then compensating the circuit accordingly based on the actual temperature change, so as to reduce the temperature coefficient of sensor sensitivity by adjusting the magnitude of the bias current.

[0047] This invention relates to a two-point calibration technique for the bias current source within a sensor chip. By calibrating the bias current at two different temperature points, the temperature coefficient of the sensor circuit's sensitivity can be effectively reduced.

[0048] This invention can be applied to most high-precision measurement circuits, such as the biasing of Hall effect sensor elements. In such applications, because the sensitivity of the sensor element is sensitive to temperature changes, the bias current needs to be adjusted accordingly to compensate for the sensitivity changes caused by temperature variations. For example, by adding an additional high-precision temperature sensor and corresponding compensation circuitry, the bias current of the sensor can be adjusted to ensure the accuracy and stability of the sensor sensitivity within a specific temperature range. However, such compensation techniques place high demands on the temperature sensor and its corresponding reference source, such as a bandgap. This increases the difficulty and cost of chip design.

[0049] Figure 1 This is a schematic diagram of the temperature compensation circuit for bias current provided by the present invention.

[0050] Reference Figure 1 The temperature compensation circuit provided by the present invention includes: a first temperature calibration module 1 and a second temperature calibration module 2;

[0051] The first temperature calibration module 1 and the second temperature calibration module 2 are connected in sequence, and the second temperature calibration module 2 outputs current.

[0052] The first temperature calibration module 1 includes a first variable resistor unit, and the second temperature calibration module 2 includes a second variable resistor unit;

[0053] The value of the first variable resistor unit is set such that the output current does not change with the value of the second variable resistor unit at the first temperature point; the value of the second variable resistor unit is set such that the output current is temperature compensated at the second temperature point.

[0054] This invention provides a temperature calibration circuit for use in a bias current circuit. By performing calibration at two different temperature points using a first temperature calibration module 1 and a second temperature calibration module 2, the bias current is adjusted to compensate for the temperature coefficient of sensitivity of subsequent sensor components. Introducing this calibration circuit eliminates the need for additional temperature measurement and corresponding compensation circuitry in the current bias circuit, thereby reducing design complexity and chip cost. Furthermore, by calibrating at two different temperature points, this technique can eliminate the first-order temperature coefficient of sensor sensitivity, making this circuit widely applicable to most high-precision measurement applications.

[0055] In one embodiment, the first temperature calibration module 1 further includes a first switch 3, which connects the first variable resistor unit to the positive power supply or the power supply ground according to the output current direction of the second temperature calibration module 2.

[0056] The first variable resistor unit includes a first resistor and a second resistor 5, and the first resistor and the second resistor 5 have different temperature coefficients;

[0057] The connection point where the first resistor and the second resistor 5 are connected in series is connected to the second temperature calibration module 2.

[0058] Specifically, the chopper switch 3 can switch the power supply direction of the temperature calibration circuit provided by the present invention, thereby changing the direction of temperature compensation and making it more widely applicable.

[0059] In one embodiment, the first resistor includes a first variable resistor matrix 4.

[0060] Specifically, the first variable resistor matrix 4 and the second resistor 5, which constitute the first variable resistor unit, have relatively different temperature coefficients. One resistor can have a relatively positive temperature coefficient (PTAT), and the other a relatively negative temperature coefficient (CTAT). They can also both have positive temperature coefficients or both have negative temperature coefficients, as long as the absolute coefficients are different. For example, the second resistor 5 is a PTAT resistor, and the first variable resistor matrix 4 is a CTAT resistor. The first variable resistor matrix 4 is composed of a digitally controlled 8-bit R2R resistor matrix. As will be explained in detail below, by adjusting the ratio of the first variable resistor units in the first temperature calibration module 1, calibration can be achieved at the first temperature point, ensuring that the sensor bias current (and sensor sensitivity) does not change with the changes in the second variable resistor units at the first temperature point.

[0061] In one embodiment, the second temperature calibration module 2 further includes a first amplifier 6;

[0062] The inverting input terminal of the first amplifier 6 is connected to the first temperature calibration module 1, and the output terminal is connected to the input terminal of the second variable resistor unit.

[0063] The output terminal of the second variable resistor unit outputs current;

[0064] The inverting input terminal and the output terminal of the first amplifier 6 are connected through a third resistor 8.

[0065] In one embodiment, the amplifier is a negative feedback amplifier 6.

[0066] In one embodiment, the second variable resistor unit includes a second variable resistor matrix 7.

[0067] For example, the second variable resistor matrix 7 is also an 8-bit R2R resistor matrix. The second temperature calibration module 2 can adjust the output bias current at a specific temperature point by adjusting the first switch 3 and the second variable resistor matrix 7, thereby compensating for the change in sensor sensitivity caused by temperature changes.

[0068] This invention utilizes two adjustable resistor matrices to regulate the sensor bias current at different temperature points, thereby compensating for sensor sensitivity variations caused by temperature changes. Adjusting the first variable resistor matrix 4 ensures that the system bias at the first temperature point is not affected by the second variable resistor matrix 7. Adjusting the second variable resistor matrix 7 and the first switch 3 ensures that the system compensates for sensor temperature drift at the second temperature point by adjusting the compensation current.

[0069] Figure 2 This is a flowchart illustrating the calibration method for the temperature compensation circuit provided by the present invention. (Refer to...) Figure 2 This invention provides a calibration method for a temperature compensation circuit, applied to the aforementioned temperature compensation circuit, the method comprising:

[0070] Adjust the value of the first variable resistor unit so that the output current does not change with the value of the second variable resistor unit at the first temperature point, and record the resistance value in the register of the first variable resistor unit.

[0071] Adjust the conduction direction of the first switch 3 and the value of the second variable resistor unit to perform temperature compensation on the output current.

[0072] Reference Figure 3 In one embodiment, adjusting the value of the first variable resistor unit so that the output current at the first temperature point does not change with the value of the second variable resistor unit includes:

[0073] A signal is applied to the sensor to be compensated; this signal is a fixed, known signal.

[0074] The resistance value of the second variable resistor unit is controlled to change at a fixed frequency between two different resistance values ​​(e.g., from maximum to minimum value), such as... Figure 3 The waveform diagram is shown below;

[0075] Adjust the value of the first variable resistor unit; observe the output signal of the sensor to be compensated (e.g., ...). Figure 3 The waveform diagram is shown below, where the output signal of the sensor to be compensated is related to the output current of this circuit.

[0076] This ensures that the output current does not change with the value of the second variable resistor unit at the first temperature point, at which point the output square wave of the sensor to be compensated disappears.

[0077] During this process, if there is any voltage difference between the voltage Vo1 at the first temperature calibration point and the voltage Vi2 at the second temperature calibration point, a corresponding current will be generated and superimposed on the sensor bias current produced by the second variable resistor matrix 7 and the fourth resistor 9. The magnitude of this current is related to the size of the second variable resistor matrix 7. Therefore, as the resistance of the second variable resistor matrix 7 continuously changes, a square wave will be generated in the sensor's output voltage. Thus, by continuously adjusting the resistance value of the first variable resistor unit, the voltage Vo1 at the first temperature calibration point can be adjusted accordingly, making this voltage close to the voltage Vi2 at the second temperature calibration point. When the two voltages are completely equal, the square wave in the sensor's output will disappear.

[0078] In one embodiment, adjusting the conduction direction of the first switch 3 and the resistance value of the second variable resistor unit includes:

[0079] A signal is applied to the sensor, which is the same signal applied when adjusting the value of the first variable resistor unit;

[0080] Adjust the current ambient temperature;

[0081] Observe the output signal of the sensor to be compensated. The output signal of the sensor to be compensated is related to the output current of this circuit. As the output current of this circuit increases, the output signal of the sensor also increases.

[0082] If the output current is opposite to the direction of the output current when the value of the first variable resistor unit is adjusted, then the conduction direction of the first switch 3 is adjusted.

[0083] Adjust the resistance value of the second variable resistor unit until the sensor output reaches the expected value, for example, the same as the output of the first temperature point sensor.

[0084] The current output signal of the sensor is exactly the same as the output signal of the sensor when the value of the first variable resistor unit is adjusted.

[0085] For example, after calibrating the first variable resistor matrix 4, the temperature is changed to calibrate the second variable resistor matrix 7. The temperature change can be determined based on the application environment, as long as it differs from the previous temperature. At this time, the sensor's sensitivity changes due to the temperature change. Therefore, under the same signal, the sensor's output will deviate from the ideal value. To compensate for this temperature-induced sensitivity deviation and ensure that the sensor's measurement results are unaffected by temperature changes, the second variable resistor matrix 7 can be used to calibrate the sensor's sensitivity.

[0086] First, at the second temperature T2, the same measured signal is applied again, and then the sensor output is observed. At this time, due to the influence of temperature, the sensor output will deviate from the ideal output Vout. The sensor output voltage at the end of the first variable resistor matrix 4 calibration can be expressed as:

[0087] V out,T1 =INPUT·S T1 ·I1

[0088] Where INPUT is the sensor's input signal. Since this bias circuit can be used in any sensor application requiring current bias, the input signal is represented by INPUT. ST1 represents the sensor's sensitivity at the first temperature T1. I1 is the sensor's bias current at the first temperature point. The sensor's output voltage during calibration using the second variable resistor matrix 7 can be expressed as:

[0089]

[0090] Where INPUT is the measured signal. I2 is the bias current of the sensor at the second temperature point. During calibration, this signal is constant and known. Vout is the output under ideal conditions. ΔT is the temperature difference between T2 and T1. This is the system's temperature coefficient (V / °C). The bias current is affected by several factors, including the temperature coefficient of the sensor's own sensitivity and the temperature coefficient of the bias circuit itself.

[0091] Therefore, the specific steps for temperature calibration of the second variable resistor matrix 7 at temperature T2 are as follows:

[0092] When the output voltage of the sensor is detected at the output terminal to be different when the calibration of the first variable resistor matrix 4 is completed and when the calibration of the second variable resistor matrix 7 is completed, the second variable resistor matrix 7 is initially adjusted so that the output voltage of the sensor when the calibration of the second variable resistor matrix 7 is completed gradually approaches the output voltage of the sensor when the calibration of the first variable resistor matrix is ​​completed.

[0093] It is worth noting that, depending on the direction of the specific temperature coefficient, the first switch 3 of the first temperature calibration module 1 can be used to change the direction of temperature calibration. For example, if the system's temperature coefficient is positive, VDD can be kept connected to the first variable resistor matrix 4 during calibration at point T2. However, if the system's temperature coefficient is negative, it is necessary to switch the first switch 3 to connect VDD to the second resistor 5 to achieve temperature compensation in the opposite direction. In the example shown in the figure, the sensor's output voltage is greater when the first variable resistor matrix 4 is calibrated than when the second variable resistor matrix 7 is calibrated. In this case, it is not necessary to adjust the chopper switch 3. It is also possible that the sensor's output voltage is less when the first variable resistor matrix calibrates is calibrated than when the second variable resistor matrix 7 is calibrated, in which case it is necessary to adjust the first switch 3.

[0094] By gradually adjusting the resistance value of the second variable resistor matrix 7, a compensation current Icomp related to the second variable resistor matrix 7 is added to the bias current through the sensor, which is based on Ibias = Vbias / fourth resistor 9. This achieves calibration of the sensor sensitivity shift at this temperature. When the sensor output voltage at the end of the calibration of the first variable resistor matrix 4 is detected to be exactly equal to the sensor output voltage at the beginning of the calibration of the second variable resistor matrix 7, the resistance value of the second variable resistor matrix 7 is recorded by fixing the register of the second variable resistor matrix 7. At this point, the calibration of the second variable resistor matrix 7 is complete.

[0095] This calibration process can be expressed as:

[0096]

[0097] Here, Icomp is the additional bias current generated by adjusting the resistance value of the second variable resistor matrix 7. This depends on the system's temperature coefficient. The direction of Icomp can be determined by adjusting the first switch 3 of the first temperature calibration module 1, thereby achieving compensation. The purpose is to ultimately ensure, through the calibration of the second variable resistor matrix 7, that...

[0098] Since calibration at temperature T1 ensures that the sensitivity of the sensor system is not affected by the second variable resistor matrix 7 at temperature T1, the adjustment of the second variable resistor matrix 7 during calibration at T2 does not affect the calibration result of the system at temperature T1. Therefore, this invention ensures that the calibration of the system at the two temperature points does not affect each other, achieving true two-point temperature calibration.

[0099] Another aspect of the present invention provides a bias circuit with temperature compensation, including a temperature compensation circuit and a bias circuit;

[0100] The temperature compensation circuit is the temperature compensation circuit described above.

[0101] The output of the temperature compensation circuit is connected to the bias circuit.

[0102] The output current is compensated for by temperature through a temperature compensation circuit, and the bias current of the bias circuit is also compensated for by temperature.

[0103] In one embodiment, the bias circuit includes a fourth resistor 9 for generating a bias current and a second field-effect transistor 12 for outputting the bias current.

[0104] The output current of the temperature compensation circuit is output to the high potential end of the fourth resistor 9.

[0105] The bias circuit further includes:

[0106] The first field-effect transistor 10, the third field-effect transistor 13, the second amplifier 15, the drain follower 14, the third amplifier 16, the first capacitor 18, and the fifth resistor 17;

[0107] The source of the first field-effect transistor 10 is connected to the power supply, and the drain is connected to one end of the fifth resistor 17 and the source of the third field-effect transistor 13.

[0108] The other end of the fifth resistor 17 is connected to one end of the first capacitor 18 and the inverting input of the third amplifier 16;

[0109] The drain of the third field-effect transistor 13 is connected to the gate of the first field-effect transistor 10, the gate of the second field-effect transistor 12, and the source of the drain follower 14.

[0110] The gate of the third field-effect transistor 13 is connected to the output terminal of the third amplifier 16 and the other end of the first capacitor 18.

[0111] The drain of the drain follower 14 is connected to one end of the fourth resistor 9, the output of the second variable resistor unit, and the inverting input of the second amplifier 15.

[0112] The gate of the drain follower 14 is connected to the output of the second amplifier 15;

[0113] The source of the second field-effect transistor 12 is connected to the power supply, and the drain is connected to the positive input terminal of the third amplifier 16 and the bias current input terminal of the sensor.

[0114] The bias circuit provided by this invention operates as follows: The second amplifier 15, the drain follower 14, and the fourth resistor 9 together form a voltage follower circuit, which applies the corresponding bias voltage Vbias to the resistor R to generate a corresponding current. Ideally, the voltage follower composed of the second amplifier 15 and the drain follower 14 has a sufficiently large loop gain, so Vbias = Vcm. Therefore, adjusting Vcm can adjust the corresponding Vbias voltage.

[0115] The current generated in the fourth resistor 9 flows into the current mirror circuit composed of the first field-effect transistor 10 and the second field-effect transistor 12, thereby mirroring the generated bias current to the source output of the second field-effect transistor 12 to drive the corresponding sensor element A.

[0116] To increase the output impedance of the voltage follower circuit (second amplifier 15, drain follower 14, and fourth resistor 9) and reduce the impact of any voltage fluctuations at the source of drain follower 14 on the bias current, a gain booster circuit consisting of a third field-effect transistor 13 and a third amplifier 16 is added. The third field-effect transistor 13 and drain follower 14 form a cascode amplifier, significantly increasing the output impedance of the voltage follower circuit. Furthermore, this design adds an additional third amplifier 16; the loop formed by the third field-effect transistor 13 and the third amplifier 16 is a typical gain boosting circuit, further enhancing the output impedance of the voltage follower used to generate the bias current.

[0117] Another aspect of the present invention provides a sensor including a temperature-compensated bias circuit as described above.

[0118] This invention aims to protect a temperature compensation circuit, comprising a first temperature calibration module 1 and a second temperature calibration module 2, wherein the first temperature calibration module 1 and the second temperature calibration module 2 are connected in sequence, and the second temperature calibration module 2 outputs an output current; the first temperature calibration module 1 includes a first variable resistor unit, and the second temperature calibration module 2 includes a second variable resistor unit; the value of the first variable resistor unit is set such that the output current does not change with the value of the second variable resistor unit at a first temperature point; the value of the second variable resistor unit is set such that the output current is used for temperature compensation at a second temperature point.

[0119] This invention provides a temperature calibration circuit for use in a bias current circuit. By performing calibration at two different temperature points using a first temperature calibration module 1 and a second temperature calibration module 2, the bias current is adjusted to compensate for the temperature coefficient of sensitivity of subsequent sensor components. Introducing this calibration circuit eliminates the need for additional temperature measurement and corresponding compensation circuitry in the current bias circuit, thereby reducing design complexity and chip cost. Furthermore, by calibrating at two different temperature points, this technique can largely eliminate the first-order temperature coefficient of sensor sensitivity, making it widely applicable to most high-precision measurement applications.

[0120] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

[0121] The present invention has been described above with reference to embodiments thereof. However, these embodiments are merely illustrative and not intended to limit the scope of the invention. The scope of the invention is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the invention, and all such substitutions and modifications should fall within the scope of the invention.

[0122] Although embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions, and modifications can be made to the embodiments of the present invention without departing from the spirit and scope of the invention.

[0123] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A temperature compensation circuit, characterized in that, include: First temperature calibration module (1) and second temperature calibration module (2); The first temperature calibration module (1) and the second temperature calibration module (2) are connected in sequence, and the second temperature calibration module (2) outputs current. The first temperature calibration module (1) includes a first variable resistor unit, and the second temperature calibration module (2) includes a second variable resistor unit; The value of the first variable resistor unit is set such that the output current does not change with the value of the second variable resistor unit at the first temperature point; the value of the second variable resistor unit is set such that the output current is temperature compensated at the second temperature point. The first temperature calibration module (1) further includes a first switch (3), which connects the first variable resistor unit to the positive power supply or the power supply ground according to the output current direction of the second temperature calibration module (2); The first variable resistor unit includes a first resistor and a second resistor (5), and the first resistor and the second resistor (5) have different temperature coefficients; The connection point where the first resistor and the second resistor (5) are connected in series is connected to the second temperature calibration module (2); The second temperature calibration module (2) also includes a first amplifier (6); The inverting input of the first amplifier (6) is connected to the first temperature calibration module (1), and the output is connected to the input of the second variable resistor unit. The output terminal of the second variable resistor unit outputs current; The inverting input terminal and the output terminal of the first amplifier (6) are connected through a third resistor (8).

2. The temperature compensation circuit according to claim 1, characterized in that, The first resistor includes a first variable resistor matrix (4).

3. The temperature compensation circuit according to claim 1, characterized in that, The second variable resistor unit includes a second variable resistor matrix (7).

4. A calibration method for a temperature compensation circuit, characterized in that, The method, applied to the temperature compensation circuit according to any one of claims 1-3, comprises: Adjust the resistance value of the first variable resistor unit so that the output current does not change with the resistance value of the second variable resistor unit at the first temperature point, and record the adjusted resistance value of the first variable resistor unit into the register of the first variable resistor unit. Adjust the conduction direction of the first switch (3) and the resistance value of the second variable resistor unit to perform temperature compensation on the output current.

5. The calibration method for the temperature compensation circuit according to claim 4, characterized in that, Adjusting the resistance value of the first variable resistor unit so that the output current does not change with the resistance value of the second variable resistor unit at the first temperature point includes: The resistance value of the second variable resistor unit is controlled to change at a fixed frequency between two different resistance values; Adjust the resistance value of the first variable resistor unit so that the output current does not change with the resistance value of the second variable resistor unit at the first temperature point.

6. The calibration method for the temperature compensation circuit according to claim 4, characterized in that, Adjusting the conduction direction of the first switch (3) and the resistance value of the second variable resistor unit includes: Adjust the current ambient temperature; If the output current is opposite to the direction of the output current when the resistance of the first variable resistor unit is adjusted, then the conduction direction of the first switch (3) is adjusted. Adjust the resistance value of the second variable resistor unit until the current output current is exactly the same as the output current when the resistance value of the first variable resistor unit was adjusted.

7. A bias circuit with temperature compensation, characterized in that, It includes a temperature compensation circuit and a bias circuit; the temperature compensation circuit is the temperature compensation circuit according to any one of claims 1-3; The output of the temperature compensation circuit is connected to the bias circuit. The output current is compensated for by temperature through a temperature compensation circuit, and the bias current of the bias circuit is also compensated for by temperature.

8. The temperature-compensated bias circuit according to claim 7, characterized in that, The bias circuit includes a fourth resistor (9) for generating bias current and a second field-effect transistor (12) for outputting bias current. The output current of the temperature compensation circuit is output to the high potential end of the fourth resistor (9).

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