Reference voltage generation circuit, chip and electronic device

Abstract

A reference voltage generating circuit, a chip and an electronic device, the reference voltage generating circuit comprising: a first current source circuit for outputting a first current having a first temperature characteristic; the first current mirror circuit is connected with the first current source circuit and used for generating second current based on the first current; the constant current source circuit is connected with the first current mirror circuit and the second current source circuit and is used for outputting third current; the second current source circuit is used for generating fourth current based on the second current and the third current, the fourth current is compensation current of the first current, the fourth current has a second temperature characteristic, and the first temperature characteristic is opposite to the second temperature characteristic; the second current mirror circuit is connected with the second current source circuit and used for generating fifth current based on the fourth current, and the fifth current is mirror current of the fourth current; and the voltage generation circuit is connected with the first current source circuit and the second current mirror circuit and is used for generating reference voltage based on the first current and the fifth current.

Description

Technical Field

[0001] The present application relates to the field of circuit technology, and more specifically to a reference voltage generating circuit, chip and electronic device. Background Art

[0002] The reference voltage generation circuit is an indispensable circuit in most chips. The reference voltage is a voltage with extremely high requirements for temperature drift coefficient. It is widely used in various circuits such as comparators and closed-loop op amps, and is related to the circuit performance of important modules such as over-temperature and under-voltage. In order to obtain a reference voltage with a lower temperature drift coefficient, it needs to be compensated. Because the temperature stability of the bandgap reference voltage after first-order compensation still cannot meet the requirements of most usage scenarios, various high-order compensation methods have emerged, such as high-order curvature compensation, exponential curvature compensation, etc., but these compensation methods are directional compensation and cannot achieve quantitative and accurate compensation. Summary of the invention

[0003] The present application is proposed to solve the above problems. According to one aspect of the present application, a reference voltage generating circuit is provided, the reference voltage generating circuit comprising:

[0004] A first current source circuit, configured to output a first current, wherein the first current has a first temperature characteristic;

[0005] a first current mirror circuit, connected to the first current source circuit, and configured to generate a second current based on the first current, wherein the second current is a mirror current of the first current;

[0006] a constant current source circuit, connected to the first current mirror circuit and the second current source circuit, and configured to output a third current, wherein the third current is a constant current;

[0007] The second current source circuit is used to generate a fourth current based on the second current and the third current, the fourth current is a compensation current of the first current, and the fourth current has a second temperature characteristic, and the first temperature characteristic is opposite to the second temperature characteristic;

[0008] a second current mirror circuit, connected to the second current source circuit, and configured to generate a fifth current based on the fourth current, wherein the fifth current is a mirror current of the fourth current;

[0009] A voltage generating circuit is connected to the first current source circuit and the second current mirror circuit, and is used to generate a reference voltage based on the first current and the fifth current.

[0010] The above technical solution has the following technical effects: by tracking the change of the original current to be compensated with temperature, a compensation current corresponding to it is generated, and the change of the compensation current with temperature is opposite to the change of the current to be compensated with temperature. In this way, quantitative compensation of the current to be compensated is achieved, and then a stable reference voltage with excellent characteristics of an ultra-low temperature drift coefficient is generated, which can solve the problem that the existing compensation method can only provide directional compensation but cannot provide quantitative and accurate compensation.

[0011] In one embodiment of the present application, the first current source circuit is a positive temperature coefficient current source, the first current is a positive temperature coefficient current, and the fourth current is a negative temperature coefficient current.

[0012] The above technical solution has the following technical effects: it can achieve accurate compensation of the positive temperature coefficient current source to generate a stable reference voltage.

[0013] In one embodiment of the present application, the first current source circuit includes:

[0014] a first transistor, wherein a gate of the first transistor is connected to a gate of the second transistor, a source of the first transistor is connected to a power supply, and a drain of the first transistor is connected to a collector of the first transistor;

[0015] the second transistor, wherein the gate of the second transistor is connected to the drain of the second transistor, and the source of the second transistor is connected to the power supply;

[0016] The first triode, the base of the first triode is connected to the collector of the first triode, and the emitter of the first triode is grounded;

[0017] a second triode, wherein the base of the second triode is connected to the base of the first triode, the collector of the second triode is connected to the drain of the second transistor, and the emitter of the second triode is connected to the first end of the first resistor;

[0018] The first resistor, a second end of the first resistor is grounded.

[0019] The above technical solution has the following technical effects: the structure of the first current source circuit can realize a current source that outputs a positive temperature coefficient current.

[0020] In one embodiment of the present application, the first current mirror circuit includes:

[0021] a fourth transistor, wherein a gate of the fourth transistor is connected to the first current source circuit, a source of the fourth transistor is connected to a power supply, and a drain of the fourth transistor is connected to a first end of a third resistor;

[0022] The third resistor, a second end of the third resistor is connected to the constant current source circuit and the second current source circuit.

[0023] The above technical solution has the following technical effects: the mirror image of the first current is realized by the fourth transistor, and the third resistor plays a role in adjusting the accuracy of the first current mirror circuit.

[0024] In one embodiment of the present application, the second current source circuit includes:

[0025] a fifth transistor, wherein a gate and a drain of the fifth transistor are connected to the first end of the fourth resistor, and a source of the fifth transistor is connected to a power supply;

[0026] The fourth resistor, a second end of the fourth resistor is connected to the constant current source circuit and the second current mirror circuit.

[0027] The above technical solution has the following technical effect: a compensation current of the first current is generated through the fifth transistor and the fourth resistor.

[0028] In one embodiment of the present application, the second current mirror circuit includes:

[0029] an operational amplifier, wherein a positive input terminal of the operational amplifier is connected to the second current source circuit, a negative input terminal of the operational amplifier is connected to an output terminal of the operational amplifier, and an output terminal of the operational amplifier is connected to a second terminal of a fifth resistor;

[0030] a third transistor, wherein a source of the third transistor is connected to a power supply, a gate of the third transistor is connected to the first current source circuit, and a drain of the third transistor is connected to the second end of the sixth resistor;

[0031] a sixth transistor, wherein a source of the sixth transistor is connected to the power supply, and a gate and a drain of the sixth transistor are connected to the first end of the fifth resistor;

[0032] a seventh transistor, wherein a gate of the seventh transistor is connected to the gate of the sixth transistor, a source of the seventh transistor is connected to the power supply, and a drain of the seventh transistor is connected to the first end of the sixth resistor;

[0033] The sixth resistor, a second end of the sixth resistor is connected to the voltage generating circuit.

[0034] The above technical solution has the following technical effects: instead of directly mirroring the current through a transistor, an operational amplifier is added, the compensation current is input into the positive input terminal of the operational amplifier, the output terminal of the operational amplifier is fed back to the negative input terminal, and then the current is mirrored through a transistor. This can further improve the accuracy of the current mirror replicating the current, thereby providing higher reliability for the subsequent generation of a stable reference voltage.

[0035] In one embodiment of the present application, the voltage generating circuit includes:

[0036] A second resistor, a first end of the second resistor is connected to the second current mirror circuit, and a second end of the second resistor is grounded.

[0037] The above technical solution has the following technical effects: by passing the first current and the compensation current through the second resistor, a stable reference voltage is output. The resistance value of the second resistor can be set according to the required reference voltage value to achieve a customized stable reference voltage.

[0038] In one embodiment of the present application, the second resistor is a resistor with adjustable resistance.

[0039] The above technical solution has the following technical effects: it can not only realize customized stable reference voltage, but also obtain real-time changing reference voltage by adjusting the resistance value of the second resistor in real time, thereby realizing more flexible application scenarios.

[0040] In one embodiment of the present application, the constant current source circuit includes:

[0041] A constant current source, wherein an output end of the constant current source is connected to a drain of the eighth transistor;

[0042] the eighth transistor, wherein the gate of the eighth transistor is connected to the drain of the eighth transistor, and the source of the eighth transistor is grounded;

[0043] A ninth transistor, wherein a gate of the ninth transistor is connected to the gate of the eighth transistor, a source of the ninth transistor is grounded, and a drain of the ninth transistor is connected to the first current mirror circuit and the second current source circuit.

[0044] The above technical solution has the following technical effects: a constant current source circuit is realized by a constant current source and two transistors.

[0045] In one embodiment of the present application, the first current source circuit is a negative temperature coefficient current source, the first current is a negative temperature coefficient current, and the fourth current is a positive temperature coefficient current.

[0046] The above technical solution has the following technical effects: it can achieve accurate compensation of the negative temperature coefficient current source to generate a stable reference voltage.

[0047] According to another aspect of the present application, a chip is further provided, wherein the chip includes the above-mentioned reference voltage generating circuit.

[0048] According to another aspect of the present application, an electronic device is provided, comprising the above-mentioned chip.

[0049] The reference voltage generating circuit, chip and electronic device according to the embodiments of the present application generate a compensation current corresponding to the original current to be compensated by tracking the change of the original current to be compensated with temperature. The change of the compensation current with temperature is opposite to the change of the current to be compensated with temperature. In this way, quantitative compensation of the current to be compensated is achieved, and a stable reference voltage with excellent characteristics of an ultra-low temperature drift coefficient is generated, which can solve the problem that the existing compensation method only provides directional compensation but cannot provide quantitative and accurate compensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0051] Figure 1 A schematic structural block diagram of a reference voltage generating circuit according to an embodiment of the present application is shown.

[0052] Figure 2 An exemplary circuit diagram of a reference voltage generating circuit according to an embodiment of the present application is shown.

[0053] Figure 3 A comparison diagram of temperature characteristic curves of the first current and the fourth current in the reference voltage generating circuit according to an embodiment of the present application is shown.

[0054] Figure 4 A comparison diagram of temperature characteristic curves of the change slopes of the first current and the fourth current in the reference voltage generating circuit according to an embodiment of the present application is shown.

[0055] Figure 5 A schematic diagram of a temperature drift coefficient when a reference voltage generating circuit according to an embodiment of the present application obtains a first reference voltage is shown.

[0056] Figure 6 A schematic diagram of a temperature drift coefficient when a reference voltage generating circuit according to an embodiment of the present application obtains a second reference voltage is shown.

[0057] Figure 7 A schematic diagram of a temperature drift coefficient when a reference voltage generating circuit according to an embodiment of the present application obtains a third reference voltage is shown. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solutions and advantages of the present application more obvious, the example embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the example embodiments described herein. Based on the embodiments of the present application described in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0059] Figure 1 FIG. 1 shows a schematic structural block diagram of a reference voltage generating circuit 1 according to an embodiment of the present application. Figure 1 As shown, the reference voltage generating circuit 1 includes a first current source circuit 11, a first current mirror circuit 12, a constant current source circuit 13, a second current source circuit 14, a second current mirror circuit 15 and a voltage generating circuit 16. Among them, the first current source circuit 11 is used to output a first current, and the first current has a first temperature characteristic. The first current mirror circuit 12 is connected to the first current source circuit 11, and is used to generate a second current based on the first current, and the second current is a mirror current of the first current. The constant current source circuit 13 is connected to the first current mirror circuit 12 and the second current source circuit 14, and is used to output a third current, and the third current is a constant current (the constant current here can be understood as relative to the first current and the second current, the third current is negligible by the temperature). The second current source circuit 14 is used to generate a fourth current based on the second current and the third current, the fourth current is a compensation current of the first current, and the fourth current has a second temperature characteristic, and the first temperature characteristic is opposite to the second temperature characteristic. The second current mirror circuit 15 is connected to the second current source circuit 14, and is used to generate a fifth current based on the fourth current, and the fifth current is a mirror current of the fourth current. The voltage generating circuit 16 is connected to the first current source circuit 11 and the second current mirror circuit 15 , and is used to generate a voltage based on the first current and the fifth current, and the voltage is the reference voltage output by the reference voltage generating circuit 1 .

[0060] In the embodiment of the present application, the first current source circuit 11 of the reference voltage generating circuit 1 can be a current source with any temperature characteristics. Here, having temperature characteristics can be understood as: the first current source circuit 11 outputs a first current, and the magnitude of the first current changes with the change of temperature. For example, the first current increases with the increase of temperature; for another example, the first current decreases with the increase of temperature; for another example, the first current first increases and then decreases with the increase of temperature, and so on. Since the first current output by the first current source circuit 11 has a temperature characteristic, it needs to be compensated. In the embodiment of the present application, the compensation method adopted is: tracking the change of the first current with temperature, generating a corresponding compensation current, the change of the compensation current with temperature is opposite to the change of the first current with temperature, that is, the first current and the compensation current have opposite temperature characteristics, and quantitative compensation of the first current is achieved in this way. Finally, the first current and the compensation current are jointly fed into the voltage generating circuit. Since the first current and the compensation current are complementary, a stable reference voltage can be generated when the resistance value in the voltage generating circuit is constant.

[0061] Specifically, the present application completes the above compensation through the following circuit structure: the first current mirror circuit 12 generates a mirror current of the first current, that is, the second current. The constant current source circuit 13 generates a third current, and the third current can be called a constant current relative to the first current and the second current. The second current source circuit 14 can generate a fourth current complementary to the first current on the basis of the second current and the third current, as a compensation current for the first current. Then, the fourth current obtains a mirror current of the fourth current, that is, the fifth current, through the second current mirror circuit 15. Finally, the fifth current and the first current are jointly merged into the voltage generating circuit 16 to obtain a reference voltage. According to the required reference voltage value, the resistance value of the corresponding voltage generating circuit 16 can be set, so that different reference voltages can be obtained.

[0062] Therefore, according to the embodiment of the present application, the reference voltage generating circuit 1 generates a corresponding compensation current by tracking the change of the original current to be compensated with temperature. The change of the compensation current with temperature is opposite to the change of the current to be compensated with temperature. In this way, quantitative compensation of the current to be compensated is achieved, and a stable reference voltage with excellent characteristics of an ultra-low temperature drift coefficient is generated, which can solve the problem that the existing compensation method can only provide directional compensation but cannot provide quantitative and accurate compensation.

[0063] In an embodiment of the present application, as described above, the first current source circuit 11 may be a current source with any temperature characteristics. In one example, the first current source circuit 11 is a positive temperature coefficient (proportional to absolute temperature, proportional to absolute temperature, referred to as PTAT) current source, and accordingly, the first current is a positive temperature coefficient current, and the fourth current is a negative temperature coefficient current. In this example, accurate compensation of the PTAT current source can be achieved to generate a stable reference voltage. In another example, the first current source circuit 11 is a negative temperature coefficient (complementary to absolute temperature, inversely proportional to absolute temperature, referred to as CTAT) current source, and accordingly, the first current is a negative temperature coefficient current, and the fourth current is a positive temperature coefficient current. In this example, accurate compensation of the CTAT current source can be achieved to generate a stable reference voltage. In other examples, the first current source circuit 11 may be a current source with other temperature characteristics.

[0064] The following description is made by taking the first current source circuit 11 as a PTAT current source as an example. In this example, the first current source circuit 11 may include a first transistor, a second transistor, a first triode, a second triode and a first resistor. Among them, the gate of the first transistor is connected to the gate of the second transistor, the source of the first transistor is connected to the power supply, and the drain of the first transistor is connected to the collector of the first triode; the gate of the second transistor is connected to the drain of the second transistor, and the source of the second transistor is connected to the power supply; the base of the first triode is connected to the collector of the first triode, and the emitter of the first triode is grounded; the base of the second triode is connected to the base of the first triode, the collector of the second triode is connected to the drain of the second transistor, and the emitter of the second triode is connected to the first end of the first resistor; the second end of the first resistor is grounded. The structure of the first current source circuit 11 can realize a PTAT current source that outputs a PTAT current. That is, in this example, the first current output by the first current source circuit 11 is a PTAT current, and accordingly, the compensation current (fourth current) generated by the second current source circuit is a CTAT current. Exemplarily, both the first transistor and the second transistor are PMOS transistors.

[0065] In an embodiment of the present application, the first current mirror circuit 12 may include a fourth transistor and a third resistor. The gate of the fourth transistor is connected to the first current source circuit 11, the source of the fourth transistor is connected to the power supply, and the drain of the fourth transistor is connected to the first end of the third resistor; the second end of the third resistor is connected to the constant current source circuit 13 and the second current source circuit 14. In this embodiment, the mirror image of the first current is realized by the fourth transistor, and the third resistor plays a role in adjusting the accuracy of the first current mirror circuit 12. When the first current mirror circuit 12 in this example is used to generate the mirror current of the PTAT current source in the previous example, the gate of the fourth transistor can be connected to the gate of the above-mentioned first transistor. Exemplarily, the fourth transistor is a PMOS transistor.

[0066] In an embodiment of the present application, the second current source circuit 14 may include a fifth transistor and a fourth resistor. Wherein, the gate and drain of the fifth transistor are connected to the first end of the fourth resistor, and the source of the fifth transistor is connected to the power supply; the fourth resistor, the second end of the fourth resistor is connected to the constant current source circuit and the second current mirror circuit. In this embodiment, a compensation current of the first current is generated by the fifth transistor and the fourth resistor. Specifically, the compensation current can be equal to the difference between the third current output by the constant current source circuit 13 and the second current output by the first current mirror circuit 12. Exemplarily, the fifth transistor is a PMOS transistor.

[0067] In an embodiment of the present application, the second current mirror circuit 15 may include an operational amplifier, a third transistor, a sixth transistor, a seventh transistor, a fifth resistor and a sixth resistor. Among them, the positive input terminal of the operational amplifier is connected to the second current source circuit, the negative input terminal of the operational amplifier is connected to the output terminal of the operational amplifier, and the output terminal of the operational amplifier is connected to the second end of the fifth resistor; the source of the third transistor is connected to the power supply, the gate of the third transistor is connected to the first current source circuit, and the drain of the third transistor is connected to the second end of the sixth resistor; the source of the sixth transistor is connected to the power supply, and the gate and drain of the sixth transistor are connected to the first end of the fifth resistor; the gate of the seventh transistor is connected to the gate of the sixth transistor, the source of the seventh transistor is connected to the power supply, and the drain of the seventh transistor is connected to the first end of the sixth resistor; the second end of the sixth resistor is connected to the voltage generating circuit.

[0068] In this embodiment, instead of directly mirroring the current through a transistor, an operational amplifier is added, the compensation current is input into the positive input of the operational amplifier, the output of the operational amplifier is fed back to the negative input, and then the current is mirrored through a transistor, which can further improve the accuracy of the current mirror copying the current, thereby providing higher reliability for the subsequent generation of a stable reference voltage. When the second current mirror circuit 15 in this example is used in combination with the first current source circuit 11 and the second current source circuit 14 in the aforementioned example, the gate of the third transistor is connected to the gate of the first transistor, and the positive input of the operational amplifier is also connected to the second end of the aforementioned fourth resistor. Exemplarily, the third transistor, the sixth transistor, and the seventh transistor are PMOS transistors.

[0069] In an embodiment of the present application, the voltage generating circuit 16 may include a second resistor, a first end of the second resistor is connected to a second current mirror circuit, and a second end of the second resistor is grounded. In this embodiment, a stable reference voltage is output by passing the first current and the compensation current through the second resistor. The resistance of the second resistor can be set according to the value of the required reference voltage to achieve a customized stable reference voltage. In a further embodiment, the second resistor can be set to an adjustable resistor, which can not only achieve a customized stable reference voltage, but also obtain a real-time changing reference voltage by adjusting the resistance of the second resistor in real time, thereby achieving a more flexible application scenario. When the voltage generating circuit 16 in this example is used in combination with the second current mirror circuit 15 in the previous example, the first end of the second resistor is connected to the drain of the third transistor and the second end of the sixth resistor.

[0070] In an embodiment of the present application, the constant current source circuit 13 may include: a constant current source, an eighth transistor and a ninth transistor. Among them, the output end of the constant current source is connected to the drain of the eighth transistor; the gate of the eighth transistor is connected to the drain of the eighth transistor, and the source of the eighth transistor is grounded; the gate of the ninth transistor is connected to the gate of the eighth transistor, the source of the ninth transistor is grounded, and the drain of the ninth transistor is connected to the first current mirror circuit 12 and the second current source circuit 14. In this embodiment, the constant current source circuit is realized by a constant current source and two transistors, wherein the constant current source can be a nanoampere constant current source or other constant current sources, as long as the fluctuation range of its output current with temperature changes is not in the same order of magnitude as the fluctuation range of the output current of the first current source circuit 11 with temperature changes, but is much smaller than the fluctuation range of the output current of the first current source circuit 11 with temperature changes. When the constant current source circuit 13 in this example is used in combination with the second current source circuit 14 and the first current mirror circuit 12 in the aforementioned example, the drain of the ninth transistor is connected to the second end of the aforementioned third resistor and the second end of the fourth resistor. Exemplarily, the eighth transistor and the ninth transistor can be NMOS transistors.

[0071] Combine the following Figure 2A specific example of a reference voltage generating circuit according to an embodiment of the present application is described. The circuit diagram shown in this example may be a combination of the above multiple examples, but it should be understood that it is only exemplary and can be replaced by Figure 2 Circuits with other structures other than .

[0072] like Figure 2 As shown, transistors P1, P2, transistors Q1, Q2 and resistor R1 can constitute the first current source circuit 11 mentioned above. Transistor P4 and resistor R3 constitute a first current mirror circuit 12. Constant current source, transistors N1 and N2 constitute a constant current source circuit 13. Transistor P5 and resistor R4 constitute a second current source circuit 14. Transistors P3, P6, P7, operational amplifier OP and resistors R5, R6 constitute a second current mirror circuit 15. R2 constitutes a voltage generating circuit 16. The power supply they are connected to is VCC, and VSS is ground. The specific working process is: using the different current densities of transistors Q1 and Q2, a PTAT current is generated on resistor R1, and the current is mirrored to PMOS tubes P1, P3 and P4 through PMOS tube P2. Icon is generated by the current of the mirror constant current source. Icon can be approximately considered as a constant current source. PMOS tubes P4, P5, NMOS tube N2 and resistors R3, R4 form a current subtraction circuit, and a current with opposite temperature characteristics to the current of R4 is generated on resistor R5. The operational amplifier OP is used to generate the follower potential Vb of the potential Va at point a, so that the current of PMOS tube P6 is equal to P5, and at the same time, it is mirrored to P7 to generate an adaptive compensation current Ic. The compensation current Ic and the mirror current Im of the original current converge and flow into resistor R2 to generate a reference voltage VBG. The reference voltage can be changed by adjusting the resistance value of resistor R2.

[0073] Combine the following Figures 3 to 7 describe Figure 2 The simulation results of the circuit shown in Figure 1 are as follows. Figure 3 A comparison diagram of temperature characteristic curves of the first current and the fourth current in the reference voltage generating circuit according to an embodiment of the present application is shown. Figure 4 A comparison diagram of temperature characteristic curves of the change slopes of the first current and the fourth current in the reference voltage generating circuit according to an embodiment of the present application is shown. Figure 5 A schematic diagram of a temperature drift coefficient when a reference voltage generating circuit according to an embodiment of the present application obtains a first reference voltage is shown. Figure 6 A schematic diagram of a temperature drift coefficient when a reference voltage generating circuit according to an embodiment of the present application obtains a second reference voltage is shown. Figure 7 A schematic diagram of a temperature drift coefficient when a reference voltage generating circuit according to an embodiment of the present application obtains a third reference voltage is shown.

[0074] like Figure 3As shown, when the current Im gradually increases with the temperature, the compensation current Ic gradually decreases. This is the same idea as different high-order compensations, but by observing the temperature characteristic curve of the current change slope, it can be seen that the compensation of this invention can be quantitative and can be very accurate. Figure 4 It can be obtained that as the temperature rises, the Im current gradually increases, but the rising slope gradually slows down as the temperature rises; while the compensation current Ic gradually decreases as the temperature rises, and the decreasing slope also gradually slows down as the temperature rises. Regardless of the current change trend or the current change slope at each temperature point, Im adaptively complements Ic, so the temperature characteristics of the current after the two currents converge are very excellent.

[0075] After the currents Im and Ic converge, they flow into the adjusting resistor R2 to generate the reference voltage VBG. By changing the resistance of the adjusting resistor R2, different reference voltages can be obtained. For example, when R2 = 109Ω, VBG = 1.2V; when R2 = 73KΩ, VBG = 800mV; when R2 = 182KΩ, VBG = 2V. Figure 5 As shown in the figure, when VBG = 1.2V, in the range of -40℃ to 50℃, the temperature deviation is only 157uV, and the temperature drift coefficient is only 0.69ppm / ℃. Figure 6 As shown in the figure, when VBG = 800mV, in the range of -40℃ to 50℃, the temperature deviation is only 103uV, and the temperature drift coefficient is only 0.44ppm / ℃. Figure 7 As shown in the figure, when VBG = 2V, the temperature deviation is only 297uV in the simulation temperature range of -40℃ to 50℃, and the temperature drift coefficient is only 0.78ppm / ℃. It can be seen that the temperature drift coefficients of the reference voltages of 800mV, 1.2V, and 2V are all controlled below 1ppm / ℃, with the characteristics of ultra-low temperature drift.

[0076] Therefore, the present application provides an ultra-low temperature drift, adjustable adaptive compensation voltage reference circuit. Regardless of the reference voltage of 800mV, 1.2V, or 2V, the temperature drift coefficient is controlled below 1ppm / ℃, and has the characteristics of ultra-low temperature drift. Since the circuit is an adaptive structure, it can track the changes in the DC value of the current and the changes in the slope of the current change, so it can quantitatively compensate for its temperature characteristics, which is different from the general high-order compensation method that is only directional. Moreover, the circuit is adjustable, and reference voltages of different DC values ​​can be obtained by changing the resistance value of the adjustment resistor. Both boosting and bucking can be achieved, and are not limited by the driving capability of the reference circuit, which is different from the voltage-type bandgap reference. Finally, the circuit is versatile. Because it adopts an adaptive adjustment method, it can compensate for currents with any temperature characteristics, not limited to PTAT / CTAT currents.

[0077] According to another aspect of the present application, a chip is further provided, the chip comprising the above-mentioned reference voltage generating circuit according to the embodiment of the present application.

[0078] According to another aspect of the present application, an electronic device is provided, which includes the above-mentioned chip.

[0079] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application to this. Those of ordinary skill in the art may make various changes and modifications therein without departing from the scope and spirit of the present application. All these changes and modifications are intended to be included within the scope of the present application as required by the appended claims.

[0080] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0081] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0082] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0083] Similarly, it should be understood that in order to streamline the present application and help understand one or more of the various aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present application should not be interpreted as reflecting the following intention: the claimed application requires more features than the features clearly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with features less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby explicitly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present application.

[0084] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0085] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0086] The various component embodiments of the present application can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. It should be understood by those skilled in the art that a microprocessor or digital signal processor (DSP) can be used in practice to implement some or all of the functions of some modules in the article analysis device according to the embodiment of the present application. The present application can also be implemented as a device program (e.g., computer program and computer program product) for executing part or all of the methods described herein. Such a program implementing the present application can be stored on a computer-readable medium, or can have the form of one or more signals. Such a signal can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0087] It should be noted that the above embodiments illustrate the present application rather than limit the present application, and that those skilled in the art may design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets should not be constructed as a limitation to the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of multiple such elements. The present application may be implemented by means of hardware including several different elements and by means of a suitably programmed computer. In a unit claim that lists several devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names.

[0088] The above is only a specific implementation method or description of a specific implementation method of the present application, and the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A reference voltage generating circuit, characterized in that: The reference voltage generating circuit comprises: A first current source circuit, configured to output a first current, wherein the first current has a first temperature characteristic; a first current mirror circuit, connected to the first current source circuit, and configured to generate a second current based on the first current, wherein the second current is a mirror current of the first current; a constant current source circuit, connected to the first current mirror circuit and the second current source circuit, and configured to output a third current, wherein the third current is a constant current; The second current source circuit is used to generate a fourth current based on the second current and the third current, the fourth current is a compensation current of the first current, and the fourth current has a second temperature characteristic, and the first temperature characteristic is opposite to the second temperature characteristic; a second current mirror circuit, connected to the second current source circuit, and configured to generate a fifth current based on the fourth current, wherein the fifth current is a mirror current of the fourth current; A voltage generating circuit is connected to the first current source circuit and the second current mirror circuit, and is used to generate a reference voltage based on the first current and the fifth current.

2. The reference voltage generating circuit according to claim 1, characterized in that: The first current source circuit is a positive temperature coefficient current source, the first current is a positive temperature coefficient current, and the fourth current is a negative temperature coefficient current.

3. The reference voltage generating circuit according to claim 2, characterized in that: The first current source circuit comprises: a first transistor, wherein a gate of the first transistor is connected to a gate of the second transistor, a source of the first transistor is connected to a power supply, and a drain of the first transistor is connected to a collector of the first transistor; the second transistor, wherein the gate of the second transistor is connected to the drain of the second transistor, and the source of the second transistor is connected to the power supply; The first triode, the base of the first triode is connected to the collector of the first triode, and the emitter of the first triode is grounded; a second triode, wherein the base of the second triode is connected to the base of the first triode, the collector of the second triode is connected to the drain of the second transistor, and the emitter of the second triode is connected to the first end of the first resistor; The first resistor, a second end of the first resistor is grounded.

4. The reference voltage generating circuit according to claim 1, characterized in that: The first current mirror circuit comprises: a fourth transistor, wherein a gate of the fourth transistor is connected to the first current source circuit, a source of the fourth transistor is connected to a power supply, and a drain of the fourth transistor is connected to a first end of a third resistor; The third resistor, a second end of the third resistor is connected to the constant current source circuit and the second current source circuit.

5. The reference voltage generating circuit according to claim 1, characterized in that: The second current source circuit comprises: a fifth transistor, wherein a gate and a drain of the fifth transistor are connected to the first end of the fourth resistor, and a source of the fifth transistor is connected to a power supply; The fourth resistor, a second end of the fourth resistor is connected to the constant current source circuit and the second current mirror circuit.

6. The reference voltage generating circuit according to claim 1, characterized in that: The second current mirror circuit comprises: an operational amplifier, wherein a positive input terminal of the operational amplifier is connected to the second current source circuit, a negative input terminal of the operational amplifier is connected to an output terminal of the operational amplifier, and an output terminal of the operational amplifier is connected to a second terminal of a fifth resistor; a third transistor, wherein a source of the third transistor is connected to a power supply, a gate of the third transistor is connected to the first current source circuit, and a drain of the third transistor is connected to the second end of the sixth resistor; a sixth transistor, wherein a source of the sixth transistor is connected to the power supply, and a gate and a drain of the sixth transistor are connected to the first end of the fifth resistor; a seventh transistor, wherein a gate of the seventh transistor is connected to the gate of the sixth transistor, a source of the seventh transistor is connected to the power supply, and a drain of the seventh transistor is connected to the first end of the sixth resistor; The sixth resistor, a second end of the sixth resistor is connected to the voltage generating circuit.

7. The reference voltage generating circuit according to claim 1, characterized in that: The voltage generating circuit comprises: A second resistor, a first end of the second resistor is connected to the second current mirror circuit, and a second end of the second resistor is grounded.

8. The reference voltage generating circuit according to claim 7, characterized in that: The second resistor is a resistor with adjustable resistance.

9. The reference voltage generating circuit according to claim 1, characterized in that: The constant current source circuit comprises: A constant current source, wherein an output end of the constant current source is connected to a drain of the eighth transistor; the eighth transistor, wherein the gate of the eighth transistor is connected to the drain of the eighth transistor, and the source of the eighth transistor is grounded; A ninth transistor, wherein a gate of the ninth transistor is connected to the gate of the eighth transistor, a source of the ninth transistor is grounded, and a drain of the ninth transistor is connected to the first current mirror circuit and the second current source circuit.

10. The reference voltage generating circuit according to claim 1, characterized in that: The first current source circuit is a negative temperature coefficient current source, the first current is a negative temperature coefficient current, and the fourth current is a positive temperature coefficient current.

11. A chip, characterized in that: The chip comprises the reference voltage generating circuit according to any one of claims 1 to 10.

12. An electronic device, characterized in that: The electronic device comprises the chip according to claim 11.

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