Low-voltage band-gap reference circuit capable of being distributed and system on chip

Abstract

The invention relates to a band-gap reference circuit, in particular to a low-voltage band-gap reference circuit capable of being arranged in a distributed mode and a system on chip, the reference circuit comprises a constant transconductance circuit module and a plurality of reference voltage generation modules distributed independently, and all the reference voltage generation modules are connected with the constant transconductance circuit module to achieve cooperative work. Core elements of the reference voltage generation module mainly comprise a resistor R1, a resistor R2, a bipolar transistor Q1 and a reference voltage output end, and are based on positive temperature coefficient current generated by the constant transconductance circuit module. And the positive temperature coefficient voltage generated on the resistor R1 and the negative temperature coefficient base-emitter voltage of the bipolar transistor Q1 are mutually offset, so that a low-voltage reference voltage can be output at the reference voltage output end, and the voltage reference circuit is suitable for distributed precise voltage supply. Compared with the structure in the prior art, the circuit also has the advantages of low power supply voltage, low power consumption, small area, no degeneracy point in power-on starting and the like.

Description

Technical Field

[0001] The present invention relates to a bandgap reference circuit, and particularly to a low-voltage bandgap reference circuit and a system-on-chip that can be distributedly arranged. Background Art

[0002] The bandgap reference (BG) circuit plays a core role in analog integrated circuits, providing a stable reference voltage for various circuits to ensure the reliable operation of the system. With the development of integrated circuit technology, especially the rise of application scenarios such as portable devices, the Internet of Things, and wearable devices, strict requirements for low power consumption, small area, and low operating voltage are imposed on the bandgap reference circuit. However, the traditional bandgap reference circuit is built based on bipolar junction transistors (BJTs), which not only has a high operating voltage, relies on multiple BJTs and operational amplifiers, resulting in a large chip area and high cost, but also has the problem of low-temperature startup degeneracy point, making it difficult to meet the design requirements of advanced CMOS processes.

[0003] Currently, various structures have been derived from the bandgap reference circuit around different indicators. The most commonly used traditional bandgap reference circuit (such as Figure 1 ) and the low-voltage current-mode bandgap reference source (such as Figure 2 ) each have their drawbacks. The former has an output voltage of about 1.25V, which is difficult to adapt to the high integration requirements under nanometer processes, and has high requirements for operational amplifiers and a large area occupied by bipolar junction transistor (BJT) units; the latter, although adapted to low supply voltages, is prone to falling into the degeneracy point at low voltages, has a complex startup circuit, and also faces the area problem of BJT units and operational amplifiers. In addition, the chip SoC trend brings problems such as scattered reference voltage requirements and transmission crosstalk, and multi-reference design will exacerbate the area and power consumption burden. Therefore, an ideal bandgap reference circuit under advanced processes needs to achieve low-voltage output, low power consumption, and small area, and also be able to distributively provide accurate reference voltages.

[0004] There is a currently available op-amp-less BG circuit as shown in Figure 3 . Based on the improvement of the traditional low-voltage current-mode structure, by removing the operational amplifier and introducing transistors M4 and M5 to construct a new structure. This structure uses the current mirror composed of transistors M1 and M2 to ensure that the two currents are equal, realizes voltage clamping at points X and Y, and effectively reduces the chip area. However, this circuit still has the following deficiencies:

[0005] First, distributed reference voltage: The distributed reference voltages generated by the current-mode structure need to be the same, and it is difficult for the resistors at a distance to meet the matching requirements with the bandgap core resistors.

[0006] Second, power consumption: The minimum supply voltage of the op-amp-less BG circuit is greater than 1.5V. The bipolar junction transistor (BJT) has a minimum current limit for stable operation, and the current consumption on the resistor is high, which limits its application in low-power scenarios.

[0007] Third, area: Multiple bipolar junction transistors (BJTs) are set in a specific ratio to achieve matching, increasing the layout area.

[0008] Fourth, power-on stability: When the closed-loop circuit is powered on, there are two solutions, zero current and stable operating current. An additional startup circuit is required, increasing the device area and circuit complexity. Summary of the Invention

[0009] To solve the above technical problems, the present invention provides a low-voltage bandgap reference circuit and a system-on-chip that can be distributed. The distributable low-voltage bandgap reference circuit includes: a constant transconductance circuit module and a plurality of independently distributed reference voltage generation modules;

[0010] Among them, the constant transconductance circuit module includes a plurality of current mirror components. The plurality of current mirror components are connected to the plurality of reference voltage generation modules in a one-to-one correspondence. Each current mirror component includes a first output terminal and a second output terminal, and is used to output two paths of mirror-replicated positive temperature coefficient currents;

[0011] Each reference voltage generation module includes a first input terminal, a second input terminal, a resistor R1, a resistor R2, a bipolar junction transistor Q1, and a reference voltage output terminal; the first output terminal is connected to the first input terminal, and the second output terminal is connected to the second input terminal;

[0012] One end of the resistor R2 is connected to the first input terminal and the reference voltage output terminal, and the other end is connected to the base of the bipolar junction transistor Q1. The base and the collector of the bipolar junction transistor Q1 are connected and grounded;

[0013] One end of the resistor R1 is connected to the second input terminal, and the other end is connected to the reference voltage output terminal. The positive temperature coefficient current output from the second input terminal generates a positive temperature coefficient voltage across the resistor R1;

[0014] The emitter of the bipolar junction transistor Q1 is connected to the second output terminal. A negative temperature coefficient voltage is generated through the bipolar junction transistor Q1, and the negative temperature coefficient voltage and the positive temperature coefficient voltage interact with each other, and a low temperature coefficient reference voltage is generated at the reference voltage output terminal.

[0015] In an embodiment of the present invention, the expression of the low temperature coefficient reference voltage V out is as follows:

[0016]

[0017] Among them, V BE is the base-emitter voltage of the bipolar junction transistor Q1, I PTAT is the positive temperature coefficient current, and K represents the multiple of mirror-replicating the positive temperature coefficient current.

[0018] In one embodiment of the present invention, the constant transconductance circuit module further includes a positive temperature coefficient current generation module, and the positive temperature coefficient current generation module is connected to the plurality of current mirror components to provide a positive temperature coefficient current independent of the power supply voltage for the plurality of current mirror components.

[0019] In one embodiment of the present invention, the current mirror component further includes a MOS transistor M1 and a MOS transistor M2, and the gates of the MOS transistor M1 and the MOS transistor M2 are connected to the positive temperature coefficient current generation module.

[0020] In one embodiment of the present invention, the drains of the MOS transistor M1 and the MOS transistor M2 are respectively connected to the first output terminal and the second output terminal.

[0021] In one embodiment of the present invention, the MOS transistor M1 and the MOS transistor M2 have the same channel length, and the width ratio is K:1, where K is an integer.

[0022] In one embodiment of the present invention, the positive temperature coefficient current generation module includes a bias voltage node, a MOS transistor MS1, a MOS transistor MS2, a MOS transistor MS3, a MOS transistor MS4, a MOS transistor MS5, and a resistor RS1; the gate of the MOS transistor MS1 is connected to the gate of the MOS transistor MS2 through the bias voltage node, the drain of the MOS transistor MS1 is connected to the source of the MOS transistor MS3 and one end of the resistor RS1, and the other end of the resistor RS1 is connected to the drain of the MOS transistor MS4 and the gate of the MOS transistor MS5; the sources of the MOS transistor MS4 and the MOS transistor MS5 are grounded;

[0023] The gate of the MOS transistor MS4 is connected to the source of the MOS transistor MS3, and the drain and the gate of the MOS transistor MS3 are connected and connected to the bias voltage node.

[0024] In one embodiment of the present invention, the gates of the MOS transistor M1 and the MOS transistor M2 are connected to the bias voltage node.

[0025] In one embodiment of the present invention, the gate of the MOS transistor MS3 is connected to the drain of the MOS transistor MS2.

[0026] Based on the same inventive concept, the present invention further provides a system-on-chip, which includes a plurality of functional units and the distributable low-voltage bandgap reference circuit, and the low-voltage bandgap reference circuit provides an adapted reference voltage for different functional units.

[0027] The above technical solutions of the present invention have the following advantages compared with the prior art:

[0028] 1. Low power consumption: By reducing the number of devices consuming voltage margin and the number of current branches in the power - ground path, the minimum power supply voltage requirement and the total current of the bandgap reference (BG) circuit are reduced, thereby effectively reducing the power consumption of the circuit.

[0029] 2. High integration: A positive temperature coefficient voltage is generated using a current and a resistor proportional to absolute temperature (PTAT). Compared with the traditional method of generating a positive temperature coefficient voltage using the voltage difference of different numbers of bipolar junction transistors (BJTs), there is no need to match large - channel - area BJTs, and at the same time, the number of metal - oxide - semiconductor (MOS) transistors and resistors used is reduced, significantly reducing the area cost of the circuit.

[0030] 3. Power - on stability (start - up problem): The construction of the closed - loop circuit is avoided, and the zero - degeneracy point during circuit power - on is eliminated. As long as the constant - transconductance (Constant - Gm) circuit can normally generate PTAT current during power - on, the probability that the bandgap reference (BG) circuit generates a zero - temperature - coefficient voltage can reach 100%, fundamentally avoiding the circuit start - up failure problem.

[0031] 4. Convenience of distributed reference voltage generation: The core part of the bandgap reference (BG) circuit for generating the reference voltage consists of only two resistors and one bipolar junction transistor (BJT), and only two sets of PTAT currents need to be mirror - introduced from the adjacent constant - transconductance bias module. The constant - transconductance bias circuit is widely used in integrated circuits and occupies a small chip area. Given that modern integrated circuits often require multiple reference voltages, the current - mirroring method adopted in the present invention is significantly less affected by crosstalk compared with direct voltage transmission, which is more conducive to the distributed and accurate generation of reference voltages. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to make the content of the present invention easier to be clearly understood, the following further details the present invention according to specific embodiments of the present invention in combination with the drawings, where

[0033] Figure 1 is a schematic structural diagram of a traditional bandgap reference circuit;

[0034] Figure 2 is a schematic structural diagram of a low - voltage current - mode bandgap reference source circuit;

[0035] Figure 3 is a schematic structural diagram of an op - amp - less BG circuit constructed by removing the op - amp and introducing transistors based on the traditional low - voltage current - mode structure;

[0036] Figure 4 is a schematic structural diagram of a distributable low - voltage bandgap reference circuit provided in the embodiment of the present invention;

[0037] Figure 5 It is a schematic diagram of the specific structure of a distributable low - voltage bandgap reference circuit provided in an embodiment of the present invention;

[0038] Figure 6 It is a schematic diagram of the circuit structure of a constant transconductance circuit module provided in an embodiment of the present invention;

[0039] Figure 7 It is a schematic diagram of the circuit structure of a reference voltage generation module provided in an embodiment of the present invention;

[0040] Explanation of the reference numerals in the specification drawings:

[0041] 10. Constant transconductance circuit module; 101. Current mirror assembly; 1011. First output terminal; 1012. Second output terminal; 102. Positive temperature coefficient current generation module; 1021. Bias voltage node; 20. Reference voltage generation module; 201. First input terminal; 202. Second input terminal; 203. Reference voltage output terminal. Specific embodiments

[0042] The following further describes the present invention in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the illustrated embodiments do not limit the present invention.

[0043] Embodiment 1

[0044] Referring to Figures 4 to 7 As shown, the present invention provides a distributable low - voltage bandgap reference circuit, which includes: a constant transconductance circuit module 10 and N independently distributed reference voltage generation modules 20. Each reference voltage generation module 20 realizes collaborative work by connecting to the constant transconductance circuit module 10.

[0045] Among them, the constant transconductance circuit module 10 includes a plurality of current mirror assemblies 101. The plurality of current mirror assemblies 101 are connected to the plurality of reference voltage generation modules 20 in one - to - one correspondence. Each current mirror assembly 101 includes a first output terminal 1011 and a second output terminal 1012, and is used to output two mirror - copied positive temperature coefficient currents;

[0046] Each reference voltage generation module 20 includes a first input terminal 201, a second input terminal 202, a resistor R1, a resistor R2, a bipolar transistor Q1, and a reference voltage output terminal 203; the first input terminal 201 is connected to the first output terminal 1011, and the second input terminal 202 is connected to the second output terminal 1012;

[0047] One end of the resistor R2 is connected to the first input terminal 201 and the reference voltage output terminal 203, and the other end is connected to the base of the bipolar transistor Q1. The base of the bipolar transistor Q1 is connected to its collector and grounded.

[0048] One end of the resistor R1 is connected to the second input terminal 202, and the other end is connected to the reference voltage output terminal 203. The positive temperature coefficient current output from the second input terminal 202 generates a positive temperature coefficient voltage across the resistor R1.

[0049] The emitter of the bipolar transistor Q1 is connected to the second output terminal 1012. A negative temperature coefficient voltage is generated through the bipolar transistor Q1, enabling the negative temperature coefficient voltage and the positive temperature coefficient voltage to interact, and a low temperature coefficient reference voltage is generated at the reference voltage output terminal 203.

[0050] As can be seen from the above technical solution, the PTAT current required to generate the reference voltage is transmitted by means of current mirroring. Compared with directly transmitting the voltage, it is less affected by crosstalk and is more suitable for distributed generation of accurate reference voltage. The positive temperature coefficient voltage is generated by the PTAT current and the resistor R1. Compared with the traditional method of generating the positive temperature coefficient voltage by using the voltage difference of different numbers of BJTs, there is no need to match large-channel area BJTs, reducing the number of MOS transistors and resistors and lowering the area cost of the circuit.

[0051] As Figure 6 shown, the constant transconductance circuit module 10 further includes a positive temperature coefficient current generation module 102. The positive temperature coefficient current generation module 102 is connected to the plurality of current mirror components 101 to provide a positive temperature coefficient current I PTAT independent of the power supply voltage for the plurality of current mirror components 101. Specifically, the current mirror component 101 further includes an MOS transistor M1 and an MOS transistor M2. The gates of the MOS transistor M1 and the MOS transistor M2 are connected to the positive temperature coefficient current generation module 102, and the drains of the MOS transistor M1 and the MOS transistor M2 are respectively connected to the first output terminal 1011 and the second output terminal 1012.

[0052] Furthermore, the MOS transistor M1 and the MOS transistor M2 have the same channel length, and the width ratio is K:1, where K is an integer. Since the gate voltages of the MOS transistor M1 and the MOS transistor M2 are equal, the PTAT current mirror-replicated through the MOS transistor M1 is K times the PTAT current (I PTAT1 ) mirror-replicated through the MOS transistor M2.

[0053] The positive temperature coefficient current I output from the drain of the MOS transistor M2 PTAT1A positive temperature coefficient voltage is generated via the resistor R1, and at the same time, a positive temperature coefficient current I is output from the drain of the MOS transistor M2 PTAT1 A negative temperature coefficient voltage is generated via the bipolar transistor Q1, and by adjusting the resistance value of the resistor R1, the negative temperature coefficient voltage and the positive temperature coefficient voltage cancel each other out.

[0054] The resistor R2 cooperates with the resistor R1 for voltage division. According to the principle of resistor voltage division, a part of the voltage from the series branch of the resistor R1 and the bipolar transistor Q1 is taken as the output reference voltage V out . The low temperature coefficient reference voltage V out can be made less than the base-emitter voltage V of the bipolar transistor Q1 BE , and its expression is as follows:

[0055]

[0056] where I PTAT is the positive temperature coefficient current generated by the positive temperature coefficient current generation module 102, and K represents the multiple of mirroring the PTAT current through the MOS transistor M1. Changing the value of K can directly affect the magnitude of the output reference voltage V out , so that the circuit can flexibly adjust the reference voltage according to different application requirements to adapt to diverse working scenarios.

[0057] In an actual application scenario, since many functional circuit modules in the chip require the constant transconductance circuit module 10 to provide bias current, the constant transconductance circuit module 10 does not incur additional circuit costs for this application.

[0058] As Figure 6 shown, the positive temperature coefficient current generation module 102 is used to generate a positive temperature coefficient current I that is independent of the power supply voltage VDD PTAT , which includes a bias voltage node 1021, MOS transistors MS1, MS2, MS3, MS4, MS5, and a resistor RS1; the gate of the MOS transistor MS1 is connected to the gate of the MOS transistor MS2 through the bias voltage node 1021, the drain of the MOS transistor MS1 is connected to the source of the MOS transistor MS3 and one end of the resistor RS1, and the other end of the resistor RS1 is connected to the drain of the MOS transistor MS4 and the gate of the MOS transistor MS5; the sources of the MOS transistors MS4 and MS5 are grounded;

[0059] The gate of the MOS transistor MS4 is connected to the source of the MOS transistor MS3. The drain and the gate of the MOS transistor MS3 are connected and are connected to the bias voltage node 1021. The gate of the MOS transistor MS3 is connected to the drain of the MOS transistor MS2.

[0060] The gates of the MOS transistors M1 and M2 are connected to the bias voltage node 1021. The positive temperature coefficient current generation module 102 provides a bias voltage V for the gates of the MOS transistors M1 and M2. B1 。

[0061] Furthermore, the sources of the MOS transistor MS1, the MOS transistor MS2, the MOS transistor M1, and the MOS transistor M2 are all connected to the power supply voltage VDD. Current flows from the power supply voltage VDD into the MOS transistor MS1 and the MOS transistor MS2. After a part of the current is mirrored by the MOS transistor MS3, it flows out through the MOS transistor MS5. Another part of the current forms a loop through the resistor RS1 and the MOS transistor MS4, and finally outputs a positive temperature coefficient current I proportional to the absolute temperature. PTAT 。

[0062] In the technical solution involved in the present application, the PTAT current proportional to the absolute temperature generated by the constant transconductance circuit module 10 is transmitted to the position where a reference voltage is required by means of a current mirror. At this position, the required reference voltage is generated by the joint action of two resistors (R1 and R2) and a bipolar junction transistor (BJT) Q1. In a metal-oxide-semiconductor (MOS) circuit, adopting a current transmission mode can ensure the efficient and stable transmission of electrical information and is relatively less affected by crosstalk.

[0063] It should be noted that there is a mutual cancellation effect between the resistor R1 in the reference voltage generation module 20 and the resistor RS1 in the constant transconductance module 10. To ensure the consistency of their process characteristics and avoid affecting the circuit performance due to excessive process corner differences, the distance between the resistor R1 and the resistor RS1 should not be too large. In other words, in an integrated circuit, in each area where a stable reference voltage needs to be generated, only two sets of PTAT currents need to be mirror-introduced from the nearest constant transconductance circuit module 10.

[0064] Compare Figure 1 with the traditional bandgap reference circuit shown in Figure 7 and the circuit structure of the reference voltage generation module 20 provided by the present invention shown in Figure 1A separate BJT is used to generate a negative temperature coefficient voltage, and the voltage difference between two BJTs with different numbers is used to generate a positive temperature coefficient voltage. Finally, the positive and negative temperature coefficients are eliminated through resistor R2. This method requires matching multiple standard BJT cells in the layout, resulting in a large area overhead. In contrast, the present invention generates a negative temperature coefficient voltage by using a separate BJT and generates a positive temperature coefficient voltage by using a PTAT current across resistor R1. Only by adjusting resistor R1 can the positive and negative temperature coefficients be eliminated, without the need for matching between multiple BJTs, thus greatly saving area and reducing circuit costs.

[0065] Comparison Figure 2 with the circuit structure of the low-voltage current-mode bandgap reference source in the prior art shown in Figure 7 and the circuit structure of the reference voltage generation module 20 provided by the present invention shown in Figure 2 In the closed-loop circuit where the operational amplifier is located, both positive and negative feedback loops exist simultaneously. To ensure the stability of the circuit and avoid oscillation, it is necessary to ensure that the loop gain of the negative feedback loop is greater than that of the positive feedback loop. More critically, this circuit structure has a degeneracy point problem. Specifically, during the power-on process of the circuit, the two branches I c1 and I c2 of the bandgap reference (BG) circuit may exhibit a degeneracy point of zero current. To prevent the abnormal operation of the circuit caused by the zero-current degeneracy point, an additional startup circuit is required.

[0066] However Figure 7 the circuit structure of the reference voltage generation module 20 provided by the present invention shown in

[0067] In addition, due to the advantages of low power consumption, small area, good power-on stability, and easy distributed generation of reference voltage provided by the low-voltage bandgap reference circuit of the present invention, its application scenarios are extensive. In the field of mobile device chips, such as the system-on-chip (SoC) of smartphones, this circuit can provide a stable reference voltage for internal complex analog and digital circuit modules, ensuring reliable operation of the chip at low power consumption and extending the battery life; in the chips of Internet of Things (IoT) sensor nodes, it can assist various sensor interface circuits in accurately processing signals, ensuring the accuracy of data acquisition, and due to its small area characteristic, it can meet the strict requirements of sensor nodes for the chip channel area; in automotive electronic chips, such as engine control units (ECUs), in-vehicle communication module chips, etc., this circuit can provide a stable reference in a complex electrical environment, ensuring the safety and reliability of automotive electronic systems; in wearable device chips, such as smartwatch chips, the low-voltage bandgap reference circuit can maintain stable operation of the device with limited battery power due to its low power consumption advantage, and at the same time, the small area feature also meets the miniaturization requirements of wearable devices, making the device thinner, lighter, and more portable.

[0068] Embodiment 2

[0069] Based on the same inventive concept as Embodiment 1, the present invention also provides a system-on-chip. The circuit board includes multiple functional units and the distributable low-voltage bandgap reference circuit described in Embodiment 1. The low-voltage bandgap reference circuit provides an adapted reference voltage for different functional units.

[0070] In this embodiment, each functional unit has specific requirements for the magnitude, accuracy, and stability of the reference voltage due to its own working characteristics and performance requirements. The distributable low-voltage bandgap reference circuit can provide an adapted reference voltage for each functional unit through precise current mirroring and voltage regulation mechanisms. For example, for an analog signal processing unit with extremely high requirements for voltage accuracy, the low-voltage bandgap reference circuit can provide a high-precision and low-noise reference voltage to ensure the accuracy and stability of signal processing; for a power consumption-sensitive functional unit, the reference circuit can reduce power consumption through optimized design and extend the battery life of the device.

[0071] Integrating the distributable low-voltage bandgap reference circuit provided by the present invention into an integrated circuit board not only improves the overall performance and reliability of the circuit but also reduces costs and power consumption. Compared with traditional reference voltage supply methods, the integrated circuit board of the present invention has better adaptability and scalability and can meet the requirements of continuously developing electronic devices for high performance, miniaturization, and low power consumption. This design concept and technical solution have broad application prospects in many fields such as smartphones, tablets, wearable devices, and IoT devices, and are expected to bring new breakthroughs and changes to the development of the electronics industry.

[0072] Obviously, the above embodiments are merely examples for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or alterations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or alterations derived therefrom still fall within the protection scope of the present invention.

Claims

1. A low-voltage bandgap reference circuit that can be distributed, characterized in that, Comprising: A constant transconductance circuit module and a plurality of independently distributed reference voltage generation modules; Wherein, the constant transconductance circuit module includes a plurality of current mirror components, and the plurality of current mirror components are connected to the plurality of reference voltage generation modules in one-to-one correspondence. Each current mirror component includes a first output terminal and a second output terminal for outputting two paths of mirror-copied positive temperature coefficient currents; Each reference voltage generation module includes a first input terminal, a second input terminal, a resistor R1, a resistor R2, a bipolar transistor Q1, and a reference voltage output terminal; the first output terminal is connected to the first input terminal, and the second output terminal is connected to the second input terminal; One end of the resistor R2 is connected to the first input terminal and the reference voltage output terminal, and the other end is connected to the base of the bipolar transistor Q1. The base and the collector of the bipolar transistor Q1 are connected and grounded; One end of the resistor R1 is connected to the second input terminal, and the other end is connected to the reference voltage output terminal. The positive temperature coefficient current output from the second input terminal generates a positive temperature coefficient voltage across the resistor R1; The emitter of the bipolar transistor Q1 is connected to the second output terminal, and a negative temperature coefficient voltage is generated through the bipolar transistor Q1, such that the negative temperature coefficient voltage and the positive temperature coefficient voltage interact, and a low temperature coefficient reference voltage is generated at the reference voltage output terminal.

2. The distributable low-voltage bandgap reference circuit according to claim 1, wherein The expression of the low temperature coefficient reference voltage V out is as follows: Among them, V BE is the base-emitter voltage of the bipolar transistor Q1, I PTAT is a positive temperature coefficient current, and K represents the multiple of mirror-copying the positive temperature coefficient current.

3. The distributable low-voltage bandgap reference circuit according to claim 1, wherein The constant transconductance circuit module further includes a positive temperature coefficient current generation module, and the positive temperature coefficient current generation module is connected to the plurality of current mirror components to provide positive temperature coefficient currents independent of the power supply voltage for the plurality of current mirror components.

4. The distributable low-voltage bandgap reference circuit according to claim 3, wherein The current mirror component further includes an MOS transistor M1 and an MOS transistor M2, and the gates of the MOS transistor M1 and the MOS transistor M2 are connected to the positive temperature coefficient current generation module.

5. The distributable low-voltage bandgap reference circuit according to claim 4, wherein The drains of the MOS transistor M1 and the MOS transistor M2 are respectively connected to the first output terminal and the second output terminal.

6. The distributed low-voltage bandgap reference circuit according to claim 4, wherein The MOS transistor M1 and the MOS transistor M2 have the same channel length, and the width ratio is K:1, where K is an integer.

7. The distributed low-voltage bandgap reference circuit according to claim 4, wherein The positive temperature coefficient current generation module includes a bias voltage node, an MOS transistor MS1, an MOS transistor MS2, an MOS transistor MS3, an MOS transistor MS4, an MOS transistor MS5, and a resistor RS1; the gate of the MOS transistor MS1 is connected to the gate of the MOS transistor MS2 through the bias voltage node, the drain of the MOS transistor MS1 is connected to the source of the MOS transistor MS3 and one end of the resistor RS1, and the other end of the resistor RS1 is connected to the drain of the MOS transistor MS4 and the gate of the MOS transistor MS5; The sources of the MOS transistor MS4 and the MOS transistor MS5 are grounded; The gate of the MOS transistor MS4 is connected to the source of the MOS transistor MS3, and the drain and the gate of the MOS transistor MS3 are connected and connected to the bias voltage node.

8. The distributed low-voltage bandgap reference circuit according to claim 7, wherein The gates of the MOS transistor M1 and the MOS transistor M2 are connected to the bias voltage node.

9. The distributable low-voltage bandgap reference circuit according to claim 7, characterized in that, The gate of the MOS transistor MS3 is connected to the drain of the MOS transistor MS2.

10. A system on a chip, characterized in that, It includes multiple functional units and a distributable low-voltage bandgap reference circuit as described in any one of claims 1 to 9, and the low-voltage bandgap reference circuit provides an adapted reference voltage for different functional units.

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