Band-gap reference circuit with wide temperature range and high precision

Abstract

The embodiment of the invention relates to the technical field of output quantity temperature compensation, and particularly provides a wide-temperature-range high-precision band-gap reference circuit, which comprises a band-gap reference voltage generation unit, a leakage current control unit, an output quantity temperature compensation unit and an output quantity temperature compensation unit, the leakage current is the leakage current flowing into the substrate of the MOS tube through a parasitic diode, and / or a temperature compensation current generation unit. According to the band-gap reference circuit, a basic band-gap reference circuit is improved, the leakage current control unit is added, and band-gap reference voltage within the range of-40 DEG C to 150 DEG C can be adjusted to be in an ideal parabola shape. According to the embodiment of the invention, only 0.9 mV band-gap reference voltage drift of the temperature compensation current generation unit in a temperature range of-40 DEG C to 150 DEG C can be increased, only extremely small temperature drift in a relatively wide temperature range (wide temperature range) is realized, and the improved band-gap reference circuit has high stability.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of temperature compensation of circuit output, and in particular to a high-precision bandgap reference circuit with a wide temperature range. Background Art

[0002] The bandgap reference voltage circuit can generate a fixed V BG (bandgap reference voltage) output, and can ensure high accuracy when the operating temperature changes. Figure 1 In the basic Brokaw structure bandgap reference voltage circuit shown in FIG. 1 , the width-to-length ratio W / L of the first MOS tube M1 and the second MOS tube M2 is 1:1, so the current of the first transistor Q1 and the second transistor Q2 are completely equal, and the V BE (base to emitter voltage difference) is the CTAT voltage (voltage that is negatively correlated with absolute temperature). Because the width of the first transistor Q1 and the second transistor Q2 is 1:8, the current density of the first transistor Q1 and the second transistor Q2 is different. The larger the width of the transistor, the greater the current density, and the smaller VBE (base to emitter voltage difference), so V BE2 =8V BE1 , Figure 1 We can get ΔV BE =V BE2 -V BE1 =V E1 -V E2 =V R1 =V T In8, transistor V T =kT / q thermal voltage, which is the PTAT voltage (voltage that is positively correlated with absolute temperature), T is the thermodynamic temperature, q is the charge of the electron, and k is the Boltzmann constant. The current of the first resistor R1 is equal to I Q2 , I Q2 =ΔV BE / R1, the current flowing through the second resistor R2 is equal to I Q1 +I Q2 =2 I Q1 , so the base voltage V of the first transistor Q1 and the second transistor Q2 B =V BE1 +V E1 =V BE2 +V R2 =V BE 1+2 I Q2 R2 = V BE1 +2 R2ΔVBE / R1, because the first resistor R1 and the second resistor R2 are the same type of resistor, so assuming 2 R2 / R1 = a, V BG =V B = V BE1 +a ΔV BE , you only need to adjust the ratio of the first resistor R1 to the second resistor R2 to make V, which is inversely proportional to the absolute temperature BE1 and a which is proportional to absolute temperature ΔV BE They cancel each other out and obtain a bandgap reference voltage that is independent of temperature.

[0003] like Figure 2 The cross-sectional view of the NPN transistor shown in the figure shows that the parasitic diode is in a reverse biased state, and the reverse saturation current flowing through it increases exponentially with the temperature. When the temperature reaches a certain value, the current is large enough to leak part of the current that should flow into the collector of the transistor into the substrate. Figure 3 As shown, because the width of the first transistor Q1 and the second transistor Q2 is in a ratio of 1:8, the size of the parasitic diode d2 of the second transistor Q2 is 8 times that of the parasitic diode d1 of the first transistor Q1. Therefore, the current leaked from the collector of the second transistor Q2 to the substrate (SUB) is also 8 times that leaked from the first transistor Q1, which ultimately leads to a large current mismatch between the emitters of the first transistor Q1 and the second transistor Q2. The ideal ΔV BE =V BE2 -V BE1 =V E1 -V E2 =V R1 =VT In8, after considering the influence of parasitic diode, ΔV BE =b (V BE2 -V BE1 ) = V R1 = b (VT In8), the higher the temperature, the larger b is, so the bandgap reference voltage V BG ΔV when working at high temperature above 125℃ BE It is large and positively correlated with the absolute temperature. This problem is more obvious in the bandgap reference voltage circuit designed for low power consumption.

[0004] To address the above-mentioned problems, no effective technical solutions have been proposed so far, which can no longer meet people's requirements and are in urgent need of improvement. Summary of the invention

[0005] The main purpose of the embodiments of the present application is to provide a high-precision bandgap reference circuit with a wide temperature range, so as to solve the problem in the related art that the bandgap reference voltage is greatly affected by the operating temperature.

[0006] According to one aspect of an embodiment of the present application, a high-precision bandgap reference circuit with a wide temperature range is provided, comprising: A bandgap reference voltage generating unit, configured to generate a bandgap reference voltage and a reference output voltage; A leakage current control unit is configured to control the leakage current of the bandgap reference voltage generating unit, wherein the leakage current is the leakage current flowing into the MOS tube substrate through the parasitic diode, and / or: The temperature compensation current generating unit is configured to divide the bandgap reference voltage to generate a corresponding zero temperature coefficient voltage, convert the zero temperature coefficient voltage into a corresponding zero temperature coefficient current, generate a compensation current according to the temperature change, and the compensation current is used to feed back to the bandgap reference voltage generating unit.

[0007] According to at least one specific implementation of the embodiment of the present application, the bandgap reference voltage generating unit includes a first MOS tube, a second MOS tube, a third MOS tube, a first transistor and a second transistor, the source of the first MOS tube and the source of the second MOS tube are respectively connected to a power supply, the gate of the first MOS tube is connected to the gate of the second MOS tube, the collector of the first transistor is connected to the drain of the first MOS tube, the collector of the second transistor is connected to the drain of the second MOS tube, the base of the first transistor is connected to the base of the second transistor, the bandgap reference voltage output end is connected to the base of the first transistor and the second transistor, the gate of the third MOS tube is respectively connected to the sources of the first and second MOS tubes, the drain of the third MOS tube is connected to the power supply, and the source of the third MOS tube is connected to the bandgap reference voltage output end.

[0008] According to at least one specific implementation of the embodiment of the present application, it also includes a first resistor, a second resistor, a third resistor and a fourth resistor, the emitter of the second transistor is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor, the other end of the second resistor is grounded, one end of the third resistor is connected to the bandgap reference voltage output terminal, the other end of the third resistor is connected to one end of the fourth resistor, the other end of the fourth resistor is grounded, and a reference output voltage output terminal is arranged between the third resistor and the fourth resistor.

[0009] According to at least one specific implementation of the embodiments of the present application, the leakage current control unit includes: a fifth resistor, a sixth resistor, a seventh resistor and a third transistor, one end of the fifth resistor is connected to the second resistor, and the other end is connected to the sixth resistor, the base and collector of the third transistor are respectively connected across the two ends of the fifth resistor, one end of the seventh resistor is connected to the emitter of the third transistor, and the other end is grounded.

[0010] According to at least one specific implementation of the embodiment of the present application, the leakage current control unit further includes a second variable resistor, a third variable resistor, a voltage-dividing resistor component, an eighth resistor, a ninth resistor, and a tenth resistor, and the voltage-dividing resistor component includes a first voltage-dividing resistor, a second voltage-dividing resistor, and a third voltage-dividing resistor, wherein: A first voltage dividing end is provided between the first voltage dividing resistor and the second voltage dividing resistor, a second voltage dividing end is provided between the second voltage dividing resistor and the third voltage dividing resistor, one end of the second variable resistor is connected to the first resistor in the bandgap reference voltage generating unit, the other end of the second variable resistor is connected to the voltage dividing resistor component, the other end of the voltage dividing resistor component is connected to the sixth resistor, the other end of the sixth resistor is grounded, the base of the third transistor is connected between the voltage dividing resistor component and the sixth resistor, the emitter of the third transistor is connected to one end of the seventh resistor, the other end of the seventh resistor is grounded, the collector of the third transistor is connected between the second variable resistor and the voltage dividing resistor component, one end of the third variable resistor is connected to the bandgap reference voltage output end, and the other end is connected to the fourth resistor, the fourth resistor is connected in series with the eighth resistor, the ninth resistor and the tenth resistor in sequence, one end of the tenth resistor is grounded, a connection end for a first reference output voltage is provided between the fourth resistor and the eighth resistor, a connection end for a second reference output voltage is provided between the eighth resistor and the ninth resistor, and a connection end for a third reference output voltage is provided between the ninth resistor and the tenth resistor.

[0011] According to at least one specific implementation of the embodiments of the present application, the temperature-compensated current generating unit includes a current conversion unit, a current mirror unit and a current distribution unit. The current conversion unit is used to convert the bandgap reference voltage into a corresponding zero temperature coefficient voltage, the current mirror unit is used to provide a bias current, and the current distribution unit is used to distribute the bias current according to temperature changes to generate a corresponding compensation current.

[0012] According to at least one specific implementation of the embodiment of the present application, the current conversion unit includes an operational amplifier, a fourth MOS tube, a fifth MOS tube and a first variable resistor, the in-phase end of the operational amplifier is connected between the ninth resistor and the tenth resistor of the leakage current control unit, the output end of the operational amplifier is connected to the gate of the fourth MOS tube, the source of the fourth MOS tube is connected to one end of the first variable resistor, the other end of the first variable resistor is grounded, the inverting end of the operational amplifier is connected between the fourth MOS tube and the first variable resistor, the drain of the fourth MOS tube is connected to the drain of the fifth MOS tube, and the source of the fifth MOS tube is connected to a power supply.

[0013] According to at least one specific implementation of the embodiment of the present application, the current mirror unit includes a fifth MOS tube, a sixth MOS tube and a seventh MOS tube, the gate of the fifth MOS tube is connected to the gate of the sixth MOS tube and the gate of the seventh MOS tube, the source of the fifth MOS tube, the sixth MOS tube and the seventh MOS tube are respectively connected to a power supply, the drain of the sixth MOS tube is connected to the source of the eighth MOS tube and the source of the ninth MOS tube, the drain of the seventh MOS tube is connected to the source of the tenth MOS tube and the source of the eleventh MOS tube, wherein the eighth, ninth, tenth and eleventh MOS tubes are arranged in the current distribution unit.

[0014] According to at least one specific implementation of the embodiments of the present application, the current distribution unit includes an eighth MOS tube, a ninth MOS tube, a tenth MOS tube and an eleventh MOS tube, the source of the eighth MOS tube is connected to the source of the ninth MOS tube, the drain of the eighth MOS tube is grounded, the source of the tenth MOS tube is connected to the source of the eleventh MOS tube, the ninth MOS tube is connected to the drain of the tenth MOS tube, a temperature compensation current is formed between the drains of the ninth MOS tube and the tenth MOS tube, and the temperature compensation current is fed back to between the emitter of the first transistor and the emitter of the second transistor in the bandgap reference voltage generating unit.

[0015] According to at least one specific implementation of the embodiments of the present application, the gate of the eighth MOS tube is connected to the connection end of the second reference output voltage, the gate of the ninth MOS tube is connected to the first voltage divider end, the gate of the tenth MOS tube is connected to the connection end of the first reference output voltage, the gate of the eleventh MOS tube is connected to the second voltage divider end, and the drain of the eleventh MOS tube is grounded.

[0016] The beneficial technical effects of the embodiments of the present application are: The embodiment of the present application improves the basic bandgap reference circuit and adds a leakage current control unit. When the temperature is higher than 125°C, the bandgap reference voltage decreases with the temperature, and the bandgap reference voltage in the range of -40°C to 150°C can be adjusted to an ideal parabola. On the basis of the above technical solution, the embodiment of the present application can also add a temperature compensation current generation unit to divide the bandgap reference voltage and generate a corresponding zero temperature coefficient current, generate a compensation current according to the temperature change and return it to the bandgap reference voltage generation unit, and only 0.9mV of bandgap reference voltage drifts in the temperature range of -40°C to 150°C, achieving only a very small temperature drift in a wider temperature range (wide temperature domain), so that the improved bandgap reference circuit has high stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the embodiments of the present application or the technical solutions in the related technologies, the drawings required for use in the specific implementation methods or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some implementation methods of the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of a bandgap reference voltage circuit in the related art; Figure 2 It is a schematic diagram of the cross-sectional structure of an NPN transistor; Figure 3 This is the schematic diagram of the bandgap reference voltage circuit after considering the parasitic diode; Figure 4 It is the ΔV of the bandgap reference voltage in the related technology when it works at a high temperature of 125℃~150℃ BE Larger waveform graph; Figure 5 It is a principle block diagram of the embodiment of the present application in the main application scenario; Figure 5A This is a circuit schematic diagram of the leakage effect caused by parasitic diodes when the fire protection works at high temperature; Figure 6 Is a complete circuit diagram of the embodiment of the present application; Figure 7 It is the curve of the bandgap reference voltage changing with temperature after temperature compensation from -40℃ to 150℃ (reference output voltage and voltage at the voltage divider terminal); Figure 8 The curve of the bandgap reference voltage after temperature compensation from -40℃ to 150℃ with temperature variation (compensation current I comp_L and I comp_H ); Fig. 9The curve of the bandgap reference voltage after temperature compensation from -40℃ to 150℃ (V BG and temperature). DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the embodiments of 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 implementation methods of a part of the embodiments of the present application, rather than all implementation methods. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the embodiments of the present application.

[0020] It should be noted that the terms "first", "second", etc. in the specification and claims of the embodiments of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0021] Figure 1 The schematic diagram of the bandgap reference voltage circuit in the related art is shown. Figure 1 In this case, we only need to adjust the ratio of the first resistor R1 to the second resistor R2 to make V inversely proportional to the absolute temperature. BE1 and a which is proportional to absolute temperature ΔV BE The mutual cancellation results in obtaining a bandgap reference voltage that is independent of temperature. The relevant contents have been described in detail in the background technology and will not be repeated here.

[0022] Figure 2 shows a cross-sectional view (schematic diagram) of an NPN transistor, Figure 3 This is the schematic diagram of the bandgap reference voltage circuit after considering the parasitic diode. Figure 4 The waveform shown shows the ΔV of the bandgap reference voltage when it is operated at a high temperature of 125℃~150℃ BE Large, and positively correlated with the absolute temperature. This problem is more obvious when the bandgap reference voltage circuit works in the subthreshold region. The relevant content has been described in detail in the background technology and will not be repeated here.

[0023] like Figure 5 As shown, Figure 5 The main application scenarios of the embodiments of the present application are shown, including: The bandgap reference voltage generating unit A is configured to generate a bandgap reference voltage V BG The bandgap reference voltage V generated by the bandgap reference voltage generating unit A is BG It is a stable voltage close to the silicon bandgap voltage (about 1.2V). The bandgap reference voltage generating unit A is equipped with MOS tubes and transistors, and the base-emitter voltage V BE The combination of negative temperature coefficient (CTAT) and positive temperature coefficient (PTAT) realizes temperature compensation.

[0024] The leakage current control unit B is configured to control the leakage current of the bandgap reference voltage generating unit A, and the leakage current is the leakage current flowing into the MOS tube substrate through the parasitic diode d2. The leakage current control unit B can reduce the voltage drift caused by the leakage current by controlling the leakage current, thereby improving the stability and accuracy of the bandgap reference voltage, so that the bandgap reference voltage forms an ideal parabolic waveform. And / or: The temperature compensation current generating unit C is configured to generate a temperature compensation current for the bandgap reference voltage V BG The voltage is divided to generate a corresponding zero temperature coefficient voltage, and the zero temperature coefficient voltage is converted into a corresponding zero temperature coefficient current, and a compensation current is generated according to the temperature change, and the compensation current is used to feed back to the bandgap reference voltage generating unit A. The temperature compensation current generating unit C generates a compensation current that is independent of temperature changes through voltage division and current conversion, and feeds the compensation current back to the bandgap reference voltage generating unit A to offset the voltage drift caused by the operating temperature change, thereby achieving more accurate temperature compensation.

[0025] The bandgap reference voltage generating unit A, the leakage current control unit B, and the temperature compensation current generating unit C work together to generate a high-precision bandgap reference voltage in a wide temperature range (wide temperature domain). The main application scenarios of the embodiments of the present application can be widely used in electronic devices that require a wide temperature range and high-precision reference voltage, such as analog-to-digital / digital-to-analog conversion chips, power management chips, and the like.

[0026] In some embodiments, the bandgap reference voltage generating unit A can be configured as the following structure: including a first MOS tube M1, a second MOS tube M2, a third MOS tube M2, a first transistor Q1 and a second transistor Q2, the source of the first MOS tube M1 and the second MOS tube M2 are connected to the power supply VDD, the gate of the first MOS tube M1 is connected to the gate of the second MOS tube M2, the collector of the first transistor Q1 is connected to the drain of the first MOS tube M1, the collector of the second transistor Q2 is connected to the drain of the second MOS tube M2, the base of the first transistor Q1 is connected to the base of the second transistor Q2, and the bandgap reference voltage VBG The output end of the third MOS tube M3 is connected to the base of the first transistor Q1 and the second transistor Q2, the gate of the third MOS tube M3 is connected to the source of the first and second MOS tubes, the drain of the third MOS tube M3 is connected to the power supply VDD, the gate of the third MOS tube M3 is connected to the source of the first and second MOS tubes (M1, M2), and the source of the third MOS tube M3 is connected to the bandgap reference voltage V BG A current source I1 is also connected between the sources of the first and second MOS tubes (M1, M2).

[0027] The bandgap reference voltage generating unit A also includes a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4, the emitter of the second transistor Q2 is connected to the first resistor R1, the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is grounded, one end of the third resistor R3 is connected to the bandgap reference voltage output end, and the other end is connected to the fourth resistor R4, the other end of the fourth resistor R4 is grounded, and a reference output voltage output end is arranged between the third resistor R3 and the fourth resistor R4.

[0028] like Figure 5A As shown, Figure 5A The provided circuit schematic diagram shows how to eliminate the influence of parasitic diode leakage during high-temperature operation. The leakage current control unit B includes: a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and a third transistor Q3. One end of the fifth resistor R5 is connected to the second resistor R2, and the other end is connected to the sixth resistor R6. The base and collector of the third transistor Q3 are respectively connected across the two ends of the fifth resistor R5. One end of the seventh resistor R7 is connected to the emitter of the third transistor Q3, and the other end is grounded.

[0029] In some embodiments, the leakage current control unit B further includes a second variable resistor R 2_trim , the third variable resistor R 3_trim , a voltage-dividing resistor component, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, and a tenth resistor, wherein the voltage-dividing resistor component includes a first voltage-dividing resistor R (5,1) , the second voltage divider resistor R (5,2) , the third voltage divider resistor R (5,3) ,in: The first voltage divider resistor R (5,1) and the second voltage divider resistor R (5,2) A first voltage divider terminal V is provided between PTAT_H , the second voltage divider resistor R (5,2) A second voltage dividing terminal V is provided between the third voltage dividing resistor and the ptat_l , the second variable resistor R 2_trimOne end of the third transistor Q3 is connected to the first resistor R1 in the bandgap reference voltage generating unit A, and the other end is connected to the voltage-dividing resistor component, the other end of the voltage-dividing resistor component is connected to the sixth resistor R6, the other end of the sixth resistor R6 is grounded, the base of the third transistor Q3 is connected between the voltage-dividing resistor component and the sixth resistor R6, the emitter of the third transistor Q3 is connected to one end of the seventh resistor R7, the other end of the seventh resistor R7 is grounded, and the collector of the third transistor Q3 is connected to the second variable resistor R 2_trim and the voltage divider resistor component, the third variable resistor R 3_trim One end is connected to the bandgap reference voltage V BG The output end of the resistor R4 is connected to the output end of the resistor R4, and the other end is connected to the fourth resistor R4. The fourth resistor R4 is connected in series with the eighth resistor R8, the ninth resistor R9 and the tenth resistor R10 in sequence. The tenth resistor R10 is grounded. A first reference output voltage V is set between the fourth resistor R4 and the eighth resistor R8. REF_H A second reference output voltage V is provided between the eighth resistor R8 and the ninth resistor R9. REF_L A third reference output voltage V is provided between the ninth resistor R9 and the tenth resistor R10. REF_V2I connection end.

[0030] and Figure 3 compared to, Figure 5A The circuit schematic diagram shown forms a combination of a second resistor R2, a fifth resistor R5, and a sixth resistor R6, and a third transistor Q3 is added between the fifth resistor R5 and the sixth resistor R6. Based on the combination of the above devices, an improved bandgap reference voltage V BG1 : ; exist Figure 5A In the circuit schematic diagram shown, the improved bandgap reference voltage is based on the original bandgap reference voltage minus one Therefore, when the temperature is higher than 125℃, the bandgap reference voltage decreases with the temperature. The bandgap reference voltage in the range of -40℃~150℃ can be adjusted to an ideal parabola. The waveform of the improved bandgap reference voltage is as follows: Figure 4 shown.

[0031] like Figure 6 As shown, Figure 6 The bandgap reference circuit provided can be used in Figure 5 On the basis of achieving higher accuracy, the influence of bandgap reference voltage change with temperature becomes smaller. Figure 6In the embodiment, the temperature compensation current generating unit C includes a current conversion unit C1, a current mirror unit C2 and a current distribution unit C3. The current conversion unit C1 is used to convert the bandgap reference voltage into a corresponding zero temperature coefficient voltage. The current mirror unit C2 is used to provide a bias current. The current distribution unit C3 is used to distribute the bias current according to the temperature change to generate a corresponding compensation current. In this embodiment, the temperature compensation current generating unit C first converts the bandgap reference voltage V BG The voltage is divided to generate the first reference output voltage V REF_H , the second reference output voltage V REF_L , the third reference output voltage V REF_V2I , and then use the MOS tube as a voltage-controlled current source to generate a zero temperature coefficient voltage that is independent of absolute temperature.

[0032] Specifically, the current conversion unit C1 includes an operational amplifier A, a fourth MOS tube M4, a fifth MOS tube M5 and a first variable resistor R V2I_TRIM The in-phase terminal of the operational amplifier A is connected between the ninth resistor R9 and the tenth resistor R10 of the leakage current control unit B, the output terminal of the operational amplifier A is connected to the gate of the fourth MOS tube M4, and the source of the fourth MOS tube M4 is connected to the first variable resistor R V2I_TRIM connected, the first variable resistor R V2I_TRIM The other end of the operational amplifier A is grounded, and the inverting end of the operational amplifier A is connected to the fourth MOS tube M4 and the first variable resistor R V2I_TRIM The drain of the fourth MOS tube M4 is connected to the fifth MOS tube M5, and the source of the fifth MOS tube M5 is connected to the power supply VDD.

[0033] The current mirror unit C2 includes a fifth MOS tube M5, a sixth MOS tube M6 and a seventh MOS tube M7, wherein the gate of the fifth MOS tube M5 is connected to the gate of the sixth MOS tube M6 and the gate of the seventh MOS tube M7, the source electrodes of the fifth MOS tube M5, the sixth MOS tube M6 and the seventh MOS tube M7 are respectively connected to the power supply VDD, the drain electrode of the sixth MOS tube M6 is connected to the source electrodes of the eighth MOS tube M8 and the ninth MOS tube M9, the drain electrode of the seventh MOS tube M7 is connected to the source electrodes of the tenth MOS tube M10 and the eleventh MOS tube M11, wherein the eighth, ninth, tenth and eleventh MOS tubes are arranged in the current distribution unit C3.

[0034] The current distribution unit C3 includes an eighth MOS tube M8, a ninth MOS tube M9, a tenth MOS tube M10 and an eleventh MOS tube M11. The source of the eighth MOS tube M8 is connected to the source of the ninth MOS tube M9, the drain of the eighth MOS tube M8 is grounded, the source of the tenth MOS tube M10 is connected to the source of the eleventh MOS tube M11, the ninth MOS tube M9 is connected to the drain of the tenth MOS tube M10, and a temperature compensation current I is formed between the drains of the ninth MOS tube M9 and the tenth MOS tube M10. comp , temperature compensation current I comp The gate of the eighth MOS tube M8 is connected to the second reference output voltage V REF_L The gate of the ninth MOS tube M9 is connected to the first voltage dividing terminal V PTAT_H The gate of the tenth MOS tube M10 is connected to the first reference output voltage V REF_H The gate of the eleventh MOS tube M11 is connected to the second voltage dividing terminal V PTAT_L The drain of the eleventh MOS tube M11 is grounded.

[0035] In this specific implementation, the bandgap reference voltage V BG Through resistor voltage division, the first reference output voltage V REF_H , the second reference output voltage V REF_L and the third reference output voltage V REF_V2I The above reference output voltages are all zero temperature coefficient voltages that are independent of absolute temperature. The second variable resistor R V2I_TRIM The third reference output voltage V REF_V2I Through the operational amplifier A, the fourth MOS tube M4, the fifth MOS tube M5, the second variable resistor R V2I_TRIM Converted into a zero temperature coefficient current I M5 =V REF_V2I / R V2I_TRIM , I M5 The current I is obtained through the current mirror (composed of the fifth MOS tube M5, the sixth MOS tube M6, and the seventh MOS tube M7). M6 、Current I M7 At the same time, the fifth resistor R5 is divided into the first voltage dividing resistor R (5,1) , the second voltage divider resistor R (5,2) , the third voltage divider resistor R (5,3) , the three voltage-dividing resistors are used to divide the voltage to obtain the first voltage-dividing terminal V PTAT_H and the second voltage divider terminal V PTAT_L , the current I of the sixth MOS tube M6 and the seventh MOS tube M7 M6 、Current IM7 They are respectively distributed to the eighth MOS tube M8 , the ninth MOS tube M9 , the tenth MOS tube M10 and the eleventh MOS tube M11 .

[0036] For ease of understanding, Figure 6 The voltage waveforms corresponding to the reference output voltage and the voltage at the voltage divider terminal are marked in FIG. REF_L The output terminal is connected to V REF_L The corresponding voltage waveform is drawn above the label. PTAT_H 、V REF_H 、V REF_L 、V PTAT_H ,I comp_L ,I comp_H ,I comp The corresponding voltage waveform is also drawn above the label.

[0037] like Figure 7 As shown, the first reference output voltage V REF_H >Second voltage divider terminal V PTAT_L When the temperature rises, the current distributed from the seventh MOS tube M7 to the tenth MOS tube M10 increases with the temperature, and the second voltage divider terminal V PTAT_H >Second reference output voltage V REF_L When the temperature decreases, the current allocated to the ninth MOS tube M9 by the sixth MOS tube M6 decreases as the temperature decreases, and I comp_L and I comp_H .

[0038] like Figure 8 As shown, the compensation current I comp =I comp_L +I comp_H , the final curve of the bandgap reference voltage changing with temperature after -40℃~150℃ temperature compensation.

[0039] like Fig. 9 As shown, a bandgap reference voltage drift of 0.9mV can be achieved in the temperature range of -40℃~150℃.

[0040] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the description of the embodiments of the present application.

[0041] In the description of the specification of the embodiments of the present application, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In the embodiments of the present application, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0042] In addition, the technical solutions between the various implementation methods of the embodiments of the present application can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the embodiments of the present application.

[0043] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and set in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and in addition, they may be divided into multiple submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive, all features disclosed in the specification of the embodiments of the present application (including the corresponding claims, abstracts and drawings) and all processes or units of any method or device disclosed in this manner may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in the specification of the embodiments of the present application (including the corresponding claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, rather than to limit them. Although the embodiments of the present application have been described in detail with reference to the aforementioned specific implementation methods, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned specific implementation methods, or replace some or all of the technical features therein with equivalents, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions in the specific implementation methods of the embodiments of the present application.

[0045] Although the implementation methods of the embodiments of the present application are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the embodiments of the present application, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A high-precision bandgap reference circuit with a wide temperature range, characterized in that: include: A bandgap reference voltage generating unit, configured to generate a bandgap reference voltage and a reference output voltage; A leakage current control unit is configured to control the leakage current of the bandgap reference voltage generating unit, wherein the leakage current is the leakage current flowing into the MOS tube substrate through the parasitic diode, and / or: The temperature compensation current generating unit is configured to divide the bandgap reference voltage to generate a corresponding zero temperature coefficient voltage, convert the zero temperature coefficient voltage into a corresponding zero temperature coefficient current, generate a compensation current according to the temperature change, and the compensation current is used to feed back to the bandgap reference voltage generating unit.

2. The wide temperature range high precision bandgap reference circuit according to claim 1, characterized in that: The bandgap reference voltage generating unit includes a first MOS tube, a second MOS tube, a third MOS tube, a first transistor and a second transistor. The source of the first MOS tube and the source of the second MOS tube are respectively connected to a power supply, the gate of the first MOS tube is connected to the gate of the second MOS tube, the collector of the first transistor is connected to the drain of the first MOS tube, the collector of the second transistor is connected to the drain of the second MOS tube, the base of the first transistor is connected to the base of the second transistor, the bandgap reference voltage output terminal is connected to the base of the first transistor and the base of the second transistor, the gate of the third MOS tube is respectively connected to the sources of the first and second MOS tubes, the drain of the third MOS tube is connected to the power supply, and the source of the third MOS tube is connected to the bandgap reference voltage output terminal.

3. The wide temperature range high precision bandgap reference circuit according to claim 2, characterized in that: It also includes a first resistor, a second resistor, a third resistor and a fourth resistor, the emitter of the second transistor is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor, the other end of the second resistor is grounded, one end of the third resistor is connected to the bandgap reference voltage output end, the other end of the third resistor is connected to one end of the fourth resistor, the other end of the fourth resistor is grounded, and a reference output voltage output end is arranged between the third resistor and the fourth resistor.

4. The wide temperature range high precision bandgap reference circuit according to claim 3, characterized in that: The leakage current control unit includes: a fifth resistor, a sixth resistor, a seventh resistor and a third transistor, one end of the fifth resistor is connected to the second resistor, and the other end is connected to the sixth resistor, the base and collector of the third transistor are respectively connected across the two ends of the fifth resistor, one end of the seventh resistor is connected to the emitter of the third transistor, and the other end is grounded.

5. The wide temperature range high precision bandgap reference circuit according to claim 4, characterized in that: The leakage current control unit further includes a second variable resistor, a third variable resistor, a voltage-dividing resistor component, an eighth resistor, a ninth resistor, and a tenth resistor, and the voltage-dividing resistor component includes a first voltage-dividing resistor, a second voltage-dividing resistor, and a third voltage-dividing resistor, wherein: A first voltage dividing end is provided between the first voltage dividing resistor and the second voltage dividing resistor, a second voltage dividing end is provided between the second voltage dividing resistor and the third voltage dividing resistor, one end of the second variable resistor is connected to the first resistor in the bandgap reference voltage generating unit, the other end of the second variable resistor is connected to the voltage dividing resistor component, the other end of the voltage dividing resistor component is connected to the sixth resistor, the other end of the sixth resistor is grounded, the base of the third transistor is connected between the voltage dividing resistor component and the sixth resistor, the emitter of the third transistor is connected to one end of the seventh resistor, the other end of the seventh resistor is grounded, the collector of the third transistor is connected between the second variable resistor and the voltage dividing resistor component, one end of the third variable resistor is connected to the bandgap reference voltage output end, and the other end is connected to the fourth resistor, the fourth resistor is connected in series with the eighth resistor, the ninth resistor and the tenth resistor in sequence, one end of the tenth resistor is grounded, a connection end for a first reference output voltage is provided between the fourth resistor and the eighth resistor, a connection end for a second reference output voltage is provided between the eighth resistor and the ninth resistor, and a connection end for a third reference output voltage is provided between the ninth resistor and the tenth resistor.

6. The wide temperature range high precision bandgap reference circuit according to claim 1, characterized in that: The temperature-compensated current generating unit includes a current conversion unit, a current mirror unit and a current distribution unit. The current conversion unit is used to convert the bandgap reference voltage into a corresponding zero temperature coefficient voltage. The current mirror unit is used to provide a bias current. The current distribution unit is used to distribute the bias current according to temperature changes to generate a corresponding compensation current.

7. The wide temperature range high precision bandgap reference circuit according to claim 6, characterized in that: The current conversion unit includes an operational amplifier, a fourth MOS tube, a fifth MOS tube and a first variable resistor, the in-phase end of the operational amplifier is connected between the ninth resistor and the tenth resistor of the leakage current control unit, the output end of the operational amplifier is connected to the gate of the fourth MOS tube, the source of the fourth MOS tube is connected to one end of the first variable resistor, the other end of the first variable resistor is grounded, the inverting end of the operational amplifier is connected between the fourth MOS tube and the first variable resistor, the drain of the fourth MOS tube is connected to the drain of the fifth MOS tube, and the source of the fifth MOS tube is connected to a power supply.

8. The wide temperature range high precision bandgap reference circuit according to claim 6, characterized in that: The current mirror unit includes a fifth MOS tube, a sixth MOS tube and a seventh MOS tube, the gate of the fifth MOS tube is connected to the gate of the sixth MOS tube and the gate of the seventh MOS tube, the source of the fifth MOS tube, the sixth MOS tube and the seventh MOS tube are respectively connected to a power supply, the drain of the sixth MOS tube is connected to the source of the eighth MOS tube and the source of the ninth MOS tube, the drain of the seventh MOS tube is connected to the source of the tenth MOS tube and the source of the eleventh MOS tube, wherein the eighth, ninth, tenth and eleventh MOS tubes are arranged in the current distribution unit.

9. The wide temperature range high precision bandgap reference circuit according to claim 6, characterized in that: The current distribution unit includes an eighth MOS tube, a ninth MOS tube, a tenth MOS tube and an eleventh MOS tube, the source of the eighth MOS tube is connected to the source of the ninth MOS tube, the drain of the eighth MOS tube is grounded, the source of the tenth MOS tube is connected to the source of the eleventh MOS tube, the ninth MOS tube is connected to the drain of the tenth MOS tube, a temperature compensation current is formed between the drains of the ninth MOS tube and the tenth MOS tube, and the temperature compensation current is fed back to between the emitter of the first transistor and the emitter of the second transistor in the bandgap reference voltage generating unit.

10. The wide temperature range high precision bandgap reference circuit according to claim 9, characterized in that: The gate of the eighth MOS tube is connected to the connection end of the second reference output voltage, the gate of the ninth MOS tube is connected to the first voltage dividing end, the gate of the tenth MOS tube is connected to the connection end of the first reference output voltage, the gate of the eleventh MOS tube is connected to the second voltage dividing end, and the drain of the eleventh MOS tube is grounded.

Images