Temperature compensation circuit

Abstract

This application discloses a temperature compensation circuit. In this circuit, the control terminals of the first to fourth transistors in the current mirror are all coupled. The output currents of the second to fourth transistors are proportional to the output current of the first transistor. A first resistor in the first branch is connected to the output terminal of the second transistor. A second resistor in the second branch is connected to the output terminal of the third transistor. The first and second resistors have different temperature coefficients. The first input terminal of the amplifier is connected to the output terminal of the first transistor; the output terminal of the amplifier is connected to the control terminal of the first transistor. The two input terminals of the comparator respectively acquire and compare the first voltage output from the output terminal of the second transistor and the second voltage output from the output terminal of the third transistor. A switching module is connected to the output terminal of the comparator, and outputs a weighted average of the first and second voltages to the second input terminal of the amplifier.

Description

Technical Field

[0001] This application relates to integrated circuit technology, and to, but is not limited to, a temperature compensation circuit. Background Technology

[0002] In radio frequency and analog integrated circuit systems and modules, circuit temperature characteristics are crucial parameters. As temperature changes, circuits can generate linearly or non-linearly changing currents. Temperature sensors or temperature-compensated current circuits are needed to compensate for both linear and non-linear current changes, reducing the impact of temperature on circuit performance. Compensating for non-linear current changes is particularly challenging, requiring complex compensation circuits and resulting in less effective temperature compensation. Summary of the Invention

[0003] In view of this, the present application provides a temperature compensation circuit to solve at least one problem existing in the prior art. The circuit has a simple structure, low power consumption, and small footprint. By changing the weighting ratio of branches with different temperature characteristics, dynamic compensation for current changes is achieved.

[0004] The technical solution of this application embodiment is implemented as follows:

[0005] This application provides a temperature compensation circuit. The temperature compensation circuit includes: a current mirror, a first branch and a second branch, an amplifier, a comparator, and a switching module.

[0006] A current mirror includes a first transistor, a second transistor, a third transistor, and a fourth transistor; the control terminals of the first transistor, the second transistor, the third transistor, and the fourth transistor are all coupled together; the current at the output terminals of the second transistor, the third transistor, and the fourth transistor is proportional to the current at the output terminal of the first transistor; a first branch includes a first resistor connected to the output terminal of the second transistor; a second branch includes a second resistor connected to the output terminal of the third transistor; wherein the temperature coefficients of the first resistor and the second resistor are different; an amplifier includes a first input terminal, a second input terminal, and an output terminal; the first input terminal is connected to the output terminal of the first transistor; the output terminal of the amplifier is connected to the control terminal of the first transistor; a comparator has its two input terminals connected to the output terminals of the second transistor and the third transistor, respectively, and is configured to acquire a first voltage output from the output terminal of the second transistor and a second voltage output from the output terminal of the third transistor, and compare them; a switching module is connected to the output terminal of the comparator and is configured to change the weighting ratio of the first voltage and the second voltage based on the comparison result, and then output the result to the second input terminal.

[0007] In some embodiments, the switching module is configured to selectively connect the output of the second transistor to the second input of the amplifier, or connect the output of the third transistor to the second input of the amplifier.

[0008] In some embodiments, the switching module includes a first switch and a second switch. A first terminal of the first switch is connected to the output terminal of the second transistor, a second terminal of the first switch is connected to the second input terminal, and a control terminal of the first switch is connected to an output terminal of the comparator. The first switch is configured to be in an ON state in response to a first control signal output by the comparator, connecting the second input terminal to the output terminal of the second transistor, wherein the voltage at the second input terminal is equal to the first voltage.

[0009] The first terminal of the second switch is connected to the output terminal of the third transistor, the second terminal of the second switch is connected to the second input terminal, and the control terminal of the second switch is connected to the other output terminal of the comparator; the second switch is configured to be in a conducting state in response to a second control signal output by the comparator, connecting the second input terminal to the output terminal of the third transistor, and the voltage of the second input terminal is equal to the second voltage.

[0010] In some embodiments, the switching module includes multiple voltage divider unit groups and a switching unit. The voltage divider unit groups include a first voltage divider element and a second voltage divider element. The input terminal of the first voltage divider element is connected to the output terminal of the second transistor, and the output terminal of the first voltage divider element is connected to the second input terminal of the amplifier. The input terminal of the second voltage divider element is connected to the output terminal of the third transistor, and the output terminal of the second voltage divider element is connected to the second input terminal of the amplifier.

[0011] The ratio of the voltage division coefficient of the first voltage dividing element to the voltage dividing element of the plurality of voltage dividing unit groups is different.

[0012] The switching unit is configured to select different groups of the voltage divider units to be connected to the second input terminal of the amplifier.

[0013] In some embodiments, the switching module includes two voltage divider unit groups; in one voltage divider unit group, the first voltage divider element includes a third resistor and the second voltage divider element includes a fourth resistor; in the other voltage divider unit group, the first voltage divider element includes a fifth resistor and the second voltage divider element includes a sixth resistor.

[0014] The switching unit includes:

[0015] The third switch and the fourth switch are connected in series between the first branch and the second input terminal, and the fourth resistor and the fourth switch are connected in series between the second branch and the second input terminal. The control terminals of the third switch and the fourth switch are both connected to one output terminal of the comparator and are configured to be in a conducting state in response to a first control signal output by the comparator, thereby connecting the second input terminal to the output terminal of the second transistor and the output terminal of the third transistor.

[0016] The fifth switch and the sixth switch are connected in series between the first branch and the second input terminal, and the sixth resistor and the sixth switch are connected in series between the second branch and the second input terminal. The control terminals of the fifth switch and the sixth switch are both connected to the other output terminal of the comparator and are configured to be in the on state in response to the second control signal output by the comparator, thereby connecting the second input terminal to the output terminal of the second transistor and the output terminal of the third transistor.

[0017] The resistance ratio of the third resistor to the fourth resistor is different from the resistance ratio of the fifth resistor to the sixth resistor.

[0018] In some embodiments, the temperature coefficients of the third resistor, the fourth resistor, the fifth resistor, and the sixth resistor are all zero temperature coefficients.

[0019] In some embodiments, the aspect ratios of the first transistor, the second transistor, and the third transistor are the same.

[0020] In some embodiments, the input terminals of the first transistor, the second transistor, the third transistor, and the fourth transistor are respectively connected to the first power supply voltage terminal.

[0021] The temperature compensation circuit further includes a first unidirectional conduction unit, one end of which is connected to the first input terminal, and the other end of which is connected to the second power supply voltage terminal.

[0022] The first branch also includes a second unidirectional conduction unit, the first end of which is connected to the first resistor, and the other end of which is connected to the second power supply voltage terminal.

[0023] The second branch also includes a third unidirectional conduction unit, one end of which is connected to the second resistor, and the other end of which is connected to the second power supply voltage terminal.

[0024] In some embodiments, the second unidirectional conduction unit, the third unidirectional conduction unit, the first resistor, and the second resistor satisfy the following relationship:

[0025] The size of the second unidirectional conduction unit is larger than that of the third unidirectional conduction unit. At a fixed temperature point, the resistance of the first resistor is greater than that of the second resistor.

[0026] The size of the second unidirectional conduction unit is equal to the size of the third unidirectional conduction unit, and at the fixed temperature point, the resistance value of the first resistor is equal to the resistance value of the second resistor.

[0027] The size of the second unidirectional conduction unit is smaller than that of the third unidirectional conduction unit, and at the fixed temperature point, the resistance value of the first resistor is smaller than that of the second resistor.

[0028] In some embodiments, the temperature coefficient of the first resistor is zero, and the temperature coefficient of the second resistor is either positive or negative; or, both the temperature coefficients of the first resistor and the temperature coefficient of the second resistor are either positive or negative.

[0029] In some embodiments, the amplifier includes at least one of a five-tube amplifier, a sleeve amplifier, and a folded amplifier.

[0030] In some embodiments, the comparator includes a static comparator or a dynamic comparator.

[0031] In the temperature compensation circuit described above, the different temperature coefficients of the first and second resistors allow the first and second branches to generate currents with different temperature coefficients. Since the first and second voltages originate from the first and second branches, they retain the temperature characteristics of those branches, and their magnitudes reflect the magnitudes of the currents flowing through them. Comparing the first and second voltages triggers the comparator's output to flip, and the comparator's comparison result further triggers the switching module to change the weighting ratio of the first and second voltages in the amplifier's negative feedback loop. Utilizing the negative feedback formed by the amplifier, the first transistor, the second transistor, and the third transistor, the current flowing through the first transistor can exhibit different temperature coefficient slopes at different temperatures. The fourth transistor replicates the current of the first transistor, and its output temperature-compensated current can have different slopes at different temperatures, thus outputting a non-linear temperature-compensated current.

[0032] This solution eliminates the need for an external temperature sensor. It achieves the switching of the temperature coefficient slope of the temperature compensation current by using the temperature characteristics of the first and second resistors and the dynamic switching mechanism of the switching module, while reducing circuit power consumption and area occupancy.

[0033] The switching module changes the weighting ratio of the first voltage and the second voltage in two ways:

[0034] First, the switching module assigns weighting coefficients of 100% and 0% to the first voltage and 0% to the second voltage, or 0% and 100%. In other words, the switching module is configured to connect the second input terminal to either the first or second branch, which allows for easy switching between the two temperature coefficient slopes.

[0035] Secondly, the voltage at the second input terminal is a weighted sum of a portion of the first voltage and a portion of the second voltage. The switching module is configured to change the mixing ratio of the first voltage and the second voltage. By mixing the ratios, any combination of temperature coefficient slopes can be achieved, thus improving flexibility.

[0036] In some embodiments, the temperature compensation circuit further includes a first unidirectional conducting unit, one end of which is connected to a first input terminal, and the other end of which is connected to a second power supply voltage terminal; the first branch further includes a second unidirectional conducting unit, one end of which is connected to a first resistor, and the other end of which is connected to the second power supply voltage terminal; the second branch further includes a third unidirectional conducting unit, one end of which is connected to a second resistor, and the other end of which is connected to the second power supply voltage terminal. The second unidirectional conducting unit, the third unidirectional conducting unit, the first resistor, and the second resistor satisfy the following relationships: the size of the second unidirectional conducting unit is larger than the size of the third unidirectional conducting unit; at a fixed temperature point, the resistance of the first resistor is greater than the resistance of the second resistor; the size of the second unidirectional conducting unit is equal to the size of the third unidirectional conducting unit, and at a fixed temperature point, the resistance of the first resistor is equal to the resistance of the second resistor; the size of the second unidirectional conducting unit is smaller than the size of the third unidirectional conducting unit; at a fixed temperature point, the resistance of the first resistor is less than the resistance of the second resistor. Based on the intersection of two currents at a fixed temperature point due to the first and second resistors, a comparator is used to achieve automatic switching of the current at the fixed temperature point, which can realize seamless connection of current switching. Attached Figure Description

[0037] In the accompanying drawings, similar reference numerals may describe similar parts in different views. Similar reference numerals with different letter suffixes may indicate different examples of similar parts. The drawings illustrate, by way of example and not limitation, the various embodiments discussed herein.

[0038] Figure 1 Schematic diagrams of temperature compensation circuits provided for some examples;

[0039] Figure 2 for Figure 1 The actual temperature compensation current output by the temperature compensation circuit shown is different from the target temperature compensation current output.

[0040] Figure 3 This is a schematic diagram of the structure of a temperature compensation circuit provided in an embodiment of this application;

[0041] Figure 4 (a) and (b) are schematic diagrams of the structures of two comparators provided in the embodiments of this application;

[0042] Figure 5 A schematic diagram showing the relationship between two temperature compensation currents with different temperature coefficients and temperature in the temperature compensation circuit provided in this embodiment of the application.

[0043] Figure 6 This is a schematic diagram of another temperature compensation circuit provided in an embodiment of this application;

[0044] Figure 7A for Figure 6 A schematic diagram of the temperature compensation circuit in the first switch-on state;

[0045] Figure 7B for Figure 6 A schematic diagram of the provided temperature compensation circuit in the second switch-on state;

[0046] Figure 8 This is a schematic diagram of another temperature compensation circuit provided in an embodiment of this application;

[0047] Figure 9 for Figure 6 A schematic diagram showing the relationship between the nonlinear temperature compensation current output by the provided temperature compensation circuit and the temperature change.

[0048] Figure 10 This is a schematic diagram of another temperature compensation circuit provided in an embodiment of this application;

[0049] Figure 11A for Figure 10 A schematic diagram of the provided temperature compensation circuit with both the third and fourth switches on.

[0050] Figure 11B for Figure 10 A schematic diagram of the temperature compensation circuit with both the fifth and sixth switches on.

[0051] Figure 12 for Figure 10 A schematic diagram showing the relationship between the nonlinear temperature compensation current output by the provided temperature compensation circuit and the temperature change. Detailed Implementation

[0052] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0053] The terms “first,” “second,” and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “connected,” “linked,” or “coupled,” and similar terms are not limited to physical or mechanical coupling, but can include electrical coupling, whether direct or indirect.

[0054] It should be understood that the phrases "some embodiments" or "some examples" mentioned throughout the specification mean that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, "some embodiments" or "some examples" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0055] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0056] It should be noted that although this specification describes the embodiments, not every embodiment includes only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0057] In RF and analog integrated circuit systems and modules, circuit temperature characteristics are a crucial parameter. For example, inconsistent gain temperature drift in the receiver link can cause changes in sensitivity and dynamic range at different temperatures; inconsistent gain temperature drift in the transmitter link may lead to a deterioration of the gain vector amplitude (EVM) at different temperatures; inconsistent gain temperature drift in the detector link can lead to increased detection errors at different temperatures; and inconsistent oscillator frequency temperature drift can cause phase-locked loop (PLL) loss of lock-in.

[0058] Therefore, it is usually necessary to ensure that the circuit characteristics remain consistent with temperature changes (of course, there may be some special scenarios where specific temperature change characteristics need to be maintained). However, since the active devices that make up the circuit usually change with temperature, temperature compensation circuits are usually needed to correct the changes in circuit temperature characteristics caused by changes in device parameters.

[0059] Temperature compensation circuits are generally divided into linear temperature compensation and nonlinear temperature compensation. Because linear temperature compensation is simpler and easier to implement, it is typically used in scenarios where the temperature compensation current requirement is not high. However, for scenarios with higher temperature compensation current requirements (e.g., where the temperature change may be nonlinear), nonlinear temperature compensation is crucial. Compared to linear temperature compensation, nonlinear temperature compensation allows the gain to remain consistent over a wider temperature range. However, it is technically more difficult and has a more complex circuit structure.

[0060] For example, such as Figure 1 As shown, a nonlinear temperature compensation circuit includes two temperature-compensated current output circuits with different temperature characteristics (the linear temperature-compensated currents IPTAT1 and IPTAT2 output by the two circuits have different slopes as temperature changes), a multiplexer, and a temperature sensor. One temperature-compensated current output circuit includes transistors M1-M3, an amplifier, transistors Q1 and Q2, and a resistor RT1; the other temperature-compensated current output circuit includes transistors M4-M6, an amplifier, transistors Q3 and Q4, and a resistor RT2. The temperature of the circuit is sensed by the temperature sensor. When the temperature is below the temperature value T, the temperature sensor generates a control signal to control the multiplexer, which selects IPTAT1 as the output. When the temperature reaches and exceeds the temperature value T, the temperature sensor generates another control signal, which selects IPTAT2 as the output through the multiplexer, thus switching the temperature-compensated current IPTAT. Figure 2 As shown in (a), because the slopes of the two linear temperature compensation currents change with temperature are different, when the two linear temperature compensation currents IPTAT1 and IPTAT2 are spliced ​​together, a nonlinear temperature compensation current is eventually generated.

[0061] The inventors discovered that by connecting an external multiplexer and temperature sensor to the temperature-compensated current output circuit, the circuit structure of the multiplexer and temperature sensor occupies a large space, which is not conducive to reducing the size of the entire integrated circuit structure of the output nonlinear temperature-compensated current, and also results in high power consumption. Furthermore, the temperature sensor has limited accuracy in sensing temperature changes, making it difficult to switch precisely at the theoretical intersection temperature T, easily leading to temperature-compensated current connection problems. For example, when two linear temperature-compensated currents IPTAT1 and IPTAT2 are combined at temperature T, the target temperature-compensated current (such as...) Figure 2 (d) shown in the figure) and the actual temperature compensation current (as shown in the figure) Figure 2 The differences shown in (b) or (c) are significant, which seriously affects the accuracy and reliability of temperature compensation.

[0062] For example, such as Figure 2As shown in (b), the temperature value sensed by the temperature sensor is greater than the actual temperature value T at the intersection of the linear temperature compensation currents IPTAT1 and IPTAT2. Therefore, the multiplexer will delay switching IPTAT1 to IPTAT2. Combined with... Figure 2 The linear temperature compensation currents IPTAT1 and IPTAT2 shown in (a) are related to the temperature value T. When the temperature is greater than T, the output nonlinear temperature compensation current IPTAT increases sharply from the current value IPTAT1 to the current value IPTAT2.

[0063] For example, such as Figure 2 As shown in (c), the temperature value sensed by the temperature sensor is less than the actual temperature value T at the intersection of the linear temperature compensation currents IPTAT1 and IPTAT2. The multiplexer will switch IPTAT1 to IPTAT2 prematurely. Combined with... Figure 2 The linear temperature-compensated currents IPTAT1 and IPTAT2 shown in (a) are related to the temperature value T. When the temperature is less than T, the output nonlinear temperature-compensated current IPTAT drops sharply from the current value IPTAT1 to the current value IPTAT2.

[0064] To address the aforementioned issues, this application provides a temperature compensation circuit that eliminates the need for a temperature sensor. This circuit, through an integrated comparator and switching module, automatically and accurately selects or mixes compensation paths from different branches based on the comparison results of the internal branch voltages. The entire circuit has a simple structure, occupies less space, and consumes less power.

[0065] like Figure 3 As shown, the temperature compensation circuit 100 includes: a current mirror 110, a first branch 120, a second branch 130, an amplifier 140, a comparator 150, and a switching module 160.

[0066] The current mirror 110 includes a first transistor T1, a second transistor T2, a third transistor T3, and a fourth transistor T4. The control terminals of the first transistor T1 to the fourth transistor T4 are all coupled together; the input terminals (sources) of the first transistor T1 to the fourth transistor T4 are respectively connected to a first power supply voltage terminal (e.g., VDD). In this way, the current at the output terminals (drains) of the second transistor T2 to the fourth transistor T4 is a proportional replica of the current at the output terminal of the first transistor T1.

[0067] The first branch 120 connects to the output terminal of the second transistor T2; the first branch 120 includes a first resistor R1. Specifically, the output terminal of the second transistor T2 is coupled to one end of the first resistor R1 through the first node N1. The potential of the first node N1 is a first voltage V1. The current flowing through the second transistor T2 and the resistance value of the first resistor R1 affect the first voltage V1 of the first node N1. Therefore, the magnitude of the first voltage V1 can characterize the temperature characteristics of the first resistor R1.

[0068] The second branch 130 connects to the output terminal of the third transistor T3, and includes a second resistor R2. Specifically, the output terminal of the second transistor T2 is coupled to one end of the second resistor R2 through the second node N2. The potential of the second node N2 is the second voltage V2. The current flowing through the third transistor T3 and the resistance of the second resistor R2 affect the second voltage V2 of the second node N2; therefore, the magnitude of the second voltage V2 can characterize the temperature characteristics of the second resistor R2.

[0069] The temperature coefficients of the first resistor R1 and the second resistor R2 are different. It should be noted that the temperature coefficient is a parameter used to describe the rate of change of current or resistance with temperature, expressed as the relative rate of change of current or resistance caused by a unit temperature change. The temperature coefficient of resistance represents the relative rate of change of resistance caused by a unit temperature change. The temperature coefficient of current represents the relative rate of change of current caused by a unit temperature change. Because the temperature coefficients of the first resistor R1 and the second resistor R2 are different, the current flowing through the first branch 120 and the second branch 130 changes with temperature at different slopes, providing a basis for subsequent nonlinear compensation through the comparator 150 and the switching module 160.

[0070] Continue reading Figure 3 Amplifier 140 includes a first input terminal, a second input terminal, and an output terminal; for example, the first input terminal of amplifier 140 is an inverting input terminal (-), and the second input terminal is a non-inverting input terminal (+). The first input terminal of amplifier 140 is connected to the output terminal of the first transistor T1; the second input terminal of amplifier 140 is connected to the switching module 160; the output terminal of amplifier 140 is connected to the control terminal of the first transistor T1, thereby forming a negative feedback loop together with the first transistor T1 and the second transistor T2 / third transistor T3 to clamp the voltage between the first input terminal and the second input terminal.

[0071] Continue reading Figure 3, the two input terminals of the comparator 150 are respectively connected to the output terminals of the second transistor T2 and the third transistor T3. One input terminal of the comparator 150 is coupled to the first node N1 to obtain the first voltage V1; the other input terminal is coupled to the second node N2 to obtain the second voltage V2. The comparator 150 compares the magnitudes of the first voltage V1 and the second voltage V2, and outputs a corresponding control signal according to the comparison result. This control signal is configured to drive the subsequent switching module 160 to achieve the switching or mixing of the branches. Specifically, when V1 < V2, the comparator 150 outputs the first comparison result; when V1 ≥ V2, the comparator 150 outputs the second comparison result. For example, as Figure 3 shown, the switching module 160 requires two control signals for switching or mixing. Therefore, the comparison results output by the comparator 150 include the first control signal Ctrl1 and the second control signal Ctrl2. Among them, the first control signal Ctrl1 and the second control signal Ctrl2 can be inverse signals to each other. When the first control signal Ctrl1 is 1, the second control signal Ctrl2 is 0; when the first control signal Ctrl1 is 0, the second control signal Ctrl2 is 1.

[0072] Continue to refer to Figure 3 , the switching module 160 includes a first input terminal connected to the first branch 120, a second input terminal connected to the second branch 130, a control terminal connected to the output terminal of the comparator 150, and an output terminal connected to the second input terminal (+) of the amplifier 140. Exemplarily, the first input terminal of the switching module 160 is configured to receive the first voltage V1 transmitted from the output terminal of the second transistor T2 in the first branch 120. The second input terminal of the switching module 160 is configured to receive the second voltage V2 transmitted from the output terminal of the third transistor T3 in the second branch 130. The two input terminals respectively connected to the two control terminals of the switching module 160 are configured to receive different control signals. The output terminal of the switching module 160 is configured to output the weighted sum of the first voltage V1 and the second voltage V2.

[0073] For example, the control terminal of the switching module 160 is connected to the comparator 150 and is configured to change the weighting ratio of the first voltage V1 and the second voltage V2 based on the comparison result of the comparator 150 (e.g., the first control signal Ctrl1 and the second control signal Ctrl2). For example, when the comparator 150 outputs the first comparison result, the voltage (voltage at point B) VB at the output terminal of the switching module 160 is: a1 × first voltage V1 + a2 × second voltage V2 (Formula 1); when the comparator 150 outputs the second comparison result, the voltage (voltage at point B) VB at the output terminal of the switching module 160 is: b1 × first voltage V1 + b2 × second voltage V2 (Formula 2), where a1:a2 ≠ b1:b2, and a1, a2, b1, and b2 are the weighting ratios. Then, the weighted voltage of the first voltage V1 and the second voltage V2 is output to the second input terminal of the amplifier 140.

[0074] Thus, in the temperature compensation circuit 100, by utilizing the different temperature coefficients of the first resistor R1 and the second resistor R2, the first branch 120 and the second branch 130 generate currents with different temperature coefficient slopes (see...). Figure 5 Since the first voltage V1 and the second voltage V2 originate from the first branch 120 and the second branch 130, the first voltage V1 and the second voltage V2 retain the temperature characteristics of their respective branches, and the magnitude relationship between the first voltage V1 and the second voltage V2 can reflect the magnitude relationship of the current flowing through the first branch 120 and the second branch 130. The comparator 150 compares the first voltage V1 and the second voltage V2, and the comparison result drives the switching module 160 to dynamically change the ratio of the first voltage V1 and the second voltage V2 connected to the negative feedback loop of the amplifier 140. Using the negative feedback of the amplifier 140, the current flowing through the first transistor T1 will follow the temperature characteristics of the connected branch. The fourth transistor T4 replicates the current of the first transistor T1, and the current output by the fourth transistor T4 can exhibit different temperature characteristics at different temperature points, thereby outputting a nonlinear temperature-compensated current I. C Furthermore, this solution eliminates the need for an external temperature sensor. By employing a dual-resistor temperature characteristic coupling and dynamic switching mechanism, it achieves switching between different temperature coefficient slopes, while simultaneously reducing circuit power consumption and footprint.

[0075] In some examples, the first transistor T1, the second transistor T2, the third transistor T3, and the fourth transistor T4 in the current mirror 110 can all be metal-oxide-semiconductor field-effect transistors (MOSFETs), bipolar transistors (BJTs), or transistors of other structures.

[0076] The example provided in this application uses a single-transistor MOS current mirror 110 as an example for illustration. Under the same design concept, other types of current mirrors can also be used for current mirror 110, such as cascode current mirrors and Wilson current mirrors. The example provided in this application does not limit the type of current mirror; it can be selected according to actual needs.

[0077] For example, such as Figure 3 As shown, the output currents of the first transistor T1, the second transistor T2, and the third transistor T3 are equal. For example, the dimensions of the second transistor T2 and the third transistor T3 can be set to be the same (the aspect ratios of the transistors are the same), indicating that the threshold voltages of the second transistor T2 and the third transistor T3 are equal. Then, the replication ratio of the second transistor T2 to the first transistor T1 is equal to the replication ratio of the third transistor T3 to the first transistor T1.

[0078] For example, comparator 150 may include a static comparator or a dynamic comparator. The examples provided in this application are not limiting; the appropriate comparator can be chosen based on actual needs. Comparator 150 may be a differential structure, thereby outputting two opposite control signals Ctrl1 and Ctrl2. For example, as... Figure 4 As shown in (a), the static comparator includes transistors M7-M13. The control terminal of transistor M7 is connected to the bias voltage VB1. The control terminals of transistors M8 and M9 are connected to the first node N1 and the second node N2, respectively. The voltages of the first node N1 and the second node N2 serve as the control signals Vin1 and Vin2 for transistors M8 and M9, respectively. The drains of transistors M11 and M12 output control signals Ctrl2 and Ctrl1, respectively. For example, as... Figure 4 As shown in (b), the dynamic comparator includes transistors M14-M22, wherein transistors M16 and M18, together with transistors M17 and M19, form a set of inverters. The control terminals of transistors M20-M22 receive the clock CLK. The control terminals of transistors M14 and M15 are connected to the first node N1 and the second node N2, respectively. The voltages of the first node N1 and the second node N2 serve as the control signals INN and INP of transistors M14 and M15. The series connection point of transistors M16 and M18 transmits signal Ctrl1, and the series connection point of transistors M17 and M19 transmits signal Ctrl2.

[0079] For example, amplifier 140 may include at least one of a five-tube amplifier, a sleeve amplifier, and a folded amplifier. The examples provided in this application are not limiting and can be selected according to actual needs.

[0080] In some examples, such as Figure 3As shown, the temperature compensation circuit 100 also includes a first unidirectional conducting unit U1, one end of which is connected to the first input terminal of the amplifier 140, and the other end of which is grounded. The first branch 120 includes a second unidirectional conducting unit U2, one end of which is connected to a first resistor R1, and the other end of which is grounded. The second branch 130 includes a third unidirectional conducting unit U3, one end of which is connected to a second resistor R2, and the other end of which is grounded. The unidirectional conducting unit can be a diode or a transistor connected in diode form. When a voltage is applied, it can generate a unidirectional current. A positive temperature coefficient voltage difference can be generated between two sets of these unidirectional conducting units of different sizes, which is used to generate a positive temperature coefficient current. For example, the first unidirectional conducting unit U1 and the second unidirectional conducting unit U2 have different dimensions, which can enable the first branch to generate a current with a positive temperature coefficient; the first unidirectional conducting unit U1 and the third unidirectional conducting unit U3 have different dimensions, which can enable the second branch to generate a current with a positive temperature coefficient. When the unidirectional conducting unit can be a diode, its size is the area of ​​the PN junction; when the unidirectional conducting unit can be a transistor connected in the form of a diode, its size is the aspect ratio of the channel.

[0081] The dimensions of the second unidirectional conducting unit U2 and the third unidirectional conducting unit U3 will affect the temperature coefficient of the current in the first and second branches. To achieve a smooth transition and seamless connection of the transmission current in the two branches before and after switching at a fixed temperature point T, the second unidirectional conducting unit U2, the third unidirectional conducting unit U3, the first resistor R1, and the second resistor R2 must satisfy the following relationship:

[0082] 1) If the size of the second unidirectional conducting unit U2 is equal to the size of the third unidirectional conducting unit U3, then the resistance values ​​of the first resistor R1 and the second resistor R2 are equal at a fixed temperature point Ta. Because the size of the second unidirectional conducting unit U2 is equal to the size of the third unidirectional conducting unit U3, the influence of the second unidirectional conducting unit U2 on the temperature coefficient of the first branch is consistent with the influence of the third unidirectional conducting unit U3 on the temperature coefficient of the second branch. If the first resistor R1 and the second resistor R2 are not set, then the temperature coefficients of the current in the first branch and the current in the second branch are the same. Because the temperature coefficients of the first resistor R1 and the second resistor R2 are different, the rate of change of the resistance value of the first resistor R1 with temperature is different from the rate of change of the resistance value of the second resistor R2 with temperature. At the temperature corresponding to the intersection of the first and second curves (i.e., the fixed temperature point Ta), the resistance value of the first resistor R1 is equal to the resistance value of the second resistor R2, characterized as follows: Figure 5The temperature-compensated currents of the first branch 120 and the second branch 130 shown are equal at a fixed temperature point Ta. The input voltages (V1 and V2) across comparator 150 are also exactly equal, causing the comparator's comparison result to flip, triggering the switching module 160 to switch. Since the voltage and current transmitted in the two branches before and after the switch are continuous at the fixed temperature point Ta, a smooth and seamless connection of the nonlinear temperature-compensated current can be achieved.

[0083] 2) If the size of the second unidirectional conducting unit U2 is larger than the size of the third unidirectional conducting unit U3, then at a fixed temperature point, the resistance of the first resistor R1 is greater than the resistance of the second resistor R2. Since the second unidirectional conducting unit U2 is larger than the third unidirectional conducting unit U3, if the first resistor R1 and the second resistor R2 are not provided, the temperature coefficient of the current in the first branch is greater than that in the second branch. Therefore, at a fixed temperature point, the resistance of the first resistor R1 is greater than that of the second resistor R2. The first resistor R1 can reduce the current in the first branch, making the temperature compensation current of the first branch 120 and the second branch 130 equal at the fixed temperature point Ta, thus achieving a smooth transition and seamless connection of the transmission current of the two branches before and after switching at the fixed temperature point T.

[0084] 3) If the size of the second unidirectional conducting unit U2 is smaller than the size of the third unidirectional conducting unit U3, then at a fixed temperature point, the resistance of the first resistor R1 is smaller than the resistance of the second resistor R2. Since the size of the second unidirectional conducting unit U2 is smaller than the size of the third unidirectional conducting unit U3, if the first resistor R1 and the second resistor R2 are not provided, then the temperature coefficient of the current in the first branch is smaller than the temperature coefficient of the current in the second branch. At a fixed temperature point, the resistance of the first resistor R1 is smaller than the resistance of the second resistor R2, and the second resistor R2 can reduce the current in the second branch, making the temperature compensation current of the first branch 120 and the second branch 130 equal at the fixed temperature point Ta. This achieves a smooth transition and seamless connection of the transmission current of the two branches before and after switching at the fixed temperature point T.

[0085] In some examples, the first resistor R1 and the second resistor R2 can be set as thermistors, and their temperature coefficients and resistance values ​​can be adjusted by setting parameters such as their dimensions (e.g., aspect ratio) and materials (e.g., polycrystalline silicon resistors). The specific dimensions and materials set can be adjusted according to actual conditions, and the examples provided in this application do not impose specific limitations on this.

[0086] It should be noted that the "fixed temperature point" corresponds to the inflection point where the slope of the current to be compensated changes significantly with temperature, i.e., the boundary temperature between two different temperature response ranges. This "fixed temperature point" can be set according to the characteristic requirements of different currents to be compensated.

[0087] For example, the first resistor R1 and the second resistor R2 are thermistors with different temperature coefficients. For instance, both the first resistor R1 and the second resistor R2 are resistors with a positive temperature coefficient; however, the positive temperature coefficient of the first resistor R1 is smaller than that of the second resistor R2. That is, the rate of change of the resistance of the first resistor R1 with temperature is less than the rate of change of the resistance of the second resistor R2 with temperature. Thus, the rates of change of the resistance of the first resistor R1 with temperature are different from those of the resistance of the second resistor R2 with temperature.

[0088] For example, both the first resistor R1 and the second resistor R2 are resistors with negative temperature coefficients; and the negative temperature coefficient of the first resistor R1 is greater than that of the second resistor R2, that is, the rate of change of the resistance value of the first resistor R1 with temperature is greater than the rate of change of the resistance value of the second resistor R2 with temperature.

[0089] For example, the first resistor R1 is a resistor with zero temperature coefficient, and the second resistor R2 is a resistor with positive or negative temperature coefficient. This makes it easier to set the resistance value of the second resistor R2 to change with temperature so that at a certain fixed temperature point Ta, the resistance value of the first resistor R1 is equal to that of the second resistor R1. The dimensions of the first unidirectional conducting unit U1 and the second unidirectional conducting unit U2 can be different. For example, both the first unidirectional conducting unit U1 and the second unidirectional conducting unit U2 can be transistors with different dimensions (channel aspect ratios). The voltage difference between the first unidirectional conducting unit U1 and the second unidirectional conducting unit U2 is a voltage difference with a positive temperature coefficient. Even if the first resistor R1 is a resistor with zero temperature coefficient, the current in the first branch 120 can still exhibit a positive temperature coefficient.

[0090] The above examples demonstrate how the temperature characteristics of the voltage and current transmitted in the first branch 120 differ from those in the second branch 130, while maintaining the same voltage and current at a fixed temperature point. When the temperature changes to the fixed temperature point Ta, the input voltages (V1 and V2) across comparator 150 become exactly equal, causing the comparator's comparison result to flip and triggering switching module 160 to switch. Since the voltage and current transmitted in the two branches are continuous at the fixed temperature point Ta before and after the switch, a smooth and seamless transition of the nonlinear temperature-compensated current can be achieved.

[0091] In some embodiments, such as Figure 6As shown, the switching module 160 is configured to selectively connect the output terminal of the second transistor (i.e., the first node N1) to the second input terminal of the amplifier 140, with the weighting coefficients of the switching module 160 for the first voltage V1 and the second voltage V2 being 100% and 0% respectively, that is, in Formula 1, a1 is 1 and a2 is 0; or, the switching module 160 connects the output terminal of the third transistor T3 (i.e., the second node N2) to the second input terminal of the amplifier 140, with the weighting coefficients of the switching module 160 for the first voltage V1 and the second voltage V2 being 0% and 100% respectively, that is, in Formula 2, b1 is 0 and b2 is 1.

[0092] like Figure 6 As shown, the switching module 160 may include a first switch S1 and a second switch S2.

[0093] The first terminal of the first switch S1 is connected to the output terminal of the second transistor T2, the second terminal of the first switch S1 is connected to the second input terminal (+) of the amplifier 140, and the control terminal of the first switch S1 is connected to one output terminal of the comparator 150. The control terminal of the first switch S1 receives a first control signal Ctrl1 output by the comparator 150, and the first switch S1 is configured to be in the on state in response to the first control signal Ctrl1 output by the comparator 150. When the first switch S1 is on, the second input terminal of the amplifier 140 is connected to the output terminal of the second transistor T2, and the voltage at the second input terminal of the amplifier 140 is equal to the first voltage V1.

[0094] The first terminal of the second switch S2 is connected to the output terminal of the third transistor T3, and the second terminal of the second switch S2 is connected to the second input terminal (+) of the amplifier 140. The control terminal of the second switch S2 is connected to the other output terminal of the comparator 150. The control terminal of the second switch S2 receives the second control signal Ctrl2, and the second switch S2 is configured to be in the on state in response to the second control signal Ctrl2 output by the comparator 150. When the second switch S2 is on, the second input terminal of the amplifier 140 is connected to the output terminal of the third transistor T3, and the voltage at the second input terminal is equal to the second voltage V2.

[0095] Taking the example that the size of the second unidirectional conducting unit U2 is equal to the size of the third unidirectional conducting unit U3, and the resistance values ​​of the first resistor R1 and the second resistor R2 are equal at a fixed temperature point Ta, as the temperature changes, within a temperature range below the fixed temperature point Ta, the resistance value of the first resistor R1 is greater than the resistance value of the second resistor R2, the current in the first branch 120 is less than the current in the second branch 130, and the first voltage V1 is less than the second voltage V2. Figure 7AAs shown, comparator 150 outputs a first control signal Ctrl1 and a second control signal Ctrl2. The first switch S1 of switching module 160 is turned on in response to the first control signal Ctrl1, connecting the output terminal of the second transistor (i.e., the first node N1) to the second input terminal (+) of amplifier 140. The second switch S2 of switching module 160 is turned off in response to the second control signal Ctrl2, preventing the second branch 130 from being connected to amplifier 140. Therefore, the weighted value of the first voltage V1 transmitted through the first node N1 of the first branch 120 can be 100%, and the weighted value of the second voltage V2 transmitted through the second node N2 of the second branch 130 can be 0%, and the first voltage V1 is output to the second input terminal of amplifier 140. The temperature change pattern of node B coupled to switching module 160 is consistent with the temperature characteristic of the first resistor R1 in the first branch 120. Furthermore, the first input terminal of amplifier 140 is coupled to node A, and the second input terminal of amplifier 140 is coupled to node B. Amplifier 140 can clamp the voltages of nodes A and B, making the voltages of nodes A and B consistent and having the same temperature characteristics. By connecting the first voltage V1 of the first branch 120 to the feedback loop of amplifier 140, the temperature-compensated current Ic output from the fourth transistor T4 is correlated with the temperature characteristics of the first resistor R1.

[0096] When the temperature reaches a fixed point Ta, the resistance of the first resistor R1 is equal to the resistance of the second resistor R2, the current in the first branch 120°C is equal to the current in the second branch 130°C, and the first voltage V1 is equal to the second voltage V2. For example... Figure 7BAs shown, comparator 150 outputs a first control signal Ctrl1 and a second control signal Ctrl2. The second switch S2 of switching module 160 is turned on in response to the second control signal Ctrl2, connecting the output of the third transistor (i.e., the second node N2) to the second input (+) of amplifier 140. Conversely, the first switch S1 of switching module 160 is turned off in response to the first control signal Ctrl1, disconnecting the first branch 120 from amplifier 140. Therefore, the weighted value of the first voltage V1 transmitted through the first node N1 of the first branch 120 can be 0%, and the weighted value of the second voltage V2 transmitted through the second node N2 of the second branch 130 can be 100%, outputting the second voltage V2 to the second input of amplifier 140. The temperature change pattern of node B coupled to switching module 160 is consistent with the temperature characteristic of the second resistor R2 in the second branch 130. Furthermore, since the first input terminal of amplifier 140 is coupled to node A and the second input terminal of amplifier 140 is coupled to node B, amplifier 140 can clamp the voltages of nodes A and B, making the voltages of nodes A and B consistent and having the same temperature characteristics. By connecting the second voltage V2 of the second branch 130 to the feedback loop of amplifier 140, the temperature-compensated current Ic output from the fourth transistor T4 is correlated with the temperature characteristics of the second resistor R2.

[0097] Furthermore, within a temperature range greater than the fixed temperature point, the resistance of the first resistor R1 is less than the resistance of the second resistor R2, the current in the first branch 120 is greater than the current in the second branch 130, and the first voltage V1 is greater than the second voltage V2. For example... Figure 7B As shown, comparator 150 outputs a first control signal Ctrl1 and a second control signal Ctrl2. Switching module 160 continues to connect the first branch 120 to amplifier 140, while disconnecting the first branch 120 from amplifier 140. It also connects the output terminal of the second transistor (i.e., the first node N1) to the second input terminal of amplifier 140, outputting the second voltage V2 to the second input terminal of amplifier 140.

[0098] In this way, different branches can be connected to amplifier 140 through switching module 160 according to different temperature change ranges. By combining the temperature coefficients of the first resistor R1 and the second resistor R2, different degrees of current compensation can be performed on the nonlinearly changing current, thereby improving the accuracy of temperature-compensated current.

[0099] In other embodiments, when the size of the second unidirectional conducting unit U2 is greater than the size of the third unidirectional conducting unit U3, and the resistance of the first resistor R1 at the fixed temperature point Ta is greater than the resistance of the second resistor R2, or when the size of the second unidirectional conducting unit U2 is smaller than the size of the third unidirectional conducting unit U3, and the resistance of the first resistor R1 at the fixed temperature point Ta is less than the resistance of the second resistor R2, when the temperature reaches the fixed temperature point Ta, the voltage between the first voltage V1 and the second voltage V2 can also trigger the first control signal Ctrl1 and the second control signal Ctrl2 output by the comparator 150 to change, so as to control the switching module 160 to connect the output terminal of the second transistor (i.e., the first node N1) to the second input terminal of the amplifier 140, or to control the switching module 160 to connect the output terminal of the third transistor T3 (i.e., the second node N2) to the second input terminal of the amplifier 140.

[0100] In the above example, the switching module 160 employs multiple independent switches to select either the first voltage V1 or the second voltage V2 to be transmitted to the second input terminal of the amplifier 140 in response to different control signals. The switching module 160 may also employ a single-pole double-throw switch, a multiplexer, or other electronic components or circuits configured to selectively connect at least one of multiple branches to the second input terminal of the amplifier 140. This application does not impose specific limitations on this, and the configuration can be tailored to actual needs.

[0101] like Figure 6 As shown, the first unidirectional conduction unit U1 includes a fifth transistor T5. The fifth transistor T5 can be a PNP transistor. The first terminal of the fifth transistor T5 is connected to the first input terminal of the amplifier 140, and the second terminal of the fifth transistor T5 is grounded. The control terminal of the fifth transistor T5 is connected to the first terminal of the fifth transistor T5. The second unidirectional conduction unit U2 includes a sixth transistor T6, which can be a PNP transistor. The first terminal of the sixth transistor T6 is connected to a first resistor R1, the second terminal of the sixth transistor T6 is grounded, and the control terminal of the sixth transistor T6 is connected to the first terminal of the sixth transistor T6. The third unidirectional conduction unit U3 includes a seventh transistor T7, which can be a PNP transistor. The first terminal of the seventh transistor T7 is connected to a second resistor R2, the second terminal of the seventh transistor T7 is grounded, and the control terminal of the seventh transistor T7 is connected to the first terminal of the seventh transistor T7.

[0102] It should be noted that the "first terminal" of a transistor can be the emitter, the "second terminal" can be the collector, and the "control terminal" can be the base; or, the "first terminal" can be the collector, the "second terminal" can be the emitter, and the "control terminal" can be the base. The examples provided in this application do not impose specific limitations on the "first terminal" and the "second terminal," and these can be adjusted according to different transistor types.

[0103] In yet another embodiment, the fifth to seventh transistors may also be NPN type transistors. Figure 8 As shown, the first terminal of the fifth transistor T5 is connected to the first input terminal of the amplifier 140, and the second terminal of the fifth transistor T5 is grounded. The control terminal of the fifth transistor T5 is connected to the second terminal of the fifth transistor T5. That is, the current transmitted by the fifth transistor T5 is characterized as a unidirectional current transmission. The first terminal of the sixth transistor T6 is connected to the first resistor R1, the second terminal of the sixth transistor T6 is grounded, and the control terminal of the sixth transistor T6 is connected to the second terminal of the sixth transistor T6. The first terminal of the seventh transistor T7 is connected to the second resistor R2, the second terminal of the seventh transistor T7 is grounded, and the control terminal of the seventh transistor T7 is connected to the second terminal of the seventh transistor T7.

[0104] exist Figure 6 and Figure 8 The temperature compensation current Ic is related to the temperature in the embodiment shown. Figure 9 As shown. Within a temperature range below the fixed temperature point Ta, the weighted value of the first voltage V1 of the first branch is 100%, and the temperature compensation current Ic is equal to the current flowing through the first branch; within a temperature range above the fixed temperature point Ta, the weighted value of the second voltage V2 of the second branch can be 100%, and the temperature compensation current Ic is equal to the current flowing through the second branch.

[0105] In this way, by connecting the second input terminal of the switching amplifier 140 to the first branch 120 or the second branch 130 through the switching module 160, it is possible to easily switch between two temperature coefficient currents and output different temperature compensation currents.

[0106] Next reference Figure 10 , Figure 10 The voltage at the second input terminal of the amplifier 140 is a weighted sum of a portion of the first voltage V1 and a portion of the second voltage V2. The switching module 160 changes the mixing ratio of the first voltage V1 of the first branch 120 and the second voltage V2 of the second branch 130 to achieve temperature-compensated current regulation.

[0107] The switching module 160 may include multiple voltage divider unit groups 161 and a switching unit. Each voltage divider unit group includes a first voltage divider element 161A and a second voltage divider element 161B. The input terminal of the first voltage divider element 161A is connected to the output terminal (i.e., the drain) of the second transistor T2, and the output terminal of the first voltage divider element 161A is connected to the second input terminal of the amplifier 140. The input terminal of the second voltage divider element 161B is connected to the output terminal of the third transistor T3, and the output terminal of the second voltage divider element 161B is connected to the second input terminal of the amplifier 140. The ratio of the voltage division coefficients of the first voltage divider element 161A to the second voltage divider element 161B in the multiple voltage divider unit groups is different, enabling different weighted sums of a portion of the first voltage V1 and a portion of the second voltage V2 to be achieved through the multiple voltage divider unit groups. For example, the voltage at the second input terminal of amplifier 140 is a weighted sum of the portion of the first voltage V1 after the first voltage divider element divides the first voltage V1 and the portion of the second voltage V2 after the second voltage divider element 161B divides the second voltage V2. That is, in formulas 1 and 2, a1, a2, b1, and b2 are all less than 1 and greater than 0, and a1:a2 ≠ b1:b2. The switching unit is configured to select different groups of voltage divider units to be connected to the second input terminal of the amplifier, and also to switch different weighting ratios.

[0108] For example, such as Figure 10 As shown, the switching module 160 includes: two voltage divider unit groups 161 (two groups of first voltage divider elements 161A and second voltage divider elements 161B); in each voltage divider unit group, the first voltage divider element 161A includes a third resistor R3, and the second voltage divider element 161B includes a fourth resistor R4; in the other voltage divider unit group, the first voltage divider element 161A includes a fifth resistor R5, and the second voltage divider element 161B includes a sixth resistor R6.

[0109] The switching unit includes: a third switch S3 and a fourth switch S4, a fifth switch S5 and a sixth switch S6. The temperature coefficients of the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 are all zero, to avoid affecting the temperature compensation current Ic. The control terminals of the third switch S3 and the fourth switch S4 are each connected to one output terminal of the comparator 150, and the control terminals of the fifth switch S5 and the sixth switch S6 are each connected to the other output terminal of the comparator 150. The control terminals of the third switch S3 and the fourth switch S4 receive a first control signal Ctrl1 and are in the ON state in response to the first control signal Ctrl1; the control terminals of the fifth switch S5 and the sixth switch S6 receive a second control signal Ctrl2 and are in the ON state in response to the second control signal Ctrl2.

[0110] The third resistor R3 and the third switch S3 are connected in series between the first branch 120 and the second input terminal of the amplifier 140. The fourth resistor R4 and the fourth switch S4 are connected in series between the second branch 130 and the second input terminal of the amplifier 140. The fifth resistor R5 and the fifth switch S5 are connected in series between the first branch 120 and the second input terminal of the amplifier 140. The sixth resistor R6 and the sixth switch S6 are connected in series between the second branch 130 and the second input terminal of the amplifier 140.

[0111] The resistance ratio of the third resistor R3 to the fourth resistor R4 (R3:R4) is different from the resistance ratio of the fifth resistor R5 to the sixth resistor R6 (R5:R6), allowing the switching of two different voltage weighting ratios. When the comparator 150 flips at a fixed temperature point Ta, it changes the contribution of the first and second branches to the temperature compensation current Ic.

[0112] Taking the example that the size of the second unidirectional conducting unit U2 is equal to the size of the third unidirectional conducting unit U3, and the resistance values ​​of the first resistor R1 and the second resistor R2 are equal at a fixed temperature point Ta, in a temperature range below the fixed temperature point Ta, the resistance value of the first resistor R1 is greater than the resistance value of the second resistor R2, the current in the first branch 120 is less than the current in the second branch 130, and the first voltage V1 is less than the second voltage V2. Figure 11AAs shown, comparator 150 outputs a first control signal Ctrl1 and a second control signal Ctrl2. Switches S3 and S4 of switching module 160 are turned on in response to the first control signal Ctrl1, connecting the first branch 120 to the second input terminal of amplifier 140 through the third resistor R3, and connecting the second branch 130 to the second input terminal of amplifier 140 through the fourth resistor R4. Switches S5 and S6 of switching module 160 are turned off in response to the second control signal Ctrl2, disconnecting the paths containing the fifth resistor R5 and the sixth resistor R6. Thus, the third resistor R3 and the fourth resistor R4 form a resistor voltage divider network, and the resistance ratio of the third resistor R3 and the fourth resistor R4 represents the mixing ratio of the first voltage V1 of the first branch 120 and the second voltage V2 of the second branch 130. For example, the ratio of the resistance of the third resistor R3 to the resistance of the fourth resistor R4 is 1 / 2; the weighting ratio of the first voltage V1 is 1 / 3, and the weighting ratio of the second voltage V2 is 2 / 3. The weighted sum of 1 / 3 of the first voltage V1 and 2 / 3 of the second voltage V2 is output to the second input terminal of amplifier 140. The temperature change pattern of node B, coupled to the switching module 160, is consistent with the temperature characteristic of the first resistor R1 in the first branch 120. Furthermore, the first input terminal of amplifier 140 is coupled to node A, and the second input terminal of amplifier 140 is coupled to node B. Amplifier 140 can clamp the voltages of nodes A and B, making their voltages and temperature characteristics consistent. By connecting the first voltage V1 of the first branch 120 and the second voltage V2 of the second branch 130 to the feedback loop of the amplifier 140 in the ratio of the resistance values ​​of the third resistor R3 and the fourth resistor R4, the temperature-compensated current Ic output from the fourth transistor T4 is related to the temperature characteristics of both the first resistor R1 and the second resistor R2, and the correlation is consistent with the resistance ratio of the third resistor R3 and the fourth resistor R4.

[0113] When the temperature reaches a fixed point Ta, the resistance of the first resistor R1 is equal to the resistance of the second resistor R2, the current in the first branch 120°C is equal to the current in the second branch 130°C, and the first voltage V1 is equal to the second voltage V2. For example... Figure 11BAs shown, comparator 150 outputs a first control signal Ctrl1 and a second control signal Ctrl2. Switches S5 and S6 of switching module 160 are turned on in response to the second control signal Ctrl2, connecting the first branch 120 to the second input terminal of amplifier 140 via resistor R5, and connecting the second branch 130 to the second input terminal of amplifier 140 via resistor R6. Switches S3 and S4 of switching module 160 are turned off in response to the first control signal Ctrl1, and the paths containing resistors R3 and R4 are not connected. Thus, resistors R5 and R6 are connected in parallel, and the resistance ratio of R5 to R6 represents the mixing ratio of the first voltage V1 of the first branch 120 and the second voltage V2 of the second branch 130. For example, the ratio of the resistance of the fifth resistor R5 to the resistance of the sixth resistor R6 is 2 / 1; the weighting ratio of the first voltage V1 is 2 / 3, and the weighting ratio of the second voltage V2 is 1 / 3. The weighted sum of 2 / 3 of the first voltage V1 and 1 / 3 of the second voltage V2 is output to the second input terminal of amplifier 140. The temperature change pattern of node B, coupled to the switching module 160, is consistent with the temperature characteristic of the first resistor R1 in the first branch 120. Furthermore, the first input terminal of amplifier 140 is coupled to node A, and the second input terminal of amplifier 140 is coupled to node B. Amplifier 140 can clamp the voltages of nodes A and B, making their voltages and temperature characteristics consistent. By connecting the first voltage V1 of the first branch 120 and the second voltage V2 of the second branch 130 to the feedback loop of the amplifier 140 in the ratio of the resistance values ​​of the fifth resistor R5 and the sixth resistor R6, the temperature-compensated current Ic output from the fourth transistor T4 is related to the temperature characteristics of both the first resistor R1 and the second resistor R2, and the correlation is consistent with the resistance ratio of the fifth resistor R5 and the sixth resistor R6.

[0114] Furthermore, within a temperature range greater than the fixed temperature point, the resistance of the first resistor R1 is less than the resistance of the second resistor R2, the current in the first branch 120 is equal to the current in the second branch 130, and the first voltage V1 is greater than the second voltage V2. For example... Figure 11B As shown, comparator 150 outputs a first control signal Ctrl1 and a second control signal Ctrl2. Switching module 160 continues to connect the first branch 120 to the second input terminal of amplifier 140 through the fifth resistor R5, and connects the second branch 130 to the second input terminal of amplifier 140 through the sixth resistor R6. Furthermore, the third switch S3 and the fourth switch S4 of switching module 160 are disconnected in response to the first control signal Ctrl1, and the paths containing the third resistor R3 and the fourth resistor R4 are no longer connected. The weighted sum of a portion of the first voltage V1 and a portion of the second voltage V2 that satisfies the relationship between the resistance values ​​of the fifth resistor R5 and the sixth resistor R6 is then output to the second input terminal of amplifier 140.

[0115] exist Figure 10 , Figure 11A and Figure 11B The temperature compensation current Ic is related to the temperature in the embodiment shown. Figure 12 As shown. Within the temperature range below the fixed temperature point Ta, the weighted value of the first voltage V1 of the first branch is 1 / 3, and the weighted value of the second voltage V2 of the second branch is 2 / 3; within the temperature range above the fixed temperature point Ta, the weighted value of the first voltage V1 of the first branch is 2 / 3, and the weighted value of the second voltage V2 of the second branch is 1 / 3, thus realizing a nonlinearly changing temperature-compensated current.

[0116] Based on this, the voltages output from multiple branches can be connected to the amplifier 140 in different mixing ratios according to different temperature variation ranges, thereby providing different degrees of current compensation for nonlinearly changing currents. Specifically, by setting the resistance ratios of the third resistor R3 and the fourth resistor R4, and the fifth resistor R5 and the sixth resistor R6, the mixing ratio of the first voltage V1 and the second voltage V2 can be changed. Furthermore, by adjusting the temperature coefficients of the first resistor R1 and the second resistor R2, the flexibility of temperature-compensated current adjustment is improved, which is beneficial for further improving the accuracy of current compensation.

[0117] In other embodiments, when the size of the second unidirectional conducting unit U2 is greater than the size of the third unidirectional conducting unit U3, and the resistance value of the first resistor R1 at the fixed temperature point Ta is greater than the resistance value of the second resistor R2, or when the size of the second unidirectional conducting unit U2 is smaller than the size of the third unidirectional conducting unit U3, and the resistance value of the first resistor R1 at the fixed temperature point Ta is less than the resistance value of the second resistor R2, when the temperature reaches the fixed temperature point Ta, the voltage magnitude between the first voltage V1 and the second voltage V2 can also trigger the first control signal Ctrl1 and the second control signal Ctrl2 output by the comparator 150 to change, so as to control the switching module 160 to be entered by different voltage divider units, thereby adjusting the weighting ratio.

[0118] In the above example, the voltage divider unit in the switching module 160 uses a resistor to achieve the voltage divider effect. The voltage divider unit can also use other electronic components or circuits such as a programmable voltage divider to achieve the voltage divider effect. The example provided in this application does not impose specific restrictions on this and can be set according to the circuit structure.

[0119] In the above example, the switching unit uses multiple independent switches, with each voltage divider element corresponding to an independent switch. In other embodiments, the third resistor R3 and the fourth resistor R4 may share a switch, as may the fifth resistor R5 and the sixth resistor R6. For example, the third resistor R3 and the fourth resistor R4 are connected in series between the output terminals of the second transistor T2 and the third transistor T3, and the intermediate node of the third resistor R3 and the fourth resistor R4 is connected to the second input terminal of the amplifier through a shared switch; the fifth resistor R5 and the sixth resistor R6 are connected in series between the output terminals of the second transistor T2 and the third transistor T3, and the intermediate node of the fifth resistor R5 and the sixth resistor R6 is connected to the second input terminal of the amplifier through a shared switch.

[0120] The above description is merely an embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A temperature compensation circuit, characterized in that, include: A current mirror includes a first transistor, a second transistor, a third transistor, and a fourth transistor; the control terminals of the first transistor, the second transistor, the third transistor, and the fourth transistor are all coupled together; the output current of the second transistor, the third transistor, and the fourth transistor are all proportional to the output current of the first transistor. The first branch includes a first resistor, which is connected to the output terminal of the second transistor; The second branch includes a second resistor connected to the output terminal of the third transistor; wherein the temperature coefficients of the first resistor and the second resistor are different. An amplifier includes a first input terminal, a second input terminal, and an output terminal; the first input terminal is connected to the output terminal of a first transistor; the output terminal of the amplifier is connected to the control terminal of the first transistor. A comparator, wherein the two input terminals of the comparator are respectively connected to the output terminals of the second transistor and the third transistor, and is configured to acquire a first voltage output from the output terminal of the second transistor and a second voltage output from the output terminal of the third transistor, and compare them; The switching module, connected to the output of the comparator, is configured to change the weighting ratio of the first voltage and the second voltage based on the comparison result, and then output it to the second input.

2. The temperature compensation circuit according to claim 1, characterized in that, The switching module is configured to selectively connect either the output of the second transistor to the second input of the amplifier, or the output of the third transistor to the second input of the amplifier.

3. The temperature compensation circuit according to claim 2, characterized in that, The switching module includes a first switch and a second switch; The first terminal of the first switch is connected to the output terminal of the second transistor, the second terminal of the first switch is connected to the second input terminal, and the control terminal of the first switch is connected to one output terminal of the comparator; the first switch is configured to be in an on state in response to a first control signal output by the comparator, connecting the second input terminal to the output terminal of the second transistor, and the voltage at the second input terminal is equal to the first voltage; The first terminal of the second switch is connected to the output terminal of the third transistor, the second terminal of the second switch is connected to the second input terminal, and the control terminal of the second switch is connected to the other output terminal of the comparator; the second switch is configured to be in a conducting state in response to a second control signal output by the comparator, connecting the second input terminal to the output terminal of the third transistor, and the voltage of the second input terminal is equal to the second voltage.

4. The temperature compensation circuit according to claim 1, characterized in that, The switching module includes multiple voltage divider unit groups and a switching unit, wherein the voltage divider unit group includes a first voltage divider element and a second voltage divider element; The input terminal of the first voltage divider element is connected to the output terminal of the second transistor, the output terminal of the first voltage divider element is connected to the second input terminal of the amplifier, the input terminal of the second voltage divider element is connected to the output terminal of the third transistor, and the output terminal of the second voltage divider element is connected to the second input terminal of the amplifier. The ratio of the voltage division coefficients of the first voltage dividing element to the second voltage dividing element in the plurality of voltage dividing unit groups is different; The switching unit is configured to select different groups of the voltage divider units to be connected to the second input terminal of the amplifier.

5. The temperature compensation circuit according to claim 4, characterized in that, The switching module includes: two voltage divider unit groups; in one voltage divider unit group, the first voltage divider element includes a third resistor and the second voltage divider element includes a fourth resistor; in the other voltage divider unit group, the first voltage divider element includes a fifth resistor and the second voltage divider element includes a sixth resistor; The switching unit includes: The third switch and the fourth switch are connected in series between the first branch and the second input terminal, and the fourth resistor and the fourth switch are connected in series between the second branch and the second input terminal. The control terminals of the third switch and the fourth switch are both connected to one output terminal of the comparator and are configured to be in the on state in response to the first control signal output by the comparator, thereby connecting the second input terminal to the output terminal of the second transistor and the output terminal of the third transistor. The fifth switch and the sixth switch are connected in series between the first branch and the second input terminal, and the sixth resistor and the sixth switch are connected in series between the second branch and the second input terminal; the control terminals of the fifth switch and the sixth switch are both connected to another output terminal of the comparator and are configured to be in the on state in response to the second control signal output by the comparator, connecting the second input terminal to the output terminal of the second transistor and the output terminal of the third transistor; The resistance ratio of the third resistor to the fourth resistor is different from the resistance ratio of the fifth resistor to the sixth resistor.

6. The temperature compensation circuit according to claim 5, characterized in that, The temperature coefficients of the third resistor, the fourth resistor, the fifth resistor, and the sixth resistor are all zero.

7. The temperature compensation circuit according to claim 1, characterized in that, The aspect ratios of the first transistor, the second transistor, and the third transistor are the same.

8. The temperature compensation circuit according to claim 1, characterized in that, The input terminals of the first transistor, the second transistor, the third transistor, and the fourth transistor are respectively connected to the first power supply voltage terminal. The temperature compensation circuit further includes a first unidirectional conduction unit, one end of which is connected to the first input terminal, and the other end of which is connected to the second power supply voltage terminal. The first branch also includes a second unidirectional conduction unit, the first end of which is connected to the first resistor, and the other end of which is connected to the second power supply voltage terminal. The second branch also includes a third unidirectional conduction unit, one end of which is connected to the second resistor, and the other end of which is connected to the second power supply voltage terminal.

9. The temperature compensation circuit according to claim 8, characterized in that, The second unidirectional conducting unit, the third unidirectional conducting unit, the first resistor, and the second resistor satisfy the following relationship: The size of the second unidirectional conduction unit is larger than that of the third unidirectional conduction unit. At a fixed temperature point, the resistance of the first resistor is greater than that of the second resistor. The size of the second unidirectional conduction unit is equal to the size of the third unidirectional conduction unit, and at the fixed temperature point, the resistance value of the first resistor is equal to the resistance value of the second resistor. The size of the second unidirectional conduction unit is smaller than that of the third unidirectional conduction unit, and at the fixed temperature point, the resistance value of the first resistor is smaller than that of the second resistor.

10. The temperature compensation circuit according to claim 8, characterized in that, The temperature coefficient of the first resistor is zero, and the temperature coefficient of the second resistor is either positive or negative. Alternatively, the temperature coefficients of the first resistor and the second resistor may both be positive or negative temperature coefficients.

11. The temperature compensation circuit according to claim 1, characterized in that, The amplifier includes at least one of a five-tube amplifier, a sleeve amplifier, and a folded amplifier.

12. The temperature compensation circuit according to claim 1, characterized in that, The comparator may be a static comparator or a dynamic comparator.

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