Temperature regulation curvature compensation circuit for concave curve band-gap reference source

Abstract

The invention relates to the field of integrated circuit design, in particular to a temperature-adjusting curvature compensation circuit for a concave curve band-gap reference source, which specifically adopts a piecewise linear compensation mode to clearly divide a low-temperature interval and a high-temperature interval, and in the low-temperature interval, the compensation circuit enables a related transistor to be conducted to generate a negative temperature coefficient compensation current to generate a negative temperature coefficient compensation current; the current presents a specific rule along with the temperature change, so that the change of the reference voltage at low temperature can be accurately compensated; and the high-temperature interval is similar. The segmented and accurate compensation mode can better meet the requirements of the concave curve band-gap reference source in different temperature segments, the overall temperature compensation effect is improved, the performance consistency of the system in different temperature environments can be better guaranteed, system errors caused by reference voltage fluctuation are avoided, and the reliability and precision of the whole system are improved. Moreover, the circuit is simple in structure, does not need to additionally adjust a resistor or a switch, and effectively saves the area of a chip.

Description

Technical Field

[0001] The invention relates to the field of integrated circuit design, in particular to a temperature-adjusting curvature compensation circuit for a concave curve bandgap reference source. Background Art

[0002] Bandgap reference voltage sources are widely used in analog circuits, digital circuits, and mixed signal circuits, such as operational amplifiers, linear regulators, memories, analog-to-digital converters, etc. Traditional bandgap reference voltage sources are limited by the structure of bipolar transistors, and their minimum supply voltage must be higher than 1.25V, and the temperature drift problem is significant. Traditional bandgap reference voltage sources may present a convex curve or a concave curve in terms of temperature characteristics. Existing temperature compensation technologies are mostly designed for convex curves, such as exponential curvature compensation, piecewise nonlinear compensation, and other methods. However, for bandgap reference voltage sources that present concave curve characteristics, these compensation technologies have limited effects and it is difficult to achieve high-precision compensation over a wide temperature range. Especially in the low temperature zone (-40℃ to 0℃) and the high temperature zone (75℃ to 140℃), the temperature drift problem of the concave curve is particularly prominent. Summary of the invention

[0003] The invention provides a temperature-adjusting curvature compensation circuit for a concave curve bandgap reference source, which can significantly reduce temperature drift in a wide temperature range.

[0004] In order to achieve the purpose of the present invention, the technical solution adopted is: a temperature-adjusted curvature compensation circuit for a concave curve bandgap reference source, comprising: The sub-1V bandgap reference source part, the temperature adjustment curvature compensation circuit part and the reference voltage output part. The sub-1V bandgap reference source part includes a transistor, an operational amplifier, a resistor and a triode, which is used to output a basic reference current Iref with a temperature coefficient, and then with the output resistor R OUT Multiply to generate a basic reference voltage Vref; The temperature-adjusting curvature compensation circuit is divided into a low-temperature zone temperature compensation module and a high-temperature zone temperature compensation module, which are composed of an enhanced PMOS tube and an enhanced NMOS tube. Through different connection methods and width-to-length ratios, the current mirror and subtraction operations are realized to generate a suitable low-temperature compensation current A3I in different temperature ranges. NTC Or high temperature compensation current B3I PTC ; Then multiply it with the resistance RC of the reference voltage output part to generate the low temperature compensation voltage V NTC Or high temperature compensation voltage V PTC , reduce the drift of the reference voltage with temperature, and generate a temperature-independent compensated reference voltage V ref1 .

[0005] As an optimal technical solution for a temperature-adjusting curvature compensation circuit of a concave curve bandgap reference source, a sub-1V bandgap reference source portion includes an operational amplifier OP1, an operational amplifier OP2, a PNP transistor Q1, a PNP transistor Q2, a resistor R1, a resistor R2, an enhanced PMOS tube M1, an enhanced PMOS tube M2, and an enhanced PMOS tube M3; the source electrodes of the enhanced PMOS tube M1, the enhanced PMOS tube M2, and the enhanced PMOS tube M3 are all connected to a power supply VDD, the gate electrode of the enhanced PMOS tube M1 is connected to the output end of the operational amplifier OP2, the gate electrode of the enhanced PMOS tube M2, the gate electrode of the enhanced PMOS tube M3 and the The output end of the operational amplifier OP1 is connected, the drain of the enhanced PMOS tube M1, the non-inverting input end of the operational amplifier OP2 and one end of the resistor R2 are connected, the drain of the enhanced PMOS tube M2, the inverting input end of the operational amplifier OP1, the inverting input end of the operational amplifier OP2 and the emitter of the PNP type transistor Q1 are connected, the drain of the enhanced PMOS tube M3, the non-inverting input end of the operational amplifier OP1 and one end of the resistor R1 are connected, the other end of the resistor R1 is connected to the emitter of the PNP type transistor Q2, and the other end of the resistor R2, the base and collector of the PNP type transistor Q1, and the base and collector of the PNP type transistor Q2 are all grounded.

[0006] As a preferred technical solution for a temperature-adjusted curvature compensation circuit for a concave curve bandgap reference source, the width and length dimensions of the enhanced PMOS tube M1, the enhanced PMOS tube M2 and the enhanced PMOS tube M3 are width W=2μm and length L=2μm.

[0007] As a preferred technical solution of a temperature-adjusting curvature compensation circuit for a concave curve bandgap reference source, the low-temperature zone temperature compensation circuit of the temperature-adjusting curvature compensation circuit part includes an enhanced PMOS tube MA1, an enhanced NMOS tube MA2, an enhanced PMOS tube MA3, an enhanced NMOS tube MA4, an enhanced PMOS tube MA5, an enhanced PMOS tube MA6, an enhanced NMOS tube MA7, and an enhanced NMOS tube MA8; The sources of the enhanced PMOS tubes MA1, MA3, MA5 and MA6 are all connected to the power supply V DDThe gate of the enhanced PMOS tube MA1 is connected to the output end of the operational amplifier OP2, the gate of the enhanced PMOS tube MA3 is connected to the output end of the operational amplifier OP1, the drain of the enhanced PMOS tube MA1, the drain and gate of the enhanced NMOS tube MA2, and the gate of the enhanced NMOS tube MA4 are connected, the drain of the enhanced PMOS tube MA3, the drain of the enhanced NMOS tube MA4, the drain and gate of the enhanced PMOS tube MA5, and the gate of the enhanced PMOS tube MA6 are connected, the drain of the enhanced PMOS tube MA6, the drain and gate of the enhanced NMOS tube MA7, and the gate of the enhanced NMOS tube MA8 are connected, the drain of the enhanced NMOS tube MA8 is connected to the connection point of the resistor R3 and the resistor RC of the reference voltage output part, and the sources of the enhanced NMOS tubes MA2, MA4, MA7, and MA8 are all grounded.

[0008] As a preferred technical solution for a temperature-adjusted curvature compensation circuit for a concave curve bandgap reference source, the width-to-length ratios of the enhanced PMOS tube MA1, enhanced NMOS tube MA2, enhanced PMOS tube MA5, enhanced PMOS tube MA6 and enhanced NMOS tube MA7 are the same as the width-to-length ratio of the enhanced PMOS tube M1 of the sub-1V bandgap reference source part, the width-to-length ratio of the enhanced PMOS tube MA3 is A1 times the width-to-length ratio of the enhanced PMOS tube MA1, the width-to-length ratio of the enhanced PMOS tube MA4 is A2 times the width-to-length ratio of the enhanced PMOS tube MA1, and the width-to-length ratio of the enhanced PMOS tube MA8 is A3 times the width-to-length ratio of the enhanced PMOS tube MA1.

[0009] As a preferred technical solution of a temperature-adjusting curvature compensation circuit for a concave curve bandgap reference source, the high-temperature zone temperature compensation circuit of the temperature-adjusting curvature compensation circuit part includes an enhanced PMOS tube MA9, an enhanced NMOS tube MA10, an enhanced PMOS tube MA11, an enhanced NMOS tube MA12, an enhanced PMOS tube MA13, an enhanced PMOS tube MA14, an enhanced NMOS tube MA15, and an enhanced NMOS tube MA16; The sources of the enhanced PMOS tubes MA9, MA11, MA13 and MA14 are all connected to the power supply V DDThe gate of the enhanced PMOS tube MA9 is connected to the output end of the operational amplifier OP1 of the sub-1V bandgap reference source part, the gate of the enhanced PMOS tube MA11 is connected to the output end of the operational amplifier OP2 of the sub-1V bandgap reference source part, the drain of the enhanced PMOS tube MA9, the drain and gate of the enhanced NMOS tube MA10, and the gate of the enhanced NMOS tube MA12 are connected, the drain of the enhanced PMOS tube MA11, the drain of the enhanced NMOS tube MA12, and the enhanced PMOS tube MA13 are connected. The drain and gate of A13 and the gate of the enhanced PMOS tube MA14 are connected, the drain of the enhanced PMOS tube MA14, the drain and gate of the enhanced NMOS tube MA15, and the gate of the enhanced NMOS tube MA16 are connected, the drain of the enhanced NMOS tube MA16 is connected to the connection point of the resistor R3 and the resistor RC of the reference voltage output part, and the sources of the enhanced NMOS tube MA10, the enhanced NMOS tube MA12, the enhanced NMOS tube MA15, and the enhanced NMOS tube MA16 are all grounded.

[0010] As a preferred technical solution for a temperature-adjusted curvature compensation circuit for a concave curve bandgap reference source, the width-to-length ratios of the enhanced PMOS tube MA9, enhanced NMOS tube MA10, enhanced PMOS tube MA13, enhanced PMOS tube MA14 and enhanced NMOS tube MA15 are the same as the width-to-length ratio of the enhanced PMOS tube M1 of the sub-1V bandgap reference source part, the width-to-length ratio of the enhanced PMOS tube MA11 is B1 times the width-to-length ratio of the enhanced PMOS tube MA1, the width-to-length ratio of the enhanced PMOS tube MA12 is B2 times the width-to-length ratio of the enhanced PMOS tube MA1, and the width-to-length ratio of the enhanced PMOS tube MA16 is B3 times the width-to-length ratio of the enhanced PMOS tube MA1.

[0011] As a preferred technical solution for a temperature-adjusted curvature compensation circuit for a concave curve bandgap reference source, the reference voltage output part includes a resistor R3, a resistor RC, an enhanced PMOS tube M4 and an enhanced PMOS tube M5; the source electrodes of the enhanced PMOS tube M4 and the enhanced PMOS tube M5 are both connected to a power supply V DD The gate of the enhanced PMOS tube M4 is connected to the output end of the operational amplifier OP1 of the sub-1V bandgap reference source part, the gate of the enhanced PMOS tube M5 is connected to the output end of the operational amplifier OP2 of the sub-1V bandgap reference source part, the drain of the enhanced PMOS tube M4 and the enhanced PMOS tube M5 is connected to one end of the resistor R3, and this connection point is the compensation reference voltage V ref1 Output point; the other end of the resistor R3 is connected to one end of the resistor RC, the other end of the resistor RC is grounded, and the resistor R3 and the resistor RC are connected in series to form an output resistor R OUT, basic reference current I ref Flowing through the output resistor R OUT Generates basic reference voltage V ref At the same time, the resistor RC is also used for low temperature compensation voltage V NTC Or high temperature compensation voltage V PTC The calculation of the final output compensation reference voltage V ref1 .

[0012] As a preferred technical solution for a temperature-adjusted curvature compensation circuit for a concave bandgap reference source, the width-to-length ratio of the enhanced PMOS tubes M4 and M5 is the same as the width-to-length ratio of the enhanced PMOS tube M1 of the sub-1V bandgap reference source part.

[0013] Beneficial effects of the present invention: The present invention provides a temperature-adjusting curvature compensation circuit for a concave curve bandgap reference source, which adopts a piecewise linear compensation method to clearly divide the low temperature interval and the high temperature interval. In the low temperature interval, the compensation circuit turns on the relevant transistors to generate a negative temperature coefficient compensation current, and the current changes with temperature in a specific pattern, which can accurately compensate for the change of the reference voltage at low temperature; the same is true in the high temperature interval. Compared with the convex curve compensation circuit, this segmented and precise compensation method can better meet the needs of the concave curve bandgap reference source in different temperature sections, improve the overall temperature compensation effect, better ensure the performance consistency of the system in different temperature environments, avoid system errors caused by reference voltage fluctuations, and improve the reliability and accuracy of the entire system. In addition, the circuit structure of the present invention is simple, and no additional adjustment of resistors or switches is required, which effectively saves chip area. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them: Figure 1 The principle block diagram of the present invention is Figure 2 It is a circuit schematic diagram of the present invention.

[0015] Reference numerals: low temperature region temperature compensation circuit 201 , high temperature region temperature compensation circuit 202 , sub-1V bandgap reference source part 100 , temperature adjustment curvature compensation circuit part 200 , reference voltage output part 300 . DETAILED DESCRIPTION

[0016] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0017] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0018] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0019] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0020] Example 1 Reference Figure 1~Figure 2 This embodiment provides a temperature adjustment curvature compensation circuit for a concave curve bandgap reference source, specifically, as Figure 1 As shown, the present invention comprises a sub 1V bandgap reference source part 100, a temperature adjustment curvature (ATC) compensation circuit part 200 and a reference voltage output part 300. The sub 1V bandgap reference source part is mainly composed of a transistor, an operational amplifier, a resistor and a triode, which is responsible for outputting a basic current I with a positive temperature coefficient. PT and a current with a negative temperature coefficient I NT The addition of the two gives the basic reference current I of the temperature coefficient. ref , and then with the output resistance R of the reference voltage output part OUT Multiply to generate the basic reference voltage V ref The ATC compensation circuit can be divided into two parts: low temperature zone temperature compensation circuit 201 and high temperature zone temperature compensation circuit 202. It is composed of enhanced PMOS tube and enhanced NMOS tube. Through different connection modes and width-to-length ratios, current mirroring and subtraction operations are realized to generate appropriate low temperature compensation current A3I in different temperature ranges. NTC Or high temperature compensation current B3I PTC , and then multiplied by the RC of the reference voltage output part to generate the low temperature compensation voltage V NTC Or high temperature compensation voltage V PTC , thereby reducing the drift of the reference voltage with temperature and achieving a high-precision, temperature-independent output compensation reference voltage V ref1.

[0021] like Figure 2 As shown, the sub-1V bandgap reference source part includes an operational amplifier OP1, an operational amplifier OP2, a PNP transistor Q1, a PNP transistor Q2, a resistor R1, a resistor R2, an enhanced PMOS tube M1, an enhanced PMOS tube M2, and an enhanced PMOS tube M3. The width and length dimensions of the enhanced PMOS tube M1, the enhanced PMOS tube M2, and the enhanced PMOS tube M3 are width W=2μm and length L=2μm, and the source electrodes of the enhanced PMOS tube M1, the enhanced PMOS tube M2, and the enhanced PMOS tube M3 are all connected to the power supply V DD The gate of the enhanced PMOS tube M1 is connected to the output end of the operational amplifier OP2, the gate of the enhanced PMOS tube M2 and the gate of the enhanced PMOS tube M3 are connected to the output end of the operational amplifier OP1, the drain of the enhanced PMOS tube M1, the non-inverting input end of the operational amplifier OP2 and one end of the resistor R2 are connected, the drain of the enhanced PMOS tube M2, the inverting input end of the operational amplifier OP1, the inverting input end of the operational amplifier OP2 and the emitter of the PNP type transistor Q1 are connected, the drain of the enhanced PMOS tube M3, the non-inverting input end of the operational amplifier OP1 and one end of the resistor R1 are connected, the other end of the resistor R1 is connected to the emitter of the PNP type transistor Q2, and the other end of the resistor R2, the base and collector of the PNP type transistor Q1, and the base and collector of the PNP type transistor Q2 are all grounded (GND).

[0022] The emitter area of ​​Q1 is marked as (1), and the emitter area of ​​Q2 is marked as (n). The difference in their areas and the combination with the resistors produce a current with a positive temperature coefficient, I PT At the same time, the negative temperature coefficient characteristic of Q1 itself is used to generate a negative temperature coefficient current I NT .

[0023] like Figure 2As shown, the ATC compensation circuit part can be divided into two parts: a low temperature zone temperature compensation circuit and a high temperature zone temperature compensation circuit. The low temperature zone temperature compensation circuit includes an enhanced PMOS tube MA1, an enhanced NMOS tube MA2, an enhanced PMOS tube MA3, an enhanced NMOS tube MA4, an enhanced PMOS tube MA5, an enhanced PMOS tube MA6, an enhanced NMOS tube MA7, and an enhanced NMOS tube MA8. The width-to-length ratio of the enhanced PMOS tube MA1, the enhanced NMOS tube MA2, the enhanced PMOS tube MA5, the enhanced PMOS tube MA6, and the enhanced NMOS tube MA7 is the same as the width-to-length ratio of the enhanced PMOS tube M1 of the sub-1V bandgap reference source part, the width-to-length ratio of the enhanced PMOS tube MA3 is A1 times the width-to-length ratio of the enhanced PMOS tube MA1, the width-to-length ratio of the enhanced PMOS tube MA4 is A2 times the width-to-length ratio of the enhanced PMOS tube MA1, and the width-to-length ratio of the enhanced PMOS tube MA8 is A3 times the width-to-length ratio of the enhanced PMOS tube MA1. The sources of the enhanced PMOS tubes MA1, MA3, MA5 and MA6 are all connected to the power supply V DD The gate of the enhanced PMOS tube MA1 is connected to the output end of the operational amplifier OP2 of the sub-1V bandgap reference source part, the gate of the enhanced PMOS tube MA3 is connected to the output end of the operational amplifier OP1 of the sub-1V bandgap reference source part, the drain of the enhanced PMOS tube MA1, the drain and gate of the enhanced NMOS tube MA2, and the gate of the enhanced NMOS tube MA4 are connected, the drain of the enhanced PMOS tube MA3, the drain of the enhanced NMOS tube MA4, the drain and gate of the enhanced PMOS tube MA5, and the gate of the enhanced PMOS tube MA6 are connected, the drain of the enhanced PMOS tube MA6, the drain and gate of the enhanced NMOS tube MA7, and the gate of the enhanced NMOS tube MA8 are connected, the drain of the enhanced NMOS tube MA8 is connected to the connection point of the resistor R3 and the resistor RC of the reference voltage output part, and the sources of the enhanced NMOS tubes MA2, MA4, MA7, and MA8 are all grounded (GND).

[0024] Generate low temperature compensation current A3I through subtraction circuit and current mirror structure NTC =A3(A2I NT -A2I PT ).

[0025] The high temperature zone temperature compensation circuit includes an enhanced PMOS tube MA9, an enhanced NMOS tube MA10, an enhanced PMOS tube MA11, an enhanced NMOS tube MA12, an enhanced PMOS tube MA13, an enhanced PMOS tube MA14, an enhanced NMOS tube MA15, and an enhanced NMOS tube MA16. The width-to-length ratio of the enhanced PMOS tube MA9, the enhanced NMOS tube MA10, the enhanced PMOS tube MA13, the enhanced PMOS tube MA14, and the enhanced NMOS tube MA15 is the same as the width-to-length ratio of the enhanced PMOS tube M1 of the sub-1V bandgap reference source part, the width-to-length ratio of the enhanced PMOS tube MA11 is B1 times the width-to-length ratio of the enhanced PMOS tube MA1, the width-to-length ratio of the enhanced PMOS tube MA12 is B2 times the width-to-length ratio of the enhanced PMOS tube MA1, and the width-to-length ratio of the enhanced PMOS tube MA16 is B3 times the width-to-length ratio of the enhanced PMOS tube MA1. The sources of the enhanced PMOS tubes MA9, MA11, MA13 and MA14 are all connected to the power supply V DD The gate of the enhanced PMOS tube MA9 is connected to the output end of the operational amplifier OP1 of the sub-1V bandgap reference source part, the gate of the enhanced PMOS tube MA11 is connected to the output end of the operational amplifier OP2 of the sub-1V bandgap reference source part, the drain of the enhanced PMOS tube MA9, the drain and gate of the enhanced NMOS tube MA10, and the gate of the enhanced NMOS tube MA12 are connected, the drain of the enhanced PMOS tube MA11, the drain of the enhanced NMOS tube MA12, and the enhanced PMOS tube MA13 are connected. The drain and gate of the enhanced PMOS tube MA14 are connected, the drain of the enhanced PMOS tube MA14, the drain and gate of the enhanced NMOS tube MA15, and the gate of the enhanced NMOS tube MA16 are connected, the drain of the enhanced NMOS tube MA16 is connected to the connection point of the resistor R3 and the resistor RC of the reference voltage output part, and the sources of the enhanced NMOS tubes MA10, MA12, MA15, and MA16 are all grounded (GND).

[0026] Generate high temperature compensation current B3I through subtraction circuit and current mirror structure PTC =B3(B2I PT -A2I NT ) like Figure 2As shown, the reference voltage output part includes a resistor R3, a resistor RC, an enhanced PMOS tube M4 and an enhanced PMOS tube M5. The width-to-length ratio of the enhanced PMOS tube M4 and the enhanced PMOS tube M5 is the same as the width-to-length ratio of the enhanced PMOS tube M1 of the sub-1V bandgap reference source part. The source electrodes of the enhanced PMOS tube M4 and the enhanced PMOS tube M5 are both connected to the power supply V DD The gate of the enhanced PMOS tube M4 is connected to the output end of the operational amplifier OP1 of the sub-1V bandgap reference source part, the gate of the enhanced PMOS tube M5 is connected to the output end of the operational amplifier OP2 of the sub-1V bandgap reference source part, the drain of the enhanced PMOS tube M4 and the enhanced PMOS tube M5 is connected to one end of the resistor R3, and this connection point is the reference voltage V ref1 Output point. The other end of the resistor R3 is connected to one end of the resistor RC, and the other end of the resistor RC is grounded (GND). The resistor R3 and the resistor RC are connected in series to form an output resistor R OUT , basic reference current I ref Flowing through the output resistor R OUT Generates basic reference voltage V ref At the same time, the resistor RC also participates in the low temperature compensation voltage V NTC Or high temperature compensation voltage V PTC The calculation of the final output compensation reference voltage V ref1 .

[0027] The enhanced PMOS tube M4 generates a current I with a positive temperature coefficient through a current mirror structure with the enhanced PMOS tube M3 of the sub-1V bandgap reference source part. PT The enhanced PMOS tube M5 generates a current with a negative temperature coefficient I through the current mirror structure of the enhanced PMOS tube M1 of the sub-1V bandgap reference source part NT .

[0028] Furthermore, Figure 2 The brackets next to the enhanced PMOS tube and the enhanced NMOS tube indicate the multiples of their width-to-length ratio relative to the width-to-length ratio of the enhanced PMOS tube M1.

[0029] The present invention provides a temperature-adjusting curvature compensation circuit for a concave curve bandgap reference source, which adopts a piecewise linear compensation method to clearly divide the low temperature interval and the high temperature interval. In the low temperature interval, the compensation circuit turns on the relevant transistors to generate a negative temperature coefficient compensation current, and the current changes with temperature in a specific pattern, which can accurately compensate for the change of the reference voltage at low temperature; the same is true in the high temperature interval. Compared with the convex curve compensation circuit, this segmented and precise compensation method can better meet the needs of the concave curve bandgap reference source in different temperature sections, improve the overall temperature compensation effect, better ensure the performance consistency of the system in different temperature environments, avoid system errors caused by reference voltage fluctuations, and improve the reliability and accuracy of the entire system. In addition, the circuit structure of the present invention is simple, and no additional adjustment resistors or switches are required, which effectively saves chip area.

[0030] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0031] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A temperature-adjusted curvature compensation circuit for a concave curve bandgap reference source, characterized in that: include, The sub-1V bandgap reference source part, the temperature adjustment curvature compensation circuit part and the reference voltage output part. The sub-1V bandgap reference source part includes a transistor, an operational amplifier, a resistor and a triode, which is used to output a basic reference current Iref with a temperature coefficient, and then with the output resistor R OUT Multiply to generate a basic reference voltage Vref; The temperature-adjusting curvature compensation circuit is divided into a low-temperature zone temperature compensation module and a high-temperature zone temperature compensation module, which are composed of an enhanced PMOS tube and an enhanced NMOS tube. Through different connection methods and width-to-length ratios, the current mirror and subtraction operations are realized to generate a suitable low-temperature compensation current A3I in different temperature ranges. NTC Or high temperature compensation current B3I PTC ; Then multiply it with the resistance RC of the reference voltage output part to generate the low temperature compensation voltage V NTC Or high temperature compensation voltage V PTC , reduce the drift of the reference voltage with temperature, and generate a temperature-independent compensated reference voltage V ref1 .

2. The temperature-adjusting curvature compensation circuit for a concave curve bandgap reference source according to claim 1, characterized in that: The sub-1V bandgap reference source part includes an operational amplifier OP1, an operational amplifier OP2, a PNP transistor Q1, a PNP transistor Q2, a resistor R1, a resistor R2, an enhanced PMOS tube M1, an enhanced PMOS tube M2, and an enhanced PMOS tube M3; the sources of the enhanced PMOS tube M1, the enhanced PMOS tube M2, and the enhanced PMOS tube M3 are all connected to the power supply VDD, the gate of the enhanced PMOS tube M1 is connected to the output end of the operational amplifier OP2, the gate of the enhanced PMOS tube M2, the gate of the enhanced PMOS tube M3 are connected to the output end of the operational amplifier OP1, The drain of the enhanced PMOS tube M1, the non-inverting input terminal of the operational amplifier OP2 and one end of the resistor R2 are connected; the drain of the enhanced PMOS tube M2, the inverting input terminal of the operational amplifier OP1, the inverting input terminal of the operational amplifier OP2 and the emitter of the PNP type transistor Q1 are connected; the drain of the enhanced PMOS tube M3, the non-inverting input terminal of the operational amplifier OP1 and one end of the resistor R1 are connected; the other end of the resistor R1 is connected to the emitter of the PNP type transistor Q2; the other end of the resistor R2, the base and collector of the PNP type transistor Q1, and the base and collector of the PNP type transistor Q2 are all grounded.

3. The temperature-adjusting curvature compensation circuit for a concave curve bandgap reference source according to claim 2, characterized in that: The width and length dimensions of the enhanced PMOS tube M1 , the enhanced PMOS tube M2 and the enhanced PMOS tube M3 are width W=2 μm and length L=2 μm.

4. The temperature-adjusting curvature compensation circuit for a concave curve bandgap reference source according to claim 3, characterized in that: The low temperature zone temperature compensation circuit of the temperature adjustment curvature compensation circuit part includes an enhanced PMOS tube MA1, an enhanced NMOS tube MA2, an enhanced PMOS tube MA3, an enhanced NMOS tube MA4, an enhanced PMOS tube MA5, an enhanced PMOS tube MA6, an enhanced NMOS tube MA7, and an enhanced NMOS tube MA8; The sources of the enhanced PMOS tubes MA1, MA3, MA5 and MA6 are all connected to the power supply V DD The gate of the enhanced PMOS tube MA1 is connected to the output end of the operational amplifier OP2, the gate of the enhanced PMOS tube MA3 is connected to the output end of the operational amplifier OP1, the drain of the enhanced PMOS tube MA1, the drain and gate of the enhanced NMOS tube MA2, and the gate of the enhanced NMOS tube MA4 are connected, the drain of the enhanced PMOS tube MA3, the drain of the enhanced NMOS tube MA4, the drain and gate of the enhanced PMOS tube MA5, and the gate of the enhanced PMOS tube MA6 are connected, the drain of the enhanced PMOS tube MA6, the drain and gate of the enhanced NMOS tube MA7, and the gate of the enhanced NMOS tube MA8 are connected, the drain of the enhanced NMOS tube MA8 is connected to the connection point of the resistor R3 and the resistor RC of the reference voltage output part, and the sources of the enhanced NMOS tubes MA2, MA4, MA7, and MA8 are all grounded.

5. The temperature-adjusting curvature compensation circuit for a concave curve bandgap reference source according to claim 4, characterized in that: The width-to-length ratios of the enhanced PMOS tube MA1, enhanced NMOS tube MA2, enhanced PMOS tube MA5, enhanced PMOS tube MA6 and enhanced NMOS tube MA7 are the same as the width-to-length ratio of the enhanced PMOS tube M1 of the sub-1V bandgap reference source part, the width-to-length ratio of the enhanced PMOS tube MA3 is A1 times the width-to-length ratio of the enhanced PMOS tube MA1, the width-to-length ratio of the enhanced PMOS tube MA4 is A2 times the width-to-length ratio of the enhanced PMOS tube MA1, and the width-to-length ratio of the enhanced PMOS tube MA8 is A3 times the width-to-length ratio of the enhanced PMOS tube MA1.

6. The temperature-adjusting curvature compensation circuit for a concave curve bandgap reference source according to claim 5, characterized in that: The high temperature zone temperature compensation circuit of the temperature adjustment curvature compensation circuit part includes an enhanced PMOS tube MA9, an enhanced NMOS tube MA10, an enhanced PMOS tube MA11, an enhanced NMOS tube MA12, an enhanced PMOS tube MA13, an enhanced PMOS tube MA14, an enhanced NMOS tube MA15, and an enhanced NMOS tube MA16; The sources of the enhanced PMOS tubes MA9, MA11, MA13 and MA14 are all connected to the power supply V DD The gate of the enhanced PMOS tube MA9 is connected to the output end of the operational amplifier OP1 of the sub-1V bandgap reference source part, the gate of the enhanced PMOS tube MA11 is connected to the output end of the operational amplifier OP2 of the sub-1V bandgap reference source part, the drain of the enhanced PMOS tube MA9, the drain and gate of the enhanced NMOS tube MA10, and the gate of the enhanced NMOS tube MA12 are connected, the drain of the enhanced PMOS tube MA11, the drain of the enhanced NMOS tube MA12, and the enhanced PMOS tube MA13 are connected. The drain and gate of A13 and the gate of the enhanced PMOS tube MA14 are connected, the drain of the enhanced PMOS tube MA14, the drain and gate of the enhanced NMOS tube MA15, and the gate of the enhanced NMOS tube MA16 are connected, the drain of the enhanced NMOS tube MA16 is connected to the connection point of the resistor R3 and the resistor RC of the reference voltage output part, and the sources of the enhanced NMOS tube MA10, the enhanced NMOS tube MA12, the enhanced NMOS tube MA15, and the enhanced NMOS tube MA16 are all grounded.

7. The temperature-adjusting curvature compensation circuit for a concave curve bandgap reference source according to claim 6, characterized in that: The width-to-length ratios of the enhanced PMOS tube MA9, the enhanced NMOS tube MA10, the enhanced PMOS tube MA13, the enhanced PMOS tube MA14 and the enhanced NMOS tube MA15 are the same as the width-to-length ratio of the enhanced PMOS tube M1 of the sub-1V bandgap reference source part, the width-to-length ratio of the enhanced PMOS tube MA11 is B1 times the width-to-length ratio of the enhanced PMOS tube MA1, the width-to-length ratio of the enhanced PMOS tube MA12 is B2 times the width-to-length ratio of the enhanced PMOS tube MA1, and the width-to-length ratio of the enhanced PMOS tube MA16 is B3 times the width-to-length ratio of the enhanced PMOS tube MA1.

8. The temperature-adjusting curvature compensation circuit for a concave curve bandgap reference source according to claim 7, characterized in that: The reference voltage output part includes a resistor R3, a resistor RC, an enhanced PMOS tube M4 and an enhanced PMOS tube M5; the source electrodes of the enhanced PMOS tube M4 and the enhanced PMOS tube M5 are both connected to the power supply V DD The gate of the enhanced PMOS tube M4 is connected to the output end of the operational amplifier OP1 of the sub-1V bandgap reference source part, the gate of the enhanced PMOS tube M5 is connected to the output end of the operational amplifier OP2 of the sub-1V bandgap reference source part, the drain of the enhanced PMOS tube M4 and the enhanced PMOS tube M5 is connected to one end of the resistor R3, and this connection point is the compensation reference voltage V ref1 Output point; the other end of the resistor R3 is connected to one end of the resistor RC, the other end of the resistor RC is grounded, and the resistor R3 and the resistor RC are connected in series to form an output resistor R OUT , basic reference current I ref Flowing through the output resistor R OUT Generates basic reference voltage V ref At the same time, the resistor RC is also used for low temperature compensation voltage V NTC Or high temperature compensation voltage V PTC The calculation of the final output compensation reference voltage V ref1 .

9. The temperature-adjusting curvature compensation circuit for a concave curve bandgap reference source according to claim 10, characterized in that: The width-to-length ratio of the enhanced PMOS transistor M4 and the enhanced PMOS transistor M5 is the same as the width-to-length ratio of the enhanced PMOS transistor M1 of the sub-1V bandgap reference source portion.

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