A bandgap reference correction circuit and method with high and low temperature compensation correction

Abstract

The embodiment of the present application provides a bandgap reference correction circuit and method with high and low temperature compensation correction, the circuit comprising: a first current generation correction circuit, used to correct and generate a first current inversely proportional to the absolute temperature to obtain a first correction current; a second current generation correction circuit, used to correct and generate a second current proportional to the absolute temperature to obtain a second correction current; a current compensation circuit, respectively connected to the first current generation correction circuit and the second current generation correction circuit, when the current temperature is less than the low temperature compensation point temperature, it is used to compensate the first correction current and the second correction current to obtain the first compensation current; when the current temperature is greater than the high temperature compensation point temperature, it is used to compensate the first correction current and the second correction current to obtain the second compensation current, and the first compensation current and the second compensation current are superimposed to obtain the final compensation current; a first resistor, connected to the current compensation circuit, used to convert the final compensation current into a compensation voltage; the bandgap reference correction circuit adjusts the bandgap reference voltage according to the final compensation voltage. The present application improves the mass production yield of low temperature drift and high precision bandgap references.

Description

Technical Field

[0001] The embodiments of the present application belong to the technical field of bandgap reference correction, and in particular, relate to a bandgap reference correction circuit and method with high and low temperature compensation correction. Background Art

[0002] In analog systems such as digital-to-analog converters, analog-to-digital converters, and linear regulators, low-temperature drift bandgap reference modules are indispensable and important modules, and their accuracy and stability directly affect the accuracy of the entire system. Traditional bandgap voltage circuits usually use first-order temperature compensation, that is, linear compensation of the temperature coefficient of the BE junction between the base and emitter junctions of the transistor to obtain a temperature inflection point; or second-order curvature temperature compensation, that is, adding square compensation for the temperature coefficient in the BE junction between the base and emitter junctions of the transistor on the basis of first-order compensation, or performing segmented compensation at high and low temperatures, with 2 to 3 temperature inflection points. Second-order curvature compensation and segmented compensation technology greatly improve the accuracy of the output voltage, making its temperature drift less than 10ppm / ℃.

[0003] The Chinese patent with patent number CN205983278U adopts segmented compensation, and through the addition compensation of positive temperature coefficient current and negative temperature coefficient current, the bandgap reference obtains more than three temperature inflection points in the operating temperature range, and obtains a high-precision low-temperature drift bandgap reference voltage source. Although the above structure can obtain good results in simulation and achieve a temperature drift of several ppm, the internal devices will still be affected by the process angle, device matching and packaging during production, and the resulting temperature drift may still be large, and the mass production yield of low-temperature drift and high-precision bandgap reference cannot be guaranteed. Summary of the invention

[0004] In order to solve or alleviate the problems in the prior art, an embodiment of the present invention provides a bandgap reference correction circuit with high and low temperature compensation correction, including: a high and low temperature compensation correction circuit and a bandgap reference correction circuit;

[0005] The high and low temperature compensation correction circuit comprises:

[0006] A first current generating and correcting circuit, used for correcting and generating a first current inversely proportional to the absolute temperature to obtain a first corrected current;

[0007] A second current generating and correcting circuit, used for correcting and generating a second current proportional to the absolute temperature to obtain a second corrected current;

[0008] a current compensation circuit, connected to the first current generation correction circuit and the second current generation correction circuit respectively, and used to compensate the first correction current and the second correction current to obtain the first compensation current when the current temperature is lower than the low temperature compensation point temperature; and used to compensate the first correction current and the second correction current to obtain the second compensation current when the current temperature is higher than the high temperature compensation point temperature, and to superimpose the first compensation current and the second compensation current to obtain the final compensation current;

[0009] A first resistor, connected to the current compensation circuit, and used to convert the final compensation current into a compensation voltage;

[0010] A bandgap reference correction circuit is connected to the first resistor and is used to adjust the bandgap reference voltage according to the final compensation voltage.

[0011] Compared with the prior art, the embodiment of the present application provides a bandgap reference correction circuit with high and low temperature compensation correction, the circuit comprising: a first current generation correction circuit, used to correct and generate a first current inversely proportional to the absolute temperature to obtain a first correction current; a second current generation correction circuit, used to correct and generate a second current proportional to the absolute temperature to obtain a second correction current; a current compensation circuit, respectively connected to the first current generation correction circuit and the second current generation correction circuit, when the current temperature is less than the low temperature compensation point temperature, it is used to compensate the first correction current and the second correction current to obtain the first compensation current; when the current temperature is greater than the high temperature compensation point temperature, it is used to compensate the first correction current and the second correction current to obtain the second compensation current, and the first compensation current and the second compensation current are superimposed to obtain the final compensation current; a first resistor, connected to the current compensation circuit, used to convert the final compensation current into a compensation voltage; the bandgap reference correction circuit adjusts the bandgap reference voltage according to the final compensation voltage. The present application adjusts the first-order temperature coefficient of the bandgap reference correction circuit. After adjustment, the temperature drift of the bandgap reference is less than 3ppm / ℃ under the influence of processing technology changes, device mismatch and packaging, which improves the mass production yield of low-temperature drift and high-precision bandgap reference.

[0012] In a second aspect, an embodiment of the present application further provides a bandgap reference correction method with high and low temperature compensation correction, the method is implemented by any correction circuit of the first aspect, and the method includes:

[0013] Obtaining a first corrected current by correcting a first current generated by a first current correction circuit and being inversely proportional to the absolute temperature;

[0014] Obtaining a second corrected current by correcting a second current generated by a second current correction circuit and being proportional to the absolute temperature;

[0015] When the current temperature is lower than the low temperature compensation point temperature, the first correction current and the second correction current are compensated by the current compensation circuit to obtain the first compensation current; when the current temperature is higher than the high temperature compensation point temperature, the first correction current and the second correction current are compensated by the current compensation circuit to obtain the second compensation current, and the first compensation current and the second compensation current are superimposed to obtain the final compensation current;

[0016] Converting the final compensation current into a compensation voltage through a first resistor;

[0017] The bandgap reference voltage is adjusted according to the final compensation voltage by a bandgap reference correction circuit.

[0018] Compared with the prior art, the beneficial effects of a bandgap reference correction method with high and low temperature compensation correction provided in the second aspect are the same as the beneficial effects of the correction circuit provided in the first aspect, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. Some specific embodiments of the present application will be described in detail in an illustrative and non-restrictive manner with reference to the drawings. The same reference numerals in the drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the drawings:

[0020] Figure 1 It is a structural schematic diagram of a bandgap reference correction circuit with high and low temperature compensation correction provided by an embodiment of the present application;

[0021] Figure 2 It is a structural schematic diagram of a bandgap reference correction circuit with high and low temperature compensation correction provided by another embodiment of the present application;

[0022] Figure 3 is a diagram showing changes in a compensation circuit obtained through a current compensation circuit provided in an embodiment of the present application;

[0023] Figure 4 This is a diagram showing the effect of correcting a bandgap reference voltage using a bandgap reference correction circuit with high and low temperature compensation correction provided by an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application.

[0025] like Figure 1 As shown, the embodiment of the present application provides a bandgap reference correction circuit with high and low temperature compensation correction, including: a high and low temperature compensation correction circuit and a bandgap reference correction circuit;

[0026] The high and low temperature compensation correction circuit comprises:

[0027] A first current generating and correcting circuit 01, used for correcting and generating a first current inversely proportional to the absolute temperature to obtain a first corrected current;

[0028] A second current generating and correcting circuit 02, used for correcting and generating a second current proportional to the absolute temperature to obtain a second corrected current;

[0029] A current compensation circuit, connected to the first current generating correction circuit 01 and the second current generating correction circuit 02, respectively, is used to compensate the first correction current and the second correction current to obtain a first compensation current when the current temperature is lower than the low temperature compensation point temperature; when the current temperature is higher than the high temperature compensation point temperature, it is used to compensate the first correction current and the second correction current to obtain a second compensation current, and the first compensation current and the second compensation current are superimposed to obtain a final compensation current;

[0030] A first resistor 06, connected to the current compensation circuit, and used to convert the final compensation current into a compensation voltage;

[0031] The bandgap reference correction circuit 05 is connected to the first resistor 06 and is used for adjusting the bandgap reference voltage according to the final compensation voltage.

[0032] In the embodiment of the present application, the current compensation circuit includes: a first current compensation circuit 03 and a second current compensation circuit 04;

[0033] When the current temperature is lower than the low temperature compensation point temperature, the first current compensation circuit 03 is used to compensate the first correction current generated by the first current generation correction circuit 01 to obtain a first compensation current;

[0034] When the current temperature is greater than the high temperature compensation point temperature, the second current compensation circuit 04 is used to compensate the second correction current generated by the second correction current 02 to obtain a second compensation current.

[0035] A control switch 07 is provided between the current compensation circuit and the bandgap reference correction circuit 05 , and the control switch 07 is used to control whether current compensation needs to be performed on the bandgap reference correction circuit 05 .

[0036] In the embodiment of the present application, the first resistor 07 is a variable resistor, and the compensation voltage input to the bandgap reference correction circuit 05 is controlled by adjusting the resistance value of the first resistor.

[0037] like Figure 2 As shown, the first current generation correction circuit includes: a first clamping circuit 12, a first current mirror 11 and a first current generation correction unit;

[0038] The first current mirror 11 is connected to the first clamping circuit 12, and one end of the first clamping circuit 12 away from the first current mirror 11 is connected to the first current generating and correcting unit;

[0039] After the first correction current is generated by the first current generation and correction unit, the first current is transmitted to the current compensation circuit through the first current mirror 11 .

[0040] The second current generation correction circuit comprises: a second clamping circuit 14, a second current mirror 13 and a second current generation correction unit;

[0041] The second current mirror 13 is connected to the second clamping circuit 14, and one end of the second clamping circuit 14 away from the second current mirror 13 is connected to the second current generating and correcting unit;

[0042] After the second correction current is generated by the second current generation and correction unit, the second current is transmitted to the current compensation circuit through the second current mirror 13 .

[0043] The first current generation correction unit includes a first transistor Q1, a second resistor R2 and a third resistor R3;

[0044] The second resistor R2 and the third resistor R3 are arranged in series, and the circuit where the second resistor R2 and the third resistor R3 are located is arranged in parallel with the circuit where the first transistor Q1 is located;

[0045] The second resistor R2 and the first transistor Q1 are respectively connected to the first clamping circuit 12;

[0046] The third resistor R3 is a variable resistor, and the current of the circuit where the second resistor R2 and the third resistor R3 are located is adjusted by adjusting the resistance value of the third resistor R3 to obtain the first correction current.

[0047] In the embodiment of the present application, the first transistor Q1 may also be multiple, one end of the first transistor group Q1 and the second resistor R2 are both grounded, and the other end is connected to the first clamping circuit 12, and the first clamping circuit 12 can keep the voltage of the circuit where the first transistor Q1 is located consistent with the voltage of the circuit where the first resistor R1 and the second resistor R2 are located;

[0048] The current I1 of the circuit where the second resistor R2 and the third resistor R3 are located is:

[0049] I1=VBE_Q1 / (R2+R3), wherein R2 is the resistance value of the second resistor R2, R3 is the resistance value of the third resistor R3, VBE_Q1 is the voltage of the circuit where the first transistor Q1 is located, and I1 is adjusted to the target current value by adjusting the resistance of the third resistor R3, and the I1 current decreases as the temperature increases.

[0050] After the current I1 of the circuit where the second resistor R2 and the third resistor R3 are located is obtained through the above calculation, the current I1 is mirrored to the first PMOS transistor M1 through the first current mirror 11 .

[0051] The second current generation correction unit includes a second transistor Q2, a third transistor Q3, a fourth resistor R4 and a fifth resistor R5;

[0052] The third transistor Q3, the fourth resistor R4 and the fifth resistor R5 are arranged in series, and the circuit where the third transistor Q3, the fourth resistor R4 and the fifth resistor R5 are located is arranged in parallel with the circuit where the second transistor Q2 is located;

[0053] The fourth resistor R4 and the second transistor Q2 are respectively connected to the second clamping circuit 14;

[0054] The fourth resistor R4 is a variable resistor, and the current of the circuit where the third transistor Q3, the fourth resistor R4 and the fifth resistor R5 are located is regulated by adjusting the resistance value of the fourth resistor R4 to obtain the second correction current.

[0055] The number of the second triode group Q2 and the third triode Q3 may also be multiple, one end of the circuit where the third resistor R3, the fourth resistor R4 and the third diode Q3 are located is grounded, and the other end is connected to the second clamping circuit 14, and the second clamping circuit 14 can keep the voltage of the circuit where the second triode Q2 is located consistent with the voltage of the circuit where the third resistor R3, the fourth resistor R4 and the third triode group Q3 are located;

[0056] The current I2 of the circuit where the fourth resistor R4 and the fifth resistor R5 are located is:

[0057] I2=(VBE_Q2-VBE_Q3) / (R4+R5), R4 is the resistance value of the fourth resistor R4, R5 is the resistance value of the fifth resistor R5, VBE_Q2 is the voltage of the circuit where the second transistor Q2 is located, VBE_Q3 is the voltage of the circuit where the third transistor Q3 is located, and I2 is adjusted to the target value by adjusting the resistance value of the fifth resistor R5, and the I2 current increases with increasing temperature.

[0058] After the current I2 of the circuit where the fourth resistor R4 and the fifth resistor R5 are located is obtained through the above calculation, the current I2 is mirrored to the third MOS tube through the second current mirror 13 .

[0059] The current compensation circuit comprises: a first current compensation circuit and a second current compensation circuit;

[0060] When the current temperature is lower than the low temperature compensation point temperature, the first current compensation circuit is used to compensate the first correction current generated by the first current generation correction circuit to obtain a first compensation current;

[0061] When the current temperature is greater than the high temperature compensation point temperature, the second current compensation circuit is used to compensate the second current for the second correction current generated by the correction current to obtain a second compensation current.

[0062] In the embodiment of the present application, the first current compensation circuit includes: a first PMOS tube M1, a third current mirror 16, a second PMOS tube M2, and a fourth current mirror 15;

[0063] The first PMOS transistor M1 is connected to the first current mirror 11 and the third current mirror 16 respectively, the second current mirror 13 is connected to the second PMOS transistor M2, and the second MOS transistor is connected to the second current generation correction circuit;

[0064] The first PMOS tube M1 transmits the first correction current output by the first current mirror 11 to the third current mirror 16, and the fourth current mirror 15 is connected to the common end between the third current mirror 16 and the second PMOS tube M2;

[0065] The magnitude of the current on the third current mirror 16 and the current on the second PMOS tube M2 are judged. When the current temperature is lower than the low temperature compensation point temperature, and the current on the third current mirror 16 is higher than the current on the second PMOS tube M2, the current on the fourth current mirror 15 is obtained by the current difference between the third current mirror 16 and the second PMOS tube M2, thereby obtaining the first compensation current.

[0066] In the embodiment of the present application, the current flowing through the first PMOS tube M1 is the same as the current flowing through the first current mirror 11. The first current mirror 11 is composed of two PMOS tubes. The function of the first current mirror 11 is that no matter whether the external input voltage encounters fluctuations or changes in a large range, the output current of the first current mirror 11 always remains unchanged. The first current mirror 11 mirrors the current to the first PMOS tube M1 and the fourth PMOS tube M4. Since the second current mirror 13 and the first PMOS tube M1 are in the same circuit, the current of the second current mirror 13 is the same as that of the first PMOS tube M1. The second current mirror 13 is composed of two PMOS tubes M3 and M4.

[0067] In the embodiment of the present application, (W / L) M6 / (W / L) M5 =K1, (W / L) M3 / (W / L) M2 =K2, (W / L) M8 / (W / L) M7 =K3, low temperature compensation current = (K1*I1-K2*I2)*K3, that is, the current flowing through the PMOS M8 of the fourth current mirror 15 = (K1*I1-K2*I2)*K3, where (W / L) M6 is the ratio of the gate channel width to length of the PMOS tube M6, (W / L) M5 is the ratio of the gate channel width to length of the PMOS tube M5, (W / L) M3 is the ratio of the gate channel width to length of the PMOS tube M3, (W / L) M2 is the ratio of the gate channel width to length of the PMOS tube M2, (W / L) M8 is the ratio of the gate channel width to length of the PMOS tube M8, (W / L) M7 It is the ratio of the gate channel width to the length of the PMOS tube M7.

[0068] like Figure 3 As shown, when K1*I1-K2*I2=0 and the current temperature is equal to T1, T1 is the low temperature compensation point temperature, so the low temperature compensation current changes with temperature: when the current temperature T1 is less than the low temperature compensation point temperature T1, the low temperature compensation current=(K1*I1-K2*I2)*K3, when the current temperature T1 is greater than the low temperature compensation point temperature T1, no compensation is required.

[0069] In the embodiment of the present application, the fourth current mirror 15 is composed of two PMOS tubes, and the fourth current mirror 15 is connected to a power supply.

[0070] As a preferred embodiment of the present application, the second current compensation circuit includes: a third MOS tube, a fifth current mirror 18, a fourth PMOS tube M4, and a sixth current mirror 17;

[0071] The third PMOS tube M3 is connected to the fifth current mirror 18 and the second current mirror 13 respectively, the fifth current mirror 18 is connected to the fourth PMOS tube M4, and the fourth PMOS tube M4 is connected to the first current generation correction circuit and the fifth current mirror 18 respectively;

[0072] The third PMOS tube M3 transmits the second correction current output by the second current mirror 13 to the fifth current mirror 18, and the sixth current mirror 17 is connected to the common end between the fifth current mirror 18 and the fourth PMOS tube M4;

[0073] The magnitude of the current on the fifth current mirror 18 and the current on the fourth PMOS tube M4 are judged. When the current temperature is greater than the high temperature compensation point temperature, and the current on the fifth current mirror 18 is greater than the current of the fourth PMOS tube M4, the current on the sixth current mirror 17 is obtained by the current difference between the fifth current mirror 18 and the fourth PMOS tube M4 to obtain the second compensation current.

[0074] In the embodiment of the present application, the current flowing through the third PMOS tube M3 is the same as the current flowing through the fifth current mirror 18. The fifth current mirror 18 is composed of two PMOS tubes. The function of the fifth current mirror 18 is to keep the output current constant regardless of whether the external input voltage fluctuates or changes over a large range. The second current mirror 13 mirrors the current to the second PMOS tube M2 and the third PMOS tube M3. Since the fifth current mirror 18 and the third PMOS tube M3 are in the same circuit, the current of the fifth current mirror 18 is the same as that of the third PMOS tube M3. The fifth current mirror 18 is composed of two PMOS tubes.

[0075] In the embodiment of the present application, (W / L) M11 / (W / L) M12 =K4, (W / L) M4 / (W / L) M1 =K5, (W / L) M10 / (W / L) M9 =K6, high temperature compensation current = (K4*I2-K5*I1)*K6, that is, the current flowing through the PMOS tube M10 on the fifth current mirror 18 = (K4*I2-K5*I1)*K6, where (W / L) M11 is the ratio of the gate channel width to length of the PMOS tube M11, (W / L) M12 is the ratio of the gate channel width to length of the PMOS tube M12, (W / L) M4 is the ratio of the gate channel width to length of the PMOS tube M4, (W / L) M1 is the ratio of the gate channel width to length of the PMOS tube M1, (W / L) M10is the ratio of the gate channel width to length of the PMOS tube M10, (W / L) M9 It is the ratio of the gate channel width to the length of the PMOS tube M9.

[0076] When K4*I2-K5*I1=0 and the current temperature is equal to T2, T2 is the high temperature compensation point, so the high temperature compensation current changes with temperature as follows: when the current temperature T is greater than the high temperature compensation point temperature T2, the high temperature compensation current = (K4*I2-K5*I1)*K6; when the current temperature T is not greater than the high temperature compensation point temperature T2, no compensation is required.

[0077] The sixth current mirror 17 is composed of two PMOS tubes, and the sixth current mirror 17 is connected to a power supply.

[0078] In the embodiment of the present application, the final compensation current of the current compensation circuit varies with temperature as follows:

[0079] When the current temperature T is less than the low temperature compensation point temperature T1, the final compensation current is (K1*I1-K2*I2)*K3; when the current temperature T is not less than the low temperature compensation point temperature T1 and not greater than the high temperature compensation point temperature T2, the final compensation current is 0; when the current temperature T is greater than the high temperature compensation point temperature T2, the final compensation current is (K4*I2-K5*I1)*K6.

[0080] After process parameter changes, internal device mismatch and packaging, by adjusting the resistance values ​​of the third resistor R3 and the fifth resistor R5 and adjusting I1 and I2 to the target values, the low temperature compensation point temperature T1 and the high temperature compensation point temperature T2 can be calibrated to a reasonable range.

[0081] The bandgap reference correction circuit includes a fourth transistor Q4, a fifth transistor Q5, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8;

[0082] The eighth resistor R8 is a variable resistor, the fourth transistor Q4 and the fifth transistor Q5 are arranged in parallel, the sixth resistor R6 and the fourth transistor Q4 are arranged in series, and the seventh resistor R7 and the eighth resistor R8 are arranged in series;

[0083] The bandgap reference correction circuit also includes a third clamping circuit, a seventh current mirror, a fifth PMOS tube M16 and a sixth PMOS tube M17. The third clamping circuit is composed of two PMOS tubes M13 and M14, the seventh current mirror is composed of two PMOS tubes, the seventh current mirror is connected to the third clamping circuit, and the third clamping circuit is also connected to a power supply. The fifth PMOS tube M16 and the sixth PMOS tube M17 are arranged on the same circuit, the fifth PMOS tube M16 mainly plays the role of a switch, and the sixth PMOS tube M17 is used to generate a voltage drop for this circuit.

[0084] The bandgap reference correction circuit also includes a ninth resistor R9 and a tenth resistor R10. The ninth resistor R9 is arranged in a circuit where a PMOS tube in the seventh current mirror is located, and the tenth resistor R10 is arranged in a circuit where another PMOS tube in the seventh current mirror is located. The ninth resistor R9 and the tenth resistor R10 are mainly used to generate a voltage drop in the circuit.

[0085] A PMOS tube is further provided on the circuit where the fifth PMOS tube M16 and the sixth PMOS tube M17 are located. The PMOS tube is used to provide current for the bandgap reference voltage.

[0086] The common end where the base of the fourth transistor Q4 and the base of the fifth transistor Q5 are connected is connected to the emitter of the PMOS tube M14, and the bandgap reference output voltage is obtained by detecting the voltage between the emitter of the PMOS tube M14 and the common end.

[0087] The resistance value of the eighth resistor R8 is changed by changing the ambient temperature, and the bandgap reference output voltage of the chip after being trimmed by different trimming codes is determined by the change in the resistance value of the eighth resistor R8.

[0088] Specifically, the bandgap reference output voltage VBG is calculated as follows:

[0089] VBG=2*ΔVBE / R6*(R7+R8+R1)+VBE_Q5+final compensation current*R1

[0090] ΔVBE=VBE_Q5-VBE_Q4

[0091] Among them, VBE_Q4 is the voltage between the base and the emitter of the fourth transistor Q4, VBE_Q5 is the voltage between the base and the emitter of the fifth transistor Q5, R6 is the resistance value of the fifth resistor R6, R7 is the resistance value of the seventh resistor R7, and R8 is the resistance value of the eighth resistor R8.

[0092] In the embodiment of the present application, the number of the fifth triode Q5 is m=8, and the number of the fourth triode group Q4 is n=4. It should be noted that as long as the number of the fifth triode Q5 is greater than that of the fourth triode group Q4, it is within the protection scope of the present application.

[0093] like Figure 4 As shown, through the effect diagram after calibration of the correction circuit provided in the present application, it can be seen that at the low temperature compensation point temperature and the high temperature compensation point temperature, the chip is calibrated to a reasonable range, and the temperature coefficient of the bandgap reference voltage is less than 3pp / ℃.

[0094] Specifically, the circuit structure performs dual-temperature calibration by changing the resistance value of the eighth resistor R8 at two different temperatures, and the calibration method includes:

[0095] 1) Determine the bandgap reference output voltage-temperature curve of the chip based on simulation.

[0096] 2) Determine that the extreme temperature T1 of the temperature curve is 42°C;

[0097] 3) When the ambient temperature is 25° C., the bandgap reference output voltage is recorded by changing the resistance value of the seventh resistor R7, and then when the ambient temperature is 42+42-25=59° C., the bandgap reference output voltage is recorded by changing the resistance value of the seventh resistor R7;

[0098] 4) The absolute value of the bandgap reference output voltages with the same resistance value of the seventh resistor R7 at two temperatures is calculated by subtracting them.

[0099] The resistance of the seventh resistor R7 corresponding to the minimum absolute value is the optimal temperature curve of the first-order compensation bandgap reference circuit. Compared with the prior art, the embodiment of the present application provides a bandgap reference correction circuit with high and low temperature compensation correction, the circuit comprising: a first current generation correction circuit, used to correct and generate a first current inversely proportional to the absolute temperature to obtain a first correction current; a second current generation correction circuit, used to correct and generate a second current proportional to the absolute temperature to obtain a second correction current; a current compensation circuit, respectively connected to the first current generation correction circuit and the second current generation correction circuit, when the current temperature is less than the low temperature compensation point temperature, it is used to compensate the first correction current and the second correction current to obtain the first compensation current; when the current temperature is greater than the high temperature compensation point temperature, it is used to compensate the first correction current and the second correction current to obtain the second compensation current, and the first compensation current and the second compensation current are superimposed to obtain the final compensation current; a first resistor, connected to the current compensation circuit, is used to convert the final compensation current into a compensation voltage; the bandgap reference correction circuit adjusts the bandgap reference voltage according to the final compensation voltage. The present application adjusts the first-order temperature coefficient of the bandgap reference correction circuit. After adjustment, the temperature drift of the bandgap reference is less than 3ppm / ℃ under the influence of processing technology changes, device mismatch and packaging, which improves the mass production yield of low-temperature drift and high-precision bandgap reference.

[0100] In a second aspect, an embodiment of the present application further provides a bandgap reference correction method with high and low temperature compensation correction, the method is implemented by any correction circuit of the first aspect, and the method includes:

[0101] Obtaining a first corrected current by correcting a first current generated by a first current correction circuit and being inversely proportional to the absolute temperature;

[0102] Obtaining a second corrected current by correcting a second current generated by a second current correction circuit and being proportional to the absolute temperature;

[0103] When the current temperature is lower than the low temperature compensation point temperature, the first correction current and the second correction current are compensated by the current compensation circuit to obtain the first compensation current; when the current temperature is higher than the high temperature compensation point temperature, the first correction current and the second correction current are compensated by the current compensation circuit to obtain the second compensation current, and the first compensation current and the second compensation current are superimposed to obtain the final compensation current;

[0104] Converting the final compensation current into a compensation voltage through a first resistor;

[0105] The bandgap reference voltage is adjusted according to the final compensation voltage by a bandgap reference correction circuit.

[0106] Compared with the prior art, the beneficial effects of a bandgap reference correction method with high and low temperature compensation correction provided in the second aspect are the same as the beneficial effects of the correction circuit provided in the first aspect, which will not be repeated here.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A bandgap reference correction circuit with high and low temperature compensation correction, characterized in that: include: High and low temperature compensation correction circuit and bandgap reference correction circuit; The high and low temperature compensation correction circuit comprises: A first current generating and correcting circuit, used for correcting and generating a first current inversely proportional to the absolute temperature to obtain a first corrected current; A second current generating and correcting circuit, used for correcting and generating a second current proportional to the absolute temperature to obtain a second corrected current; a current compensation circuit, connected to the first current generation correction circuit and the second current generation correction circuit respectively, and used to compensate the first correction current and the second correction current to obtain the first compensation current when the current temperature is lower than the low temperature compensation point temperature; and used to compensate the first correction current and the second correction current to obtain the second compensation current when the current temperature is higher than the high temperature compensation point temperature, and to superimpose the first compensation current and the second compensation current to obtain the final compensation current; A first resistor, connected to the current compensation circuit, and used to convert the final compensation current into a compensation voltage; a bandgap reference correction circuit, connected to the first resistor, and configured to adjust the bandgap reference voltage according to the compensation voltage; The first current generation correction circuit includes: a first clamping circuit, a first current mirror and a first current generation correction unit; The first current mirror is connected to the first clamping circuit, and one end of the first clamping circuit away from the first current mirror is connected to the first current generating and correcting unit; After the first current generating and correcting unit generates a first correction current, the first current is transmitted to a current compensation circuit through the first current mirror; The second current generation correction circuit comprises: a second clamping circuit, a second current mirror and a second current generation correction unit; The second current mirror is connected to the second clamping circuit, and one end of the second clamping circuit away from the second current mirror is connected to the second current generating and correcting unit; After the second current generating and correcting unit generates the second correction current, the second current is transmitted to the current compensation circuit through the second current mirror; The current compensation circuit includes: a first current compensation circuit and a second current compensation circuit; the first current compensation circuit includes: a first PMOS tube, a third current mirror, a second PMOS tube, and a fourth current mirror; The first PMOS tube is connected to the first current mirror and the second current mirror respectively, the second current mirror is connected to the second PMOS tube, and the second PMOS tube is connected to the second current generation correction circuit; The first PMOS tube transmits the first correction current output by the first current mirror to the third current mirror, and the fourth current mirror is connected to the common end between the third current mirror and the second PMOS tube; the magnitude of the current on the third current mirror and the current on the second PMOS tube is judged, and when the current temperature is lower than the low temperature compensation point temperature, and the current on the third current mirror is higher than the current on the second PMOS tube, the current on the fourth current mirror is obtained by the current difference between the third current mirror and the second PMOS tube, so as to obtain the first compensation current.

2. A bandgap reference correction circuit with high and low temperature compensation correction as claimed in claim 1, characterized in that: The first current generation correction unit includes a first transistor, a second resistor and a third resistor; The second resistor and the third resistor are arranged in series, and the circuit where the second resistor and the third resistor are located is arranged in parallel with the circuit where the first transistor is located; The second resistor and the first transistor are respectively connected to the first clamping circuit; The third resistor is a variable resistor, and the current of the circuit where the second resistor and the third resistor are located is adjusted by adjusting the resistance value of the third resistor to obtain the first correction current.

3. A bandgap reference correction circuit with high and low temperature compensation correction as claimed in claim 1, characterized in that: The second current generation correction unit includes a second triode, a third triode, a fourth resistor and a fifth resistor; The third triode, the fourth resistor and the fifth resistor are arranged in series, and the circuit where the third triode, the fourth resistor and the fifth resistor are located is arranged in parallel with the circuit where the second triode is located; The fourth resistor and the second transistor are respectively connected to the second clamping circuit; The fourth resistor is a variable resistor, and the current of the circuit where the third transistor, the fourth resistor and the fifth resistor are located is regulated by adjusting the resistance value of the fourth resistor to obtain the second correction current.

4. A bandgap reference correction circuit with high and low temperature compensation correction as claimed in claim 1, characterized in that: When the current temperature is lower than the low temperature compensation point temperature, the first current compensation circuit is used to compensate the first correction current generated by the first current generation correction circuit to obtain a first compensation current; When the current temperature is greater than the high temperature compensation point temperature, the second current compensation circuit is used to compensate the second correction current generated by the second current generation correction circuit to obtain a second compensation current.

5. A bandgap reference correction circuit with high and low temperature compensation correction as claimed in claim 4, characterized in that: The second current compensation circuit includes: a third PMOS tube, a fifth current mirror, a fourth PMOS tube, and a sixth current mirror; The third PMOS tube is connected to the fifth current mirror and the second current mirror respectively, the fifth current mirror is connected to the fourth PMOS tube, and the fourth PMOS tube is connected to the first current generation correction circuit; The third PMOS tube transmits the second correction current output by the second current mirror to the fifth current mirror, and the sixth current mirror is connected to the common end between the fifth current mirror and the fourth PMOS tube; The magnitude of the current on the fifth current mirror and the current on the fourth PMOS tube are judged. When the current temperature is greater than the high temperature compensation point temperature, and the current on the fifth current mirror is greater than the current on the fourth PMOS tube, the current on the sixth current mirror is obtained by the current difference between the fifth current mirror and the fourth PMOS tube to obtain the second compensation current.

6. A bandgap reference correction circuit with high and low temperature compensation correction as claimed in claim 1, characterized in that: A control switch is provided between the current compensation circuit and the bandgap reference correction circuit, and whether current compensation needs to be performed on the bandgap reference correction circuit is controlled by the control switch.

7. A bandgap reference calibration method with high and low temperature compensation calibration, characterized in that: The method is implemented by a correction circuit according to any one of claims 1 to 6, and the method comprises: Obtaining a first corrected current by correcting a first current generated by a first current correction circuit and being inversely proportional to the absolute temperature; Obtaining a second corrected current by correcting a second current generated by a second current correction circuit and being proportional to the absolute temperature; When the current temperature is lower than the low temperature compensation point temperature, the first correction current and the second correction current are compensated by the current compensation circuit to obtain the first compensation current; when the current temperature is higher than the high temperature compensation point temperature, the first correction current and the second correction current are compensated by the current compensation circuit to obtain the second compensation current, and the first compensation current and the second compensation current are superimposed to obtain the final compensation current; Converting the final compensation current into a compensation voltage through a first resistor; The bandgap reference voltage is adjusted according to the compensation voltage by a bandgap reference correction circuit.

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