CN116301159A - Low-temperature-drift bipolar band-gap reference voltage source - Google Patents

Abstract

The invention belongs to the field of analog integrated circuits, and discloses a bipolar band gap reference voltage source with low temperature drift, which comprises a band gap reference module, a temperature compensation module and a direct current bias module; the temperature compensation module is connected with the band gap reference module, and the direct current bias module is connected with the band gap reference module and the temperature compensation module; the band gap reference module is used for generating a band gap reference voltage with first-order compensation; the temperature compensation module is used for generating a high-order PTAT current and compensating a high-order item of a negative temperature coefficient in the band-gap reference voltage through the high-order PTAT current to obtain a band-gap reference voltage with low temperature drift; the direct current bias module is used for generating a first bias current and a second bias current and sending the first bias current and the second bias current to the band gap reference module and the temperature compensation module respectively. The circuit can ensure that the reference voltage output by the band gap reference voltage source is not subject to temperature change under the working states of different temperatures, has the characteristics of low temperature drift and adaptability to bipolar process, and improves the application applicability of the reference voltage source circuit.

Description

A Bipolar Bandgap Reference Voltage Source with Low Temperature Drift

technical field

The invention belongs to the field of analog integrated circuits, and relates to a low-temperature drift bipolar bandgap reference voltage source.

Background technique

In recent years, with the continuous development and upgrading of electronic products, the performance requirements of integrated circuit chips are getting higher and higher. As an important part of systems such as digital-to-analog converters, analog-to-digital converters and switching power supplies, the bandgap reference voltage source has the characteristics of high precision, low temperature drift and stability, and can provide the system with independent power supply voltage, operating temperature and Stabilized voltage influenced by process parameters.

The existing bandgap reference voltage source uses the base-emitter voltage VBE with a negative temperature coefficient to superimpose the N Vt structure with a positive temperature coefficient, lacks a temperature compensation structure, and cannot eliminate the high-order influence of temperature on the output reference voltage, the output The reference voltage is significantly affected by temperature changes, which is not conducive to the selection and design of system-level users.

Contents of the invention

The purpose of the present invention is to overcome the disadvantages of the above-mentioned prior art that the existing bandgap reference voltage source cannot eliminate the high-order influence of temperature on the output reference voltage, and the output reference voltage is obviously affected by temperature changes, and provide a low-temperature drift Bipolar Bandgap Voltage Reference.

In order to achieve the above object, the present invention adopts the following technical solutions to achieve:

A low-temperature drift bipolar bandgap reference voltage source, including a bandgap reference module, a temperature compensation module and a DC bias module; the temperature compensation module is connected to the bandgap reference module, and the DC bias module is connected to the bandgap reference module and temperature compensation The modules are all connected; the bandgap reference module is used to generate a first-order compensated bandgap reference voltage; the temperature compensation module is used to generate a high-order PTAT current, and compensate the high-order term of the negative temperature coefficient in the bandgap reference voltage through the high-order PTAT current , to obtain a bandgap reference voltage with low temperature drift; the DC bias module is used to generate a first bias current and a second bias current, and send them to the bandgap reference module and the temperature compensation module respectively.

Optionally, the bandgap reference module includes a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4, and a first resistor R1, a second resistor R2, and a third resistor R3; the third resistor R3 The first end of the first output node is set as the first output node, the second end is connected to the first end of the second resistor R2; the second end of the second resistor R2 is connected to the emitter of the first transistor Q1 and the emitter of the second transistor Q2; the first A second output node is provided on the base of the transistor Q1 and connected to the base of the second transistor Q2; the collector of the first transistor Q1 is connected to the collector of the third transistor Q3; the collector of the second transistor Q2 is connected to the fourth transistor The collector of Q4; the base of the third transistor Q3 is connected to the base of the fourth transistor Q4; the base of the fourth transistor Q4 is short-circuited to the collector, and the emitter is connected to the first end of the first resistor R1.

Optionally, the emitter of the third transistor Q3 is grounded; the second end of the first resistor R1 is grounded.

Optionally, the area ratio of the emitter regions of the third transistor Q3 and the fourth transistor Q4 is 1:8.

Optionally, the temperature compensation module includes a sixth transistor Q6, a seventh transistor Q7, an eighth transistor Q8, a ninth transistor Q9, a tenth transistor Q10, an eleventh transistor Q11, a fourth resistor R4, and a fifth resistor R5 and the sixth resistor R6; the emitter of the sixth transistor Q6 is connected to the first output node, the collector is connected to the first end of the second resistor R2, and the base is connected to the base of the seventh transistor Q7; the emitter of the seventh transistor Q7 is connected to The first output node, the collector and the base are short-circuited; the collector of the ninth transistor Q9 is connected to the collector of the seventh transistor Q7, the base is connected to the second end of the fifth resistor R5, and the emitter is connected to the second end of the fourth resistor R4 One end; the collector of the eighth transistor Q8 is connected to the first output node, the base is connected to the base of the tenth transistor Q10, and the emitter is connected to the first end of the fourth resistor R4; the collector of the tenth transistor Q10 is short to the base The emitter is connected to the collector of the eleventh transistor Q11; the base of the eleventh transistor Q11 is short-circuited to the collector; the first end of the fifth resistor R5 is connected to the base of the eighth transistor Q8, and the second end is connected to the first The first end of the sixth resistor R6; the second end of the sixth resistor R6 is connected to the emitter of the tenth transistor Q10.

Optionally, the second end of the fourth resistor R4 is grounded; the emitter of the eleventh transistor Q11 is grounded.

Optionally, the first resistor R1 , the second resistor R2 , the third resistor R3 , the fourth resistor R4 , the fifth resistor R5 and the sixth resistor R6 are all polysilicon resistors.

Optionally, the emitter area ratio of the sixth transistor Q6 and the seventh transistor Q7 is 1:1; the emitter areas of the eighth transistor Q8, the ninth transistor Q9, the tenth transistor Q10, and the eleventh transistor Q11 The area ratio is 1:1:2:2.

Optionally, the DC bias module includes a fifth transistor Q5, a first current source I1, a second current source I2, and a third current source I3; the base of the fifth transistor Q5 is connected to the first current source of the third current source I3. terminal, the collector is connected to the first output node; the first terminal of the first current source I1 is connected to the collector of the tenth transistor Q10; the first terminal of the second current source I2 is connected to the second output node.

Optionally, the emitter of the fifth transistor Q5, the second terminal of the first current source I1, the second terminal of the second current source I2 and the second terminal of the third current source I3 are all connected to the power supply VCC.

Compared with the prior art, the present invention has the following beneficial effects:

The low-temperature drift bipolar bandgap reference voltage source of the present invention is provided with a bandgap reference module, a temperature compensation module and a DC bias module, and provides a first-order compensated bandgap reference voltage through the bandgap reference module, and provides a high voltage through the temperature compensation module. order PTAT current, and compensate the high-order term of the negative temperature coefficient in the bandgap reference voltage through the high-order PTAT current to obtain a low-temperature drift bandgap reference voltage, and provide the work of the bandgap reference module and temperature compensation module through the DC bias module DC bias. The bipolar bandgap reference voltage source can work at different temperatures. Based on the changing high-order PTAT current generated by the temperature compensation module, the output bandgap reference voltage is not affected by temperature changes, and has low temperature drift and adapts to dual The characteristics of the pole-type process improve the application applicability of the reference voltage source circuit, and can be widely used in various power supply management and drive chips, with good application prospects and economic benefits. Effectively solve the problem that the existing bandgap reference structure does not include a temperature compensation structure, which cannot eliminate the high-order influence of temperature on the output bandgap reference voltage, resulting in the output bandgap reference voltage being significantly affected by temperature changes, which is not conducive to system-level users Defects in the selection design.

Description of drawings

FIG. 1 is a schematic structural diagram of an existing bandgap reference voltage source.

Fig. 2 is a schematic structural diagram of the low-temperature drift bipolar bandgap reference voltage source of the present invention.

FIG. 3 is a temperature characteristic curve diagram of the reference voltage of the temperature compensation of the present invention.

Detailed ways

In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only It is an embodiment of a part of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

It should be noted that the terms "first" and "second" in the description and claims of the present invention and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a sequence of steps or elements is not necessarily limited to the expressly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

The present invention is described in further detail below in conjunction with accompanying drawing:

Referring to Figure 1, the existing bandgap reference voltage source usually uses the base-emitter voltage VBE with a negative temperature coefficient to superimpose the N Vt with a positive temperature coefficient, lacks a temperature compensation structure, and cannot eliminate the temperature-to-output bandgap reference Due to the high-order influence of voltage, the output bandgap reference voltage is significantly affected by temperature changes, which is not conducive to the selection and design of system-level users.

Referring to Fig. 2, the present invention provides a bipolar bandgap reference voltage source with low temperature drift. Its circuit structure design is simple, it has the characteristics of low temperature drift, high reliability, adaptability to bipolar technology, small chip area and low cost, and improves The application suitability of the reference voltage source circuit is improved.

Specifically, the low-temperature drift bipolar bandgap reference voltage source includes a bandgap reference module, a temperature compensation module and a DC bias module; the temperature compensation module is connected to the bandgap reference module, and the DC bias module is connected to the bandgap reference module and the temperature The compensation modules are all connected; the bandgap reference module is used to generate a first-order compensated bandgap reference voltage; the temperature compensation module is used to generate a high-order PTAT current, and compensate the high-order of the negative temperature coefficient in the bandgap reference voltage through the high-order PTAT current item to obtain the bandgap reference voltage with low temperature drift; the DC bias module is used to generate the first bias current and the second bias current, and send them to the bandgap reference module and the temperature compensation module respectively.

Wherein, the bandgap reference module includes a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4 and a first resistor R1, a second resistor R2 and a third resistor R3; the first terminal of the third resistor R3 The first output node A is set, and the second end is connected to the first end of the second resistor R2; the second end of the second resistor R2 is connected to the emitter of the first transistor Q1 and the emitter of the second transistor Q2; A second output node B is set on the base and connected to the base of the second transistor Q2; the collector of the first transistor Q1 is connected to the collector of the third transistor Q3; the collector of the second transistor Q2 is connected to the collector of the fourth transistor Q4 collector; the base of the third transistor Q3 is connected to the base of the fourth transistor Q4; the base of the fourth transistor Q4 is short-circuited to the collector, and the emitter is connected to the first terminal of the first resistor R1.

The bandgap reference module uses the first transistor Q1, the second transistor Q2, the third transistor Q3, the fourth transistor Q4 and the first resistor R1 to generate a current positively related to temperature (ie PTAT current), and uses the second resistor R2 and the third The resistor R3 generates a PTAT voltage, and the base-emitter voltage VBE of the first transistor Q1 is used to superimpose the PTAT voltage to generate a first-order compensated bandgap reference voltage.

The temperature compensation module includes a sixth transistor Q6, a seventh transistor Q7, an eighth transistor Q8, a ninth transistor Q9, a tenth transistor Q10, an eleventh transistor Q11, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6; The emitter of the sixth transistor Q6 is connected to the first output node A, the collector is connected to the first end of the second resistor R2, and the base is connected to the base of the seventh transistor Q7; the emitter of the seventh transistor Q7 is connected to the first output node A , the collector is short-circuited to the base; the collector of the ninth transistor Q9 is connected to the collector of the seventh transistor Q7, the base is connected to the second end of the fifth resistor R5, and the emitter is connected to the first end of the fourth resistor R4; The collector of the eighth transistor Q8 is connected to the first output node A, the base is connected to the base of the tenth transistor Q10, and the emitter is connected to the first end of the fourth resistor R4; the collector of the tenth transistor Q10 is short-circuited to the base, and the emitter The pole is connected to the collector of the eleventh transistor Q11; the base of the eleventh transistor Q11 is short-circuited to the collector; the first end of the fifth resistor R5 is connected to the base of the eighth transistor Q8, and the second end is connected to the sixth resistor R6 The first terminal of the sixth resistor R6 is connected to the emitter of the tenth transistor Q10.

The temperature compensation module uses the eighth transistor Q8, the ninth transistor Q9, the tenth transistor Q10, the eleventh transistor Q11, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 to generate a high-order PTAT current, and the high-order PTAT current The mirror image of the sixth transistor Q6 and the seventh transistor Q7 acts on the third resistor R3, which is used to compensate the high-order term of the negative temperature coefficient in the base-emitter voltage VBE of the second transistor Q2, so that the band gap of the output after compensation The reference voltage obtains low temperature drift characteristics.

The DC bias module includes a fifth transistor Q5, a first current source I1, a second current source I2, and a third current source I3; the base of the fifth transistor Q5 is connected to the first end of the third current source I3, and the collector is connected to the first end of the third current source I3. An output node A; the first terminal of the first current source I1 is connected to the collector of the tenth transistor Q10; the first terminal of the second current source I2 is connected to the second output node B.

The second current source I2 and the third current source I3 in the DC bias module provide bias currents for the fifth transistor Q5, the first transistor Q1 and the second transistor Q2. Wherein, the third current source I3 provides a DC bias for the temperature compensation module, and the fifth transistor Q5 provides a DC bias for the bandgap reference module.

When in use, the emitter of the third transistor Q3 is grounded; the second end of the first resistor R1 is grounded, the second end of the fourth resistor R4 is grounded; the emitter of the eleventh transistor Q11 is grounded, and the emitter of the fifth transistor Q5, The second terminal of the first current source I1 , the second terminal of the second current source I2 and the second terminal of the third current source I3 are all connected to the power supply VCC.

In summary, because the existing bandgap reference structure does not include a temperature compensation structure, the high-order influence of temperature on the output reference voltage cannot be eliminated, and the output reference voltage is significantly affected by temperature changes, which is not conducive to the selection of system-level users. Due to the defect of type design, the temperature compensation structure adopted in the present invention can allow the circuit to generate a changing high-order PTAT compensation current under the working conditions of different temperatures, so that the bandgap reference voltage output by the bandgap reference voltage source is not affected by temperature changes. , has the characteristics of low temperature drift and adapts to bipolar technology, improves the application applicability of the bandgap reference voltage source circuit, and can be widely used in various power supply management and drive chips, with good application prospects and economic benefits.

Optionally, assuming that the ratio of the emitter area of the third transistor Q3 to the emitter area of the fourth transistor Q4 is 1:N, the relationship between the base-emitter voltage difference ΔV _BE of the third transistor Q3 and the fourth transistor Q4 is It is: ΔV _BE ＝V _BE3 -V _BE4 ＝V _T lnN, wherein, V _T is thermal voltage, proportional to temperature T,

流经第一电阻R1和第二电阻R2的电流为两倍的I_PTAT。ΔV _BE acts on the first resistor R1 to generate PTAT current I _PTAT :

The current flowing through the first resistor R1 and the second resistor R2 is twice I _PTAT .

The bandgap reference voltage relation is as follows:

Optionally, in this embodiment, N is designed to be 8, the first resistor R1 is a polysilicon resistor with a resistance value of 52kΩ, the second resistor R2 is a polysilicon resistor with a resistance value of 138kΩ, and the third resistor R3 is a polysilicon resistor with a resistance value of 98kΩ resistance.

Optionally, it is assumed that the emission area ratio of the sixth transistor Q6 and the seventh transistor Q7 is 1:1; the emission area areas of the eighth transistor Q8, the ninth transistor Q9, the tenth transistor Q10, and the eleventh transistor Q11 are The ratio is 1:1:2:2.

流经第十一晶体管Q11、第九晶体管Q9与第八晶体管Q8的集电极电流满足：/>

When the operating temperature of the circuit is low, the base-emitter voltage of the tenth transistor Q10 is lower than the turn-on voltage of the transistor, and is in an off state. The bias current I1 is sent to ground through the fifth resistor R5, the sixth resistor R6 and the eleventh transistor Q11. The collector currents of the ninth transistor Q9 and the eighth transistor Q8 satisfy:

The collector currents flowing through the eleventh transistor Q11, the ninth transistor Q9 and the eighth transistor Q8 satisfy: />

第九晶体管Q9与第八晶体管Q8的集电极电流关系满足：/>

As the operating temperature of the circuit increases, the currents of the fifth resistor R5 and the sixth resistor R6 gradually increase, and at the same time, the turn-on voltage of the tenth transistor Q10 decreases, and the tenth transistor Q10 will be turned on and working. The bias current I1 is connected to the ground through the tenth transistor 10 and the eleventh transistor Q11, so the current flowing through the fifth resistor R5 and the sixth resistor R6 decreases. The relationship between the collector currents of the eleventh transistor Q11, the ninth transistor Q9 and the eighth transistor Q8 still satisfies:

The collector current relationship between the ninth transistor Q9 and the eighth transistor Q8 satisfies: />

According to the above, it can be seen that the compensation current I _C9 is a positive temperature coefficient current containing a high-order term lnT. The reference voltage value output by the circuit after compensation satisfies:

In this embodiment, the fourth resistor R4 is a polysilicon resistor with a resistance of 90kΩ, the fifth resistor R5 is a polysilicon resistor with a resistance of 19.5kΩ, and the sixth resistor R6 is a polysilicon resistor with a resistance of 212kΩ.

Referring to FIG. 3 , the simulation results of the circuit application of the low-temperature drift bipolar bandgap reference voltage source in this embodiment, it can be seen that, in the temperature range of -55°C to 125°C, the temperature of the circuit is scanned, and the output voltage of the bandgap reference The simulated value is 1.202V, the variation range of the output reference voltage with temperature changes is 3.052mV, and the temperature drift is 14ppm/℃, which has good temperature characteristics.

According to the above description, it can be seen that the temperature compensation structure adopted by the low-temperature drift bipolar bandgap reference voltage source of the present invention can allow the circuit to produce a variable high-order PTAT compensation current under the working conditions of different temperatures, so that the output of the bandgap reference voltage source The reference voltage is not subject to temperature changes, has the characteristics of low temperature drift and adapts to bipolar technology, improves the application applicability of the reference voltage source circuit, and can be widely used in various power supply management and drive chips, and has good application Prospects and economic benefits.

The above content is only to illustrate the technical ideas of the present invention, and cannot limit the protection scope of the present invention. Any changes made on the basis of the technical solutions according to the technical ideas proposed in the present invention shall fall within the scope of the claims of the present invention. within the scope of protection.

Claims (10)

1. a low-temperature drift bipolar bandgap reference voltage source, characterized in that, comprises a bandgap reference module, a temperature compensation module and a DC bias module; the temperature compensation module is connected with the bandgap reference module, and the DC bias module is connected with the bandgap reference module Both the gap reference module and the temperature compensation module are connected; The bandgap reference module is used to generate a first-order compensated bandgap reference voltage; The temperature compensation module is used to generate a high-order PTAT current, and compensate the high-order term of the negative temperature coefficient in the bandgap reference voltage through the high-order PTAT current to obtain a bandgap reference voltage with low temperature drift; The DC bias module is used to generate the first bias current and the second bias current, and send them to the bandgap reference module and the temperature compensation module respectively. 2. The low-temperature drift bipolar bandgap reference voltage source according to claim 1, wherein the bandgap reference module comprises a first transistor Q1, a second transistor Q2, a third transistor Q3, and a fourth transistor Q4 and the first resistor R1, the second resistor R2 and the third resistor R3; the first end of the third resistor R3 sets the first output node, and the second end is connected to the first end of the second resistor R2; the second end of the second resistor R2 The terminal is connected to the emitter of the first transistor Q1 and the emitter of the second transistor Q2; the base of the first transistor Q1 is provided with a second output node, and is connected to the base of the second transistor Q2; the collector of the first transistor Q1 connected to the collector of the third transistor Q3; the collector of the second transistor Q2 connected to the collector of the fourth transistor Q4; the base of the third transistor Q3 connected to the base of the fourth transistor Q4; the base of the fourth transistor Q4 and the collector The electrodes are short-circuited, and the emitter is connected to the first end of the first resistor R1. 3 . The low temperature drift bipolar bandgap reference voltage source according to claim 2 , wherein the emitter of the third transistor Q3 is grounded; the second end of the first resistor R1 is grounded. 4 . 4 . The low-temperature drift bipolar bandgap reference voltage source according to claim 2 , wherein the area ratio of the emitter regions of the third transistor Q3 and the fourth transistor Q4 is 1:8. 5. The low-temperature drift bipolar bandgap reference voltage source according to claim 2, wherein the temperature compensation module includes a sixth transistor Q6, a seventh transistor Q7, an eighth transistor Q8, a ninth transistor Q9, The tenth transistor Q10, the eleventh transistor Q11, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6; the emitter of the sixth transistor Q6 is connected to the first output node, and the collector is connected to the first end of the second resistor R2 , the base is connected to the base of the seventh transistor Q7; the emitter of the seventh transistor Q7 is connected to the first output node, and the collector and the base are short-circuited; the collector of the ninth transistor Q9 is connected to the collector of the seventh transistor Q7, and the base The pole is connected to the second end of the fifth resistor R5, the emitter is connected to the first end of the fourth resistor R4; the collector of the eighth transistor Q8 is connected to the first output node, the base is connected to the base of the tenth transistor Q10, and the emitter is connected to The first end of the fourth resistor R4; the collector of the tenth transistor Q10 is short-circuited to the base, and the emitter is connected to the collector of the eleventh transistor Q11; the base of the eleventh transistor Q11 is short-circuited to the collector; the fifth The first terminal of the resistor R5 is connected to the base of the eighth transistor Q8, and the second terminal is connected to the first terminal of the sixth resistor R6; the second terminal of the sixth resistor R6 is connected to the emitter of the tenth transistor Q10. 6 . The low temperature drift bipolar bandgap reference voltage source according to claim 5 , wherein the second end of the fourth resistor R4 is grounded; the emitter of the eleventh transistor Q11 is grounded. 7. The low-temperature drift bipolar bandgap reference voltage source according to claim 5, wherein the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, and the fifth resistor R5 And the sixth resistor R6 is a polysilicon resistor. 8. The low-temperature drift bipolar bandgap reference voltage source according to claim 5, characterized in that, the emitter area ratio of the sixth transistor Q6 and the seventh transistor Q7 is 1:1; the eighth transistor The area ratio of the emitter regions of Q8 , the ninth transistor Q9 , the tenth transistor Q10 and the eleventh transistor Q11 is 1:1:2:2. 9. The low-temperature drift bipolar bandgap reference voltage source according to claim 5, wherein the DC bias module comprises a fifth transistor Q5, a first current source I1, a second current source I2 and a third Current source I3; the base of the fifth transistor Q5 is connected to the first end of the third current source I3, and the collector is connected to the first output node; the first end of the first current source I1 is connected to the collector of the tenth transistor Q10; the second A first terminal of the current source I2 is connected to the second output node. 10. The low temperature drift bipolar bandgap reference voltage source according to claim 9, characterized in that, the emitter of the fifth transistor Q5, the second end of the first current source I1, the second end of the second current source I2 Both the second terminal and the second terminal of the third current source I3 are connected to the power supply VCC.

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