Full temperature compensation circuit and method for bandgap reference circuit and bandgap reference chip

Abstract

The embodiment of the present disclosure provides a full-temperature compensation circuit and method of a bandgap reference circuit, and a bandgap reference chip. The full-temperature compensation circuit comprises a temperature compensation circuit and a temperature comparison circuit. The temperature compensation circuit is configured to be composed of n compensation modules. Each compensation module automatically adjusts the resistance or current in the compensation module according to a corresponding trimming amplitude. The trimming amplitude is determined in combination with ATE testing. The temperature comparison circuit is configured to construct a first voltage with a positive temperature characteristic, compare the first voltage with n second voltages through n temperature comparison modules respectively, and obtain n compensation control signals. The temperature compensation circuit is coupled with the bandgap reference circuit, and the temperature comparison circuit is coupled with the temperature compensation circuit. When any compensation control signal is valid, the corresponding compensation module is triggered to start automatic adjustment to compensate the output voltage of the bandgap reference circuit. The problem that related technologies cannot effectively guarantee the high requirement of full-temperature accuracy of the bandgap reference is solved.

Description

Technical Field

[0001] The embodiments disclosed herein relate to the field of integrated analog circuit technology, and more specifically, to a full-temperature compensation circuit and method for a bandgap reference circuit, and a bandgap reference chip. Background Technology

[0002] A bandgap (BG) reference voltage or current source is a general-purpose module in analog circuits, widely used in power supplies, signal chains, and various other chips. It is one of the most important modules in analog circuits. With the development of technology, the market demands increasingly higher full-temperature accuracy from bandgap references; only high-precision references can produce high-precision outputs.

[0003] High-order compensation is often used in technologies that achieve high accuracy across the entire temperature range. For example, piecewise linear compensation is employed. Figure 1 As shown, waveform D1 is the temperature curve before compensation. Piecewise linear compensation between high and low temperature ranges is achieved by applying currents I2 and I1 at points A (high temperature point) and B (low temperature point), resulting in curve D2 after compensation. Curve D2 shows a reduction in the temperature coefficient. However, in actual production, device and process mismatches and manufacturing defects are common. Not all bandgap reference circuits exhibit typical temperature curves like D1. Some temperature curves are as shown in D3. If the above compensation method is also used, the resulting curve is as shown in D4, indicating no improvement in the temperature characteristics, and potentially even a worsening. D3 is just one possibility; many other situations exist in practical applications. Therefore, using the above compensation method for all cases cannot guarantee the compensation effect on the temperature characteristics. Furthermore, the compensation currents I1 and I2 are typically small, possibly in the nanoamp range, making quantification difficult in practical applications. Moreover, the required I1 and I2 values ​​may vary for each bandgap reference circuit, making it impossible to quantify the intensity of higher-order compensation and affecting overall temperature accuracy.

[0004] In summary, the technologies for achieving high accuracy across the entire temperature range cannot effectively guarantee the high accuracy requirements of bandgap references across the entire temperature range in practical applications. Summary of the Invention

[0005] The embodiments described herein provide a full-temperature compensation circuit and method for a bandgap reference circuit, as well as a bandgap reference chip, which solves the problem that related technologies for achieving high precision at full temperature cannot effectively guarantee the high requirements of full-temperature accuracy of bandgap references in practical applications.

[0006] According to a first aspect of this disclosure, a full-temperature compensation circuit for a bandgap reference circuit is provided. The full-temperature compensation circuit includes a temperature compensation circuit and a temperature comparison circuit. The temperature compensation circuit is configured to consist of n compensation modules, each compensation module automatically adjusting the resistance or current in its corresponding register according to an adjustment amplitude value to compensate the output voltage of the bandgap reference circuit. The adjustment amplitude value is determined in conjunction with ATE testing. One compensation module corresponds to one test temperature, and one test temperature corresponds to one adjustment amplitude value, where n is a positive integer greater than or equal to 2. The temperature comparison circuit is configured to construct a first voltage exhibiting positive temperature characteristics based on a first transistor, and to pass the first voltage through n temperature comparison circuits. The comparison module compares with n second voltages to obtain n compensation control signals. Each compensation control signal corresponds to one second voltage, and each second voltage corresponds to one compensation temperature. Each compensation control signal indicates whether the current ambient temperature of the bandgap reference circuit has reached the corresponding compensation temperature. The compensation temperature is set according to the test temperature, and one test temperature corresponds to one compensation temperature. The temperature compensation circuit is coupled to the bandgap reference circuit, and the temperature comparison circuit is coupled to the temperature compensation circuit. When any compensation control signal is valid, the compensation control signal triggers the corresponding compensation module to start automatic adjustment, so as to connect the adjusted resistance or current to the bandgap reference circuit. One compensation control signal corresponds to one compensation module.

[0007] Optionally, the temperature comparison circuit includes: a first transistor, a bias current source, and n temperature comparison modules, wherein the control electrode of the first transistor is coupled to a zero-temperature reference voltage, the first electrode of the first transistor is coupled to one end of the bias current source, the second electrode of the first transistor is coupled to a power supply voltage, the other end of the bias current source is coupled to a ground terminal, and the voltage output by the first electrode of the first transistor is the first voltage; each temperature comparison module includes a comparator, wherein the first input terminal of the comparator is coupled to the first electrode of the first transistor, the second terminal of the comparator is coupled to a second voltage corresponding to the corresponding temperature comparison module, and the output terminal of the comparator is coupled to a corresponding compensation module to output a corresponding compensation control signal.

[0008] Optionally, each temperature comparison module includes a comparator and an OR gate, wherein the first input terminal of the comparator is coupled to the first terminal of the first transistor, the second terminal of the comparator is coupled to the second voltage corresponding to the corresponding temperature comparison module, the output terminal of the comparator is coupled to one input terminal of the OR gate, the other input terminal of the OR gate is coupled to a flip-flop analog signal, and the output terminal of the OR gate is coupled to the corresponding compensation module to output a corresponding compensation control signal.

[0009] Optionally, if each compensation module includes an adjustable resistor, then n compensation modules are connected in series and then connected to the bandgap reference circuit; if each compensation module includes a transistor group with adjustable current, then n compensation modules are connected in parallel and then connected to the bandgap reference circuit.

[0010] Optionally, the adjustment amplitude is determined in conjunction with ATE testing, including: testing the output voltage at room temperature using ATE; if the output voltage at room temperature is not equal to the typical process value, then adjusting the output voltage at room temperature to the typical process value using the precision adjustment resistor in the bandgap reference circuit, where room temperature is a preset room temperature value; testing the output voltage at each test temperature using ATE, where each test temperature has a set voltage change threshold; if the difference between the output voltage at a certain test temperature and the output voltage at room temperature is greater than the corresponding voltage change threshold, then adjusting the resistor or current in the compensation module corresponding to that test temperature, where one test temperature corresponds to one compensation module, and the test temperature is a non-temperature test temperature; determining whether the change in output voltage before and after adjustment is equal to the corresponding preset voltage threshold, where one test temperature corresponds to one preset voltage threshold, and the preset voltage threshold is less than the corresponding voltage change threshold; if it is not equal to the corresponding preset voltage threshold, then continuing adjustment until it equals the corresponding preset voltage threshold, and then saving the corresponding adjustment amplitude value in a register.

[0011] According to a second aspect of this disclosure, a bandgap reference chip is provided, the bandgap reference chip including at least a bandgap reference circuit and a full-temperature compensation circuit for the bandgap reference circuit according to any one of the preceding first aspects, the bandgap reference circuit including a voltage-type bandgap reference circuit or a current-type bandgap reference circuit.

[0012] According to a third aspect of this disclosure, a full-temperature compensation method for a bandgap reference circuit is provided. The method is implemented based on the bandgap reference chip described in the second aspect above. The method includes: testing the output voltage of the bandgap reference circuit at room temperature using an ATE (Automatic Test Equipment); if the output voltage at room temperature is not equal to a typical process value, adjusting the output voltage at room temperature to the typical process value using a precision adjustment resistor in the bandgap reference circuit, where room temperature is a preset value; testing the output voltage of the bandgap reference circuit at each test temperature using an ATE, where a voltage change threshold is set for each test temperature; if the difference between the output voltage at a certain test temperature and the output voltage at room temperature is greater than the corresponding voltage change threshold, adjusting the resistor or current in the compensation module corresponding to that test temperature, where one test temperature corresponds to one compensation module, and the compensation module is a compensation module in the full-temperature compensation circuit of the bandgap reference circuit, where the test temperature is a non-full-temperature test temperature; determining whether the change in output voltage before and after adjustment is equal to the corresponding preset voltage threshold. Each temperature corresponds to a preset voltage threshold, which is less than the corresponding voltage change threshold. If the temperature is not equal to the preset voltage threshold, the adjustment continues until it equals the preset voltage threshold. Then, the adjustment amplitude is saved in a register. One test temperature corresponds to one adjustment amplitude. During the operation of the bandgap reference chip, the temperature comparison circuit compares the first voltage with n second voltages through n temperature comparison modules to obtain n compensation control signals. One compensation control signal corresponds to one second voltage, and one second voltage corresponds to one compensation temperature. Based on the compensation control signal, it is determined whether the current ambient temperature has reached the corresponding compensation temperature. One compensation control signal corresponds to one compensation module. The compensation temperature is set according to the corresponding test temperature, and one test temperature corresponds to one compensation temperature. If the corresponding compensation temperature is reached, the corresponding compensation module is triggered by the corresponding compensation control signal to automatically adjust the voltage according to the corresponding adjustment amplitude stored in the register. The adjusted resistance or current is then connected to the bandgap reference circuit to compensate the output voltage.

[0013] Optionally, if the test temperature is greater than the room temperature, the corresponding compensation temperature is greater than the corresponding compensation temperature; if the test temperature is less than the room temperature, the corresponding compensation temperature is less than the corresponding compensation temperature.

[0014] Optionally, before determining whether the change in output voltage before and after adjustment is equal to the corresponding preset voltage threshold, the method further includes: after each adjustment, after the corresponding compensation control signal triggers the corresponding compensation module to connect the adjusted resistor or current to the bandgap reference circuit, the adjusted output voltage is tested at the corresponding test temperature using ATE; the change in output voltage before and after adjustment is calculated based on the output voltage after adjustment at the corresponding test temperature and the output voltage at the corresponding test temperature before adjustment.

[0015] Optionally, before determining whether the change in output voltage before and after adjustment is equal to the corresponding preset voltage threshold, the method further includes: after each adjustment, controlling the corresponding compensation module to be triggered at room temperature by flipping the analog signal so that the adjusted resistor or current is connected to the bandgap reference circuit, and then testing the adjusted output voltage at room temperature by ATE; calculating the change in output voltage before and after adjustment based on the adjusted output voltage at room temperature and the output voltage at room temperature before adjustment.

[0016] In the full-temperature compensation circuit and method of the bandgap reference circuit in the embodiments of this disclosure, a temperature comparison circuit determines whether the current ambient temperature has reached the corresponding compensation temperature. That is, the temperature comparison circuit determines each compensation temperature point. After reaching a certain compensation temperature, the corresponding compensation module in the temperature compensation circuit is automatically adjusted to compensate the output voltage through the corresponding compensation control signal. The adjustment amplitude (i.e., the direction and magnitude of compensation) is finally determined by the measured value of ATE at full temperature. Compared with related technologies of full-temperature high precision, the full-temperature compensation method of the bandgap reference circuit in the embodiments of this disclosure is not full-temperature compensation implemented for any typical temperature curve, but can adjust the temperature curve of the bandgap reference circuit of any temperature curve to a better one, obtaining a better full-temperature temperature coefficient. There is no need to worry about the problem of different temperature curves due to process deviations, process adaptation, or process defects. It can achieve point-to-point adjustment, and the amount of compensation can be quantified by ATE, which has very good effect in engineering applications. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly described below. It should be understood that the drawings described below only relate to some embodiments of this disclosure and are not intended to limit this disclosure, wherein:

[0018] Figure 1 The diagram illustrates the techniques used to achieve high accuracy across the entire temperature range, including the application of high-order compensation to different temperature profiles before and after compensation. Figure 2 A schematic block diagram of a full-temperature compensation circuit for a bandgap reference circuit according to an embodiment of the present disclosure is shown. Figure 3A schematic diagram of temperature curves before and after compensation is shown for a full-temperature compensation circuit using a bandgap reference circuit according to an embodiment of the present disclosure. Figure 4 A schematic diagram is shown of a full-temperature compensation circuit for a bandgap reference circuit according to an embodiment of the present disclosure before and after compensation of different types of temperature profiles. Figure 5 A schematic diagram of the temperature curve after compensation is shown using a full-temperature compensation circuit of a bandgap reference circuit according to another embodiment of the present disclosure. Figure 6-8 Exemplary circuit diagrams of three temperature comparison circuits according to embodiments of this disclosure are shown respectively; Figure 9-11 The structure of the temperature compensation circuit according to an embodiment of the present disclosure and three schematic circuit diagrams for connection to the bandgap reference circuit are shown. The elements in the attached diagram are schematic and not drawn to scale. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are also within the scope of protection of this disclosure.

[0020] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this subject matter pertains. It will be further understood that terms such as those defined in commonly used dictionaries shall be interpreted as having the meaning consistent with their meaning in the context of the specification and in the relevant art, and shall not be interpreted in an idealized or overly formal form unless otherwise explicitly defined herein. As used herein, the statement of “connecting” or “coupling” two or more parts together shall mean that these parts are directly joined together or joined through one or more intermediate components.

[0021] In all embodiments of this disclosure, since the source and drain of a metal-oxide-semiconductor (MOS) transistor are symmetrical, and the conduction current directions between the source and drain of an N-type transistor and a P-type transistor are opposite, the controlled middle terminal of the MOS transistor is referred to as the control terminal, and the remaining two terminals are referred to as the first terminal and the second terminal, respectively. Furthermore, for the sake of consistency, in this context, the base of a bipolar junction transistor (BJT), i.e., a triode, is referred to as the control terminal, the emitter of the BJT as the first terminal, and the collector of the BJT as the second terminal. The transistors used in the embodiments of this disclosure are primarily switching transistors. In all embodiments of this disclosure, terms such as "first" and "second" are used only to distinguish one component (or part of a component) from another component (or another part of a component).

[0022] To address the issue that existing technologies for achieving high accuracy across the entire temperature range often fail to effectively guarantee the required accuracy of bandgap references in practical applications, a novel full-temperature compensation circuit and method for bandgap reference circuits are proposed. The full-temperature compensation method for the bandgap reference circuit in this disclosure can effectively improve the full-temperature accuracy of the bandgap reference and reduce the impact of process deviations, mismatches, and process defects on the bandgap reference. The full-temperature compensation circuit and method for the bandgap reference circuit of this disclosure will be described in detail below.

[0023] Figure 2 A schematic block diagram of a full-temperature compensation circuit 100 for a bandgap reference circuit according to an embodiment of this disclosure is shown. Figure 2 As shown, the full-temperature compensation circuit 100 includes: a temperature compensation circuit 110 and a temperature comparison circuit 120; The temperature compensation circuit 110 is configured to consist of n compensation modules. Each compensation module is used to automatically adjust the resistance or current in the compensation module according to the adjustment amplitude value in its corresponding register, so as to compensate the output voltage V of the bandgap reference circuit 200. BGThe adjustment amplitude is determined by combining ATE (Automatic Test Equipment) testing. One compensation module corresponds to one test temperature, and one test temperature corresponds to one adjustment amplitude. n is a positive integer greater than or equal to 2. The temperature comparison circuit 120 is configured to construct a first voltage V1 with positive temperature characteristics based on the first transistor Q1, and compare the first voltage V1 with n second voltages V2 through n temperature comparison modules to obtain n compensation control signals Tc. One compensation control signal Tc corresponds to one second voltage V2, and one second voltage V2 corresponds to one compensation temperature. Each compensation control signal Tc is used to indicate whether the current ambient temperature of the bandgap reference circuit 200 has reached the corresponding compensation temperature. The compensation temperature is set according to the test temperature, and one test temperature corresponds to one compensation temperature. The compensation temperature is typically a temperature higher or lower than room temperature. The specific compensation temperature setting follows these principles: if the test temperature is higher than room temperature, the corresponding compensation temperature value should fall between the test temperature and the smaller of its adjacent values; if the test temperature is lower than room temperature, the corresponding compensation temperature value should fall between the test temperature and the larger of its adjacent values. Room temperature is also considered as a test temperature when determining the compensation temperature range.

[0024] The temperature compensation circuit 100 is coupled to the bandgap reference circuit 200, and the temperature comparison circuit 120 is coupled to the temperature compensation circuit 110. When any compensation control signal Tc is valid, that is, when the ambient temperature of the bandgap reference circuit 200 reaches the corresponding compensation temperature, the compensation control signal Tc triggers the corresponding compensation module to start automatic adjustment, so as to connect the adjusted resistor or current to the bandgap reference circuit 200 to adjust the output voltage V of the bandgap reference circuit 200. BG Compensation is performed, with one compensation control signal Tc corresponding to one compensation module 111. Here, "reaching the corresponding compensation temperature" means either exceeding the corresponding compensation temperature (for cases where the compensation temperature is above room temperature) or falling below the corresponding compensation temperature (for cases where the compensation temperature is below room temperature).

[0025] The adjustment amplitude determined by the ATE test mentioned above is specifically achieved as follows: 1) The output voltage V at room temperature is tested by the ATE test. BG If the output voltage V at room temperature BG If the output voltage V at room temperature is not equal to the typical process value (e.g., 1.2V), then the precision adjustment resistor in the bandgap reference circuit 200 will be used to adjust the output voltage V. BG Adjust to typical process values, with room temperature set to a preset value (e.g., for automotive-grade chips, the room temperature in the three-temperature test is typically 27°C, but other values ​​can be used depending on the actual situation); 2) Test the output voltage V at each test temperature using ATE. BGA voltage change threshold is set for each test temperature. If the output voltage V at a certain test temperature... BG Output voltage V at room temperature BG If the difference is greater than the corresponding voltage change threshold, the resistor or current in the compensation module corresponding to that test temperature is adjusted. One test temperature corresponds to one compensation module, and the test temperature is a non-critical test temperature. The test temperature is also a preset value. For example, for automotive-grade chips, the test temperature is usually -40℃ or 150℃, but other values ​​can be used depending on the actual situation. In addition, the number of test temperatures can also be adjusted. The more test temperatures, the better the final full-temperature accuracy. 3) Determine the output voltage V before and after adjustment. BG 4) If the change in voltage is not equal to the corresponding preset voltage threshold, continue adjusting until it equals the corresponding preset voltage threshold. Then, save the corresponding adjustment amplitude value in the register. This adjustment amplitude value includes the adjustment direction, i.e., whether it is adjusted down or up. Both the voltage change threshold and the preset voltage threshold can be adjusted adaptively.

[0026] Additionally, it should be noted that for a given test temperature, to measure the adjusted output voltage V at that test temperature... BG Therefore, it is necessary to ensure that the adjusted resistor or current in the compensation module has been connected to the bandgap reference circuit 200 before reaching the test temperature. However, the circuit principle in this embodiment is that the compensation module is only triggered when the ambient temperature reaches the compensation temperature. That is, the resistor or current connected to the bandgap reference circuit 200 before triggering is the one before adjustment, and the resistor or current connected to the bandgap reference circuit 200 after triggering is the one after adjustment. Since the adjustment of the resistor or current during the adjustment amplitude determination stage is usually performed at room temperature, the output voltage V before and after adjustment is determined. BG Before determining whether the change in voltage is equal to the corresponding preset voltage threshold, the output voltage V before and after adjustment needs to be determined using the following method. BG Changes: After each adjustment, the corresponding compensation module is triggered by the corresponding compensation control signal Tc to connect the adjusted resistor or current to the bandgap reference circuit 200. Then, the adjusted output voltage V is tested at the corresponding test temperature using ATE. BG The output voltage V is adjusted according to the corresponding test temperature. BG Output voltage V at the test temperature before adjustment BG Calculate the output voltage V before and after adjustment BG The change in quantity.

[0027] The above determines the output voltage V before and after adjustment. BGThe change in voltage needs to be tested at the corresponding test temperature, which is very inconvenient. Therefore, this disclosure also provides a method to determine the output voltage V before and after adjustment at room temperature. BG The specific implementation method for the change in voltage is as follows: After each adjustment, the corresponding compensation module is triggered at room temperature by flipping the analog signal, so that the adjusted resistor or current is connected to the bandgap reference circuit 200. Then, the adjusted output voltage V at room temperature is tested by ATE. BG Based on the adjusted output voltage V at room temperature BG Compared to the output voltage V at room temperature before adjustment BG Calculate the output voltage V before and after adjustment BG The change in voltage. In this method, the flipped analog signal can cause the temperature comparison module 121 to output an effective compensation control signal Tc at room temperature, thereby triggering the corresponding compensation module. This allows the adjusted resistor or current to be connected to the bandgap reference circuit 200 at room temperature, thereby measuring the adjusted output voltage V. BG The value of is used to calculate the output voltage V before and after adjustment. BG The change in voltage is easier to achieve than testing at high or low temperatures. It should be noted that this method assumes that for the same adjustment amount, the output voltage V before and after adjustment at room temperature will be... BG The change in voltage V before and after adjustment at other test temperatures BG The changes are equal. Additionally, it should be noted that the flip-over analog signal is only used to determine the adjustment amplitude value. When the determined bandgap reference circuit 200 is operating normally, this signal needs to be set to an invalid signal so as not to affect the normal judgment logic of the temperature comparison module in the temperature comparison circuit 120.

[0028] Furthermore, the implementation principle of the full-temperature compensation circuit 100 of the bandgap reference circuit in this embodiment will be explained more clearly with specific examples: Assuming n=2, that is, the temperature compensation circuit 110 includes two compensation modules, a first compensation module and a second compensation module, and the temperature comparison circuit 120 includes two temperature comparison modules, a first temperature comparison module and a second temperature comparison module. For a certain bandgap reference circuit 200, at room temperature V BG The typical process value is 1.2V. The corresponding test temperatures for ATE testing are 150℃ and -40℃. The V values ​​obtained at these two test temperatures are... BGBoth are 1.197V, with a difference of 3mV from room temperature. Based on the foregoing explanation, assuming a preset voltage threshold of 2mV, the adjustment amplitude determined by ATE testing at 150℃ is a 1K increase in resistance, and the adjustment amplitude at -40℃ is also a 1K increase in resistance. Let's assume the corresponding two compensation temperatures are 110℃ and -10℃ respectively. When the circuit is operating, when the ambient temperature is below -10℃, the compensation control signal Tc output by the corresponding second temperature comparison module is high (e.g., active high), which controls the corresponding second compensation module to start automatic adjustment, i.e., increasing the resistance by 1K, so that the output voltage V below -10℃... BG The overall voltage is increased by 2mV; similarly, when the ambient temperature exceeds 110℃, the compensation control signal Tc output by the corresponding first temperature comparison module is high, which controls the corresponding first compensation module to start automatic adjustment, that is, the resistance is increased by 1K, so that the output voltage V increases when the temperature exceeds 110℃. BG Raise the overall height by 2mV. For example... Figure 3 The figure shows a schematic diagram of the temperature curves of the output voltage before and after compensation by the full-temperature compensation circuit of the bandgap reference circuit of the present disclosure embodiment in the above example. It can be seen that the output voltage was compensated after being below -10℃ and above 110℃ respectively. Moreover, the temperature curve before compensation (VBG0) shows that the maximum change is 3mV with the temperature, while the temperature curve after compensation (VBG1) decreases to 2mV with the maximum change in temperature.

[0029] Figure 3 The temperature curve in the image is a common type, for Figure 4 For other types of temperature curves E1-E4, reasonable compensation can also be obtained. For example, for the E1 curve, the V values ​​at high temperature (150℃) and normal temperature... BG If the difference is minimal, the ATE test determines that the adjustment amplitude should be zero, meaning no adjustment is needed for the resistance or current. Furthermore, no adjustment will occur when the corresponding compensation module is triggered. The V value at low temperature (-50℃) and normal temperature is... BG The difference is minor; the resistance or current needs adjustment. The adjustment range is determined based on ATE testing. When the corresponding compensation module is triggered, the adjustment is made according to this range to ensure V... BG Increase; similarly, for E2, V at low and normal temperatures. BG The difference is not significant, so only adjustments are needed at high temperatures to make V BG Improvement; for E3, the low-temperature V needs to be increased. BG Adjust to higher settings, high temperature V BG Adjust to a lower setting; for E4, the low-temperature V needs to be adjusted. BG Adjust to lower settings, high temperature V BG Adjust it to a higher level.

[0030] The above embodiments are all illustrated using n=2 as an example, that is, one is the high-temperature test temperature and the other is the low-temperature test temperature. In practical applications, n can be set to a larger value to meet more accurate compensation requirements. Figure 5 As shown, a method is provided when n=6. Figure 3 The corresponding temperature curve is a schematic diagram of the temperature curve after VBG0 compensation.

[0031] In summary, the full-temperature compensation method in this embodiment does not have to worry about the different temperature profiles of each chip (bandgap reference circuit chip) due to process deviations, process adaptations, or process defects. It can be combined with ATE testing and adjustment to adjust the temperature profile of each chip to a better level, thereby obtaining a better full-temperature coefficient.

[0032] As can be seen from the above description, the full-temperature compensation circuit 100 of the bandgap reference circuit in the embodiments of this disclosure can accurately determine the direction and magnitude of compensation, i.e., the adjustment amplitude value mentioned above, based on ATE testing, thus realizing the quantification of compensation. Then, through multiple temperature comparison modules in the temperature comparison circuit 120, the compensation module in the temperature compensation circuit 110 is triggered to perform adjustment based on the adjustment amplitude value obtained by ATE testing after the ambient temperature reaches the corresponding compensation temperature, so as to achieve point-to-point compensation, which is applicable to bandgap reference circuits with any temperature profile. There is no need to worry about different temperature profiles due to process deviations, process adaptation, or process defects.

[0033] Furthermore, such as Figure 6 As shown, the temperature comparison circuit 120 includes: a first transistor Q1, a bias current source Ib, and n temperature comparison modules 121. The control electrode of the first transistor Q1 is coupled to a zero-temperature reference voltage Vref. The first electrode of the first transistor Q1 is coupled to one end of the bias current source Ib. The second electrode of the first transistor Q1 is coupled to a power supply voltage Vcc. The other end of the bias current source Ib is coupled to ground. The voltage output from the first electrode of the first transistor Q1 is a first voltage V1. Each temperature comparison module 121 includes a comparator A. The n temperature comparison modules 121 correspond to n comparators A (A1-An). The first input terminal of comparator A is coupled to the first electrode of the first transistor Q1. The second terminal of comparator A is coupled to a second voltage V2 corresponding to the corresponding temperature comparison module 121 (the n second voltages V2 corresponding to the n comparators A are V21-V2n respectively). The output terminal of comparator A is coupled to a corresponding compensation module to output a corresponding compensation control signal Tc. The compensation control signals Tc corresponding to the n comparators A are Tc1-Tcn respectively. The first transistor Q1 is specifically a triode.

[0034] Combination Figure 6The circuit principle of temperature comparator circuit 120 is explained as follows: Vref is the zero-temperature voltage, V1 = Vref - VBE, where VBE is the base-emitter voltage of the first transistor Q1. VBE exhibits a negative temperature coefficient, therefore V1 exhibits a positive temperature coefficient. That is, V1 changes proportionally with the ambient temperature. V2 is the voltage value that V1 can reach at the compensation temperature. Thus, when the ambient temperature reaches the corresponding compensation temperature, the corresponding temperature comparator A will flip, and the output will be high. The value of V2 is different for different compensation temperatures. Furthermore, the connection of the positive and negative input terminals of comparator A differs depending on whether the compensation temperature is higher or lower than the ambient temperature. Specifically, if the compensation temperature is higher than the ambient temperature, the connection of the positive and negative input terminals of comparator A is as follows: Figure 6 As shown in A1, the first input terminal (positive input terminal) of comparator A is coupled to the first terminal of the first transistor Q1, and the second input terminal (negative input terminal) of comparator A is coupled to the corresponding second voltage V2. If the compensation temperature is lower than the room temperature, the connection of the positive and negative input terminals of comparator A is as follows: Figure 6 As shown in Figure An, the first input terminal (positive input terminal) of comparator A is coupled to the corresponding second voltage V2, and the second input terminal (negative input terminal) of comparator A is coupled to the first terminal of the first transistor Q1. The connection method of A1 indicates that when the ambient temperature is higher than the compensation temperature, the output Tc is high. The connection method of An indicates that when the ambient temperature is lower than the compensation temperature, the output Tc is high.

[0035] In addition, in practical applications, to ensure circuit stability, such as Figure 7 As shown, it can also be found in Figure 6 Based on this, a third voltage V3 close to V2 is set for each comparator A (V31-V3n corresponding to n comparators). For A1, the working principle after adding V3 is as follows: when the ambient temperature rises from low to make V1 greater than V21, A1 outputs high; when the ambient temperature falls from high to make V1 less than V21, A1 does not immediately flip, but instead flips low only when V1 falls to make V31 less than V31. If V21 is the value V1 can reach at 110℃, then V31 can be a value close to but less than V21, such as the value V1 can reach at 100℃. For An, the working principle after adding V3 is as follows: when the ambient temperature drops to make V1 less than V2n, An outputs high; when the ambient temperature rises from low to make V1 greater than V2n, An does not immediately flip, but instead flips low only when V1 rises to make V3n greater than V3n. If V2n is the value that V1 can reach at -30℃, then V3n can be a value that is close to but greater than V2n, such as the value that V1 can reach at -28℃.

[0036] Furthermore, this disclosure also provides another structure for the temperature comparison module 121, such as... Figure 8As shown, each temperature comparison module 121 includes a comparator A and an OR gate. n temperature comparison modules 121 correspond to n comparators (A1-An) and n OR gates (OR1-ORn). The first input terminal of comparator A is coupled to the first terminal of the first transistor Q1. The second terminal of comparator A is coupled to the second voltage V2 corresponding to the corresponding temperature comparison module 121. The output terminal of comparator A is coupled to one input terminal of the OR gate. The other input terminal of the OR gate is coupled to a toggling analog signal F (n OR gates correspond to n toggling analog signals F1-Fn). The output terminal of the OR gate is coupled to the corresponding compensation module to output a corresponding compensation control signal Tc. The compensation control signals Tc corresponding to the n OR gates are Tc1-Tcn. Figure 6 The difference is, Figure 8 The output of comparator A does not directly output the compensation control signal Tc, but instead outputs the compensation control signal Tc after passing through an OR gate. Figure 8 The added OR gate is to achieve the aforementioned "by toggling the analog signal F, the temperature comparison module 121 can output an effective compensation control signal Tc at room temperature." Figure 8 In the process, when the flip analog signal F is high, the compensation control signal Tc can be high, thereby triggering the corresponding compensation module. This process is only used during the stage of determining the adjustment amplitude. Afterwards, during the normal operation of the bandgap reference circuit, the flip module signal is always low, and the level of the compensation control signal Tc is still determined by the output of comparator A, without affecting the working principle of the temperature comparison circuit 120. Furthermore, it is also possible to... Figure 8 Based on this, V3 is added to each comparator A to increase the stability of the circuit.

[0037] Furthermore, corresponding to the two cases of adjusting resistance or current, the structure of the compensation module and temperature compensation circuit also includes two cases: First, each compensation module includes an adjustable resistor, and the n compensation modules contained in the corresponding temperature compensation circuit 110 are connected in series and then connected to the bandgap reference circuit 200; Second, each compensation module includes a transistor group with adjustable current, and the n compensation modules contained in the corresponding temperature compensation circuit 110 are connected in parallel and then connected to the bandgap reference circuit 200.

[0038] Furthermore, such as Figure 9 As shown, taking a specific bandgap reference circuit as an example, the structure of the temperature compensation circuit 110 and its connection to the bandgap reference circuit 200 are explained. Figure 9In the circuit, n compensation modules 111 are connected in series. The bandgap reference circuit 200 is a voltage-type structure, including: second to fifth transistors (Q2, Q3, M4, M5), a first operational amplifier OP1, a first resistor R1, and a precision adjustment resistor. The control electrode of the second transistor Q2 is coupled to the control electrode of the third transistor Q3, the second electrode of the second transistor Q2, the second electrode of the third transistor Q3, and ground. The first electrode of the second transistor Q2 is coupled to the first input terminal of the first operational amplifier OP1 and the second electrode of the fourth transistor M4. The first electrode of the third transistor Q3 is coupled to one end of the first resistor R1. The first operational amplifier... The second input terminal of the first operational amplifier OP1 is coupled to the other end of the first resistor R1 and one end of the nth compensation module 111 in the temperature compensation circuit 110. The output terminal of the first operational amplifier OP1 is coupled to the control terminals of the fourth transistor M4 and the fifth transistor M5. The first terminals of the fourth transistor M4 and the fifth transistor M5 are both coupled to the power supply voltage Vcc. The second terminal of the fifth transistor M5 is coupled to one end of the precision adjustment resistor. The other end of the precision adjustment resistor is coupled to one end of the first compensation module 111 in the temperature compensation circuit 110. The second terminal of the fifth transistor M5 serves as the output terminal of the bandgap reference circuit 200, outputting V. BG A precision adjustment resistor may be a single unit composed of multiple resistors, primarily used to adjust the voltage at room temperature (V). BG Adjusted to more precise typical process values. R1 is a fixed resistor. Q2 and Q3 are transistors, and M4 and M5 are MOSFETs. Figure 9 In the middle, V BG The expression is as follows: V BG =VBE3+[(VBE2-VBE3) / R1] (R1+Rc1+…+Rcn+Rt) =VBE3+[ VBE / R1] (R1+Rc1+…+Rcn+Rt).

[0039] In the formula, VBE2 is the base-emitter voltage of Q2, exhibiting a negative temperature characteristic; VBE3 is the base-emitter voltage of Q3. VBE is the difference between VBE2 and VBE3, exhibiting a positive temperature coefficient; "Rc1+...+Rcn" is the sum of the adjustment resistors corresponding to the n compensation modules 111, Rt is the resistance value of the precision adjustment resistor, and (R1+Rc1+...+Rcn+Rt) / R1 is an adjustable proportional coefficient. By reasonably setting the value of (R1+Rc1+...+Rcn+Rt) / R1, the zero temperature coefficient V can be obtained. BG With R1 and Rt unchanged, V can be adjusted by adjusting the resistance value of the adjustment resistor in the temperature compensation circuit 110. BG .

[0040] Figure 9 The bandgap reference circuit 200 shown is an example of a voltage-type circuit, and this disclosure does not limit this to any particular type; it can be a voltage-type bandgap reference circuit of any structure. Furthermore, as... Figure 10 As shown, a current-type bandgap reference circuit 200 is also provided, including transistors six through ten (Q6, Q7, M8-M10), a second operational amplifier OP2, resistors two through four (R2-R4), and a precision adjustment resistor. Figure 10 In the middle, V BG The expression is as follows: V BG =α (I1a+I1b) (Rt + Rc1 + ... + Rcn) =α ((VBE6-VBE7) / R3 +VBE6 / R2) (Rt + Rc1 + ... + Rcn) Where α is the size ratio of M10 and M9, "Rc1+...+Rcn" is the sum of the adjustment resistors corresponding to the n compensation modules 111, Rt is the resistance value of the precision adjustment resistor, VBE6 is the base-emitter voltage of Q6, and VBE7 is the base-emitter voltage of Q7. Similarly, when α, R1, and Rt are constant, V can be adjusted by adjusting the resistance value of the adjustment resistor in the temperature compensation circuit 110. BG . Figure 10 The bandgap reference circuit 200 in the figure is an example of a current-type bandgap reference circuit. This disclosure does not limit this type of bandgap reference circuit and it can be a current-type bandgap reference circuit of any structure.

[0041] Figure 9 and Figure 10 The compensation module 111 adjusts the voltage V by changing the resistance value of the adjustment resistor. BG Compensation always includes adjusting the resistor. Furthermore, such as... Figure 11 As shown in the embodiment of this disclosure, a compensation module 111 is provided that changes the current of the compensation module 111 to V. BG A schematic diagram of the compensation process, wherein each compensation module 111 includes a group of transistors with adjustable current. Figure 11 In the diagram, n compensation modules 111 are connected in parallel, and all are connected in parallel with M10. By changing the size ratio of the transistors in each transistor group to M10, the current flowing through the transistor group can be changed, thereby changing V. BG .

[0042] Furthermore, this disclosure also provides a bandgap reference chip, which includes at least a bandgap reference circuit 200 and a full-temperature compensation circuit 100 for the bandgap reference circuit according to any of the foregoing embodiments. The bandgap reference circuit 200 can be a voltage-type bandgap reference circuit or a current-type bandgap reference circuit. The specific connection relationship between the full-temperature compensation circuit 100 and the bandgap reference circuit can be referred to the foregoing embodiments. Figure 2 , Figure 9-11 The corresponding descriptions are not repeated here.

[0043] Furthermore, this disclosure also provides a full-temperature compensation method 200 for a bandgap reference circuit. This method is implemented based on the bandgap reference chip of any of the foregoing embodiments, and includes the following steps: S1: Test the output voltage V of the bandgap reference circuit 200 at room temperature using ATE. BG If the output voltage V at room temperature BG If the value is not equal to the typical process value, the output voltage V at room temperature will be adjusted using the precision adjustment resistor in the bandgap reference circuit 200. BG Adjust to the typical process value, with the room temperature being the preset room temperature value; S2: Test the output voltage V of the bandgap reference circuit 200 at each test temperature using ATE. BG A voltage change threshold is set for each test temperature. If the output voltage V at a certain test temperature... BG Output voltage V at room temperature BG If the difference is greater than the corresponding voltage change threshold, the resistance or current in the compensation module 111 corresponding to the test temperature will be adjusted. One test temperature corresponds to one compensation module 111. The compensation module 111 is the compensation module 111 in the full-temperature compensation circuit 100 of the bandgap reference circuit. The test temperature is the non-temperature test temperature. S3: Determine the output voltage V before and after adjustment. BG Whether the change is equal to the corresponding preset voltage threshold. One test temperature corresponds to one preset voltage threshold. The preset voltage threshold is less than the corresponding voltage change threshold. S4: If it is not equal to the corresponding preset voltage threshold, continue to adjust until it is equal to the corresponding preset voltage threshold. Then, save the corresponding adjustment value in the register. One test temperature corresponds to one adjustment value. S1 to S4 is the process of determining the adjustment amplitude value in conjunction with ATE testing, which belongs to the testing phase. The following S5-S7 is the working process of connecting the bandgap reference circuit 200 and the full-temperature compensation circuit 100 of the bandgap reference circuit into the actual circuit.

[0044] S5: During the operation of the bandgap reference chip, the temperature comparison circuit 120 compares the first voltage V1 with n second voltages V2 through n temperature comparison modules 121 respectively to obtain n compensation control signals Tc. One compensation control signal Tc corresponds to one second voltage V2, and one second voltage V2 corresponds to one compensation temperature. S6: Determine whether the current ambient temperature has reached the corresponding compensation temperature based on the compensation control signal Tc. One compensation control signal Tc corresponds to one compensation module 111. The compensation temperature is set according to the corresponding test temperature, and one test temperature corresponds to one compensation temperature. If the compensation control signal Tc is a valid signal (high level signal), it is determined that the corresponding compensation temperature has been reached; otherwise, it is determined that the corresponding compensation temperature has not been reached.

[0045] S7: If the corresponding compensation temperature is reached, the corresponding compensation module 111 is triggered by the corresponding compensation control signal Tc to automatically adjust the corresponding adjustment amplitude value stored in the register, so that the adjusted resistance or current is connected to the bandgap reference circuit 200 to compensate the output voltage V. BG Specifically, if the test temperature is higher than room temperature, the corresponding compensation temperature will be greater than the corresponding compensation temperature; if the test temperature is lower than room temperature, the corresponding compensation temperature will be less than the corresponding compensation temperature.

[0046] Furthermore, before executing step S3, the method further includes: after each adjustment, after the corresponding compensation control signal Tc triggers the corresponding compensation module 111 to connect the adjusted resistor or current to the bandgap reference circuit, the adjusted output voltage V is tested at the corresponding test temperature using ATE. BG The output voltage V is adjusted according to the corresponding test temperature. BG Output voltage V at the test temperature before adjustment BG Calculate the output voltage V before and after adjustment BG The change in quantity.

[0047] Furthermore, before performing step S3, the method may further include: after each adjustment, controlling the corresponding compensation module 111 to be triggered at room temperature by flipping the analog signal F, so that the adjusted resistor or current is connected to the bandgap reference circuit, and then testing the adjusted output voltage V at room temperature using ATE. BG Based on the adjusted output voltage V at room temperature BG Compared to the output voltage V at room temperature before adjustment BG Calculate the output voltage V before and after adjustment BG The change in quantity.

[0048] For a detailed description of each step in this method embodiment, please refer to the foregoing. Figure 2-11 The relevant descriptions in the corresponding embodiments will not be repeated here.

[0049] In summary, the full-temperature compensation method of the bandgap reference circuit in this embodiment can better adjust the temperature curve of any bandgap reference circuit to obtain a better full-temperature coefficient. It does not need to worry about the difference in temperature curves due to process deviations, process adaptation, or process defects. It can achieve point-to-point adjustment, and the amount of compensation can be quantified by ATE, which has a very good effect in engineering applications.

[0050] Unless otherwise expressly indicated by the context, the singular form of words used herein and in the appended claims includes the plural form, and vice versa. Thus, when referring to the singular, the plural form of the corresponding term is generally included. Similarly, the terms “comprising” and “including” shall be interpreted as including rather than exclusively. Likewise, the terms “including” and “or” shall be interpreted as including unless such interpretation is expressly prohibited herein. Where the term “example” is used herein, particularly when it follows a set of terms, “example” is merely exemplary and illustrative and should not be considered exclusive or extensive.

[0051] Further aspects and scope of adaptation become apparent from the description provided herein. It should be understood that various aspects of this disclosure may be implemented individually or in combination with one or more other aspects. It should also be understood that the descriptions and specific embodiments herein are for illustrative purposes only and are not intended to limit the scope of this disclosure.

[0052] Several embodiments of this disclosure have been described in detail above. However, it is obvious that those skilled in the art can make various modifications and variations to the embodiments of this disclosure without departing from the spirit and scope of this disclosure. The scope of protection of this disclosure is defined by the appended claims.

Claims

1. A full-temperature compensation circuit for a bandgap reference circuit, characterized in that, The full-temperature compensation circuit includes: a temperature compensation circuit and a temperature comparison circuit; The temperature compensation circuit is configured to consist of n compensation modules. Each compensation module is used to automatically adjust the resistance or current in the compensation module according to the adjustment amplitude value in its corresponding register in order to compensate the output voltage of the bandgap reference circuit. The adjustment amplitude value is determined in conjunction with ATE test. One compensation module corresponds to one test temperature, and one test temperature corresponds to one adjustment amplitude value. n is a positive integer greater than or equal to 2. The temperature comparison circuit is configured to construct a first voltage with a positive temperature characteristic based on the first transistor, and compare the first voltage with n second voltages through n temperature comparison modules to obtain n compensation control signals. Each compensation control signal corresponds to a second voltage, and each second voltage corresponds to a compensation temperature. Each compensation control signal is used to indicate whether the current ambient temperature of the bandgap reference circuit has reached the corresponding compensation temperature. The compensation temperature is set according to the test temperature, and each test temperature corresponds to a compensation temperature. The temperature compensation circuit is coupled to the bandgap reference circuit, and the temperature comparison circuit is coupled to the temperature compensation circuit. When any compensation control signal is valid, the compensation control signal triggers the corresponding compensation module to start automatic adjustment so that the adjusted resistance or current is connected to the bandgap reference circuit. One compensation control signal corresponds to one compensation module.

2. The full-temperature compensation circuit for the bandgap reference circuit according to claim 1, characterized in that, The temperature comparison circuit includes: a first transistor, a bias current source, and n temperature comparison modules. Wherein, the control electrode of the first transistor is coupled to a zero-temperature reference voltage, the first electrode of the first transistor is coupled to one end of the bias current source, the second electrode of the first transistor is coupled to a power supply voltage, the other end of the bias current source is coupled to a ground terminal, and the voltage output by the first electrode of the first transistor is the first voltage. Each temperature comparison module includes a comparator, wherein the first input terminal of the comparator is coupled to the first terminal of the first transistor, the second terminal of the comparator is coupled to the second voltage corresponding to the corresponding temperature comparison module, and the output terminal of the comparator is coupled to the corresponding compensation module to output the corresponding compensation control signal.

3. The full-temperature compensation circuit for the bandgap reference circuit according to claim 2, characterized in that, Each temperature comparison module includes a comparator and an OR gate. The comparator has a first input terminal coupled to the first electrode of the first transistor, a second terminal coupled to the second voltage corresponding to the temperature comparison module, an output terminal coupled to one input terminal of the OR gate, another input terminal coupled to the flipping analog signal, and an output terminal coupled to the corresponding compensation module to output the corresponding compensation control signal.

4. The full-temperature compensation circuit for the bandgap reference circuit according to claim 1, characterized in that, If each compensation module includes an adjustable resistor, then n compensation modules are connected in series and then connected to the bandgap reference circuit; if each compensation module includes a transistor group with adjustable current, then n compensation modules are connected in parallel and then connected to the bandgap reference circuit.

5. The full-temperature compensation circuit for the bandgap reference circuit according to claim 1, characterized in that, The adjustment amplitude is determined in conjunction with ATE testing and includes: The output voltage at room temperature is tested using an ATE (Automatic Test Equipment). If the output voltage at room temperature is not equal to the typical process value, the output voltage at room temperature is adjusted to the typical process value using a precision adjustment resistor in the bandgap reference circuit. The room temperature is a preset value. The output voltage at each test temperature is tested using an ATE. Each test temperature has a set voltage change threshold. If the difference between the output voltage at a certain test temperature and the output voltage at room temperature is greater than the corresponding voltage change threshold, the resistor or current in the compensation module corresponding to that test temperature is adjusted. One compensation module corresponds to one test temperature. The test temperature is a non-temperature test temperature. It is determined whether the change in output voltage before and after adjustment is equal to the corresponding preset voltage threshold. One preset voltage threshold corresponds to one test temperature. The preset voltage threshold is less than the corresponding voltage change threshold. If it is not equal to the corresponding preset voltage threshold, adjustment continues until it equals the corresponding preset voltage threshold. The corresponding adjustment amplitude is then saved in a register.

6. A bandgap reference chip, characterized in that, The bandgap reference chip includes at least a bandgap reference circuit and a full-temperature compensation circuit for the bandgap reference circuit according to any one of claims 1 to 5, wherein the bandgap reference circuit includes a voltage-type bandgap reference circuit or a current-type bandgap reference circuit.

7. A full-temperature compensation method for a bandgap reference circuit, characterized in that, The method is implemented based on the bandgap reference chip described in claim 6, and the method includes: The output voltage of the bandgap reference circuit at room temperature is tested by ATE. If the output voltage at room temperature is not equal to the typical process value, the output voltage at room temperature is adjusted to the typical process value by the precision adjustment resistor in the bandgap reference circuit. The room temperature is a preset room temperature value. The output voltage of the bandgap reference circuit is tested at each test temperature using ATE. A voltage change threshold is set for each test temperature. If the difference between the output voltage at a certain test temperature and the output voltage at room temperature is greater than the corresponding voltage change threshold, the resistor or current in the compensation module corresponding to that test temperature is adjusted. One test temperature corresponds to one compensation module. The compensation module is the compensation module in the full-temperature compensation circuit of the bandgap reference circuit. The test temperature is a non-temperature test temperature. Determine whether the change in output voltage before and after adjustment is equal to the corresponding preset voltage threshold. One test temperature corresponds to one preset voltage threshold, and the preset voltage threshold is less than the corresponding voltage change threshold. If it is not equal to the corresponding preset voltage threshold, continue to adjust until it equals the corresponding preset voltage threshold. Then, save the corresponding adjustment value in the register. One test temperature corresponds to one adjustment value. During the operation of the bandgap reference chip, the temperature comparison circuit compares the first voltage with n second voltages through n temperature comparison modules to obtain n compensation control signals. One compensation control signal corresponds to one second voltage, and one second voltage corresponds to one compensation temperature. The compensation control signal determines whether the current ambient temperature has reached the corresponding compensation temperature. One compensation control signal corresponds to one compensation module. The compensation temperature is set according to the corresponding test temperature. One test temperature corresponds to one compensation temperature. If the corresponding compensation temperature is reached, the corresponding compensation module is triggered by the corresponding compensation control signal to automatically adjust the corresponding adjustment amplitude value stored in the register, so that the adjusted resistance or current is connected to the bandgap reference circuit to compensate the output voltage.

8. The full-temperature compensation method for the bandgap reference circuit according to claim 7, characterized in that, If the test temperature is greater than the room temperature, the corresponding compensation temperature is greater than the corresponding compensation temperature; if the test temperature is less than the room temperature, the corresponding compensation temperature is less than the corresponding compensation temperature.

9. The full-temperature compensation method for the bandgap reference circuit according to claim 7, characterized in that, Before determining whether the change in output voltage before and after adjustment is equal to the corresponding preset voltage threshold, the method further includes: After each adjustment, the corresponding compensation module is triggered by the corresponding compensation control signal to connect the adjusted resistor or current to the bandgap reference circuit, and the adjusted output voltage is tested at the corresponding test temperature by ATE. Calculate the change in output voltage before and after adjustment based on the output voltage after adjustment at the corresponding test temperature and the output voltage at the corresponding test temperature before adjustment.

10. The full-temperature compensation method for the bandgap reference circuit according to claim 7, characterized in that, Before determining whether the change in output voltage before and after adjustment is equal to the corresponding preset voltage threshold, the method further includes: After each adjustment, the corresponding compensation module is triggered at room temperature by flipping the analog signal to connect the adjusted resistor or current to the bandgap reference circuit, and then the adjusted output voltage at room temperature is tested by ATE. The change in output voltage before and after adjustment is calculated based on the output voltage after adjustment at room temperature and the output voltage at room temperature before adjustment.

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