Band-gap reference source circuit and circuit module

Abstract

The invention provides a band-gap reference source circuit and a circuit module wherein the band-gap reference source circuit comprises a first field effect transistor, a second field effect transistor, a third field effect transistor, a first triode, a second triode, a first resistor, a third triode and a second resistor; wherein the first triode, the second triode and the third triode are all NPN triodes; the first end of the second resistor is connected to the collector electrode of the third triode, and the second end of the second resistor and the drain electrode of the third field effect transistor are connected and jointly used for outputting reference voltage. According to the band-gap reference source circuit, the working voltage can be minimum, the contribution mismatch is lower, and the performance is better.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of analog circuits or mixed signal circuits, and in particular to a bandgap reference source circuit and a circuit module. BACKGROUND

[0002] A bandgap reference source is a reference voltage source with high precision and stability in an analog circuit or a mixed signal circuit, which affects the precision and performance of the entire circuit system and is one of the most basic and critical modules in electronic system design.

[0003] The technical development of a bandgap reference source mainly includes low-voltage operation, low temperature coefficient, high power voltage rejection ratio, low power consumption, and the like. The structure of a bandgap reference source is constructed using a PNP-type transistor and an operational amplifier or a self-biased current mirror, and the power voltage thereof is limited by the working voltage of the operational amplifier or the current mirror. The devices that contribute to the mismatch mainly include a PNP-type transistor, a resistor, a PMOS current mirror tube, an NMOS current mirror tube, and an operational amplifier differential pair tube.

[0004] As shown in Figure 1 , a bandgap reference source constructed using a self-biased current mirror in the related art mainly includes P tubes (m1, m2, m3), N tubes (m4, m5), resistors (r1, r2), and PNP-type transistors (q1, q2, q3). As shown in Figure 2 , a bandgap reference source constructed using an operational amplifier in the related art mainly includes P tubes (m6, m7), an operational amplifier op, resistors (r3, r4), and PNP-type transistors (q4, q5); as shown in Figure 3 , the operational amplifier op mainly includes P tubes (m8, m9) and N tubes (m10, m11). The P tube is a P-channel field effect transistor, also known as a PMOS tube, and the N tube is an N-channel field effect tube, also known as an NMOS tube.

[0005] The working voltage of the two bandgap reference sources: for the bandgap reference source adopting the self-bias current mirror structure, the minimum working voltage is Vgsn+Vdsp+Vbe, about 2.5V when CMOS technology is adopted, wherein Vgsn is the voltage between the gate and the source of N tube m4, Vdsp is the voltage between the drain and the source of P tube m1, and Vbe is the on voltage between the base and the emitter of PNP type transistor q1. For the bandgap reference source adopting the operational amplifier structure, a smaller working voltage can be achieved than the bandgap reference source adopting the self-bias current mirror structure; but in practical application, in order to improve the accuracy of the reference voltage and achieve a smaller high power supply rejection ratio, the P tubes (m1, m2, m3) and the N tubes (m4, m5) in the bandgap reference source adopting the self-bias current mirror structure need to adopt the common source common gate structure respectively, and similarly, the P tubes (m6, m7) in the bandgap reference source adopting the operational amplifier structure also need to adopt the common source common gate structure, and the operational amplifier needs to use the folded common source common gate structure or the sleeve type common source common gate structure with higher gain. Since the two bandgap reference sources need to adopt the common source common gate structure, they cannot work normally under a lower working voltage, such as 2V power supply, under the premise of ensuring performance.

[0006] The contribution mismatch of the two bandgap reference sources: for the bandgap reference source adopting the self-bias current mirror structure, the devices mainly contributing to the mismatch are P tubes (m1, m2, m3), N tubes (m4, m5), PNP type transistors (q1, q2) and resistor r1; for the bandgap reference source adopting the operational amplifier structure, the devices mainly contributing to the mismatch are P tubes (m6, m7), resistor r3, PNP type transistors (q4, q5), P tubes (m8, m9) and N tubes (m10, m11). The devices contributing to the mismatch in the two bandgap reference sources are relatively many, among which the N tube current mirror composed of N tubes (m4, m5) or the differential pair composed of N tubes (m10, m11) contributes the most. SUMMARY

[0007] In view of the above problems of the related art, the present application provides a bandgap reference source circuit and a circuit module to solve the problems that the bandgap reference source in the related art cannot work normally under a lower working voltage under the premise of ensuring performance and cannot achieve a lower contribution mismatch.

[0008] To solve the above technical problems, in a first aspect, the present application provides a bandgap reference source circuit, which comprises a first field effect tube, a second field effect tube, a third field effect tube, a first transistor, a second transistor, a first resistor, a third transistor and a second resistor; wherein the first transistor, the second transistor and the third transistor are all NPN transistors. The source of the first field effect transistor, the source of the second field effect transistor and the source of the third field effect transistor are connected to a working voltage, the gate of the first field effect transistor and the gate of the third field effect transistor are connected to the gate of the second field effect transistor respectively, and the gate of the second field effect transistor is connected to the drain of the second field effect transistor; The collector of the first transistor is connected to the drain of the first field effect transistor and the base of the first transistor respectively; The base of the second transistor is connected to the base of the first transistor, and the collector of the second transistor is connected to the drain of the second field effect transistor; The first end of the first resistor is connected to the emitter of the second transistor, and the second end of the second resistor is connected to the emitter of the first transistor and grounded together; The emitter of the third transistor is connected to the second end of the first resistor, and the base of the third transistor is connected to the collector of the third transistor; The first end of the second resistor is connected to the collector of the third transistor, and the second end of the second resistor and the drain of the third field effect transistor are connected and used for outputting a reference voltage together.

[0009] Preferably, the bandgap reference source circuit further comprises a fourth field effect transistor, a fifth field effect transistor and a sixth field effect transistor; The gate of the fourth field effect transistor and the gate of the sixth field effect transistor are connected to the gate of the fifth field effect transistor respectively and used for accessing a first driving voltage, the source of the fourth field effect transistor is connected to the drain of the first field effect transistor, the source of the fifth field effect transistor is connected to the drain of the second field effect transistor, and the source of the sixth field effect transistor is connected to the drain of the third field effect transistor; The gate of the second field effect transistor is connected to the drain of the fifth field effect transistor; The collector of the first transistor is connected to the drain of the fourth field effect transistor; The collector of the second transistor is connected to the drain of the fifth field effect transistor; The second end of the second resistor and the drain of the sixth field effect transistor are connected and used for outputting a reference voltage together.

[0010] Preferably, the bandgap reference source circuit further comprises a seventh field effect transistor and an eighth field effect transistor; The drain of the seventh field effect transistor is connected to the drain of the fourth field effect transistor and the gate of the seventh field effect transistor respectively; The gate of the eighth field effect transistor is connected to the gate of the seventh field effect transistor, and the drain of the eighth field effect transistor is connected to the drain of the fifth field effect transistor; a collector of the first triode is connected to a source of the seventh field effect tube; a collector of the second triode is connected to a source of the eighth field effect tube.

[0011] Preferably, the bandgap reference source circuit further comprises a seventh field effect tube and an eighth field effect tube; a drain of the seventh field effect tube is connected to a drain of the fourth field effect tube; a gate of the eighth field effect tube is connected to a gate of the seventh field effect tube and is used to access a second driving voltage, and a drain of the eighth field effect tube is connected to a drain of the fifth field effect tube; a collector of the first triode is connected to a source of the seventh field effect tube; a collector of the second triode is connected to a source of the eighth field effect tube.

[0012] In a second aspect, the present application provides a circuit module, which comprises the bandgap reference source circuit as described above, and the bandgap reference source circuit is used to provide a reference voltage for the circuit module.

[0013] Preferably, the circuit module is any one of low voltage stabilizer, direct current-direct current converter, filter, phase-locked loop, analog-digital converter and digital-analog converter.

[0014] Compared with the related art, the bandgap reference source circuit in the present application not only limits the connection mode of the first field effect tube, the second field effect tube, the third field effect tube, the first triode, the second triode, the first resistor, the third triode and the second resistor, but also limits the first triode, the second triode and the third triode to be NPN triodes, so that not only the minimum working voltage of the bandgap reference source circuit can be reduced, but also the performance is better because the NMOS common source tube or NMOS differential pair tube is not used, and the contribution mismatch is lower. BRIEF DESCRIPTION OF DRAWINGS

[0015] The present application will be described in detail below with reference to the drawings. The above or other aspects of the present application will become more apparent and more readily appreciated through detailed description, taken in conjunction with the following drawings, in which: Figure 1 A circuit diagram of the bandgap reference source provided by the related art and adopting a self-biased current mirror structure; Figure 2 A schematic diagram of the bandgap reference source provided by the related art and adopting an operational amplifier structure; Figure 3 A circuit diagram of the operational amplifier in the bandgap reference source provided by the related art and adopting the operational amplifier structure; Figure 4 A circuit diagram of the bandgap reference source circuit provided by the first embodiment of the present application; Figure 5 This is a circuit diagram of the bandgap reference source circuit provided in Embodiment 2 of the present invention; Figure 6 The circuit diagram of the bandgap reference source circuit provided in Embodiment 3 of the present invention; Figure 7 The circuit diagram is provided for the bandgap reference source circuit in Embodiment 4 of the present invention. Detailed Implementation

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application, are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0017] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1 This invention provides a bandgap reference source circuit 100, which includes a first field-effect transistor M1, a second field-effect transistor M2, a third field-effect transistor M3, a first transistor Q1, a second transistor Q2, a first resistor R1, a third transistor Q3, and a second resistor R2; wherein the first transistor Q1, the second transistor Q2, and the third transistor Q3 are all NPN transistors.

[0020] The source of the first field-effect transistor M1, the source of the second field-effect transistor M2, and the source of the third field-effect transistor M3 are all connected to the operating voltage VDD. The gate of the first field-effect transistor M1 and the gate of the third field-effect transistor M3 are respectively connected to the gate of the second field-effect transistor M2. The gate of the second field-effect transistor M2 is connected to the drain of the second field-effect transistor M2.

[0021] The collector of the first transistor Q1 is connected to the drain of the first field-effect transistor M1 and the base of the first transistor Q1, respectively.

[0022] The base of the second transistor Q2 is connected to the base of the first transistor Q1, and the collector of the second transistor Q2 is connected to the drain of the second field-effect transistor M2.

[0023] The first end of the first resistor R1 is connected to the emitter of the second transistor Q2, and the second end of the second resistor R2 is connected to the emitter of the first transistor Q1 and both are grounded.

[0024] The emitter of the third transistor Q3 is connected to the second terminal of the first resistor R1, and the base of the third transistor Q3 is connected to the collector of the third transistor Q3.

[0025] The first end of the second resistor R2 is connected to the collector of the third transistor Q3, and the second end of the second resistor R2 is connected to the drain of the third field-effect transistor M3 and together they are used to output the reference voltage VREF.

[0026] In this embodiment, the first field-effect transistor M1, the second field-effect transistor M2, the first transistor Q1, the second transistor Q2, and the first resistor R1 are used to generate a positive temperature coefficient current IPTAT, where IPTAT = (V BE1 -V BE2 The second resistor R2 and the third MOSFET M3 replicate the positive temperature coefficient current and flow through the second resistor R2 and the third MOSFET M3 to obtain the zero temperature coefficient voltage VREF, where VREF = IPTAT • R2 + V BE3 , where V BE1 V represents the voltage from the base to the emitter in the first transistor Q1. BE2 V represents the voltage from the base to the emitter in transistor Q2. BE3 R1 represents the voltage from the base to the emitter in the third transistor Q3, R2 represents the resistance value of the first resistor R1, and R2 represents the resistance value of the second resistor R2.

[0027] like Figures 1 to 3As shown, the transistors (q1, q2, q3, q4, q5) in related technologies are all PNP transistors, and their connection method limits their actual function to that of diodes, resulting in a higher forward voltage. However, this embodiment limits the first transistor Q1, the second transistor Q2, and the third transistor Q3 to NPN transistors, and also limits their connection method. This makes the actual function of the first transistor Q1, the second transistor Q2, and the third transistor Q3 in this embodiment equivalent to that of transistors, resulting in a lower forward voltage, equivalent to V. GSP +V BE It can operate normally under a power supply of approximately 1.6V. Furthermore, the bandgap reference source circuit 100 in this embodiment uses fewer components, including no NMOS common-source transistors or NMOS differential pairs. Therefore, its contribution mismatch is lower, its performance is better, and its structure is simpler. Alternatively, with the same contribution mismatch, the circuit area can be significantly reduced, lowering costs and improving product yield. Wherein, V GSP V is the voltage difference between the gate and source of the PMOS transistor. BE This is the forward voltage between the base and emitter of the transistor.

[0028] If the bandgap reference source circuit 100 in this embodiment uses sigma to represent the dispersion of the normal distribution, where 1sigma = 1.177mV and 3sigma = 3.531mV, 3sigma accounts for only 0.33% of the average value of 1.058V. Under the same device size, the proportion of 3sigma to the average value of the bandgap reference source in related technologies is about 1.2%, and the contribution mismatch is about four times that of the bandgap reference source circuit 100 in this embodiment. Moreover, the proportion of 3sigma to the average value is only about one-quarter of that of the bandgap reference source in related technologies.

[0029] Compared with related technologies, the bandgap reference source circuit 100 in this invention not only limits the connection method of the first field-effect transistor M1, the second field-effect transistor M2, the third field-effect transistor M3, the first transistor Q1, the second transistor Q2, the first resistor R1, the third transistor Q3, and the second resistor R2, but also limits the first transistor Q1, the second transistor Q2, and the third transistor Q3 to be NPN transistors. This not only reduces the minimum operating voltage of the bandgap reference source circuit 100, but also results in lower contribution mismatch and better performance because it does not use NMOS common-source transistors or NMOS differential pairs.

[0030] Example 2 Based on Embodiment 1, the bandgap reference source circuit 200 in this embodiment includes the fourth field-effect transistor M4, the fifth field-effect transistor M5, and the sixth field-effect transistor M6.

[0031] The gates of the fourth field-effect transistor M4 and the sixth field-effect transistor M6 are respectively connected to the gate of the fifth field-effect transistor M5 and are used to connect the first driving voltage VBP. The source of the fourth field-effect transistor M4 is connected to the drain of the first field-effect transistor M1, the source of the fifth field-effect transistor M5 is connected to the drain of the second field-effect transistor M2, and the source of the sixth field-effect transistor M6 is connected to the drain of the third field-effect transistor M3.

[0032] The gate of the second field-effect transistor M2 is connected to the drain of the fifth field-effect transistor M5.

[0033] The collector of the first transistor Q1 is connected to the drain of the fourth field-effect transistor M4.

[0034] The collector of the second transistor Q2 is connected to the drain of the fifth field-effect transistor M5.

[0035] The second terminal of the second resistor R2 is connected to the drain of the sixth field-effect transistor M6 and together they are used to output the reference voltage VREF.

[0036] In this embodiment, the bandgap reference source circuit 200 changes the first P-tube current mirror, composed of the first field-effect transistor M1, the second field-effect transistor M2, and the third field-effect transistor M3, to a wide-swing common-source and common-gate structure. This is equivalent to changing the first P-tube current mirror to a common-source and common-gate structure by adding a second P-tube current mirror composed of the third field-effect transistor M3, the fourth field-effect transistor M4, and the fifth field-effect transistor M5, thus forming a double-layer current mirror. This optimizes the high power supply voltage rejection ratio and the deviation of the reference voltage VREF output under PVT in the bandgap reference source circuit 200, where PVT represents process corner, voltage, and temperature, respectively. At the same time, the first driving voltage VBP is also connected, so the operating voltage of the bandgap reference source circuit 200 is not excessively increased. In addition, although the bandgap reference source circuit 200 in this embodiment adds the third field-effect transistor M3, the fourth field-effect transistor M4, and the fifth field-effect transistor M5, as common-gate transistors, they contribute almost no mismatch.

[0037] Example 3 Based on Embodiment 2, the bandgap reference source circuit 300 in this embodiment also includes a seventh field-effect transistor M7 and an eighth field-effect transistor M8.

[0038] The drain of the seventh field-effect transistor M7 is connected to the drain of the fourth field-effect transistor M4 and the gate of the seventh field-effect transistor M7, respectively.

[0039] The gate of the eighth field-effect transistor M8 is connected to the gate of the seventh field-effect transistor M7, and the drain of the eighth field-effect transistor M8 is connected to the drain of the fifth field-effect transistor M5.

[0040] The collector of the first transistor Q1 is connected to the source of the seventh field-effect transistor M7.

[0041] The collector of the second transistor Q2 is connected to the source of the eighth field-effect transistor M8.

[0042] In this embodiment, the bandgap reference source circuit 300 adds an N-channel current mirror composed of a seventh field-effect transistor M7 and an eighth field-effect transistor M8. This N-channel current mirror, along with the fourth field-effect transistor M4 and the fifth field-effect transistor M5, forms a common-source, common-gate structure. This further optimizes the high power supply voltage rejection ratio and the deviation of the output reference voltage VREF under PVT in the bandgap reference source circuit 300. Furthermore, although the bandgap reference source circuit 300 in this embodiment adds the seventh and eighth field-effect transistors M7 and M8, as common-gate transistors, they contribute almost no mismatch.

[0043] Example 4 Based on Embodiment 2, the bandgap reference source circuit 400 in this embodiment also includes a seventh field-effect transistor M7 and an eighth field-effect transistor M8.

[0044] The drain of the seventh field-effect transistor M7 is connected to the drain of the fourth field-effect transistor M4.

[0045] The gate of the eighth field-effect transistor M8 is connected to the gate of the seventh field-effect transistor M7 and is used to apply the second driving voltage VBN. The drain of the eighth field-effect transistor M8 is connected to the drain of the fifth field-effect transistor M5.

[0046] The collector of the first transistor Q1 is connected to the source of the seventh field-effect transistor M7.

[0047] The collector of the second transistor Q2 is connected to the source of the eighth field-effect transistor M8.

[0048] In this embodiment, the bandgap reference source circuit 400 connects a second driving voltage VBN separately to the N-tube current mirror composed of the seventh field-effect transistor M7 and the eighth field-effect transistor M8, thus avoiding excessive increase in the operating voltage of the bandgap reference source circuit 400.

[0049] Example 5 This embodiment provides a circuit module, which includes a bandgap reference source circuit (100, 200, 300, 400) from any one of the embodiments one to four above. The bandgap reference source circuit is used to provide a reference voltage for the circuit module.

[0050] The circuit module can be any one of the following: low-voltage regulator, DC-DC converter, filter, phase-locked loop, analog-to-digital converter, and digital-to-analog converter.

[0051] Since the reference voltage of the circuit module in this embodiment is provided by the bandgap reference source circuit (100, 200, 300, 400) of any one of the embodiments 1 to 4 above, it can also achieve the technical effect achieved by the bandgap reference source circuit (100, 200, 300, 400) of any one of the embodiments 1 to 4 above, and will not be elaborated here.

[0052] It should be noted that the various embodiments described above with reference to the accompanying drawings are merely illustrative of the present invention and not intended to limit its scope. Those skilled in the art should understand that any modifications or equivalent substitutions made to the present invention without departing from its spirit and scope should be included within the scope of the present invention. Furthermore, unless the context otherwise requires, words appearing in the singular include those in the plural, and vice versa. Additionally, unless specifically stated otherwise, all or part of any embodiment may be used in conjunction with all or part of any other embodiment.

Claims

1. A bandgap reference source circuit, characterized in that, The bandgap reference source circuit includes a first field-effect transistor, a second field-effect transistor, a third field-effect transistor, a first transistor, a second transistor, a first resistor, a third transistor, and a second resistor; wherein the first transistor, the second transistor, and the third transistor are all NPN transistors; The source of the first field-effect transistor, the source of the second field-effect transistor, and the source of the third field-effect transistor are all connected to the operating voltage. The gate of the first field-effect transistor and the gate of the third field-effect transistor are respectively connected to the gate of the second field-effect transistor. The gate of the second field-effect transistor is connected to the drain of the second field-effect transistor. The collector of the first transistor is connected to the drain of the first field-effect transistor and the base of the first transistor, respectively; The base of the second transistor is connected to the base of the first transistor, and the collector of the second transistor is connected to the drain of the second field-effect transistor. The first end of the first resistor is connected to the emitter of the second transistor, and the second end of the second resistor is connected to the emitter of the first transistor and is grounded together. The emitter of the third transistor is connected to the second terminal of the first resistor, and the base of the third transistor is connected to the collector of the third transistor. The first end of the second resistor is connected to the collector of the third transistor, and the second end of the second resistor is connected to the drain of the third field-effect transistor and together they are used to output a reference voltage.

2. The bandgap reference source circuit as described in claim 1, characterized in that, The bandgap reference source circuit also includes a fourth field-effect transistor, a fifth field-effect transistor, and a sixth field-effect transistor; The gate of the fourth field-effect transistor and the gate of the sixth field-effect transistor are respectively connected to the gate of the fifth field-effect transistor and are used to apply the first driving voltage. The source of the fourth field-effect transistor is connected to the drain of the first field-effect transistor, the source of the fifth field-effect transistor is connected to the drain of the second field-effect transistor, and the source of the sixth field-effect transistor is connected to the drain of the third field-effect transistor. The gate of the second field-effect transistor is connected to the drain of the fifth field-effect transistor; The collector of the first transistor is connected to the drain of the fourth field-effect transistor; The collector of the second transistor is connected to the drain of the fifth field-effect transistor; The second terminal of the second resistor is connected to the drain of the sixth field-effect transistor and together they are used to output the reference voltage.

3. The bandgap reference source circuit as described in claim 2, characterized in that, The bandgap reference source circuit also includes a seventh field-effect transistor and an eighth field-effect transistor; The drain of the seventh field-effect transistor is connected to the drain of the fourth field-effect transistor and the gate of the seventh field-effect transistor, respectively. The gate of the eighth field-effect transistor is connected to the gate of the seventh field-effect transistor, and the drain of the eighth field-effect transistor is connected to the drain of the fifth field-effect transistor. The collector of the first transistor is connected to the source of the seventh field-effect transistor; The collector of the second transistor is connected to the source of the eighth field-effect transistor.

4. The bandgap reference source circuit as described in claim 2, characterized in that, The bandgap reference source circuit also includes a seventh field-effect transistor and an eighth field-effect transistor; The drain of the seventh field-effect transistor is connected to the drain of the fourth field-effect transistor; The gate of the eighth field-effect transistor is connected to the gate of the seventh field-effect transistor and is used to apply the second driving voltage; the drain of the eighth field-effect transistor is connected to the drain of the fifth field-effect transistor. The collector of the first transistor is connected to the source of the seventh field-effect transistor; The collector of the second transistor is connected to the source of the eighth field-effect transistor.

5. A circuit module, characterized in that, The circuit module includes a bandgap reference source circuit as described in any one of claims 1 to 4, the bandgap reference source circuit being used to provide a reference voltage for the circuit module.

6. The circuit module as described in claim 5, characterized in that, The circuit module can be any one of the following: low-voltage regulator, DC-DC converter, filter, phase-locked loop, analog-to-digital converter, and digital-to-analog converter.

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