Band-gap reference source based on index compensation and control method thereof

Abstract

The invention discloses a band-gap reference source based on index compensation and a control method thereof.The band-gap reference source comprises a starting module, a first-order compensation band-gap reference module, an index compensation current generation module, a bias module and an operational amplification module, and the starting module is used for discharging the first-order compensation band-gap reference module; the first-order compensation band-gap reference module is used for generating first-order compensated reference voltage, and the index compensation current generation module is used for generating index compensation current according to the reference voltage and performing index compensation on the reference voltage through the index compensation current, so that the first-order compensation band-gap reference module is separated from the degenerate working point. The operational amplification module is used for assisting the first-order compensation band-gap reference module to generate reference current, and the bias module is used for providing bias voltage for the first-order compensation band-gap reference module, the index compensation current generation module and the operational amplification module. The band-gap reference source with low power consumption, low temperature drift coefficient and high power supply rejection ratio can be realized, and the band-gap reference source can be widely applied to the technical field of integrated circuits.

Description

Technical Field

[0001] The invention relates to the technical field of integrated circuits, and in particular to a bandgap reference source based on exponential compensation and a control method thereof. Background Art

[0002] With the rapid development of integrated circuit technology, as the basic module of analog circuits, the accuracy and speed requirements of bandgap reference sources are constantly increasing. Bandgap reference sources are widely used in the field of high-precision voltage references due to their excellent temperature stability, and their own performance has a crucial impact on the accuracy and performance of the entire system. Traditional bandgap reference sources use positive and negative temperature coefficient currents for first-order compensation to reduce the temperature drift coefficient of the output voltage, but the accuracy of their output reference voltage is difficult to meet current application requirements. Among the existing high-order compensation technologies, the segmented compensation technology uses different curvature compensation branches to perform curvature correction on the characteristic curve of the reference source in different temperature ranges, but the circuit structure of this type of method is relatively complex, greatly affected by the process, and has high power consumption; exponential compensation technology can achieve a higher power supply rejection ratio, but it also requires higher power consumption and the output voltage accuracy is not high; while the second-order temperature compensation circuit can eliminate the influence of the second-order term in the temperature coefficient, and the temperature drift is small, but the circuit structure is complex and occupies a large chip area. Summary of the invention

[0003] To solve the above technical problems, the object of the present invention is to provide a bandgap reference source based on exponential compensation and a control method thereof with low power consumption, low temperature drift coefficient and high power supply rejection ratio.

[0004] To achieve the above-mentioned purpose, one aspect of an embodiment of the present application proposes a bandgap reference source based on exponential compensation, including a startup module, a first-order compensation bandgap reference module, an exponential compensation current generation module, a bias module and an operational amplifier module, wherein one end of the startup module is connected to one end of the first-order compensation bandgap reference module, the other end of the first-order compensation bandgap reference module is connected to one end of the exponential compensation current generation module, the other end of the exponential compensation current generation module is connected to one end of the operational amplifier module, and the first-order compensation bandgap reference module, the exponential compensation current generation module and the operational amplifier module are also connected to the bias module. The startup module is used to discharge the first-order compensation bandgap reference module so that the first-order compensation bandgap reference module is separated from the degenerate working point. The operational amplifier module is used to assist the first-order compensation bandgap reference module in generating a reference current. The first-order compensation bandgap reference module is used to generate a reference voltage after first-order compensation. The exponential compensation current generation module is used to generate an exponential compensation current according to the reference voltage, and perform exponential compensation on the reference voltage through the exponential compensation current. The bias module is used to provide a bias voltage for the first-order compensation bandgap reference module, the exponential compensation current generation module and the operational amplifier module.

[0005] In some embodiments, the first-order compensated bandgap reference module includes a first current generating circuit, a second current generating circuit and a voltage generating circuit, the output ends of the first current generating circuit and the second current generating circuit are connected to the input end of the voltage generating circuit, the output end of the voltage generating circuit is connected to the output end of the exponential compensation current generating module, the first current generating circuit is used to generate a positive temperature coefficient current, the second current generating circuit is used to generate a negative temperature coefficient current, and the voltage generating circuit is used to generate the reference voltage after first-order compensation based on the positive temperature coefficient current and the negative temperature coefficient current.

[0006] In some embodiments, the exponential compensation current generating module includes a subthreshold gate voltage generating circuit and a compensation current generating circuit, the input end of the subthreshold gate voltage generating circuit is connected to the output end of the first-order compensation bandgap reference module, the output end of the subthreshold gate voltage generating circuit is connected to the input end of the compensation current generating circuit, the output end of the compensation current generating circuit is connected to the output end of the first-order compensation bandgap reference module, the subthreshold gate voltage generating circuit is used to generate a gate voltage according to the reference current, and the compensation current generating circuit is used to generate the exponential compensation current according to the gate voltage.

[0007] In some embodiments, the bias module includes a first bias circuit and a second bias circuit, the input ends of the first-order compensation bandgap reference module and the exponential compensation current generation module are both connected to the output end of the first bias circuit, the input end of the first bias circuit is connected to the output end of the operational amplifier module, and the output end of the second bias circuit is connected to the input end of the operational amplifier module, the first bias circuit is used to provide the bias voltage for the first-order compensation bandgap reference module and the exponential compensation current generation module, and the second bias circuit is used to provide the bias voltage for the operational amplifier module.

[0008] In some embodiments, the operational amplifier module includes a five-tube operational amplifier circuit, a common source amplifier circuit and a Miller compensation circuit, the input end of the five-tube operational amplifier circuit is connected to the output end of the first-order compensation bandgap reference module, the five-tube operational amplifier circuit is connected to the common source amplifier circuit, and the Miller compensation circuit is connected between the five-tube operational amplifier circuit and the common source amplifier circuit.

[0009] In some embodiments, the subthreshold gate voltage generating circuit includes a first transistor, a second transistor, a common-source common-gate current mirror and a first resistor, the gates of the first transistor and the second transistor are both connected to the output end of the first-order compensated bandgap reference module, the source of the first transistor is connected to one end of the first resistor, the drain of the first transistor is connected to the source of the second transistor, the drain of the second transistor is connected to the input end of the common-source common-gate current mirror, the output end of the common-source common-gate current mirror is connected to the other end of the first resistor, the first transistor and the second transistor are used to copy the reference current to the common-source common-gate current mirror, the common-source common-gate current mirror is used to copy the reference current to the first resistor, and the first resistor is used to generate the gate voltage according to the reference current.

[0010] In some embodiments, the compensation current generating circuit includes a third transistor, the gate of the third transistor is connected between the first resistor and the common-source and common-gate current mirror, the drain of the third transistor is connected to the output end of the first-order compensation bandgap reference module, and the third transistor is used to generate the exponential compensation current according to the gate voltage.

[0011] In some embodiments, the common-source amplifier circuit includes a fourth transistor and a fifth transistor, the source of the fourth transistor is connected to one end of the five-tube operational amplifier circuit, the drains of the Miller compensation circuit and the fifth transistor are both connected to the drain of the fourth transistor, the five-tube operational amplifier circuit and the Miller compensation circuit are both connected to the gate of the fifth transistor, and the source of the fifth transistor is connected to one end of the five-tube operational amplifier circuit.

[0012] In some embodiments, the Miller compensation circuit includes a first capacitor and a second resistor, one end of the first capacitor is connected between the drain of the fourth transistor and the drain of the fifth transistor, the other end of the first capacitor is connected to one end of the second resistor, and the other end of the second resistor is connected between the five-transistor operational amplifier circuit and the gate of the fifth transistor.

[0013] To achieve the above object, another aspect of an embodiment of the present application provides a control method for a bandgap reference source based on exponential compensation, comprising the following steps:

[0014] Discharging the first-order compensation bandgap reference module through the startup module to make the first-order compensation bandgap reference module leave the degenerate working point;

[0015] The first-order compensation bandgap reference module is assisted by an operational amplifier module to generate a reference current;

[0016] Generate a first-order compensated reference voltage by using the first-order compensated bandgap reference module;

[0017] Generate an exponential compensation current according to the reference voltage by an exponential compensation current generating module, and perform exponential compensation on the reference voltage by the exponential compensation current;

[0018] A bias voltage is provided to the first-order compensation bandgap reference module, the exponential compensation current generating module and the operational amplifier module through a bias module.

[0019] The beneficial effects of the present invention are as follows: a bandgap reference source based on exponential compensation and a control method thereof of the present invention include a startup module, a first-order compensation bandgap reference module, an exponential compensation current generation module, a bias module and an operational amplifier module, wherein the startup module is used to discharge the first-order compensation bandgap reference module so as to make the first-order compensation bandgap reference module escape from the degenerate working point, the first-order compensation bandgap reference module is used to generate a reference voltage after first-order compensation, the exponential compensation current generation module is used to generate an exponential compensation current according to the reference voltage, and perform exponential compensation on the reference voltage through the exponential compensation current, the operational amplifier module is used to assist the first-order compensation bandgap reference module in generating a reference current, and the bias module is used to provide a bias voltage for the first-order compensation bandgap reference module, the exponential compensation current generation module and the operational amplifier module. The present invention introduces an operational amplifier module into the first-order compensation bandgap reference module, and designs a bias module to reduce the use of resistance at the same time, and through the coordinated work of the five modules of the startup module, the first-order compensation bandgap reference module, the exponential compensation current generation module, the bias module and the operational amplifier module, a bandgap reference source with low power consumption, low temperature drift coefficient and high power supply rejection ratio can be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution in the embodiments of the present invention, the following introduction is made to the drawings required for use in the embodiments of the present invention. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments of the technical solution of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 A structural block diagram of a bandgap reference source based on exponential compensation provided by an embodiment of the present invention;

[0022] Figure 2 A circuit schematic diagram of a bandgap reference source based on exponential compensation provided by an embodiment of the present invention;

[0023] Figure 3 A flow chart of steps of a control method of a bandgap reference source based on exponential compensation provided by an embodiment of the present invention.

[0024] Figure numerals: PM7, first transistor; PM8, second transistor; PM9, third transistor; NM10, fourth transistor; NM17, fifth transistor; R5, first resistor; R6, second resistor; C1, first capacitor. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application. They are only examples of devices and methods consistent with some aspects of the embodiments of the present application as detailed in the attached claims.

[0026] It is understood that the terms "first", "second", etc. used in this application can be used to describe various concepts in this article, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another concept. For example, without departing from the scope of the embodiment of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the words "if" and "if" as used herein can be interpreted as "at the time of" or "when" or "in response to determination".

[0027] The terms "at least one", "multiple", "each", "any", etc. used in this application, at least one includes one, two or more, multiple includes two or more, each refers to each of the corresponding multiple, and any refers to any one of the multiple.

[0028] With the rapid development of integrated circuit technology, as a basic module of analog circuits, the accuracy and speed requirements of bandgap reference sources are constantly increasing. Bandgap reference sources are widely used in the field of high-precision voltage references due to their excellent temperature stability, and their own performance has a crucial impact on the accuracy and performance of the entire system. At present, the main challenges faced by the design of bandgap reference sources are: how to maintain a low temperature drift coefficient over a wide temperature range, how to reduce power consumption while ensuring high accuracy, and how to reduce the sensitivity of the reference source to the power supply voltage.

[0029] The traditional bandgap reference source uses positive and negative temperature coefficient currents for first-order compensation to reduce the temperature drift coefficient of the output voltage, but the accuracy of its output reference voltage is difficult to meet current application requirements. Among the existing high-order compensation technologies, the segmented compensation technology uses different curvature compensation branches to perform curvature correction on the characteristic curve of the reference source in different temperature ranges, but the circuit structure of this type of method is relatively complex, greatly affected by the process, and has high power consumption; the exponential compensation technology can achieve a higher power supply rejection ratio, but it also requires higher power consumption and the output voltage accuracy is not high; the second-order temperature compensation circuit can eliminate the influence of the second-order term in the temperature coefficient, and the temperature drift is small, but the circuit structure is complex and occupies a large chip area.

[0030] To this end, the embodiment of the present invention proposes a bandgap reference source based on exponential compensation, including a startup module, a first-order compensation bandgap reference module, an exponential compensation current generation module, a bias module and an operational amplifier module, wherein the startup module is used to discharge the first-order compensation bandgap reference module so that the first-order compensation bandgap reference module is separated from the degenerate working point, the first-order compensation bandgap reference module is used to generate a reference voltage after first-order compensation, the exponential compensation current generation module is used to generate an exponential compensation current according to the reference voltage, and perform exponential compensation on the reference voltage through the exponential compensation current, the operational amplifier module is used to assist the first-order compensation bandgap reference module in generating a reference current, and the bias module is used to provide a bias voltage for the first-order compensation bandgap reference module, the exponential compensation current generation module and the operational amplifier module. The present invention introduces an operational amplifier module into the first-order compensation bandgap reference module, and uses the bias module to reduce the use of resistance. Through the coordinated work of the five modules of the startup module, the first-order compensation bandgap reference module, the exponential compensation current generation module, the bias module and the operational amplifier module, a bandgap reference source with low power consumption, low temperature drift coefficient and high power supply rejection ratio can be realized.

[0031] Reference Figure 1 , Figure 1 A structural block diagram of a bandgap reference source based on exponential compensation provided by an embodiment of the present invention. The embodiment of the present invention proposes a bandgap reference source based on exponential compensation, including a startup module, a first-order compensation bandgap reference module, an exponential compensation current generation module, a bias module and an operational amplifier module, one end of the startup module is connected to one end of the first-order compensation bandgap reference module, the other end of the first-order compensation bandgap reference module is connected to one end of the exponential compensation current generation module, the other end of the exponential compensation current generation module is connected to one end of the operational amplifier module, the first-order compensation bandgap reference module, the exponential compensation current generation module and the operational amplifier module are also connected to the bias module, the startup module is used to discharge the first-order compensation bandgap reference module to make the first-order compensation bandgap reference module out of the degenerate working point, the operational amplifier module is used to assist the first-order compensation bandgap reference module to generate a reference current, the first-order compensation bandgap reference module is used to generate a reference voltage after first-order compensation, the exponential compensation current generation module is used to generate an exponential compensation current according to the reference voltage, and exponentially compensate the reference voltage through the exponential compensation current, and the bias module is used to provide a bias voltage for the first-order compensation bandgap reference module, the exponential compensation current generation module and the operational amplifier module.

[0032] Specifically, the startup module is used to ensure that the bandgap reference circuit can start normally. In the initial state of the circuit, since all nodes may be at the same potential (i.e., the degenerate operating point), the circuit may not work properly. The startup module provides an instantaneous discharge current to the first-order compensation bandgap reference module to make the module leave the degenerate operating point, thereby starting the entire circuit.

[0033] In some optional embodiments, such as Figure 2 The figure shows a circuit schematic diagram of a bandgap reference source based on exponential compensation, wherein the startup module includes MOS tube NM11, MOS tube NM12, MOS tube NM13, MOS tube PM18, MOS tube PM19 and MOS tube PM20. In the startup phase, MOS tube NM11 and MOS tube NM12 in the startup module are turned on, and MOS tube NM13 is turned off. The VBP node is discharged through MOS tube NM11, so that the circuit quickly leaves the degenerate working point and enters a normal working state. When the circuit works in a normal state, MOS tube NM13 is turned on and discharges the gates of MOS tube NM11 and MOS tube NM12, so that they are turned off, thereby no longer affecting the operation of the core circuit.

[0034] The first-order compensated bandgap reference module is used to generate an initial reference voltage. The voltage difference generated by two transistors with different temperature coefficients is used to achieve preliminary compensation for temperature changes.

[0035] The exponential compensation current generation module is used to provide a current with exponential temperature compensation characteristics according to the reference voltage after first-order compensation, thereby reducing the temperature coefficient of the reference voltage.

[0036] The operational amplifier module is used to make the first current generating circuit, the second current generating circuit and the voltage generating circuit operate at specified operating currents and voltages, and to assist the first-order compensation bandgap reference module in generating reference currents.

[0037] The bias module is used to provide a stable bias voltage for the first-order compensation bandgap reference module, the exponential compensation current generation module and the operational amplifier module, so that each module can operate stably near a specified operating point.

[0038] Further as an optional implementation, the first-order compensated bandgap reference module includes a first current generating circuit, a second current generating circuit and a voltage generating circuit, the output ends of the first current generating circuit and the second current generating circuit are connected to the input end of the voltage generating circuit, the output end of the voltage generating circuit is connected to the output end of the exponential compensation current generating module, the first current generating circuit is used to generate a positive temperature coefficient current, the second current generating circuit is used to generate a negative temperature coefficient current, and the voltage generating circuit is used to generate a first-order compensated reference voltage based on the positive temperature coefficient current and the negative temperature coefficient current.

[0039] In some optional embodiments, such as Figure 2 As shown, the first current generating circuit includes MOS transistor PM1, MOS transistor PM2, MOS transistor PM3, MOS transistor PM4, triode Q1, triode Q2 and resistor R3; the second current generating circuit includes MOS transistor PM1, MOS transistor PM2, triode Q1, resistor R1 and resistor R2; the voltage generating circuit includes MOS transistor PM5, MOS transistor PM6 and resistor R4.

[0040] Specifically, the first-order compensation bandgap reference module uses the operational amplifier and current mirror feedback mechanism of the operational amplifier module to ensure that the voltages of the VP node and the VN node are equal, and uses the common source and common gate current mirror to ensure that the currents flowing through the MOS tube PM1, MOS tube PM3, and MOS tube PM5 are consistent. In this process, the base-emitter voltage of the transistor Q1 has a negative temperature coefficient characteristic and is converted into a negative temperature coefficient current on the resistor R1; while the base-emitter voltage difference between the transistor Q1 and the transistor Q2 has a positive temperature coefficient characteristic and is converted into a positive temperature coefficient current on the resistor R3. These two currents are copied along the way to the MOS tube PM5 through the current mirror, and a reference voltage after first-order compensation is generated on the resistor R4.

[0041] Further as an optional implementation, the exponential compensation current generating module includes a subthreshold gate voltage generating circuit and a compensation current generating circuit, the input end of the subthreshold gate voltage generating circuit is connected to the output end of the first-order compensation bandgap reference module, the output end of the subthreshold gate voltage generating circuit is connected to the input end of the compensation current generating circuit, the output end of the compensation current generating circuit is connected to the output end of the first-order compensation bandgap reference module, the subthreshold gate voltage generating circuit is used to generate a gate voltage according to a reference current corresponding to the reference voltage, and the compensation current generating circuit is used to generate an exponential compensation current according to the gate voltage.

[0042] Reference Figure 2 , further as an optional implementation, the subthreshold gate voltage generating circuit includes a first transistor, a second transistor, a common-source common-gate current mirror and a first resistor, the gates of the first transistor and the second transistor are both connected to the output end of the first-order compensated bandgap reference module, the source of the first transistor is connected to one end of the first resistor, the drain of the first transistor is connected to the source of the second transistor, the drain of the second transistor is connected to the input end of the common-source common-gate current mirror, the output end of the common-source common-gate current mirror is connected to the other end of the first resistor, the first transistor and the second transistor are used to copy the reference current to the common-source common-gate current mirror, the common-source common-gate current mirror is used to copy the reference current to the first resistor, and the first resistor is used to generate a gate voltage according to the reference current.

[0043] In some optional embodiments, such as Figure 2 As shown, the cascode current mirror includes a MOS transistor NM1, a MOS transistor NM2, a MOS transistor NM3 and a MOS transistor NM4.

[0044] Reference Figure 2 , further as an optional implementation, the compensation current generating circuit includes a third transistor, the gate of the third transistor is connected between the first resistor and the common-source common-gate current mirror, the drain of the third transistor is connected to the output end of the first-order compensation bandgap reference module, and the third transistor is used to generate an exponential compensation current according to the gate voltage.

[0045] Specifically, the exponential compensation current generation module uses a current mirror composed of the first transistor PM7 and the second transistor PM8 to copy the reference current after the first-order compensation to the MOS transistors NM1 and NM2, and then uses a common source and common gate current mirror composed of the MOS transistors NM1 to NM4 to copy the first-order compensation current to the first resistor R5, providing a stable gate voltage with a small temperature drift coefficient for the third transistor PM9. The third transistor PM9 works in the subthreshold region and uses its subthreshold exponential conduction characteristics to inject current into the output node to achieve accurate exponential compensation.

[0046] Further as an optional implementation, the bias module includes a first bias circuit and a second bias circuit, the input ends of the first-order compensation bandgap reference module and the exponential compensation current generating module are both connected to the output end of the first bias circuit, the input end of the first bias circuit is connected to the output end of the operational amplifier module, and the output end of the second bias circuit is connected to the input end of the operational amplifier module, the first bias circuit is used to provide a bias voltage for the first-order compensation bandgap reference module and the exponential compensation current generating module, and the second bias circuit is used to provide a bias voltage for the operational amplifier module.

[0047] In some optional embodiments, such as Figure 2 As shown, the first bias circuit includes MOS transistor PM10, MOS transistor PM11, MOS transistor PM12, MOS transistor NM5 and MOS transistor NM6; the second bias circuit includes MOS transistor PM13, MOS transistor PM14, MOS transistor NM7 and MOS transistor NM8.

[0048] Specifically, the first bias circuit is a bias circuit of a common-source common-gate current mirror, wherein the MOS transistor PM11 adopts a diode connection method to provide a bias voltage for the VNQ node in the exponential compensation current generation module (i.e., the gates of the MOS transistor NM2 and the MOS transistor NM4); the MOS transistor NM5 also adopts a diode connection method to provide a bias voltage for the VPQ node in the first-order compensation bandgap reference module (i.e., the gates of the MOS transistor PM2 and the MOS transistor PM4), and the VPQ node between the first-order compensation bandgap reference module and the exponential compensation current generation module (i.e., the gates of the MOS transistor PM6 and the MOS transistor PM8). The second bias circuit is a bias circuit of an operational amplifier, wherein the MOS transistor NM7 adopts a diode connection method to provide a bias voltage for the VB node in the operational amplifier module (i.e., the gates of the MOS transistor NM9 and the fourth transistor NM10).

[0049] Further as an optional implementation, the operational amplifier module includes a five-tube operational amplifier circuit, a common source amplifier circuit and a Miller compensation circuit, the input end of the five-tube operational amplifier circuit is connected to the output end of the first-order compensation bandgap reference module, the five-tube operational amplifier circuit is connected to the common source amplifier circuit, and the Miller compensation circuit is connected between the five-tube operational amplifier circuit and the common source amplifier circuit.

[0050] In some optional embodiments, such as Figure 2As shown, the first stage of the operational amplifier module adopts a five-tube OTA (Operational Transconductance Amplifier) ​​structure (i.e., a five-tube operational amplifier circuit), and the five-tube operational amplifier circuit includes MOS tube NM9, MOS tube NM11, MOS tube NM12, MOS tube PM15, and MOS tube PM16. Among them, MOS tube NM11 and MOS tube NM12 are used as differential input tubes, MOS tube NM9 is a tail current source, and MOS tube PM15 and MOS tube PM16 are current mirror loads.

[0051] Reference Figure 2 , further as an optional implementation, the common source amplifier circuit includes a fourth transistor and a fifth transistor, the source of the fourth transistor is connected to one end of the five-tube operational amplifier circuit, the drains of the Miller compensation circuit and the fifth transistor are both connected to the drain of the fourth transistor, the five-tube operational amplifier circuit and the Miller compensation circuit are both connected to the gate of the fifth transistor, and the source of the fifth transistor is connected to one end of the five-tube operational amplifier circuit.

[0052] Reference Figure 2 , further as an optional implementation, the Miller compensation circuit includes a first capacitor and a second resistor, one end of the first capacitor is connected to the drain of the fourth transistor, one end of the first capacitor is connected between the drain of the fourth transistor and the drain of the fifth transistor, and the other end of the second resistor is connected between the five-tube operational amplifier circuit and the gate of the fifth transistor.

[0053] Specifically, the second stage of the operational amplifier module adopts a common source amplifier with a current source load (i.e., a common source amplifier circuit), including a fourth transistor NM10 and a fifth transistor PM17, wherein the fourth transistor NM10 is a current source load, and the fifth transistor PM17 is a common source amplifier. In order to ensure the stability of the operational amplifier, the embodiment of the present invention also introduces Miller compensation to ensure the stable operation of the operational amplifier, and this function is implemented by the second resistor R6 and the first capacitor C1 of the device.

[0054] The structure and working principle of the bandgap reference source based on exponential compensation of the embodiment of the present invention are described above. It can be recognized that the embodiment of the present invention includes a startup module, a first-order compensation bandgap reference module, an exponential compensation current generation module, a bias module and an operational amplifier module. By introducing an operational amplifier in the first-order compensation circuit and designing the bias module to reduce the use of resistors, the power supply rejection ratio reaches -62.78dB, which is a great improvement compared to the -28dB in the design of similar compensation methods. Compared with the design of similar first-order compensation circuits, it can achieve a similar temperature drift coefficient, and significantly reduce the power consumption from 36uA to 28.9uA, while reducing the overall structural complexity.

[0055] Reference Figure 3 The embodiment of the present invention provides a control method of a bandgap reference source based on exponential compensation, which is used to control the bandgap reference source based on exponential compensation, and includes the following steps S101 to S105:

[0056] S101, discharging the first-order compensation bandgap reference module through the startup module to make the first-order compensation bandgap reference module leave the degenerate working point;

[0057] S102, using an operational amplifier module to assist a first-order compensation bandgap reference module in generating a reference current;

[0058] S103, generating a first-order compensated reference voltage through a first-order compensated bandgap reference module;

[0059] S104, generating an exponential compensation current according to a reference voltage by using an exponential compensation current generating module, and performing exponential compensation on the reference voltage by using the exponential compensation current;

[0060] S105 , providing a bias voltage for a first-order compensation bandgap reference module, an exponential compensation current generation module, and an operational amplifier module through a bias module.

[0061] The contents of the above-mentioned bandgap reference source embodiment based on exponential compensation are all applicable to the control method embodiment of the present bandgap reference source based on exponential compensation. The functions specifically implemented by the control method embodiment of the present bandgap reference source based on exponential compensation are the same as those of the above-mentioned bandgap reference source embodiment based on exponential compensation, and the beneficial effects achieved are also the same as those achieved by the above-mentioned bandgap reference source embodiment based on exponential compensation.

[0062] It should be appreciated that embodiments of the present invention may be implemented or enforced by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer-readable memory. The above methods may be implemented in a computer program using standard programming techniques, including a non-transitory computer-readable storage medium configured with a computer program, wherein the storage medium so configured causes the computer to operate in a specific and predefined manner, according to the methods and drawings described in the specific embodiments. Each program may be implemented in a high-level procedural or object-oriented programming language to communicate with a computer system. However, if desired, the program may be implemented in an assembly or machine language. In any case, the language may be a compiled or interpreted language. In addition, the program may be run on a programmed dedicated integrated circuit for this purpose.

[0063] Furthermore, the operations of the processes described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The processes described herein (or variations and / or combinations thereof) may be performed under the control of one or more computer systems configured with executable instructions, and may be implemented as code (e.g., executable instructions, one or more computer programs, or one or more applications) that is executed collectively on one or more processors, by hardware, or a combination thereof. The computer programs described above include a plurality of instructions that may be executed by one or more processors.

[0064] Further, the above method can be implemented in any type of computing platform that is operably connected to a suitable computer, including but not limited to a personal computer, a minicomputer, a mainframe, a workstation, a network or distributed computing environment, a separate or integrated computer platform, or in communication with a charged particle tool or other imaging device, etc. Various aspects of the present invention can be implemented in machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into a computing platform, such as a hard disk, an optical read and / or write storage medium, a RAM, a ROM, etc., so that it can be read by a programmable computer, and when the storage medium or device is read by the computer, it can be used to configure and operate the computer to perform the process described herein. In addition, the machine-readable code, or a portion thereof, can be transmitted via a wired or wireless network. When such media includes instructions or programs that implement the steps described above in conjunction with a microprocessor or other data processor, the invention described herein includes these and other different types of non-transitory computer-readable storage media. When programmed according to the methods and techniques described in the present invention, the present invention also includes the computer itself.

[0065] The computer program can be applied to input data to perform the functions described herein, thereby converting the input data to generate output data stored in a non-volatile memory. The output information can also be applied to one or more output devices such as a display. In a preferred embodiment of the present invention, the converted data represents physical and tangible objects, including specific visual depictions of physical and tangible objects produced on the display.

[0066] In the above description of this specification, the description with reference to the terms "one embodiment / example", "another embodiment / example" or "certain embodiments / examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0067] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

[0068] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A bandgap reference source based on exponential compensation, characterized in that: The invention comprises a startup module, a first-order compensation bandgap reference module, an exponential compensation current generation module, a bias module and an operational amplifier module, wherein one end of the startup module is connected to one end of the first-order compensation bandgap reference module, the other end of the first-order compensation bandgap reference module is connected to one end of the exponential compensation current generation module, the other end of the exponential compensation current generation module is connected to one end of the operational amplifier module, the first-order compensation bandgap reference module, the exponential compensation current generation module and the operational amplifier module are also connected to the bias module, the startup module is used to discharge the first-order compensation bandgap reference module so that the first-order compensation bandgap reference module is separated from the degenerate working point, the operational amplifier module is used to assist the first-order compensation bandgap reference module to generate a reference current, the first-order compensation bandgap reference module is used to generate a reference voltage after first-order compensation, the exponential compensation current generation module is used to generate an exponential compensation current according to the reference voltage, and perform exponential compensation on the reference voltage through the exponential compensation current, and the bias module is used to provide a bias voltage for the first-order compensation bandgap reference module, the exponential compensation current generation module and the operational amplifier module.

2. A bandgap reference source based on exponential compensation according to claim 1, characterized in that: The first-order compensated bandgap reference module includes a first current generating circuit, a second current generating circuit and a voltage generating circuit. The output ends of the first current generating circuit and the second current generating circuit are both connected to the input end of the voltage generating circuit. The output end of the voltage generating circuit is connected to the output end of the exponential compensation current generating module. The first current generating circuit is used to generate a positive temperature coefficient current, the second current generating circuit is used to generate a negative temperature coefficient current, and the voltage generating circuit is used to generate the reference voltage after first-order compensation according to the positive temperature coefficient current and the negative temperature coefficient current.

3. A bandgap reference source based on exponential compensation according to claim 1, characterized in that: The exponential compensation current generating module includes a subthreshold gate voltage generating circuit and a compensation current generating circuit, the input end of the subthreshold gate voltage generating circuit is connected to the output end of the first-order compensation bandgap reference module, the output end of the subthreshold gate voltage generating circuit is connected to the input end of the compensation current generating circuit, the output end of the compensation current generating circuit is connected to the output end of the first-order compensation bandgap reference module, the subthreshold gate voltage generating circuit is used to generate a gate voltage according to the reference current, and the compensation current generating circuit is used to generate the exponential compensation current according to the gate voltage.

4. The bandgap reference source based on exponential compensation according to claim 1, characterized in that: The bias module includes a first bias circuit and a second bias circuit. The input ends of the first-order compensation bandgap reference module and the exponential compensation current generation module are both connected to the output end of the first bias circuit. The input end of the first bias circuit is connected to the output end of the operational amplifier module. The output end of the second bias circuit is connected to the input end of the operational amplifier module. The first bias circuit is used to provide the bias voltage for the first-order compensation bandgap reference module and the exponential compensation current generation module. The second bias circuit is used to provide the bias voltage for the operational amplifier module.

5. The bandgap reference source based on exponential compensation according to claim 1, characterized in that: The operational amplifier module includes a five-tube operational amplifier circuit, a common source amplifier circuit and a Miller compensation circuit. The input end of the five-tube operational amplifier circuit is connected to the output end of the first-order compensation bandgap reference module, the five-tube operational amplifier circuit is connected to the common source amplifier circuit, and the Miller compensation circuit is connected between the five-tube operational amplifier circuit and the common source amplifier circuit.

6. The bandgap reference source based on exponential compensation according to claim 3, characterized in that: The subthreshold tube gate voltage generating circuit includes a first transistor, a second transistor, a common source and common gate current mirror and a first resistor. The gates of the first transistor and the second transistor are both connected to the output end of the first-order compensation bandgap reference module, the source of the first transistor is connected to one end of the first resistor, the drain of the first transistor is connected to the source of the second transistor, the drain of the second transistor is connected to the input end of the common source and common gate current mirror, the output end of the common source and common gate current mirror is connected to the other end of the first resistor, the first transistor and the second transistor are used to copy the reference current to the common source and common gate current mirror, the common source and common gate current mirror is used to copy the reference current to the first resistor, and the first resistor is used to generate the tube gate voltage according to the reference current.

7. The bandgap reference source based on exponential compensation according to claim 6, characterized in that: The compensation current generating circuit includes a third transistor, the gate of the third transistor is connected between the first resistor and the common-source common-gate current mirror, the drain of the third transistor is connected to the output end of the first-order compensation bandgap reference module, and the third transistor is used to generate the exponential compensation current according to the gate voltage.

8. The bandgap reference source based on exponential compensation according to claim 5, characterized in that: The common-source amplifier circuit includes a fourth transistor and a fifth transistor, the source of the fourth transistor is connected to one end of the five-tube operational amplifier circuit, the drains of the Miller compensation circuit and the fifth transistor are both connected to the drain of the fourth transistor, the five-tube operational amplifier circuit and the Miller compensation circuit are both connected to the gate of the fifth transistor, and the source of the fifth transistor is connected to one end of the five-tube operational amplifier circuit.

9. The bandgap reference source based on exponential compensation according to claim 8, characterized in that: The Miller compensation circuit includes a first capacitor and a second resistor, one end of the first capacitor is connected between the drain of the fourth transistor and the drain of the fifth transistor, the other end of the first capacitor is connected to one end of the second resistor, and the other end of the second resistor is connected between the five-transistor operational amplifier circuit and the gate of the fifth transistor.

10. A control method for a bandgap reference source based on exponential compensation, used for controlling a bandgap reference source based on exponential compensation according to any one of claims 1 to 9, characterized in that: The following steps are involved: Discharging the first-order compensation bandgap reference module through the startup module to make the first-order compensation bandgap reference module leave the degenerate working point; The first-order compensation bandgap reference module is assisted by an operational amplifier module to generate a reference current; Generate a first-order compensated reference voltage by using the first-order compensated bandgap reference module; Generate an exponential compensation current according to the reference voltage by an exponential compensation current generating module, and perform exponential compensation on the reference voltage by the exponential compensation current; A bias voltage is provided to the first-order compensation bandgap reference module, the exponential compensation current generating module and the operational amplifier module through a bias module.

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