Band-gap reference circuit, electronic chip, and electronic device

Abstract

The invention belongs to the technical field of electronic circuits, and provides a band-gap reference circuit, an electronic chip and electronic equipment. The band-gap reference circuit comprises a first pre-adjusting module, a second pre-adjusting module and a band-gap reference module, the first pre-adjusting module is connected with the second pre-adjusting module and the band-gap reference module, and the first pre-adjusting module is used for receiving power supply voltage. According to the invention, suppression of power supply voltage fluctuation is realized only through loop feedback between the first pre-adjustment module and the second pre-adjustment module, and the stability of reference voltage is ensured. Compared with a band-gap reference circuit adopting an LDO (Low Dropout Regulator) pre-regulator, the band-gap reference circuit is simple in implementation structure, the area, the power consumption and the cost of the circuit can be reduced, and the band-gap reference circuit can have high PSR (Power Supply Ratio).

Description

Technical Field

[0001] The present application belongs to the technical field of electronic circuits, and in particular relates to a bandgap reference circuit, an electronic chip, and an electronic device. Background Art

[0002] Bandgap reference circuits are widely used in power management chips and analog-to-digital / digital-to-analog converters. Their signal accuracy significantly impacts system accuracy, making the design of a high-precision bandgap reference circuit essential. However, the accuracy of bandgap reference circuits is susceptible to power supply voltage fluctuations, so improving their PSR (power supply rejection) is crucial.

[0003] To improve the PSR of the bandgap reference circuit, a pre-regulator is currently used. The principle is to add a low-dropout linear regulator (LDO) before the power input path of the bandgap reference circuit. This LDO itself has a high PSR in the low and medium frequency bands, which can significantly attenuate the ripple and noise of the input power supply, providing a "cleaner" local power supply for the bandgap reference. However, this structure increases area, power consumption, and cost.

[0004] Therefore, proposing a bandgap reference circuit with small area, low power consumption, low cost and high PSR is an urgent problem to be solved. Summary of the Invention

[0005] The embodiments of the present application provide a bandgap reference circuit, an electronic chip, and an electronic device, which can solve the problems that the existing bandgap reference circuit using an LDO pre-regulator can achieve high PSR but has a large area, high power consumption, and high cost.

[0006] In a first aspect, an embodiment of the present application provides a bandgap reference circuit, comprising a first pre-adjustment module, a second pre-adjustment module, and a bandgap reference module, wherein the first pre-adjustment module is connected to the second pre-adjustment module and the bandgap reference module, respectively, and the first pre-adjustment module is configured to receive a power supply voltage; The first pre-adjustment module is used to output a first voltage based on the power supply voltage; the bandgap reference module is used to output a reference voltage based on the first voltage; when the power supply voltage fluctuates, both the first voltage and the reference voltage fluctuate, and the first pre-adjustment module is further used to output a first feedback voltage to the second pre-adjustment module; the second pre-adjustment module is used to output a second feedback voltage based on the first feedback voltage, so that the first pre-adjustment module suppresses the fluctuation of the power supply voltage based on the second feedback voltage.

[0007] In a possible implementation of the first aspect, the first pre-regulation module includes a first current source, a second current source, a first field-effect transistor, a second field-effect transistor, and a first capacitor. The first end of the first current source and the drain of the first field-effect transistor are both used to receive the power supply voltage. The second end of the first current source is respectively connected to the first end of the first capacitor, the gate of the first field-effect transistor, and the second pre-regulation module. The second end of the first capacitor is respectively connected to the drain of the second field-effect transistor, the first end of the second current source, and the second pre-regulation module. The source of the first field-effect transistor is respectively connected to the source of the second field-effect transistor and the bandgap reference module. The gate of the second field-effect transistor is connected to the bandgap reference module. The second end of the second current source is grounded.

[0008] In a possible implementation of the first aspect, the second pre-regulation module includes a third field-effect transistor, a gate of the third field-effect transistor is connected to the first pre-regulation module, a drain of the third field-effect transistor is connected to the first pre-regulation module, and a source of the third field-effect transistor is grounded.

[0009] In a possible implementation of the first aspect, the bandgap reference module includes a current mirror unit, a feedback adjustment unit, a differential pair unit, and an output unit, wherein a first end of the current mirror unit is used to receive a first voltage, a second end of the current mirror unit is respectively connected to the first end of the feedback adjustment unit and the first end of the differential pair unit, a third end of the current mirror unit is respectively connected to the second end of the feedback adjustment unit and the second end of the differential pair unit, a fourth end of the current mirror unit is respectively connected to the output unit and the first pre-adjustment module, and a third end of the feedback adjustment unit is connected to a fifth end of the current mirror unit; The current mirror unit is used to output equal first and second currents according to the first voltage; the differential pair unit is used to generate a third current according to the first and second currents; the current mirror unit is also used to mirror the third current to obtain a fourth current; the output unit is used to output the reference voltage according to the fourth current; the feedback adjustment unit is used to output an adjustment signal according to the first and second voltages, so that the current mirror unit adjusts the first voltage or the second voltage according to the adjustment signal, thereby making the first voltage equal to the second voltage; wherein the first voltage is the voltage at the first end of the feedback adjustment unit, and the second voltage is the voltage at the second end of the feedback adjustment unit.

[0010] In a possible implementation of the first aspect, the current mirror unit includes a fourth field effect transistor, a fifth field effect transistor, a sixth field effect transistor, a seventh field effect transistor, an eighth field effect transistor, and a second capacitor, the source of the fourth field effect transistor is respectively connected to the source of the fifth field effect transistor, the source of the sixth field effect transistor, the source of the seventh field effect transistor, and the first pre-adjustment module, and the gate of the fourth field effect transistor is respectively connected to the drain of the fourth field effect transistor, the drain of the eighth field effect transistor, the gate of the fifth field effect transistor, the gate of the sixth field effect transistor, and the The gate of the seventh field effect transistor is connected, the gate of the eighth field effect transistor is respectively connected to the first end of the second capacitor and the third end of the feedback adjustment unit, the drain of the fifth field effect transistor is respectively connected to the first end of the feedback adjustment unit and the first end of the differential pair unit, the drain of the sixth field effect transistor is respectively connected to the second end of the feedback adjustment unit and the second end of the differential pair unit, the drain of the seventh field effect transistor is respectively connected to the output unit and the first pre-adjustment module, and the source of the eighth field effect transistor and the second end of the second capacitor are both grounded.

[0011] In a possible implementation of the first aspect, the feedback adjustment unit includes an operational amplifier, a first input terminal of the operational amplifier is respectively connected to the second terminal of the current mirror unit and the first terminal of the differential pair unit, a second input terminal of the operational amplifier is respectively connected to the third terminal of the current mirror unit and the second terminal of the differential pair unit, and an output terminal of the operational amplifier is connected to the fifth terminal of the current mirror unit.

[0012] In a possible implementation of the first aspect, the differential pair unit includes a first resistor, a first transistor, and a second transistor. The first end of the first resistor is respectively connected to the second end of the feedback adjustment unit and the third end of the current mirror unit, the second end of the first resistor is connected to the emitter of the second transistor, the emitter of the first transistor is respectively connected to the first end of the feedback adjustment unit and the second end of the current mirror unit, and the base of the first transistor, the collector of the first transistor, the base of the second transistor, and the collector of the second transistor are all grounded.

[0013] In a possible implementation of the first aspect, the output unit includes a third triode and a resistance trimming subunit, the resistance trimming subunit is respectively connected to the fourth end of the current mirror unit, the first pre-adjustment module, and the emitter of the third triode, and the base of the third triode and the collector of the third triode are both grounded.

[0014] In a second aspect, an embodiment of the present application provides an electronic chip comprising the bandgap reference circuit described in any one of the first aspects.

[0015] In a third aspect, an embodiment of the present application provides an electronic device comprising the bandgap reference circuit described in any one of the second aspects.

[0016] Compared with the prior art, the embodiments of the present application have the following beneficial effects: An embodiment of the present application provides a bandgap reference circuit, including a first pre-adjustment module, a second pre-adjustment module and a bandgap reference module, wherein the first pre-adjustment module is connected to the second pre-adjustment module and the bandgap reference module respectively, and the first pre-adjustment module is used to receive a power supply voltage.

[0017] The first pre-regulation module is configured to output a first voltage based on the power supply voltage. The bandgap reference module is configured to output a reference voltage based on the first voltage. When the power supply voltage fluctuates, both the first voltage and the reference voltage fluctuate. The first pre-regulation module is further configured to output a first feedback voltage to the second pre-regulation module. The second pre-regulation module is configured to output a second feedback voltage based on the first feedback voltage. This allows the first pre-regulation module to suppress power supply voltage fluctuations based on the second feedback voltage, thereby suppressing fluctuations in the first voltage and the reference voltage, ultimately improving the PSR of the bandgap reference circuit.

[0018] This application suppresses power supply voltage fluctuations and ensures the stability of the reference voltage VBG solely through loop feedback between the first and second pre-regulator modules. Compared to bandgap reference circuits using LDO pre-regulators, this application has a simpler implementation structure, reducing circuit area, power consumption, and cost while also enabling the bandgap reference circuit to have a high PSR.

[0019] It can be understood that the beneficial effects of the second to third aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] Figure 1 This is a principle block diagram of a bandgap reference circuit provided by an embodiment of the present application; Figure 2 is a principle block diagram of a bandgap reference circuit provided by another embodiment of the present application; Figure 3 1 is a circuit connection diagram of a bandgap reference circuit provided in one embodiment of the present application; Figure 41 is a circuit connection diagram of a bandgap reference circuit provided by another embodiment of the present application; Figure 5 Schematic diagram of the small signal model of the bandgap reference module in this application; Figure 6 1 is a schematic diagram of a small signal model of a bandgap reference circuit provided in one embodiment of the present application; Figure 7 This is a simulation waveform diagram of a bandgap reference circuit provided by an embodiment of the present application.

[0022] In the figure: 10, first pre-adjustment module; 20, second pre-adjustment module; 30, bandgap reference module; 31, current mirror unit; 32, feedback adjustment unit; 33, differential pair unit; 34, output unit; 341, resistance trimming subunit; 40, power supply. DETAILED DESCRIPTION

[0023] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0024] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0025] It will also be understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0026] As used in this specification and the appended claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0027] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0028] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0029] To improve the PSR of the bandgap reference circuit, the following methods can be used: (1) Using a common-source common-gate current mirror: Because of its high output impedance, the change in power supply voltage has little effect on the output current of the current mirror. However, this method not only consumes voltage margin but also increases design complexity.

[0030] (2) Adding a filter capacitor at the output of the bandgap reference circuit: This method has a significant effect on suppressing high-frequency power supply noise, but has limited effect on suppressing low-frequency power supply noise.

[0031] (3) Use a pre-regulator: The principle is to add an LDO before the power input path of the bandgap reference circuit. The LDO itself has a high PSR in the medium and low frequency bands, which can significantly attenuate the ripple and noise of the input power supply and provide a cleaner local power supply for the bandgap reference. However, this structure will increase the area, power consumption and cost.

[0032] Based on this, the present application proposes a bandgap reference circuit that can not only achieve the same suppression effect on power supply voltage fluctuations as the bandgap reference circuit using an LDO pre-regulator, that is, has a high PSR, but also has a smaller area, lower power consumption and cost. Figure 1 As shown, the bandgap reference circuit includes a first pre-adjustment module 10, a second pre-adjustment module 20 and a bandgap reference module 30. The first pre-adjustment module 10 is connected to the second pre-adjustment module 20 and the bandgap reference module 30 respectively. The first pre-adjustment module 10 is used to be connected to the positive electrode of the power supply 40 to receive the power supply voltage VPP. The negative electrode of the power supply 40 is grounded.

[0033] Specifically, the first pre-regulation module 10 is configured to output a first voltage VLL based on the power supply voltage VPP. The bandgap reference module 30 is configured to output a reference voltage VBG based on the first voltage VLL. When the power supply voltage VPP fluctuates, both the first voltage VLL and the reference voltage VBG fluctuate. The first pre-regulation module 10 is further configured to output a first feedback voltage to the second pre-regulation module 20. The second pre-regulation module 20 is configured to output a second feedback voltage based on the first feedback voltage. This allows the first pre-regulation module 10 to suppress fluctuations in the power supply voltage VPP based on the second feedback voltage, thereby suppressing fluctuations in the first voltage VLL and the reference voltage VBG, ultimately improving the PSR of the bandgap reference circuit. More specifically, when the power supply voltage VPP fluctuates more, both the first voltage VLL and the reference voltage VBG increase accordingly, and the first feedback voltage output by the first pre-regulation module 10 also increases. Upon receiving the increased first feedback voltage, the second pre-regulation module 20 decreases its output second feedback voltage. Ultimately, the first pre-adjustment module 10, based on the decreasing second feedback voltage, suppresses the increasing trend of the power supply voltage VPP, thereby suppressing the fluctuations of the first voltage VLL and the reference voltage VBG, and ultimately improving the PSR of the bandgap reference circuit. Similarly, when the power supply voltage VPP fluctuates and decreases, the first voltage VLL and the reference voltage VBG also decrease accordingly, and the first feedback voltage output by the first pre-adjustment module 10 also decreases. After receiving the decreasing first feedback voltage, the second pre-adjustment module 20 increases the second feedback voltage it outputs. Ultimately, the first pre-adjustment module 10, based on the increasing second feedback voltage, suppresses the decreasing trend of the power supply voltage VPP, thereby suppressing the fluctuations of the first voltage VLL and the reference voltage VBG, and ultimately improving the PSR of the bandgap reference circuit.

[0034] In summary, the present application suppresses fluctuations in the power supply voltage VPP and ensures the stability of the reference voltage VBG solely through loop feedback between the first pre-regulator module 10 and the second pre-regulator module 20. Compared to a bandgap reference circuit using an LDO pre-regulator, the present application has a simpler implementation structure, which not only reduces circuit area, power consumption, and cost, but also enables the bandgap reference circuit to have a high PSR.

[0035] It should be noted that the bandgap reference circuit provided in the embodiments of the present application can be applied to circuits such as power management systems, high-precision comparators, mixed digital-analog circuits, and phase-locked loops.

[0036] In some embodiments, as Figure 2As shown, the bandgap reference module 30 includes a current mirror unit 31, a feedback adjustment unit 32, a differential pair unit 33 and an output unit 34. The first end of the current mirror unit 31 is used to receive the first voltage VLL, the second end of the current mirror unit 31 is connected to the first end of the feedback adjustment unit 32 and the first end of the differential pair unit 33 respectively, the third end of the current mirror unit 31 is connected to the second end of the feedback adjustment unit 32 and the second end of the differential pair unit 33 respectively, the fourth end of the current mirror unit 31 is connected to the output unit 34 and the first pre-adjustment module 10 respectively, and the third end of the feedback adjustment unit 32 is connected to the fifth end of the current mirror unit 31.

[0037] Specifically, the current mirror unit 31 is used to output equal first and second currents based on the first voltage VLL. The differential pair unit 33 is used to generate a third current based on the first and second currents. The current mirror unit 31 is also used to mirror the third current to obtain a fourth current. The output unit 34 is used to output a reference voltage VBG based on the fourth current. The feedback adjustment unit 32 is used to output an adjustment signal based on the first voltage VX and the second voltage VY, so that the current mirror unit 31 adjusts the first voltage VX or the second voltage VY based on the adjustment signal, thereby making the first voltage VX equal to the second voltage VY to ensure the stability of the reference voltage VBG. Among them, the first voltage VX is the voltage at the first end of the feedback adjustment unit 32, and the second voltage VY is the voltage at the second end of the feedback adjustment unit 32.

[0038] In some embodiments, as Figure 3 As shown, the current mirror unit 31 includes a fourth field effect transistor M4, a fifth field effect transistor M5, a sixth field effect transistor M6, a seventh field effect transistor M7, an eighth field effect transistor M8 and a second capacitor C2, the source of the fourth field effect transistor M4 is connected to the source of the fifth field effect transistor M5, the source of the sixth field effect transistor M6, the source of the seventh field effect transistor M7 and the first pre-regulation module 10 respectively, and the gate of the fourth field effect transistor M4 is connected to the drain of the fourth field effect transistor M4, the drain of the eighth field effect transistor M8, the gate of the fifth field effect transistor M5, the gate of the sixth field effect transistor M6 and the gate of the seventh field effect transistor M8 respectively. The gate of the field effect transistor M7 is connected to the first end of the second capacitor C2 and the third end of the feedback adjustment unit 32, respectively. The drain of the fifth field effect transistor M5 is connected to the first end of the feedback adjustment unit 32 and the first end of the differential pair unit 33, respectively. The drain of the sixth field effect transistor M6 is connected to the second end of the feedback adjustment unit 32 and the second end of the differential pair unit 33, respectively. The drain of the seventh field effect transistor M7 is connected to the output unit 34 and the first pre-regulation module 10, respectively. The source of the eighth field effect transistor M8 and the second end of the second capacitor C2 are both grounded. The second capacitor C2 is used for filtering.

[0039] Specifically, the fourth field-effect transistor M4, the fifth field-effect transistor M5, the sixth field-effect transistor M6, and the seventh field-effect transistor M7 form a current mirror structure, and the current in each branch is equal. The fourth field-effect transistor M4, the fifth field-effect transistor M5, the eighth field-effect transistor M8, and the first voltage VX form positive feedback, while the fourth field-effect transistor M4, the sixth field-effect transistor M6, the eighth field-effect transistor M8 and the second voltage VY form negative feedback. The negative feedback gain is greater than the positive feedback gain, resulting in negative feedback in the bandgap reference module 30.

[0040] In some embodiments, as Figure 3 As shown, the feedback adjustment unit 32 includes an operational amplifier OP, a first input terminal of the operational amplifier OP is respectively connected to the second terminal of the current mirror unit 31 and the first terminal of the differential pair unit 33, a second input terminal of the operational amplifier OP is respectively connected to the third terminal of the current mirror unit 31 and the second terminal of the differential pair unit 33, and an output terminal of the operational amplifier OP is connected to the fifth terminal of the current mirror unit 31.

[0041] Specifically, the operational amplifier OP is the core component of feedback regulation, used to ensure that the first voltage VX and the second voltage VY are equal. Assuming that the first voltage VX increases, the output of the operational amplifier OP will increase, that is, the gate voltage of the eighth field-effect transistor M8 will increase. When the gate voltage of the eighth field-effect transistor M8 increases, the current in the branch in which it is located increases, and the drain voltage of the eighth field-effect transistor M8 decreases. In other words, the gate voltage of the fifth field-effect transistor M5 decreases, the current in the branch in which the fifth field-effect transistor M5 is located increases, and the drain voltage of the fifth field-effect transistor M5 also increases, thus forming positive feedback. Assuming that the second voltage VY increases, the output of the operational amplifier OP will decrease, that is, the gate voltage of the eighth field-effect transistor M8 will decrease. When the gate voltage of the eighth field-effect transistor M8 decreases, the current in its branch decreases, and the drain voltage of the eighth field-effect transistor M8 increases. This also increases the gate voltage of the fifth field-effect transistor M5, which in turn decreases the current in the branch in which the fifth field-effect transistor M5 resides. This also decreases the drain voltage of the fifth field-effect transistor M5, thus forming negative feedback. The ultimate goal of the operational amplifier OP is to regulate the first voltage VX or the second voltage VY to ensure that the first voltage VX is equal to the second voltage VY.

[0042] In some embodiments, as Figure 3As shown, the differential pair unit 33 includes a first resistor R1, a first transistor Q1, and a second transistor Q2. The first end of the first resistor R1 is connected to the second end of the feedback adjustment unit 32 and the third end of the current mirror unit 31, respectively. The second end of the first resistor R1 is connected to the emitter of the second transistor Q2. The emitter of the first transistor Q1 is connected to the first end of the feedback adjustment unit 32 and the second end of the current mirror unit 31, respectively. The base of the first transistor Q1, the collector of the first transistor Q1, the base of the second transistor Q2, and the collector of the second transistor Q2 are all grounded.

[0043] Specifically, under the action of the current mirror unit 31 , the first transistor Q1 and the second transistor Q2 are used to generate a voltage difference with a positive temperature coefficient, and the voltage difference generates a third current with a positive temperature coefficient on the first resistor R1 .

[0044] In some embodiments, as Figure 3 As shown, the output unit 34 includes a third transistor Q3 and a resistance adjustment sub-unit 341. The resistance adjustment sub-unit 341 is connected to the fourth terminal of the current mirror unit 31, the first pre-adjustment module 10 and the emitter of the third transistor Q3 respectively. The base and collector of the third transistor Q3 are both grounded. Figure 4 As shown, the resistance adjustment subunit 341 can be equivalent to a second resistor R2 capable of changing resistance.

[0045] Specifically, the fourth current is mirrored from the third current. Since the third current has a positive temperature coefficient, the fourth current also has a positive temperature coefficient. The third transistor Q3 generates a negative temperature coefficient voltage based on the fourth current. The fourth current generates a positive temperature coefficient voltage difference across the second resistor R2. The positive temperature coefficient voltage difference and the negative temperature coefficient voltage are superimposed, and by adjusting their coefficients, a zero temperature coefficient reference voltage VBG is obtained.

[0046] Combine Figure 4 , explaining the working principle of the bandgap reference module 30.

[0047] After the bandgap reference module 30 enters a stable working state, under the action of the current mirror unit 31, the first transistor Q1 and the second transistor Q2 will generate a first voltage difference ΔV1 with a positive temperature coefficient, as shown in formula (1). The first voltage difference ΔV1 generates a third current I3 with a positive temperature coefficient on the first resistor R1, as shown in formula (2). The third current I3 is mirrored by the current mirror to obtain a fourth current I4 with a positive temperature coefficient. The fourth current I4 will generate a negative temperature coefficient voltage V through the third transistor Q3. BE3, the fourth current I4 will generate a second voltage difference ΔV2 with a positive temperature coefficient through the second resistor R2. The expression is shown in formula (3). The second voltage difference ΔV2 with a positive temperature coefficient is superimposed on a negative temperature coefficient voltage V BE3 By adjusting their coefficients, a reference voltage VBG with zero temperature coefficient can be obtained, and the expression is shown in formula (4).

[0048] (1); Wherein, ΔV1 represents the first pressure difference, V BE1 Represents the emitter junction voltage of the first transistor Q1, V BE2 represents the emitter junction voltage of the second transistor Q2, K represents the Boltzmann function, T represents the thermodynamic temperature, q represents the amount of electron charge, and N represents the ratio of the number of the first transistor Q1 to the second transistor Q2; (2); Wherein, I3 represents the third current, r1 represents the resistance value of the first resistor R1; (3); Wherein, ΔV2 represents the second voltage difference, and r2 represents the resistance value of the second resistor R2; (4); Among them, V BE3 Represents negative temperature coefficient voltage, and VBG represents reference voltage.

[0049] Figure 5 The small signal model of the bandgap reference module 30 is shown. Figure 5 r in 05 Represents the small signal impedance of the seventh field effect transistor M7, r b3 represents the small signal impedance of the third transistor Q3, vpp Represents the small signal voltage of the power supply voltage VPP, vbg represents the small signal voltage of the reference voltage VBG, r2 represents the resistance of the second resistor R2, and k represents the ratio of the resistance of the second resistor R2. Then the expression of the PSR of the bandgap reference module 30 is shown in formula (5); (5).

[0050] In some embodiments, as Figure 3As shown, the first pre-regulation module 10 includes a first current source IB1, a second current source IB2, a first field-effect transistor M1, a second field-effect transistor M2, and a first capacitor C1. The first end of the first current source IB1 and the drain of the first field-effect transistor M1 are both used to connect to the positive electrode of the power supply 40 to receive the power supply voltage VPP. The second end of the first current source IB1 is respectively connected to the first end of the first capacitor C1, the gate of the first field-effect transistor M1, and the second pre-regulation module 20. The second end of the first capacitor C1 is respectively connected to the drain of the second field-effect transistor M2, the first end of the second current source IB2, and the second pre-regulation module 20. The source of the first field-effect transistor M1 is respectively connected to the source of the second field-effect transistor M2 and the bandgap reference module 30. The gate of the second field-effect transistor M2 is connected to the bandgap reference module 30. The second end of the second current source IB2 is grounded.

[0051] Specifically, when the power supply voltage VPP fluctuates and increases, the gate voltage of the first field-effect transistor M1 increases accordingly, causing the first voltage VLL to increase. After the first voltage VLL increases, the reference voltage VBG also increases accordingly. Because the gate voltage of the first field-effect transistor M1 increases, the current flowing through the first field-effect transistor M1 becomes greater than the current of the second current source IB2. As a result, the drain voltage of the second field-effect transistor M2 increases, and thus the output first feedback voltage increases.

[0052] Similarly, when the power supply voltage VPP fluctuates and decreases, the gate voltage of the first FET M1 decreases accordingly, causing the first voltage VLL to decrease. As the first voltage VLL decreases, the reference voltage VBG also decreases accordingly. Because the gate voltage of the first FET M1 decreases, the current flowing through the first FET M1 becomes less than the current of the second current source IB2. Consequently, the drain voltage of the second FET M2 decreases, and the output first feedback voltage decreases.

[0053] The function of the second field effect transistor M2 is to ensure that the first voltage VLL is higher than the reference voltage VBG by Vgs2 (Vgs2 is the gate-source voltage of the second field effect transistor M2).

[0054] The first capacitor C1 is used to provide a compensation to ensure that the negative feedback loop of the bandgap reference module 30 is more stable.

[0055] In some embodiments, as Figure 3 As shown, the second pre-regulation module 20 includes a third field effect transistor M3, a gate of the third field effect transistor M3 is connected to the first pre-regulation module 10, a drain of the third field effect transistor M3 is connected to the first pre-regulation module 10, and a source of the third field effect transistor M3 is grounded.

[0056] Specifically, when the power supply voltage VPP fluctuates and increases, the gate voltage of the first field-effect transistor M1 increases accordingly, causing the first voltage VLL to increase. After the first voltage VLL increases, the reference voltage VBG also increases accordingly. Because the gate voltage of the first field-effect transistor M1 increases, the current flowing through the first field-effect transistor M1 becomes greater than the current of the second current source IB2. Consequently, the drain voltage of the second field-effect transistor M2 increases, increasing the output first feedback voltage and, consequently, the gate voltage of the third field-effect transistor M3. After the gate voltage of the third field-effect transistor M3 increases, the drain voltage of the third field-effect transistor M3 decreases, decreasing the output second feedback voltage and, consequently, the gate voltage of the first field-effect transistor M1. This can suppress the increasing trend of the power supply voltage VPP, thereby suppressing fluctuations in the first voltage VLL and the reference voltage VBG, and ultimately improving the PSR of the bandgap reference circuit.

[0057] Similarly, when the power supply voltage VPP fluctuates and decreases, the gate voltage of the first field-effect transistor M1 decreases accordingly, causing the first voltage VLL to decrease. After the first voltage VLL decreases, the reference voltage VBG also decreases accordingly. Since the gate voltage of the first field-effect transistor M1 decreases, the current flowing through the first field-effect transistor M1 becomes less than the current of the second current source IB2. As a result, the drain voltage of the second field-effect transistor M2 decreases, which in turn decreases the output first feedback voltage and the gate voltage of the third field-effect transistor M3. After the gate voltage of the third field-effect transistor M3 decreases, the drain voltage of the third field-effect transistor M3 increases, which in turn increases the output second feedback voltage and the gate voltage of the first field-effect transistor M1. This suppresses the decreasing trend of the power supply voltage VPP, thereby suppressing fluctuations in the first voltage VLL and the reference voltage VBG, ultimately improving the PSR of the bandgap reference circuit.

[0058] Figure 6 The small signal model of the bandgap reference circuit is shown. For node A, the KCL (Kirchhoff's Current Law) equation is listed as shown in equation (6). (6); in, represents the transconductance of the third field effect tube M3, v B2 Represents the small signal voltage of the gate of the third field effect tube M3, r ds2 Represents the small signal impedance of the third field effect transistor M3, vpp Represents the small signal voltage of the power supply voltage VPP, v B1 Represents the gate small signal voltage of the first field effect tube M1, r on1represents the impedance of the first current source IB1, s=jw, j represents an imaginary unit, w represents an angular frequency, and c1 represents the capacitance of the first capacitor C1.

[0059] For the B node, the KCL equation is as shown in formula (7): (7); in, vll represents the small signal voltage of the first voltage VLL, r on2 represents the impedance of the second current source IB2, represents the transconductance of the second field effect tube M2, r ds3 represents the small signal impedance of the second field effect transistor M2, vx Represents the small signal voltage of the gate of the second field effect transistor M2.

[0060] For the C node KCL equation, the expression is as shown in formula (8): (8); Among them, r ds1 represents the small signal impedance of the first field effect transistor M1, represents the transconductance of the first field effect tube M1, r 05 Represents the small signal impedance of the seventh field effect transistor M7, r b3 It represents the small signal impedance of the third transistor Q3.

[0061] Small signal voltage of reference voltage VBG vbg The expression of is shown in formula (9), (9); The small signal voltage of the gate of the second field effect transistor M2 vx The expression of is shown in formula (10), (10); Based on the above formula, the PSR of the bandgap reference circuit at low frequency can be obtained, as shown in formula (11): (11).

[0062] Figure 7 shows the simulation waveform of the bandgap reference circuit, Figure 7 PSR1 in the figure represents the PSR of the bandgap reference module 30, and PSR2 represents the PSR of the bandgap reference circuit. Figure 7 It can be seen that the bandgap reference circuit provided in the embodiment of the present application greatly improves the PSR, and its implementation structure is simple. It can not only achieve the same suppression effect on power supply voltage fluctuations as the bandgap reference circuit using an LDO pre-regulator, but also has a smaller area, lower power consumption and cost.

[0063] In summary, the bandgap reference circuit provided in the embodiments of the present application suppresses fluctuations in the power supply voltage VPP and ensures the stability of the reference voltage VBG through loop feedback between the first pre-regulator module 10 and the second pre-regulator module 20. Compared to bandgap reference circuits using LDO pre-regulators, the implementation structure of the present application is simple, reducing circuit area, power consumption, and cost while also enabling the bandgap reference circuit to maintain a high PSR over a wide range.

[0064] The present invention also provides an electronic chip including the aforementioned bandgap reference circuit. Because the electronic chip includes the aforementioned bandgap reference circuit, the electronic chip has the advantages of high PSR, small area, low power consumption, and low cost.

[0065] Exemplarily, the electronic chip includes a power management chip, a digital-to-analog conversion chip, an analog-to-digital conversion chip, etc.

[0066] The present application also provides an electronic device including the aforementioned electronic chip. Because the electronic device provided by the present application includes the aforementioned electronic chip, the electronic device provided by the present application has the advantages of being compact, cost-effective, highly stable, and having strong anti-interference capabilities.

[0067] Exemplarily, electronic devices include smart phones, smart tablets, wearable devices, etc.

[0068] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0069] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A bandgap reference circuit, characterized in that: It includes a first pre-adjustment module, a second pre-adjustment module and a bandgap reference module, wherein the first pre-adjustment module is connected to the second pre-adjustment module and the bandgap reference module respectively, and the first pre-adjustment module is used to receive a power supply voltage; The first pre-adjustment module is used to output a first voltage based on the power supply voltage; the bandgap reference module is used to output a reference voltage based on the first voltage; when the power supply voltage fluctuates, both the first voltage and the reference voltage fluctuate, and the first pre-adjustment module is further used to output a first feedback voltage to the second pre-adjustment module; the second pre-adjustment module is used to output a second feedback voltage based on the first feedback voltage, so that the first pre-adjustment module suppresses the fluctuation of the power supply voltage based on the second feedback voltage.

2. The bandgap reference circuit according to claim 1, wherein: The first pre-adjustment module includes a first current source, a second current source, a first field-effect transistor, a second field-effect transistor, and a first capacitor. The first end of the first current source and the drain of the first field-effect transistor are both used to receive the power supply voltage. The second end of the first current source is respectively connected to the first end of the first capacitor, the gate of the first field-effect transistor, and the second pre-adjustment module. The second end of the first capacitor is respectively connected to the drain of the second field-effect transistor, the first end of the second current source, and the second pre-adjustment module. The source of the first field-effect transistor is respectively connected to the source of the second field-effect transistor and the bandgap reference module. The gate of the second field-effect transistor is connected to the bandgap reference module. The second end of the second current source is grounded.

3. The bandgap reference circuit according to claim 1 or 2, characterized in that: The second pre-adjustment module includes a third field effect transistor, a gate of the third field effect transistor is connected to the first pre-adjustment module, a drain of the third field effect transistor is connected to the first pre-adjustment module, and a source of the third field effect transistor is grounded.

4. The bandgap reference circuit according to claim 1 or 2, characterized in that: The bandgap reference module includes a current mirror unit, a feedback adjustment unit, a differential pair unit, and an output unit, wherein a first end of the current mirror unit is used to receive a first voltage, a second end of the current mirror unit is respectively connected to a first end of the feedback adjustment unit and a first end of the differential pair unit, a third end of the current mirror unit is respectively connected to a second end of the feedback adjustment unit and a second end of the differential pair unit, a fourth end of the current mirror unit is respectively connected to the output unit and the first pre-adjustment module, and a third end of the feedback adjustment unit is connected to a fifth end of the current mirror unit; The current mirror unit is configured to output a first current and a second current that are equal according to the first voltage; the differential pair unit is configured to generate a third current according to the first current and the second current; the current mirror unit is further configured to mirror the third current to obtain a fourth current; and the output unit is configured to output the reference voltage according to the fourth current; The feedback adjustment unit is used to output an adjustment signal according to the first voltage and the second voltage, so that the current mirror unit adjusts the first voltage or the second voltage according to the adjustment signal, thereby making the first voltage equal to the second voltage; wherein the first voltage is the voltage at the first end of the feedback adjustment unit, and the second voltage is the voltage at the second end of the feedback adjustment unit.

5. The bandgap reference circuit according to claim 4, wherein: The current mirror unit includes a fourth field-effect transistor, a fifth field-effect transistor, a sixth field-effect transistor, a seventh field-effect transistor, an eighth field-effect transistor, and a second capacitor. The source of the fourth field-effect transistor is respectively connected to the source of the fifth field-effect transistor, the source of the sixth field-effect transistor, the source of the seventh field-effect transistor, and the first pre-adjustment module. The gate of the fourth field-effect transistor is respectively connected to the drain of the fourth field-effect transistor, the drain of the eighth field-effect transistor, the gate of the fifth field-effect transistor, the gate of the sixth field-effect transistor, and the gate of the seventh field-effect transistor. The gate of the eighth field-effect transistor is respectively connected to the first end of the second capacitor and the third end of the feedback adjustment unit. The drain of the fifth field-effect transistor is respectively connected to the first end of the feedback adjustment unit and the first end of the differential pair unit. The drain of the sixth field-effect transistor is respectively connected to the second end of the feedback adjustment unit and the second end of the differential pair unit. The drain of the seventh field-effect transistor is respectively connected to the output unit and the first pre-adjustment module. The source of the eighth field-effect transistor and the second end of the second capacitor are both grounded.

6. The bandgap reference circuit according to claim 4, wherein: The feedback regulation unit includes an operational amplifier, a first input end of the operational amplifier is respectively connected to the second end of the current mirror unit and the first end of the differential pair unit, a second input end of the operational amplifier is respectively connected to the third end of the current mirror unit and the second end of the differential pair unit, and an output end of the operational amplifier is connected to the fifth end of the current mirror unit.

7. The bandgap reference circuit according to claim 4, wherein: The differential pair unit includes a first resistor, a first transistor, and a second transistor. The first end of the first resistor is respectively connected to the second end of the feedback adjustment unit and the third end of the current mirror unit, the second end of the first resistor is connected to the emitter of the second transistor, the emitter of the first transistor is respectively connected to the first end of the feedback adjustment unit and the second end of the current mirror unit, and the base of the first transistor, the collector of the first transistor, the base of the second transistor, and the collector of the second transistor are all grounded.

8. The bandgap reference circuit according to claim 4, wherein: The output unit includes a third transistor and a resistance trimming subunit, the resistance trimming subunit is respectively connected to the fourth end of the current mirror unit, the first pre-adjustment module and the emitter of the third transistor, and the base and the collector of the third transistor are both grounded.

9. An electronic chip, characterized in that: The invention comprises the bandgap reference circuit according to any one of claims 1 to 8.

10. An electronic device, characterized in that: Comprising the electronic chip according to claim 9.

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