Bandgap reference source based on exponential compensation and its control method

Abstract

The present invention discloses a bandgap reference source based on exponential compensation and a control method thereof. The reference source includes a startup module, a first-order compensated bandgap reference module, an exponentially compensated current generation module, a bias module, and an operational amplifier module. The startup module is used to discharge the first-order compensated bandgap reference module to allow the first-order compensated bandgap reference module to break away from a degenerate operating point. The first-order compensated bandgap reference module is used to generate a first-order compensated reference voltage. The exponentially compensated current generation module is used to generate an exponentially compensated current based on the reference voltage and exponentially compensate the reference voltage using the exponentially compensated current. The operational amplifier module is used to assist the first-order compensated bandgap reference module in generating the reference current. The bias module is used to provide a bias voltage for the first-order compensated bandgap reference module, the exponentially compensated current generation module, and the operational amplifier module. The present invention can realize a bandgap reference source with low power consumption, low temperature drift coefficient, and high power supply rejection ratio, and can be widely used in the field of integrated circuit technology.

Description

Technical Field

[0001] The present 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 advancement of integrated circuit technology, the accuracy and speed requirements for bandgap references, a fundamental building block of analog circuits, are constantly increasing. Bandgap references are widely used in high-precision voltage references due to their excellent temperature stability. Their performance is crucial to the accuracy and performance of the entire system. Traditional bandgap references use positive and negative temperature coefficient currents for first-order compensation, reducing the temperature drift of the output voltage. However, the accuracy of the output reference voltage cannot meet current application requirements. Among existing high-order compensation techniques, segmented compensation uses different curvature compensation branches to correct the curvature of the reference characteristic curve at different temperature ranges. However, this method has a complex circuit structure, is significantly affected by process factors, and consumes high power. Exponential compensation achieves a higher power supply rejection ratio, but also requires higher power consumption and suffers from lower output voltage accuracy. Second-order temperature compensation circuits eliminate the second-order term in the temperature coefficient, minimizing temperature drift, but the circuit structure is complex and occupies a large chip area. Summary of the Invention

[0003] To solve the above technical problems, the present invention aims 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, 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 first-order compensation bandgap reference module is connected to the first-order compensation bandgap reference module, the startup module is used to discharge the first-order compensation bandgap reference module to make the first-order compensation bandgap reference module leave the degenerate operating 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 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.

[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 both connected to the input end of the voltage generating circuit, and 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 generation module includes a subthreshold gate voltage generation circuit and a compensation current generation circuit, the input end of the subthreshold gate voltage generation circuit is connected to the output end of the first-order compensation bandgap reference module, the output end of the subthreshold gate voltage generation circuit is connected to the input end of the compensation current generation circuit, the output end of the compensation current generation circuit is connected to the output end of the first-order compensation bandgap reference module, the subthreshold gate voltage generation circuit is used to generate a gate voltage according to the reference current, and the compensation current generation 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 compensated 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 transistor gate voltage generation circuit includes a first transistor, a second transistor, a cascode 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 cascode current mirror, the output end of the cascode 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 cascode current mirror, the cascode current mirror is used to copy the reference current to the first resistor, and the first resistor is used to generate the transistor 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 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 drain 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 objectives, another aspect of the present invention provides a method for controlling 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 escape from the degenerate operating point;

[0015] Assisting the first-order compensation bandgap reference module to generate a reference current through an operational amplifier module;

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

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

[0018] A bias voltage is provided to the first-order compensation bandgap reference module, the exponential compensation current generation 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 compensated bandgap reference module, an exponentially compensated current generation module, a bias module, and an operational amplifier module. The startup module is used to discharge the first-order compensated bandgap reference module to allow the first-order compensated bandgap reference module to break away from a degenerate operating point. The first-order compensated bandgap reference module is used to generate a first-order compensated reference voltage. The exponentially compensated current generation module is used to generate an exponentially compensated current based on the reference voltage and exponentially compensate the reference voltage using the exponentially compensated current. The operational amplifier module is used to assist the first-order compensated bandgap reference module in generating a reference current. The bias module is used to provide a bias voltage for the first-order compensated bandgap reference module, the exponentially compensated current generation module, and the operational amplifier module. The present invention introduces an operational amplifier module into the first-order compensated bandgap reference module and designs a bias module to reduce the use of resistors. Through the coordinated operation of the five modules of the startup module, the first-order compensated bandgap reference module, the exponentially compensated 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 achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions 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 solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any 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 flowchart of the steps of a control method for a bandgap reference source based on exponential compensation provided by an embodiment of the present invention.

[0024] Reference 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 with reference to 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 merely examples of devices and methods consistent with some aspects of the embodiments of the present application as detailed in the appended claims.

[0026] It will be understood that the terms "first", "second", etc. used in this application may be used herein to describe various concepts, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments 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 may be interpreted as "at the time of" or "when" or "in response to determining".

[0027] The terms "at least one", "plurality", "each", "any", etc. used in this application include "at least one", "two" or more, "plurality" or "each", "any" or "any one", "each" or "any one" as used herein.

[0028] With the rapid development of integrated circuit technology, the accuracy and speed requirements for bandgap references (Bandgap References), a fundamental building block of analog circuits, continue to increase. Bandgap references are widely used in high-precision voltage references due to their excellent temperature stability. Their performance has a crucial impact on the accuracy and performance of the entire system. Currently, the main challenges facing bandgap reference design include maintaining a low temperature drift coefficient over a wide temperature range, reducing power consumption while ensuring high accuracy, and reducing the reference's sensitivity to supply voltage.

[0029] Traditional bandgap reference sources use positive and negative temperature coefficient currents for first-order compensation, thereby reducing the temperature drift coefficient of the output voltage. However, the accuracy of the output reference voltage cannot meet the current application requirements. Among existing high-order compensation technologies, segmented compensation technology uses different curvature compensation branches to correct the curvature of the reference source characteristic curve in different temperature ranges. However, this method has a complex circuit structure, is significantly affected by the process, and consumes high power. Exponential compensation technology can achieve a higher power supply rejection ratio, but also requires higher power consumption and has low output voltage accuracy. Second-order temperature compensation circuits can eliminate the influence of the second-order term in the temperature coefficient and have a smaller temperature drift, but the circuit structure is complex and occupies a large chip area.

[0030] To this end, an embodiment of the present invention proposes a bandgap reference source based on exponential compensation, comprising a startup module, a first-order compensated bandgap reference module, an exponentially compensated current generation module, a bias module, and an operational amplifier module. The startup module is configured to discharge the first-order compensated bandgap reference module to release it from a degenerate operating point. The first-order compensated bandgap reference module is configured to generate a first-order compensated reference voltage. The exponentially compensated current generation module is configured to generate an exponentially compensated current based on the reference voltage and exponentially compensate the reference voltage using the exponentially compensated current. The operational amplifier module is configured to assist the first-order compensated bandgap reference module in generating the reference current. The bias module is configured to provide a bias voltage for the first-order compensated bandgap reference module, the exponentially compensated current generation module, and the operational amplifier module. The present invention introduces an operational amplifier module into the first-order compensated bandgap reference module and utilizes the bias module to reduce the use of resistors. Through the coordinated operation of the startup module, the first-order compensated bandgap reference module, the exponentially compensated 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 achieved.

[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 provides a bandgap reference source based on exponential compensation, comprising a startup module, a first-order compensated bandgap reference module, an exponentially compensated current generating module, a bias module, and an operational amplifier module. One end of the startup module is connected to one end of the first-order compensated bandgap reference module, the other end of the first-order compensated bandgap reference module is connected to one end of the exponentially compensated current generating module, and the other end of the exponentially compensated current generating module is connected to one end of the operational amplifier module. The first-order compensated bandgap reference module, the exponentially compensated current generating module, and the operational amplifier module are also connected to the bias module. The startup module is configured to discharge the first-order compensated bandgap reference module to enable the first-order compensated bandgap reference module to escape a degenerate operating point. The operational amplifier module is configured to assist the first-order compensated bandgap reference module in generating a reference current. The first-order compensated bandgap reference module is configured to generate a reference voltage after first-order compensation. The exponentially compensated current generating module is configured to generate an exponentially compensated current based on the reference voltage and exponentially compensate the reference voltage using the exponentially compensated current. The bias module is configured to provide a bias voltage for the first-order compensated bandgap reference module, the exponentially compensated current generating module, and the operational amplifier module.

[0032] Specifically, the startup module ensures the bandgap reference circuit starts up properly. In the initial state of the circuit, all nodes may be at the same potential (i.e., a degenerate operating point), causing the circuit to malfunction. The startup module provides a momentary discharge current to the first-order compensated bandgap reference module, allowing it to escape the degenerate operating point and thus start the entire circuit.

[0033] In some optional embodiments, such as Figure 2 The figure shows a circuit schematic for a bandgap reference source based on exponential compensation. The startup module includes MOS transistors NM11, NM12, NM13, PM18, PM19, and PM20. During the startup phase, MOS transistors NM11 and NM12 in the startup module are turned on, while MOS transistor NM13 is turned off. MOS transistor NM11 discharges the VBP node, allowing the circuit to quickly exit the degenerate operating point and enter normal operation. When the circuit is operating normally, MOS transistor NM13 turns on and discharges the gates of MOS transistors NM11 and NM12, turning them off and thus 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. It achieves preliminary compensation for temperature changes by utilizing the voltage difference generated by two transistors with different temperature coefficients.

[0035] The exponential compensation current generation module is used to provide a current with exponential temperature compensation characteristics based on 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 compensated bandgap reference module in generating a reference current.

[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 the specified operating point.

[0038] Further as an optional embodiment, 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, and 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 transistors PM1, PM2, PM3, PM4, triodes Q1, Q2, and resistor R3; the second current generating circuit includes MOS transistors PM1, PM2, Q1, resistors R1, and R2; and the voltage generating circuit includes MOS transistors PM5, PM6, and resistor R4.

[0040] Specifically, the first-order compensated bandgap reference module utilizes the operational amplifier and current mirror feedback mechanism of the operational amplifier module to ensure that the voltages at the VP and VN nodes are equal. Simultaneously, a cascode current mirror ensures that the currents flowing through MOS transistors PM1, PM3, and PM5 are consistent. During this process, the base-emitter voltage of transistor Q1 has a negative temperature coefficient and is converted into a negative temperature coefficient current across resistor R1. Meanwhile, the base-emitter voltage difference between transistors Q1 and Q2 has a positive temperature coefficient and is converted into a positive temperature coefficient current across resistor R3. These two currents are replicated along the way to MOS transistor PM5 through the current mirror, generating the first-order compensated reference voltage across resistor R4.

[0041] As a further optional embodiment, the exponential compensation current generation module includes a subthreshold gate voltage generation circuit and a compensation current generation circuit, wherein the input end of the subthreshold gate voltage generation circuit is connected to the output end of the first-order compensation bandgap reference module, the output end of the subthreshold gate voltage generation circuit is connected to the input end of the compensation current generation circuit, and the output end of the compensation current generation circuit is connected to the output end of the first-order compensation bandgap reference module. The subthreshold gate voltage generation circuit is used to generate a gate voltage based on a reference current corresponding to a reference voltage, and the compensation current generation circuit is used to generate an exponential compensation current based on the gate voltage.

[0042] Reference Figure 2 As an optional embodiment, the subthreshold gate voltage generating circuit includes a first transistor, a second transistor, a cascode 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 cascode current mirror, the output end of the cascode 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 cascode current mirror, the cascode 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 As an optional embodiment, 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 formed by first and second transistors PM7 and PM8 to copy the first-order compensated reference current to MOS transistors NM1 and NM2. A cascode current mirror formed by MOS transistors NM1 to NM4 then copies the first-order compensation current to first resistor R5, providing a stable gate voltage with a small temperature drift coefficient for third transistor PM9. Third transistor PM9 operates in the subthreshold region and utilizes its subthreshold exponential conduction characteristic to inject current into the output node, achieving precise 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 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 a 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 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 transistors PM10, PM11, PM12, NM5, and NM6; the second bias circuit includes MOS transistors PM13, PM14, NM7, and NM8.

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

[0049] As a further 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 compensated 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-transistor OTA (Operational Transconductance Amplifier) structure (i.e., a five-transistor operational amplifier circuit). The five-transistor operational amplifier circuit includes MOS transistors NM9, NM11, NM12, PM15, and PM16. MOS transistors NM11 and NM12 serve as differential input transistors, MOS transistor NM9 serves as a tail current source, and MOS transistors PM15 and PM16 serve as current mirror loads.

[0051] Reference Figure 2 , further as an optional embodiment, 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 drain 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 embodiment, 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-transistor operational amplifier circuit and the gate of the fifth transistor.

[0053] Specifically, the second stage of the operational amplifier module utilizes 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. The fourth transistor NM10 acts as a current source load, while the fifth transistor PM17 functions as a common-source amplifier. To ensure operational stability, the present embodiment also incorporates Miller compensation, implemented by the second resistor R6 and the first capacitor C1.

[0054] The above describes the structure and operating principle of the exponentially compensated bandgap reference source according to an embodiment of the present invention. It can be appreciated that the embodiment of the present invention includes a startup module, a first-order compensated bandgap reference module, an exponentially compensated current generation module, a bias module, and an operational amplifier module. By introducing an operational amplifier into the first-order compensation circuit and designing a bias module to reduce the use of resistors, the power supply rejection ratio reaches -62.78dB, a performance significantly improved compared to the -28dB in a similar compensation scheme. Compared to a similar first-order compensation circuit design, a similar temperature drift coefficient can be achieved, and the power consumption is significantly reduced 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 for a bandgap reference source based on exponential compensation, which is used to control the bandgap reference source based on exponential compensation, including 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 escape from the degenerate operating 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 an exponential compensation current generating module, and performing exponential compensation on the reference voltage by the exponential compensation current;

[0060] S105 , providing a bias voltage to the first-order compensation bandgap reference module, the exponential compensation current generation module, and the operational amplifier module through the 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 bandgap reference source based on exponential compensation. The functions specifically implemented by the control method embodiment of the 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 can be implemented or practiced by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer-readable memory. The above methods can 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 figures described in the specific embodiments. Each program can be implemented in a high-level procedural or object-oriented programming language to communicate with the computer system. However, if desired, the program can be implemented in assembly or machine language. In any case, the language can be a compiled or interpreted language. In addition, the program can be run on a programmed application-specific 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 the 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] Furthermore, the above methods 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 as 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, RAM, 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 processes described herein. In addition, the machine-readable code, or portions thereof, can be transmitted over 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 herein, 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 that is 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 a physical and tangible object, including a specific visual depiction of the physical and tangible object produced on the display.

[0066] In the above description of this specification, reference to the terms "one embodiment / example," "another embodiment / example," or "certain embodiments / examples" 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 suitable manner in any one or more embodiments or examples.

[0067] While 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 invention, and that the scope of the 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 can 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 system comprises a startup module, a first-order compensated bandgap reference module, an exponentially compensated current generating module, a bias module, and an operational amplifier module. One end of the startup module is connected to one end of the first-order compensated bandgap reference module, the other end of the first-order compensated bandgap reference module is connected to one end of the exponentially compensated current generating module, and the other end of the exponentially compensated current generating module is connected to one end of the operational amplifier module. The first-order compensated bandgap reference module, the exponentially compensated current generating module, and the operational amplifier module are all connected to the bias module. The startup module is used to discharge the first-order compensated bandgap reference module to allow the first-order compensated bandgap reference module to escape from a degenerate operating point. The operational amplifier module is used to assist the first-order compensated bandgap reference module in generating a reference current. The first-order compensated bandgap reference module is used to generate a reference voltage after first-order compensation. The exponentially compensated current generating module is used to generate an exponentially compensated current based on the reference voltage and perform exponential compensation on the reference voltage using the exponentially compensated current. The bias module is used to provide a bias voltage for the first-order compensated bandgap reference module, the exponentially compensated current generating module, and the operational amplifier module. 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 terminals of the first current generating circuit and the second current generating circuit are both connected to the input terminal of the voltage generating circuit. The output terminal of the voltage generating circuit is connected to the output terminal 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. The exponential compensation current generation module includes a subthreshold gate voltage generation circuit and a compensation current generation circuit. The input end of the subthreshold gate voltage generation circuit is connected to the output end of the first-order compensation bandgap reference module, the output end of the subthreshold gate voltage generation circuit is connected to the input end of the compensation current generation circuit, and the output end of the compensation current generation circuit is connected to the output end of the first-order compensation bandgap reference module. The subthreshold gate voltage generation circuit is used to generate a gate voltage based on the reference current, and the compensation current generation circuit is used to generate the exponential compensation current based on the gate voltage.

2. 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, 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.

3. 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 compensated 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.

4. The bandgap reference source based on exponential compensation according to claim 1, characterized in that: The subthreshold transistor gate voltage generation circuit includes a first transistor, a second transistor, a cascode 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 cascode current mirror, the output end of the cascode 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 cascode current mirror, the cascode current mirror is used to copy the reference current to the first resistor, and the first resistor is used to generate the transistor gate voltage according to the reference current.

5. The bandgap reference source based on exponential compensation according to claim 4, 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.

6. The bandgap reference source based on exponential compensation according to claim 3, 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.

7. The bandgap reference source based on exponential compensation according to claim 6, 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.

8. A method for controlling a bandgap reference source based on exponential compensation, for controlling a bandgap reference source based on exponential compensation according to any one of claims 1 to 7, 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 escape from the degenerate operating point; Assisting the first-order compensation bandgap reference module to generate a reference current through an operational amplifier module; Generate a first-order compensated reference voltage by using the first-order compensated bandgap reference module; generating an exponential compensation current according to the reference voltage by an exponential compensation current generating module, and performing exponential compensation on the reference voltage by using the exponential compensation current; A bias voltage is provided to the first-order compensation bandgap reference module, the exponential compensation current generation module and the operational amplifier module through a bias module.

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