阅读说明：本技术 一种超高精度的带隙基准源电路 (Ultra-high precision band gap reference source circuit ) 是由 王军 任贺宇 周小洁 赵传阵 于 2018-12-29 设计创作，主要内容包括：本发明涉及一种超高精度的带隙基准源电路,包括启动电路,主要电路,电阻电路以及分段补偿电路。本发明基于电阻电路利用电阻温度特性通过调节电阻比值得到乘数修调补偿曲线并实现乘数修调补偿技术,通过乘数修调补偿技术和五段分段补偿技术,对带隙基准源进行曲率补偿以获得超高精度的带隙基准源。本发明的优越性在于乘数修调补偿技术的实现无需增加附加电路,简便高效,在消除传统设计方法中电阻温度特性影响的同时,极大地改善了带隙基准源的精度。(The invention relates to an ultra-high precision band gap reference source circuit which comprises a starting circuit, a main circuit, a resistance circuit and a segmented compensation circuit. The invention obtains a multiplier trimming compensation curve and realizes a multiplier trimming compensation technology by adjusting the resistance ratio based on the resistance temperature characteristic of a resistance circuit, and carries out curvature compensation on a band gap reference source by the multiplier trimming compensation technology and a five-section segmented compensation technology so as to obtain the ultra-high-precision band gap reference source. The invention has the advantages that the multiplier trimming compensation technology is realized without adding an additional circuit, is simple and efficient, and greatly improves the precision of the band-gap reference source while eliminating the influence of the resistance temperature characteristic in the traditional design method.)

1. A band-gap reference source circuit with ultra-high precision is characterized by comprising a starting circuit, a main circuit, a resistance circuit and a segmented compensation circuit,

the main circuit specifically comprises a first differential operational amplifier A1, a second differential operational amplifier A2, a first bipolar transistor Q1, a second bipolar transistor Q2, a third bipolar transistor Q3, a first field effect transistor P1, a second field effect transistor P2, a third field effect transistor P3, a fourth field effect transistor P4, a fifth field effect transistor P5, a sixth field effect transistor P6, a seventh field effect transistor P7, an eighth field effect transistor P8, a ninth field effect transistor P9, a tenth field effect transistor P10, an eleventh field effect transistor P11, a twelfth field effect transistor P12, a first resistor R1, a second resistor R2, a third resistor R3, a sixth resistor R6, and a seventh resistor R7;

The resistance circuit specifically comprises a fourth resistor R4 and a fifth resistor R5;

The non-inverting input of A1 is connected with the drain of P2, the emitter of Q through R1, the emitter of Q3 through R5, the drains of P3 and P6 through R5, the inverting input is connected with the drain of P1, the emitter of Q1, the emitter of Q3 through R4, and the output is connected with the gates of P1, P2, P3 and P4; the non-inverting input end of A2 is connected with the emitter of Q1, the drain of P1, the emitter of Q3 through R4, the drains of P3 and P6 through R4, the inverting input end is grounded through R2, the drain of P5 through R3, the gates of P6 and P7 through R3, the output end is connected with the gate of P12, and the bases and collectors of Q1, Q2 and Q3 are grounded.

2. the bandgap reference source circuit as claimed in claim 1, wherein the segmented compensation circuit is a five-segment segmented compensation circuit for generating 5 segments of voltages with different curvatures in 5 continuous temperature intervals, and respectively compensating the reference voltage in the corresponding temperature intervals.

3. The bandgap reference source circuit as claimed in claim 1, wherein the resistors R1, R2, R3, R4, R5, R6 and R7 are each formed by a plurality of discrete resistors having the same resistance value connected in series.

4. the bandgap reference source circuit as claimed in claim 3, wherein the discrete resistors R1, R2, R3, R4 and R5 have the same resistance.

5. The bandgap reference source circuit as recited in claim 3, wherein the discrete resistance value of R6 is less than the discrete resistance value of R2.

6. the bandgap reference source circuit as claimed in claim 4, wherein the resistance values of R4 and R5 are the same.

Technical Field

The invention relates to the field of circuits, in particular to an ultra-high precision band-gap reference source circuit.

Background

The band-gap reference source is used as a power supply, a reference voltage and the like of a precise circuit system, and the precision of the band-gap reference source plays an important role in the stability of the system. In order to improve the precision of the band gap reference source, various technologies for performing curvature compensation on a temperature characteristic curve of the band gap reference source are proposed, but the application requirement of ultrahigh precision is still difficult to meet.

Disclosure of Invention

The invention aims to provide an ultra-high precision band-gap reference source circuit, which adopts a multiplier trimming compensation technology and a 5-segment segmented compensation technology on the basis of high-order nonlinear compensation to overcome the defects of the prior art.

In order to achieve the above object, the present invention provides an ultra-high precision bandgap reference source circuit, which comprises a start circuit, a main circuit, a resistor circuit and a segmented compensation circuit,

The main circuit specifically comprises a first differential operational amplifier A1, a second differential operational amplifier A2, a first bipolar transistor Q1, a second bipolar transistor Q2, a third bipolar transistor Q3, a first field effect transistor P1, a second field effect transistor P2, a third field effect transistor P3, a fourth field effect transistor P4, a fifth field effect transistor P5, a sixth field effect transistor P6, a seventh field effect transistor P7, an eighth field effect transistor P8, a ninth field effect transistor P9, a tenth field effect transistor P10, an eleventh field effect transistor P11, a twelfth field effect transistor P12, a first resistor R1, a second resistor R2, a third resistor R3, a sixth resistor R6, and a seventh resistor R7;

The resistance circuit specifically comprises a fourth resistor R4 and a fifth resistor R5;

The non-inverting input of A1 is connected with the drain of P2, the emitter of Q through R1, the emitter of Q3 through R5, the drains of P3 and P6 through R5, the inverting input is connected with the drain of P1, the emitter of Q1, the emitter of Q3 through R4, and the output is connected with the gates of P1, P2, P3 and P4; the non-inverting input end of A2 is connected with the emitter of Q1, the drain of P1, the emitter of Q3 through R4, the drains of P3 and P6 through R4, the inverting input end is grounded through R2, the drain of P5 through R3, the gates of P6 and P7 through R3, the output end is connected with the gate of P12, and the bases and collectors of Q1, Q2 and Q3 are grounded.

furthermore, the segmented compensation circuit is a five-segment segmented compensation circuit, and is used for generating 5 segments of voltages with different curvatures in 5 continuous temperature intervals and compensating the reference voltage in corresponding temperature intervals respectively.

Further, the resistors R1, R2, R3, R4, R5, R6 and R7 are all formed by connecting a plurality of discrete resistors with the same resistance value in series.

Further, the discrete resistors R1, R2, R3, R4 and R5 have the same resistance value.

Further, the discrete resistance value of R6 is less than the discrete resistance value of R2.

Further, the resistance values of the R4 and the R5 are the same.

By adopting the technical scheme, the invention obtains the ultra-high-precision temperature characteristic curve by combining 5 sections of segmented compensation technology on the basis of greatly improving the precision of the band gap reference source by utilizing the multiplier trimming compensation technology, thereby greatly improving the precision of the band gap reference source and ensuring the stability of the whole system.

Drawings

The invention will be further described with reference to the accompanying drawings in which:

FIG. 1 is a circuit diagram of the basic structure of an ultra-high precision bandgap reference source circuit provided by the present invention;

FIG. 2 is a schematic diagram of the multiplier trim compensation used in the present invention;

FIG. 3 is a 5-segment sectional compensation circuit in the ultra-high precision bandgap reference source circuit proposed by the present invention;

FIG. 4 is a schematic diagram of a 5-segment compensation scheme used in the present invention;

FIG. 5 is a graph of the variation of the higher order nonlinear compensation voltage and the relative position to the first order compensated reference voltage in an embodiment of the present invention;

FIG. 6 is a graph showing the temperature characteristics of a reference voltage at-40 ℃ to 125 ℃ in the embodiment of the present invention;

FIG. 7 is a schematic diagram of the multiplier trimming compensation technique used in the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

the structures, proportions, sizes, and other dimensions shown in the drawings and described in the specification are for understanding and reading the present disclosure, and are not intended to limit the scope of the present disclosure, which is defined in the claims, and are not essential to the art, and any structural modifications, changes in proportions, or adjustments in size, which do not affect the efficacy and attainment of the same are intended to fall within the scope of the present disclosure. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention.

The circuit diagram structure is as shown in fig. 1, the ultra-high precision bandgap reference source circuit includes a start circuit, a main circuit, a resistor circuit and a segmented compensation circuit, the main circuit specifically includes a first differential operational amplifier a1, a second differential operational amplifier a2, a first bipolar transistor Q1, a second bipolar transistor Q2, a third bipolar transistor Q3, a first field effect transistor P1, a second field effect transistor P2, a third field effect transistor P3, a fourth field effect transistor P4, a fifth field effect transistor P5, a sixth field effect transistor P6, a seventh field effect transistor P7, an eighth field effect transistor P8, a ninth field effect transistor P9, a tenth field effect transistor P10, an eleventh field effect transistor P11, a twelfth field effect transistor P12, a first resistor R1, a second resistor R2, a third resistor R3, a sixth resistor R6 and a seventh resistor R7; the resistor circuit comprises in particular a fourth resistor R4 and a fifth resistor R5.

The non-inverting input of A1 is connected with the drain of P2, the emitter of Q through R1, the emitter of Q3 through R5, the drains of P3 and P6 through R5, the inverting input is connected with the drain of P1, the emitter of Q1, the emitter of Q3 through R4, and the output is connected with the gates of P1, P2, P3 and P4; the non-inverting input end of A2 is connected with the emitter of Q1, the drain of P1, the emitter of Q3 through R4, the drains of P3 and P6 through R4, the inverting input end is grounded through R2, the drain of P5 through R3, the gates of P6 and P7 through R3, the output end is connected with the gate of P12, and the bases and collectors of Q1, Q2 and Q3 are grounded. The connection relationship of the elements is shown in fig. 1, and will not be described in detail. In this embodiment, the start-up circuit is a commonly used start-up circuit.

The main circuit and the resistance circuit form a multiplier trimming compensation circuit based on high-order nonlinear compensation.

On the basis of the above scheme, further, the segmented compensation circuit includes five segmented compensation circuits, and is configured to generate 5 segments of voltages with different curvatures in 5 continuous temperature intervals, and compensate the reference voltage in corresponding temperature intervals respectively. The structure diagram of the five-segment compensation circuit is shown in fig. 3, and the schematic diagram of the five-segment compensation circuit is shown in fig. 4.

On the basis of the scheme, the resistors R1, R2, R3, R4, R5, R6 and R7 are all formed by connecting a plurality of discrete resistors with the same resistance value in series.

On the basis of the scheme, the R1, the R2, the R3, the R4 and the R5 are the same in resistance value.

on the basis of the scheme, the discrete resistance value of the R6 is smaller than that of the R2.

The resistance circuit reduces the resistance values of R4 and R5, thereby realizing the shift of the inflection point of the reference voltage temperature characteristic curve on the temperature axis, as shown in fig. 5. The shift of the inflection point of the reference voltage temperature characteristic in the temperature axis can be realized, the inflection point of the reference voltage temperature characteristic can be shifted in the low temperature direction in the temperature axis when the resistance values of R4 and R5 are decreased, and the inflection point of the reference voltage temperature characteristic can be shifted in the high temperature direction in the temperature axis when the resistance values of R4 and R5 are increased.

The final trimming compensated reference voltage is obtained by multiplying the total current flowing into the sixth resistor R6 by the resistance of the sixth resistor R6.

And the total current flowing into the sixth resistor R6 is controlled by the current I positively correlated with the temperature_PTATA current inversely related to temperatureAnd a high-order nonlinear compensation current I_CAnd (4) forming. Wherein I_PTATandand performing first-order compensation, obtaining the reference voltage after the first-order compensation as shown in fig. 5 in a temperature range of-40 ℃ to 125 ℃, and matching with the traditional high-order nonlinear compensation realized by the fourth resistor R4 and the fifth resistor R5, wherein the resistance values of R4 and R5 are the same, and obtaining the traditional high-order nonlinear compensation reference voltage with a similar sine shape as shown in fig. 6 in the temperature range of-40 ℃ to 125 ℃.

the expression of the reference voltage after the traditional high-order nonlinear compensation is as follows,

Wherein, V_TThe collector current ratio of thermal voltage 26mV to N Q2 and Q1, V_EBIs the voltage from the base E to the emitter B in Q2 and Q1, T is the temperature, T_rIs the reference temperature 0 ℃.

because the resistors used in the traditional design are all composed of a plurality of same discrete resistors, all the resistor ratios in the above formula are constant in a temperature range of-40 ℃ to 125 ℃, namely, the temperature drift curve is a straight line parallel to a temperature axis.

in the invention, the precision of the reference voltage is improved by changing the resistance ratio, adjusting the temperature drift curve and correspondingly adjusting the reference voltage after the traditional high-order nonlinear compensation.

and (4) adjusting the traditional high-order nonlinear compensation.

in the conventional high-order nonlinear compensation, when the fourth resistor R4 and the fifth resistor R5 are lowered, since potentials at both ends thereof are substantially unchanged, a high-order nonlinear current flowing therethrough is increased, so that an intersection of a high-order nonlinear voltage generated by the high-order nonlinear current in the sixth resistor R6 and a first-order compensation reference voltage of a lower-opening parabola-like obtained after the first-order compensation is moved to a low-temperature stage, as shown in fig. 5. Therefore, the reference voltage obtained by reducing the fourth resistor R4 and the fifth resistor R5 exhibits a temperature characteristic of high accuracy in the low temperature range and low accuracy in the high temperature range, as shown in fig. 6.

The multiplier trims the compensation curve.

The invention provides a multiplier trimming compensation technology. The temperature drift curve of the resistor ratio in the temperature range of-40-125 ℃ is influenced by the resistance values of the discrete resistors respectively forming the resistors on the numerator and the denominator, when the resistance value of the discrete resistor forming the resistor on the numerator is smaller than the resistance value of the discrete resistor forming the resistor on the denominator, the temperature drift curve of the resistor ratio is reduced along with the rise of the temperature, and when the denominator is the same, the smaller the ratio is, the larger the temperature drift is.

When the ratio is constant, the smaller the resistance value of the discrete resistor on the numerator and the denominator is, the larger the temperature drift is, the resistance value is reduced by half, and the temperature drift is increased by about one time.

when the resistance value of the discrete resistor constituting the on-numerator resistor is larger than the resistance value of the discrete resistor constituting the on-denominator resistor, the temperature drift curve of the resistance ratio increases with the temperature increase.

when the resistance value of the discrete resistor constituting the resistance on the numerator is equal to the resistance value of the discrete resistor constituting the resistance on the denominator, the temperature drift of the resistance ratio is equal to 0.

Therefore, the reference voltage expression after the traditional high-order nonlinear compensation can be subjected to the high-order nonlinear compensation according to the change rule of the resistance ratio valueDesigning a temperature drift curve in a temperature range of-40-125 ℃ to ensure that the discrete resistance value of R6 is smaller than that of R2, obtaining a multiplier trimming compensation curve and realizing a multiplier trimming compensation technology.

The formula of the multiplier trimming compensation curve is as follows:

WhereinIs composed ofA temperature drift curve in a temperature range of-40 ℃ to 125 ℃,Is R at a reference temperature₂And R₆The ratio of (a) to (b).

Multiplier trimming compensation curve T_KThe maximum value is 1, and the difference between the maximum value and the minimum value is small.

Multiplier trimming compensation techniques.

Based on the multiplier trimming compensation curve provided by the invention. After the reference voltage curve with the characteristics of high precision of the low-temperature section and low precision of the high-temperature section and with the reduced fourth resistor and the reduced fifth resistor as shown in fig. 6 is obtained, the multiplier trimming compensation curve TK provided by the patent is adopted, and the multiplier trimming compensation curve as shown in fig. 7 is multiplied by the reference voltage with the reduced fourth resistor and the reduced fifth resistor as shown in fig. 6.

Since the multiplication of the reference voltage and the reference voltage is performed by a number less than 1, the temperature drift amplitude of the high-temperature section is reduced, the precision of the low-temperature section can be basically maintained, and the precision of the high-temperature section is improved, so that the overall precision of the reference voltage after trimming compensation is greatly improved, as shown in fig. 7, the reference voltage is the multiplier trimming compensation technology of the invention.

through data fitting, the expression of the reference voltage after the multiplier trimming compensation is as follows:

V_ref≈T_K×V_ref′。

And (4) a five-segment segmented compensation technology.

On the basis of greatly improving the precision of the band gap reference source by utilizing a multiplier trimming compensation technology, the invention combines 5-segment segmental compensation technology to obtain an ultra-high precision temperature characteristic curve, as shown in figure 4.

The multiplier trimming compensation curve is obtained by adjusting the resistance ratio by using the resistance temperature characteristic. And curvature compensation is carried out on the band gap reference source through a multiplier trimming compensation technology and a five-section segmentation compensation technology to obtain the ultra-high-precision band gap reference source. The invention has the advantages that the multiplier trimming compensation technology is realized without adding an additional circuit, is simple and efficient, and greatly improves the precision of the band-gap reference source while eliminating the influence of the resistance temperature characteristic in the traditional design method.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.