Temperature compensation circuit

Abstract

The application provides a temperature compensation circuit, comprising: a first resistance unit, the first resistance unit being used for outputting a reference voltage changing with temperature; a second resistance unit, the second resistance unit being used for outputting a control voltage changing with temperature; a transconductance unit, a first input end of the transconductance unit being connected to the reference voltage, and a second input end of the transconductance unit being connected to the control voltage; wherein the transconductance unit is used for performing common-mode signal cancellation on the reference voltage and the control voltage changing with temperature, and outputting an output voltage with a temperature coefficient of 0. The application outputs the reference voltage changing with temperature through the first resistance unit, outputs the control voltage changing with temperature through the second resistance unit, and finally performs common-mode signal cancellation on the reference voltage and the control voltage changing with temperature through the transconductance unit, so as to output the output voltage with the temperature sensitive coefficient of 0, and avoid the phenomenon that the temperature compensation is abnormal due to the non-ideal reference element with positive and negative temperature coefficients.

Description

Technical Field

[0001] This application relates to the field of integrated circuit technology, specifically to a temperature compensation circuit. Background Technology

[0002] Currently, chip reference sources typically require temperature compensation to provide stable voltage, current, or clock references within the rated operating temperature range of each module. This is usually achieved by placing a reference element with a positive temperature sensitivity coefficient (e.g., a resistor with a positive temperature coefficient) and a reference element with a negative temperature sensitivity coefficient (e.g., a resistor with a negative temperature coefficient) on the chip. By appropriately assigning weights to these two elements in the addition operation, zero temperature sensitivity of the target reference source can be achieved. However, reference elements with positive and negative temperature coefficients are often not ideal; for example, there may be reference elements with abruptly negative temperature sensitivity coefficients, leading to abnormal temperature compensation. Summary of the Invention

[0003] This application provides a temperature compensation circuit, which aims to solve the technical problem that the current reference elements for positive and negative temperature coefficients are not ideal, resulting in abnormal temperature compensation.

[0004] This application provides a temperature compensation circuit, including:

[0005] The first resistor unit is used to output a reference voltage that changes with temperature.

[0006] The second resistor unit is used to output a control voltage that changes with temperature.

[0007] The transconductance unit has a first input terminal connected to a reference voltage and a second input terminal connected to a control voltage.

[0008] The transconductance unit is used to cancel the common-mode signal of the reference voltage and control voltage, which change with temperature, and outputs an output voltage with a temperature coefficient of 0.

[0009] In some embodiments, the output terminal of the transconductance unit is coupled to the second resistor unit, and the transconductance unit has an initial operating state and a stable operating state;

[0010] When the transconductance unit is in its initial operating state, the control voltage changes with the output voltage of the transconductance unit so that the control voltage is close to the reference voltage.

[0011] When the transconductance unit is in a stable operating state, the output voltage remains constant and the reference voltage and control voltage remain equal during temperature changes.

[0012] In some embodiments, the first resistor unit includes a first resistor and a second resistor connected in series;

[0013] The end of the first resistor furthest from the second resistor is coupled to the ground terminal, the end of the second resistor furthest from the first resistor is coupled to the power supply terminal, and the first input terminal of the transconductance unit is coupled to the first node between the first resistor and the second resistor;

[0014] The first resistor has a first temperature coefficient, and the second resistor has a second temperature coefficient. The first temperature coefficient and the second temperature coefficient are not equal.

[0015] In some embodiments, the second resistor unit includes a third resistor connected in series and an equivalent resistor;

[0016] The end of the third resistor furthest from the equivalent resistance is coupled to the ground terminal, the end of the equivalent resistance furthest from the third resistor is coupled to the power supply terminal, and the second input terminal of the transconductance unit is coupled to the second node between the third resistor and the equivalent resistance.

[0017] The third resistor has a third temperature coefficient, and the equivalent resistance changes based on the output voltage.

[0018] In some embodiments, when the transconductance unit is in its initial operating state, the output voltage changes the resistance of the equivalent resistor so that the control voltage is close to the reference voltage.

[0019] When the transconductance unit is in a stable operating state, the output voltage and the resistance of the equivalent resistance remain unchanged, and the reference voltage and control voltage remain equal during temperature changes.

[0020] In some embodiments, when the transconductance unit is in a stable operating state, the first resistor, the second resistor, the third resistor, and the equivalent resistance satisfy the following relationship:

[0021] (r1*(1+ΔT*TCR2)) / (r1*(1+ΔT*TCR1)+r2*(1+ΔT*TCR2))=(r3*(1+ΔT*TCR

[0022] 3)) / (r3*(1+ΔT*TCR3)+rc)

[0023] Where r1 is the resistance of the first resistor, r2 is the resistance of the second resistor, r3 is the resistance of the third resistor, TCR1 is the first temperature coefficient of the first resistor, TCR2 is the second temperature coefficient of the second resistor, TCR3 is the third temperature coefficient of the third resistor, ΔT is the temperature change value, and rc is the resistance of the equivalent resistor.

[0024] In some embodiments, the equivalent resistance includes a first capacitor, a first switch, a second switch, a third switch, and a fourth switch;

[0025] One end of the first switch is coupled to the ground terminal, and the other end is coupled to the third resistor;

[0026] One end of the second switch is coupled to the third resistor, and the other end is coupled to the second input terminal of the transconductance unit;

[0027] One end of the third switch is coupled to the third node between the third resistor and the second switch, and the other end is coupled to the power supply.

[0028] One end of the fourth switch is coupled to the first input terminal of the transconductance unit, and the other end is coupled to the second input terminal of the transconductance unit;

[0029] One end of the first capacitor is coupled to the fourth node between the third resistor and the second switch, and the other end is coupled to the ground terminal. The fourth node is closer to the third resistor than the third node.

[0030] In some embodiments, the equivalent resistance includes an adjustable resistor connected in series with a third resistor, the adjustable resistor changing its resistance value based on the output voltage.

[0031] In some embodiments, the equivalent resistance includes a voltage-controlled current source connected in parallel with the third resistor;

[0032] The voltage-controlled current source controls the current magnitude based on the output voltage to change the current flowing through the third resistor, thereby changing the voltage at the end of the third resistor adjacent to the voltage-controlled current source.

[0033] In some embodiments, the first temperature coefficient and the second temperature coefficient have the same polarity.

[0034] In some embodiments, the third temperature coefficient is equal to the first temperature coefficient; or

[0035] The third temperature coefficient is equal to the second temperature coefficient.

[0036] In some embodiments, the transconductance unit includes an integrator;

[0037] The non-inverting input of the integrator is connected to the reference voltage, and the inverting input of the integrator is connected to the control voltage.

[0038] This application outputs a reference voltage that changes with temperature through a first resistor unit and a control voltage that changes with temperature through a second resistor unit. Finally, the common-mode signal cancellation of the reference voltage and control voltage that change with temperature is performed through a transconductance unit, thereby outputting an output voltage with a temperature sensitivity coefficient of 0. This eliminates the need for reference elements with positive and negative temperature coefficients, avoiding the phenomenon of abnormal temperature compensation caused by the non-ideal nature of reference elements with positive and negative temperature coefficients. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of a temperature compensation circuit provided in an embodiment of this application;

[0041] Figure 2 This is a graph showing the relationship between the reference voltage, control voltage, and output voltage and temperature provided in the embodiments of this application.

[0042] Figure 3 This is another schematic diagram of the temperature compensation circuit provided in the embodiments of this application;

[0043] Figure 4 This is a schematic diagram showing the changes in the reference voltage, control voltage, and output voltage of the transconductance unit under different operating states provided in the embodiments of this application;

[0044] Figure 5 This is a schematic diagram of another circuit structure of the temperature compensation circuit provided in the embodiments of this application;

[0045] Figure 6 This is a schematic diagram of another circuit structure of the temperature compensation circuit provided in the embodiments of this application;

[0046] Figure 7 This is a pulse diagram of a switching signal provided in an embodiment of this application;

[0047] Figure 8 This is a schematic diagram of the change between the control voltage and the reference voltage provided in the embodiments of this application;

[0048] Figure 9 This is a schematic diagram of another circuit structure of the temperature compensation circuit provided in the embodiments of this application;

[0049] Figure 10 This is a schematic diagram of another circuit structure of the temperature compensation circuit provided in the embodiments of this application.

[0050] Among them, 10 is the first resistance unit, 20 is the second resistance unit, and 30 is the transconductance unit;

[0051] First resistor R1, second resistor R2, third resistor R3, equivalent resistance R0, first capacitor C0, first switch S1, second switch S2, third switch S3, fourth switch S4, adjustable resistor Rt, voltage-controlled current source Ic.

[0052] Reference voltage VR, control voltage VC, output voltage Vout;

[0053] First pulse signal ΦDCHG, second pulse signal ΦINT, third pulse signal ΦRST, fourth pulse signal ΦINTB, voltage-controlled oscillator VCRO;

[0054] First node M1, second node M2, third node M3, fourth node M4. Detailed Implementation

[0055] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0057] In this application, the term "exemplary" is used to mean "serving as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0058] This application provides a temperature compensation circuit, which will be described in detail below.

[0059] First, refer to Figure 1 as well as Figure 2 , Figure 1 This paper shows a schematic diagram of a temperature compensation circuit module in an embodiment of the present application. Figure 2 The graphs showing the relationship between the reference voltage VR, control voltage VC, and output voltage Vout and temperature in an embodiment of this application are illustrated, wherein the temperature compensation circuit includes:

[0060] The first resistor unit 10 is used to output a reference voltage VR that changes with temperature.

[0061] The second resistor unit 20 is used to output a control voltage VC that changes with temperature.

[0062] Transconductance unit 30, the first input terminal of transconductance unit 30 is connected to reference voltage VR, and the second input terminal of transconductance unit 30 is connected to control voltage VC;

[0063] The transconductance unit 30 is used to cancel the common-mode signal of the reference voltage VR and the control voltage VC, which change with temperature, and outputs an output voltage Vout with a temperature coefficient of 0.

[0064] Specifically, the first resistor unit 10 includes multiple resistors, which can be connected in series or in a combination of series and parallel. At least one of the resistors has a temperature coefficient that is not zero. Therefore, when the ambient temperature changes, the resistance value of one or more resistors in the first resistor unit 10 changes, thereby changing the voltage at a certain node of the first resistor unit 10, and finally outputting a reference voltage VR that changes with temperature.

[0065] As an example, see Figure 3 , Figure 3 A schematic diagram of a temperature compensation circuit in an embodiment of this application is shown. The first resistor unit 10 includes a first resistor R1 and a second resistor R2 connected in series. The end of the first resistor R1 away from the second resistor R2 is coupled to a ground terminal, and the end of the second resistor R2 away from the first resistor R1 is coupled to a power supply terminal. The first input terminal of the transconductance unit 30 is coupled to a first node M1 between the first resistor R1 and the second resistor R2. The first resistor R1 has a first temperature coefficient, and the second resistor R2 has a second temperature coefficient. The first temperature coefficient and the second temperature coefficient are not equal.

[0066] In the above embodiment, when the temperature changes, since the first temperature coefficient of the first resistor R1 is not equal to the second temperature coefficient of the second resistor R2, the resistance ratio of the first resistor R1 and the second resistor R2 changes, thereby changing the voltage at the first node M1 between the first resistor R1 and the second resistor R2, and finally providing a reference voltage VR that changes with temperature to the first input terminal of the transconductance unit 30.

[0067] In some embodiments of this application, such as embodiments where the first resistor R1 has a first temperature coefficient and the second resistor R2 has a second temperature coefficient, the first temperature coefficient and the second temperature coefficient have the same polarity, that is, the first temperature coefficient and the second temperature coefficient can both be positive temperature coefficients or both be negative temperature coefficients.

[0068] The control voltage VC of the second resistor unit 20 can change with temperature. It includes at least one resistor with a temperature coefficient that is not zero. When the ambient temperature changes, the resistance value of one or more resistors in the second resistor unit 20 changes, thereby changing the voltage of a certain node of the second resistor unit 20, and finally outputting a control voltage VC that changes with temperature.

[0069] As an example, see further. Figure 3 The second resistor unit 20 includes a third resistor R3 connected in series and an equivalent resistor R0; the end of the third resistor R3 away from the equivalent resistor R0 is coupled to the ground terminal, and the end of the equivalent resistor R0 away from the third resistor R3 is coupled to the power supply terminal. The second input terminal of the transconductance unit 30 is coupled to the second node M2 ​​between the third resistor R3 and the equivalent resistor R0. The third resistor R3 has a third temperature coefficient, and the equivalent resistor R0 changes its resistance based on the output voltage Vout of the transconductance unit 30.

[0070] In the above embodiment, the resistance of the third resistor R3 can change with temperature, while the resistance of the equivalent resistor R0 changes based on the output voltage Vout of the transconductance unit 30. When the output voltage Vout of the transconductance unit 30 remains constant in a stable operating state, the resistance of the equivalent resistor R0 remains constant. After the temperature changes, the resistance of the third resistor R3 changes accordingly. Therefore, the voltage at the second node M2 ​​of the third resistor R3 and the equivalent resistor R0 changes, thereby providing a temperature-dependent control voltage VC to the second input terminal of the transconductance unit 30, and keeping the control voltage VC equal to the reference voltage VR. When the transconductance unit 30 is in its initial operating state and the temperature remains constant, the resistance of the third resistor R3 remains constant, while the resistance of the equivalent resistor R0 is controlled by the output voltage Vout, thereby making the control voltage VC approach the reference voltage VR.

[0071] In some embodiments of this application, the third temperature coefficient is equal to the first temperature coefficient; or the third temperature coefficient is equal to the second temperature coefficient.

[0072] The transconductance unit 30 has a differential pair, thereby canceling the common-mode signals of the temperature-dependent reference voltage VR and the control voltage VC, and outputting an output voltage Vout with a temperature coefficient of 0. As an example, the transconductance unit 30 may include an integrator, with the non-inverting input of the integrator connected to the reference voltage VR and the inverting input connected to the control voltage VC. The integrator integrates the voltage difference between the reference voltage VR and the control voltage VC. When the reference voltage VR equals the control voltage VC, the integrator stops outputting and outputs a stable, temperature-independent output voltage Vout.

[0073] Understandably, the transconductance unit 30 can also be other circuit structures that can cancel common-mode signals between the reference voltage VR and the control voltage VC, such as comparators, inverting amplifiers, etc.

[0074] In this embodiment, the first resistor unit 10 outputs a reference voltage VR that changes with temperature, and the second resistor unit 20 outputs a control voltage VC that changes with temperature. Finally, the transconductance unit 30 cancels the common-mode signal of the reference voltage VR and the control voltage VC that change with temperature, thereby outputting an output voltage Vout with a temperature sensitivity coefficient of 0. This eliminates the need for reference elements with positive and negative temperature coefficients, avoiding the phenomenon of abnormal temperature compensation caused by the non-ideal reference elements with positive and negative temperature coefficients.

[0075] In some embodiments of this application, see Figure 4 , Figure 4 This illustration shows a variation of the reference voltage VR, control voltage VC, and output voltage Vout under different operating states of the transconductance unit 30 in this embodiment of the application. The output terminal of the transconductance unit 30 is coupled to the second resistor unit 20. The transconductance unit 30 has an initial operating state and a stable operating state. When the transconductance unit 30 is in the initial operating state, the control voltage VC changes with the output voltage Vout of the transconductance unit 30, so that the control voltage VC approaches the reference voltage VR. When the transconductance unit 30 is in the stable operating state, the output voltage Vout remains unchanged and keeps the reference voltage VR and the control voltage VC equal during temperature changes.

[0076] It should be noted that when the transconductance unit 30 is in the initial working state, the transconductance unit 30 performs feedback control on the second resistor unit 20 to change the magnitude of the control voltage VC until it is equal to the magnitude of the reference voltage VR. Since the completion time of this process is short, it can be assumed that the ambient temperature has not changed at this time, and the magnitude of the reference voltage VR remains unchanged in this initial working state. However, since the magnitude of the control voltage VC is not equal to the magnitude of the reference voltage VR at this time, the magnitude of the output voltage Vout of the transconductance unit 30 continues to change. For example, taking the transconductance unit 30 as including an integrator, the integrator integrates the voltage difference between the reference voltage VR and the control voltage VC and raises the output voltage Vout. The output voltage Vout then changes the resistance value of the equivalent resistor R0 in the second resistor unit 20, thereby making the control voltage VC approach the reference voltage VR and stop integrating until they are equal.

[0077] When the transconductance unit 30 is in a stable operating state, since the control voltage VC is equal to the reference voltage VR, the output voltage Vout of the transconductance unit 30 remains unchanged. As a result, the resistance of the equivalent resistor R0 in the second resistor unit 20 remains unchanged. During long-term stable operation, after the temperature changes, although the resistance values ​​of the first resistor R1 and the second resistor R2 change, causing the reference voltage VR to change, and the resistance value of the equivalent resistor R0 remains unchanged, the resistance of the third resistor R3 changes due to the influence of the ambient temperature. Thus, during the stable operating state of the transconductance unit 30, the reference voltage VR and the control voltage VC remain equal.

[0078] Furthermore, in some embodiments of this application, when the transconductance unit 30 is in a stable operating state, the first resistor R1, the second resistor R2, the third resistor R3, and the equivalent resistance R0 satisfy the following relationship:

[0079] (r1*(1+ΔT*TCR2)) / (r1*(1+ΔT*TCR1)+r2*(1+ΔT*TCR2))=(r3*(1+ΔT*TCR

[0080] 3)) / (r3*(1+ΔT*TCR3)+rc)

[0081] Where r1 is the resistance of the first resistor R1, r2 is the resistance of the second resistor R2, r3 is the resistance of the third resistor R3, TCR1 is the first temperature coefficient of the first resistor R1, TCR2 is the second temperature coefficient of the second resistor R2, TCR3 is the third temperature coefficient of the third resistor R3, ΔT is the temperature change value, and rc is the resistance of the equivalent resistor R0.

[0082] It should be noted that when the transconductance unit 30 is in a stable operating state, the resistance of the equivalent resistance R0 remains unchanged. At the same time, the first temperature coefficient of the first resistor R1, the second temperature coefficient of the second resistor R2, and the third temperature coefficient of the third resistor R3 usually remain unchanged. Therefore, by changing the resistance of the first resistor R1, the second resistor R2, and the third resistor R3, the above relationship can be made to hold. Finally, the control voltage VC follows the magnitude of the reference voltage VR, so that the transconductance unit 30 is connected to the temperature-varying control voltage VC and the reference voltage VR and performs common-mode cancellation, and finally the transconductance unit 30 outputs an output voltage Vout with a temperature coefficient of 0.

[0083] In some embodiments of this application, see further reference. Figure 5 , Figure 5 A schematic diagram of another circuit structure of the temperature compensation circuit in an embodiment of this application is shown, wherein the equivalent resistance R0 includes a first capacitor C0, a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4; one end of the first switch S1 is coupled to the ground terminal, and the other end is coupled to the third resistor R3; one end of the second switch S2 is coupled to the third resistor R3, and the other end is coupled to the second input terminal of the transconductance unit 30; one end of the third switch S3 is coupled to the third node M3 between the third resistor R3 and the second switch S2, and the other end is coupled to the power supply terminal; one end of the fourth switch S4 is coupled to the first input terminal of the transconductance unit 30, and the other end is coupled to the second input terminal of the transconductance unit 30; one end of the first capacitor C0 is coupled to the fourth node M4 between the third resistor R3 and the second switch S2, and the other end is coupled to the ground terminal, wherein the fourth node M4 is closer to the third resistor R3 than the third node M3.

[0084] It should be noted that the first switch S1, the first capacitor C0, and the third switch S3 form a switched capacitor. When the first switch S1 is closed, the first capacitor C0 discharges; when the third switch S3 is closed, the first capacitor C0 charges. According to the formula for calculating the equivalent resistance R0 of the switched capacitor, changing the frequency of closing and opening the first switch S1 and the third switch S3 can change the magnitude of the equivalent resistance R0 of the switched capacitor, thereby allowing the control voltage VC to approach the reference voltage VR when the transconductance unit 30 is in its initial operating state. Simultaneously, the switching states of the second switch S2 and the fourth switch S4 are mutually exclusive. That is, when the second switch S2 is closed, the fourth switch S4 is open, and the input voltage at the second input terminal of the transconductance unit 30 is the voltage at the first capacitor C0; when the second switch S2 is open, the fourth switch S4 is closed, and the input voltage at the second input terminal of the transconductance unit 30 is equal to the reference voltage VR, thus preventing fluctuations in the input voltage at the second input terminal of the transconductance unit 30 due to changes in the first switch S1 and the third switch S3.

[0085] Furthermore, in some embodiments of this application, see section 6. Figure 7 as well as Figure 8 , Figure 6 This paper shows a schematic diagram of another circuit structure of the temperature compensation circuit in an embodiment of this application. Figure 7 This invention illustrates a pulse diagram of a switching signal in an embodiment of the present application. Figure 8 The diagram illustrates a variation of the control voltage VC and the reference voltage VR in an embodiment of this application. The output voltage Vout of the transconductance unit 30 controls the oscillation frequency of the voltage-controlled oscillator VCRO, and then generates a first pulse signal ΦDCHG, a second pulse signal ΦINT, a third pulse signal ΦRST, and a fourth pulse signal ΦINTB via a clock generator. The first pulse signal ΦDCHG controls the first switch S1 to open or close, the second pulse signal ΦINT controls the second switch S2 to open or close, the third pulse signal ΦRST controls the third switch S3 to open or close, and the fourth pulse signal ΦINTB controls the fourth switch S4 to open or close.

[0086] Specifically, when the third switch S3 is closed, the voltage at the first capacitor C0 is the power supply voltage VDD. When the first switch S1 is closed, the voltage of the first capacitor C0 discharges and decreases to the reference voltage VR. Thus, when the second switch S2 is closed and the fourth switch S4 is open, the output is a control voltage VC equal to the reference voltage VR. When the second switch S2 is open and the fourth switch S4 is closed, the input voltage at the second input terminal of the transconductance unit 30 is equal to the reference voltage VR. This ensures that when the transconductance unit 30 is in a stable operating state, the voltages at the first output terminal and the second input terminal of the transconductance unit 30 remain equal during the opening or closing of all switches and common-mode signal cancellation is performed.

[0087] It should be noted that, since the control voltage VC remains stable after the transconductance unit 30 is in a stable working state in the above embodiment, the oscillation frequency of the voltage-controlled oscillator VCRO is fixed, thereby fixing the frequencies of the first pulse signal ΦDCHG, the second pulse signal ΦINT, the third pulse signal ΦRST, and the fourth pulse signal ΦINTB. This ultimately fixes the equivalent resistance R0 corresponding to the switched capacitor composed of the first switch S1, the first capacitor C0, and the third switch S3, thus achieving a pulse signal with locked output frequency and a temperature coefficient of 0, i.e., a frequency lock.

[0088] Understandably, the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4 mentioned above can be transistors with switching functions such as MOSFETs, IGBTs, or triodes; or they can directly output the corresponding output voltage Vout to generate a voltage signal with a temperature coefficient of 0.

[0089] In some embodiments of this application, see further reference. Figure 9 , Figure 9 A schematic diagram of another circuit structure of the temperature compensation circuit in this application embodiment is shown, wherein the equivalent resistance R0 includes an adjustable resistor Rt connected in series with the third resistor R3. The adjustable resistor Rt changes its resistance based on the output voltage Vout, so that the transconductance unit 30, in its initial operating state, changes the value of the adjustable resistor Rt to make the control voltage VC equal to the reference voltage VR and ultimately output a stable output voltage Vout. For example, the adjustable resistor Rt can refer to a MOSFET operating in the linear region, whose resistance changes with the output voltage Vout at the input gate, and becomes fixed when the output voltage Vout stabilizes.

[0090] In some embodiments of this application, see further reference. Figure 10 , Figure 10 The diagram shows another circuit structure of the temperature compensation circuit in the embodiment of this application. The equivalent resistance R0 includes a voltage-controlled current source Ic connected in parallel with the third resistance R3. The voltage-controlled current source Ic controls the current based on the output voltage Vout, thereby changing the current flowing through the third resistance R3 and ultimately changing the voltage at one end of the third resistance R3 adjacent to the voltage-controlled current source Ic, that is, the control voltage VC.

[0091] It is worth noting that the above description of the temperature compensation circuit is intended to clearly illustrate the implementation and verification process of this application. Those skilled in the art can also make equivalent modifications under the guidance of this application. For example, by changing the number of parallel resistors through the output voltage Vout, the resistance of the equivalent resistor R0 in the second resistor unit 20 can be changed.

[0092] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed descriptions of other embodiments above, which will not be repeated here.

[0093] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0094] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0095] Similarly, it should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the application requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0096] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of scope in some embodiments of this application are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0097] For each patent, patent application, patent application publication, and other material such as articles, books, specifications, publications, and documents referenced in this application, the entire contents of that patent application are incorporated herein by reference, except for historical application documents that are inconsistent with or conflict with the content of this application, and documents that limit the broadest scope of the claims of this application (currently or subsequently appended to this application). It should be noted that if there are any inconsistencies or conflicts between the descriptions, definitions, and / or terminology used in the supplementary materials of this application and the content of this application, the descriptions, definitions, and / or terminology used in this application shall prevail.

[0098] The temperature compensation circuit provided in the embodiments of this application has been described in detail above. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A temperature compensation circuit, characterized in that, include: The first resistor unit is used to output a reference voltage that changes with temperature. The second resistor unit is used to output a control voltage that changes with temperature. A transconductance unit, wherein the first input terminal of the transconductance unit is connected to the reference voltage, and the second input terminal of the transconductance unit is connected to the control voltage; The output terminal of the transconductance unit is coupled to the second resistor unit to make the control voltage close to the reference voltage, or to keep the control voltage equal to the reference voltage, so as to cancel the common-mode signal of the reference voltage and the control voltage that change with temperature, and output an output voltage with a temperature coefficient of 0.

2. The temperature compensation circuit as described in claim 1, characterized in that, The transconducting unit has an initial operating state and a stable operating state; When the transconductance unit is in its initial operating state, the control voltage changes in accordance with the output voltage of the transconductance unit, so that the control voltage is close to the reference voltage. When the transconductance unit is in a stable operating state, the output voltage remains unchanged and the reference voltage remains equal to the control voltage during temperature changes.

3. The temperature compensation circuit as described in claim 2, characterized in that, The first resistor unit includes a first resistor and a second resistor connected in series; The end of the first resistor furthest from the second resistor is coupled to a ground terminal, the end of the second resistor furthest from the first resistor is coupled to a power supply terminal, and the first input terminal of the transconductance unit is coupled to a first node between the first resistor and the second resistor; The first resistor has a first temperature coefficient, and the second resistor has a second temperature coefficient, wherein the first temperature coefficient and the second temperature coefficient are not equal.

4. The temperature compensation circuit as described in claim 3, characterized in that, The second resistor unit includes a third resistor connected in series and an equivalent resistance; The end of the third resistor away from the equivalent resistance is coupled to the ground terminal, the end of the equivalent resistance away from the third resistor is coupled to the power supply terminal, and the second input terminal of the transconductance unit is coupled to the second node between the third resistor and the equivalent resistance; The third resistor has a third temperature coefficient, and the equivalent resistance changes based on the output voltage.

5. The temperature compensation circuit as described in claim 4, characterized in that, When the transconductance unit is in its initial operating state, the output voltage changes the resistance of the equivalent resistor so that the control voltage is close to the reference voltage. When the transconductance unit is in a stable operating state, the output voltage and the resistance of the equivalent resistor remain unchanged, and the reference voltage and the control voltage remain equal during temperature changes.

6. The temperature compensation circuit as described in claim 5, characterized in that, When the transconductance unit is in a stable operating state, the first resistor, the second resistor, the third resistor, and the equivalent resistance satisfy the following relationship: (r1*(1+ T*TCR2)) / (r1*(1+ T*TCR1)+r2*(1+ T*TCR2))=(r3*(1+ T*TCR3)) / (r3*(1+ T*TCR3)+rc) Where r1 is the resistance of the first resistor, r2 is the resistance of the second resistor, r3 is the resistance of the third resistor, TCR1 is the first temperature coefficient of the first resistor, TCR2 is the second temperature coefficient of the second resistor, and TCR3 is the third temperature coefficient of the third resistor. T is the temperature change value, and rc is the resistance of the equivalent resistance.

7. The temperature compensation circuit as described in claim 4, characterized in that, The equivalent resistance includes a first capacitor, a first switch, a second switch, a third switch, and a fourth switch; One end of the first switch is coupled to the ground terminal, and the other end is coupled to the third resistor; One end of the second switch is coupled to the third resistor, and the other end is coupled to the second input terminal of the transconductance unit; One end of the third switch is coupled to the third node between the third resistor and the second switch, and the other end is coupled to the power supply. One end of the fourth switch is coupled to the first input terminal of the transconductance unit, and the other end is coupled to the second input terminal of the transconductance unit; One end of the first capacitor is coupled to a fourth node between the third resistor and the second switch, and the other end is coupled to a ground terminal. The fourth node is closer to the third resistor than the third node.

8. The temperature compensation circuit as described in claim 4, characterized in that, The equivalent resistance includes an adjustable resistor connected in series with the third resistor, the adjustable resistor changing its resistance value based on the output voltage.

9. The temperature compensation circuit as described in claim 4, characterized in that, The equivalent resistance includes a voltage-controlled current source connected in parallel with the third resistor; The voltage-controlled current source controls the current magnitude based on the output voltage to change the current flowing through the third resistor, thereby changing the voltage of the third resistor near the end of the voltage-controlled current source.

10. The temperature compensation circuit as described in claim 3, characterized in that, The first temperature coefficient and the second temperature coefficient have the same polarity.

11. The temperature compensation circuit as described in claim 4, characterized in that, The third temperature coefficient is equal to the first temperature coefficient; or The third temperature coefficient is equal to the second temperature coefficient.

12. The temperature compensation circuit as described in claim 1, characterized in that, The transconducting unit includes an integrator; The non-inverting input of the integrator is connected to the reference voltage, and the inverting input of the integrator is connected to the control voltage.

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