Low-voltage reference voltage generation circuit, chip and electronic equipment
By designing a low-voltage reference voltage generation circuit that uses two transistors and two resistors, the problem that the prior art cannot be applied in low power supply voltage scenarios is solved, and stable low-voltage reference voltage generation is achieved, reducing circuit complexity and cost.
Patent Information
- Application Number
- CN202411960573.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-04-25
AI Technical Summary
The existing reference voltage generation circuit cannot be applied in low power supply voltage scenarios, and the circuit is complex, high cost and high power consumption.
A low-voltage reference voltage generation circuit is designed, using two transistors and two resistors to compensate each other through positive temperature characteristics and negative temperature characteristics to generate a low-voltage reference voltage signal independent of temperature.
Generating a stable reference voltage under low power supply voltage conditions reduces circuit complexity and cost, reduces power consumption, and improves circuit stability.
Smart Images
Figure CN119882907A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present application belong to the field of electronic technology, and in particular, relate to a low-voltage reference voltage generation circuit, a chip, and an electronic device. Background Art
[0002] Currently, when a temperature-independent reference voltage needs to be generated, it is usually possible to Figure 1 The reference voltage generation circuit shown in the figure is used to achieve this. Figure 1 As shown in the figure, due to the clamping effect of the op amp OP, the potential of the positive input terminal A of the op amp OP is equal to the potential of the negative input terminal B of the op amp OP, that is, V BE,Q2 =VA=VB=V R2 +V BE,Q1 , the voltage V on resistor R2 R2 That is, the base (base, B) and emitter (Emitter, E) bias voltage V of transistor Q2 BE,Q2 The base and emitter bias voltage V BE,Q1 The difference, V R2 =V BE,Q2 -V BE,Q1 =((KT / Q)*lnN), with positive temperature characteristics, the current flowing through R2 is [(KT / Q)*lnN] / R2, the voltage divider V on the two R1s R1 They are all R1*[(KT / Q)*lnN] / R2, Q is the charge of the electron, and N is the area ratio of transistor Q1 to transistor Q2. Correspondingly, the reference voltage VBG is the base and emitter bias voltage V BE,Q2 and the voltage divider V on R1 R1 The sum of the base and emitter bias voltages of transistor Q2 is V BE,Q2 Possessing negative temperature characteristics (for silicon-based processes, its temperature characteristics are approximately -1.5mV / ○ K), the voltage divider V on R1 R1 Depends on the base (base, B) and emitter (Emitter, E) bias voltage V of transistor Q2 BE,Q2 The base and emitter bias voltage V BE,Q1 The difference between them has a positive temperature characteristic. The addition of the two can play a role in temperature compensation, so that when the temperature T changes (increases or decreases), the reference voltage VBG can remain basically stable (such as remaining within a small voltage range), and the reference voltage VBG can be regarded as independent of temperature.
[0003] However, the above-mentioned reference voltage generating circuit has the following defects when the power supply voltage is less than 1V:
[0004] 1. Since the generated reference voltage is about 1.2V, the power supply voltage of this structure cannot be less than 1.2V, and it cannot be applied to low power supply voltage scenarios;
[0005] 2. The circuit structure is complex and requires an operational amplifier OP to clamp it, which occupies a large chip area and has a high cost.
[0006] 3. The power consumption is relatively high, which is not conducive to low-power design.
[0007] Therefore, how to design a reference voltage generation circuit that is suitable for low voltage, low power consumption and low cost has become a technical problem that needs to be solved urgently. Summary of the invention
[0008] The embodiments of the present application provide a low-voltage reference voltage generating circuit, a chip and an electronic device, which can solve the problem that the existing reference voltage generating circuit cannot meet the low-voltage, low-power and low-cost application scenarios.
[0009] In order to achieve the above objectives, the embodiments of the present application adopt the following technical solutions:
[0010] In a first aspect, a low voltage reference voltage generating circuit is provided, comprising: a current source, a first transistor, a second transistor, a first resistor, and a second resistor;
[0011] The first end and the second end of the first triode are connected to one end of the first resistor, the third end of the first triode and the second end of the second triode are connected to the output end of the low voltage reference voltage generating circuit, the first end of the second triode is connected to the other end of the first resistor and one end of the second resistor, and the third end of the second triode is connected to the other end of the second resistor;
[0012] The second end of the first triode or the third end of the second triode is connected to a current source, and the output end of the low-voltage reference voltage generating circuit is used to output a low-voltage reference voltage signal according to the positive temperature characteristic of the bias voltage between the first end and the third end of the second triode, and the negative temperature characteristic of the difference between the bias voltage between the first end and the third end of the second triode and the bias voltage between the first end and the third end of the first triode.
[0013] In a possible design scheme, the first triode and the second triode are both NPN triodes, and the second end of the first triode or the third end of the second triode is connected to a current source, including:
[0014] The second end of the first triode is connected to a power source through a current source, and the third end of the second triode is grounded.
[0015] Optionally, the first ends of the first triode and the second triode are both bases, the second ends of the first triode and the second triode are both collectors, and the third ends of the first triode and the second triode are both emitters.
[0016] Furthermore, the low voltage reference voltage signal satisfies:
[0017] VBG=V1-V BE,Q1 ;
[0018] in,
[0019] but
[0020] make
[0021] but
[0022] Among them, VBG is the low voltage reference voltage signal, V1 is the voltage of the base and collector of the first transistor, V BE,Q1 is the bias voltage between the base and emitter of the first transistor, V BE,Q2 is the bias voltage between the base and emitter of the second transistor, R1 is the first resistor, R2 is the second resistor, ⊿V BE is the difference between the bias voltage between the base and emitter of the second transistor and the bias voltage between the base and emitter of the first transistor, K is the Boltzmann constant, T is the absolute temperature, Q is the charge of the electron, β is the ratio of the collector current to the base current of the transistor, N is the ratio of the area occupied by the first transistor to the area occupied by the second transistor, and N>1.
[0023] In another possible design, the second end of the first triode or the third end of the second triode is connected to a current source, including:
[0024] The second end of the first transistor is grounded through a current source, and the third end of the second transistor is connected to a power source.
[0025] Optionally, the first triode and the second triode are both PNP triodes, the first ends of the first triode and the second triode are both bases, the second ends of the first triode and the second triode are both collectors, and the third ends of the first triode and the second triode are both emitters.
[0026] Furthermore, the low voltage reference voltage signal satisfies:
[0027] ΔV=VCC-VBG
[0028] =VCC-(V1+V BE,Q1 )
[0029] =VCC-(VCC-V BE,Q2 -V R1 )-V BE,Q1
[0030] =V R1 +VBE,Q2 -V BE,Q1
[0031] in, but
[0032]
[0033] Wherein, ⊿V is the difference between the power supply voltage VCC and the low voltage reference voltage signal VBG, V1 is the voltage between the base and collector of the first transistor, V BE,Q1 is the bias voltage between the base and emitter of the first transistor, V BE,Q2 is the bias voltage between the base and emitter of the second transistor, R1 is the first resistor, R2 is the second resistor, V R1 is the voltage divided by the first resistor R1, ⊿V BE is the difference between the bias voltage between the base and the emitter of the second transistor and the bias voltage between the base and the emitter of the first transistor, K is the Boltzmann constant, T is the absolute temperature, Q is the electron charge, β is the ratio of the collector current to the base current of the transistor, N is the ratio of the area occupied by the first transistor to the area occupied by the second transistor, and N>1.
[0034] Optionally, the second resistor is greater than the first resistor.
[0035] In a second aspect, a chip is provided, comprising: one or more low-voltage reference voltage generating circuits as described in any implementation manner in the first aspect.
[0036] According to a third aspect, an electronic device is provided, comprising: one or more chips as described in any implementation of the second aspect.
[0037] Compared with the existing reference voltage generation circuit, the low-voltage reference voltage generation circuit provided in the embodiment of the present application can not only generate a low-voltage reference voltage signal by utilizing the positive temperature characteristics and negative temperature characteristics of components, but also has the following advantages:
[0038] The low voltage reference voltage generating circuit provided in the embodiment of the present application has a lower power supply voltage requirement than the power supply voltage of the existing reference voltage generating circuit, and is more suitable for low power supply voltage application scenarios;
[0039] The low-voltage reference voltage generation circuit provided in the embodiment of the present application uses only two resistors and two transistors as core components. The number of components used is greatly reduced compared to the number of components of the existing reference voltage generation circuit, and no operational amplifier is required, which greatly reduces the complexity of the circuit, can reduce the chip area, and save costs;
[0040] The low-voltage reference voltage generating circuit provided in the embodiment of the present application is a single-pole circuit, which operates more stably than the reference voltage generating circuit in the prior art (including an operational amplifier, which is a double-pole circuit), has no stability problems, and is simple and reliable. BRIEF DESCRIPTION OF THE DRAWINGS
[0041] 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:
[0042] Figure 1 It is a structural schematic diagram of a reference voltage generating circuit in the prior art;
[0043] Figure 2 A schematic diagram of the structure of a reference voltage generating circuit provided in an embodiment of the present application;
[0044] Figure 3 A schematic diagram of the structure of another reference voltage generating circuit provided in an embodiment of the present application;
[0045] Figure 4 for Figure 2 The waveform diagram of the reference voltage generating circuit shown. DETAILED DESCRIPTION
[0046] 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.
[0047] The technical solution provided in the embodiments of the present application is described in detail below in conjunction with the accompanying drawings.
[0048] For example, Figure 2 and Figure 3 Two low voltage reference voltage generation circuits are provided in the embodiments of the present application. Figure 2 and Figure 3 As shown, the circuit includes: a current source I, a first transistor Q1, a second transistor Q2, a first resistor R1 and a second resistor R2, and R2>R1;
[0049] The first end of the first transistor Q1 ( Figure 2 and Figure 3 The second end ( Figure 2 and Figure 3 The third terminal of the first transistor Q1 is connected to one end of the first resistor R1 and the .... Figure 2 and Figure 3 The second end of the second transistor Q2 (marked as e) Figure 2 and Figure 3 The output terminal (marked as c) of the low voltage reference voltage generating circuit is connected to Figure 2 and Figure 3 The first terminal of the second transistor Q2 ( Figure 2 and Figure 3 The other end of the first resistor R1 and one end of the second resistor R2 are connected, and the third end of the second transistor Q2 ( Figure 2 and Figure 3 The other end of the second resistor R2 is connected to the other end of the second resistor R2;
[0050] The second end of the first transistor Q1 or the third end of the second transistor Q2 is connected to the current source I, and the output end of the low-voltage reference voltage generating circuit is used to output the low-voltage reference voltage signal VBG according to the negative temperature characteristic of the bias voltage between the first end and the third end of the second transistor Q2, and the positive temperature characteristic of the difference between the bias voltage between the first end and the third end of the second transistor Q2 and the bias voltage between the first end and the third end of the first transistor Q1.
[0051] In one possible design, Figure 2 As shown, the first transistor Q1 and the second transistor Q2 are both NPN transistors, and the second end of the first transistor Q1 or the third end of the second transistor Q2 is connected to the current source I, including:
[0052] The second end of the first transistor Q1 is connected to the power source VCC through the current source I, and the third end of the second transistor Q2 is grounded.
[0053] Optionally, the first ends of the first triode Q1 and the second triode Q2 are bases, the second ends of the first triode Q1 and the second triode Q2 are collectors, and the third ends of the first triode Q1 and the second triode Q2 are emitters.
[0054] Figure 2The working principle of the low voltage reference voltage generating circuit shown is as follows: the first transistor Q1 and the second transistor Q2 work in the linear amplification region, so the base current Ib of the two transistors is much smaller than the collector current and emitter current of the two transistors. It can be considered that the current provided by the current source I is divided into two parts, one part is the current flowing through the first resistor R1 and the second resistor R2 in sequence, and the other part is the current flowing through the collector and emitter of the first transistor Q1, and the collector and emitter of the second transistor Q2 in sequence. Accordingly, the low voltage reference voltage signal VBG satisfies:
[0055] VBG=V1-V BE,Q1 ; (1)
[0056]
[0057] Substituting formula (2) into formula (1), we can obtain:
[0058]
[0059] make
[0060] Substituting formula (4) into formula (3), we can obtain:
[0061]
[0062] Among them, VBG is the low voltage reference voltage signal, V1 is the voltage of the base and collector of the first transistor Q1, V R1 =R1*V BE,Q2 / R2 is the voltage divided by the first resistor R1, V BE,Q1 is the bias voltage between the base and emitter of the first transistor Q1, V BE,Q2 is the bias voltage between the base and emitter of the second transistor Q2, which has a negative temperature characteristic, R1 is the first resistor R1, R2 is the second resistor R2, ⊿V BE It is the difference between the bias voltage between the base and the emitter of the second transistor Q2 and the bias voltage between the base and the emitter of the first transistor Q1, and has a positive temperature characteristic. K is the Boltzmann constant, T is the absolute temperature, Q is the charge of the electron, β is the ratio of the collector current to the base current of the transistor, and N is the ratio of the area occupied by the first transistor to the area occupied by the second transistor, and N>1.
[0063] From the above formula (3), we can see that due to V BE,Q2 Possessing negative temperature characteristics, ⊿V BEWith a positive temperature characteristic, the two can compensate each other when the temperature changes, so that the low-voltage reference voltage signal VBG output by the low-voltage reference voltage generating circuit can be maintained within a smaller voltage range, and the generated low-voltage reference voltage signal VBG can be regarded as independent of temperature.
[0064] And, since V1 = V BE,Q1 +V CE,Q2 ≈0.7V+0.15V=0.85V, the current source I consumes 50mV~100mV of voltage, then the demand for power supply voltage of this circuit can be reduced to 0.95V, and no power supply voltage higher than 1.2V is required, which can be suitable for low power supply voltage application scenarios;
[0065] and, Figure 2 Only two resistors and two transistors are used as the core components of the low voltage reference voltage generation circuit. The number of components used is greatly reduced compared with the existing reference voltage generation circuit. For example, the operational amplifier OP is not included, which greatly reduces the complexity of the circuit, reduces the chip area, and saves costs.
[0066] also, Figure 2 The low voltage reference voltage generation circuit shown is a single-pole circuit. Figure 1 The reference voltage generating circuit shown (the operational amplifier OP is a double-pole circuit) operates more stably, has no stability problem, and is simple and reliable.
[0067] For example, Figure 4 for Figure 2 The waveform diagram of the reference voltage generating circuit shown in FIG. Figure 4 As shown, during the process of large temperature changes (-40℃~120℃), the voltage value of the low-voltage reference voltage signal VBG basically remains stable in a small range (about 310MV~330MV), and the V1 voltage is also less than 976mV, which meets the requirements of low power supply voltage applications and is consistent with design expectations.
[0068] Another possible design is Figure 3 As shown, the second end of the first transistor Q1 or the third end of the second transistor Q2 is connected to the current source I, including:
[0069] A second end of the first transistor Q1 is grounded through a current source I, and a third end of the second transistor Q2 is connected to a power source.
[0070] Optionally, the first transistor Q1 and the second transistor Q2 are both PNP transistors, the first ends of the first transistor Q1 and the second transistor Q2 are both bases, the second ends of the first transistor Q1 and the second transistor Q2 are both collectors, and the third ends of the first transistor Q1 and the second transistor Q2 are both emitters.
[0071] Furthermore, the low voltage reference voltage signal VBG satisfies:
[0072] ΔV=VCC-VBG
[0073] =VCC-(V1+V BE,Q1 )
[0074] =VCC-(VCC-V BE,Q2 -V R1 )-V BE,Q1
[0075] =V R1 +V BE,Q2 -V BE,Q1 ; (6)
[0076] in, but
[0077]
[0078] Wherein, ⊿V is the difference between the power supply voltage VCC and the low voltage reference voltage signal VBG, is the voltage between the base and collector of the first transistor, V BE,Q1 is the bias voltage between the base and emitter of the first transistor, V BE,Q2 is the bias voltage between the base and emitter of the second transistor, R1 is the first resistor, R2 is the second resistor, V R1 is the voltage divided by the first resistor R1, ⊿V BE is the bias voltage V between the base and emitter of the second transistor BE,Q2 , and the bias voltage V between the base and emitter of the first transistor BE,Q1 The difference between the two, K is the Boltzmann constant, T is the absolute temperature, Q is the electron charge, β is the ratio of the collector current to the base current of the transistor, N is the ratio of the area occupied by the first transistor Q1 to the area occupied by the second transistor Q2, and N>1.
[0079] From the above formula (6), we can see that due to V BE,Q2 Possessing negative temperature characteristics, ⊿V BE It has a positive temperature characteristic, and the two can compensate each other when the temperature changes, so that the deviation between the power supply voltage VCC and the low-voltage reference voltage signal VBG output by the low-voltage reference voltage generating circuit can be maintained within a smaller voltage range. It can be regarded that the deviation between the generated low-voltage reference voltage signal VBG and the power supply voltage is independent of the temperature and the size of the power supply voltage VCC.
[0080] and, Figure 3Only two resistors and two transistors are used as the core components of the low voltage reference voltage generation circuit. The number of components used is greatly reduced compared with the existing reference voltage generation circuit. For example, the operational amplifier OP is not included, which greatly reduces the complexity of the circuit, reduces the chip area, and saves costs.
[0081] also, Figure 3 The low voltage reference voltage generation circuit shown is a single-pole circuit. Figure 1 The reference voltage generating circuit shown (the operational amplifier OP is a double-pole circuit) operates more stably, has no stability problem, and is simple and reliable.
[0082] and Figure 2 The low voltage reference voltage generation circuit shown is similar to Figure 3 In the low voltage reference voltage generating circuit shown, the second resistor R2 is larger than the first resistor R1, and its working principle and technical effect are not described in detail.
[0083] It should be noted that in Figure 2 and Figure 3 In the figure, the second resistor R2 can be one or more. The second resistor R2 shown in the figure can be regarded as the equivalent resistance of one or more resistive loads connected between the base and the emitter of the second transistor, which is not limited in the embodiment of the present application.
[0084] In addition, the magnitude of the low-voltage reference voltage signal VBG is related to the magnitude of the current provided by the current source I (such as 200nA or less), the type (NPN type or PNP type) and material (silicon-based, germanium-based or other compound materials) of the first transistor Q1 and the second transistor Q2, and the resistance value of the first resistor R1 and the second resistor R2. The parameters, processes, materials, etc. of the above-mentioned components can be adjusted to generate a low-voltage reference voltage signal VBG that can meet different values to meet different needs.
[0085] Furthermore, Figure 2 and Figure 3 The circuit structure shown in the figure is slightly adjusted to change the magnitude of the low voltage reference voltage signal VBG. Figure 2 For example, a resistor may be connected in series between the emitter of the second transistor Q2 and the ground to increase the magnitude of the low voltage reference voltage signal VBG.
[0086] The present application embodiment provides a chip. The chip includes: one or more Figure 2 or Figure 3 The low voltage reference voltage generating circuit shown.
[0087] An embodiment of the present application provides an electronic device, which includes: one or more of the above chips.
[0088] 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 low voltage reference voltage generating circuit, characterized in that: include: A current source, a first transistor, a second transistor, a first resistor, and a second resistor; The first end and the second end of the first triode are connected to one end of the first resistor, the third end of the first triode and the second end of the second triode are connected to the output end of the low voltage reference voltage generating circuit, the first end of the second triode is connected to the other end of the first resistor and one end of the second resistor, and the third end of the second triode is connected to the other end of the second resistor; The second end of the first transistor or the third end of the second transistor is connected to the current source, and the output end of the low-voltage reference voltage generating circuit is used to output a low-voltage reference voltage signal according to the positive temperature characteristic of the bias voltage between the first end and the third end of the second transistor, and the negative temperature characteristic of the difference between the bias voltage between the first end and the third end of the second transistor and the bias voltage between the first end and the third end of the first transistor.
2. The circuit according to claim 1, characterized in that The first transistor and the second transistor are both NPN transistors, and the second end of the first transistor or the third end of the second transistor is connected to the current source, including: The second end of the first transistor is connected to a power source through the current source, and the third end of the second transistor is grounded.
3. The circuit according to claim 2, characterized in that The first ends of the first transistor and the second transistor are both bases, the second ends of the first transistor and the second transistor are both collectors, and the third ends of the first transistor and the second transistor are both emitters.
4. The circuit according to claim 3, characterized in that The low voltage reference voltage signal satisfies: VBG=V1-V BE,Q1 ; in, but make but Wherein, VBG is the low voltage reference voltage signal, V1 is the voltage of the base and collector of the first transistor, V BE,Q1 is the bias voltage between the base and emitter of the first transistor, V BE,Q2 is the bias voltage between the base and emitter of the second transistor, R1 is the first resistor, R2 is the second resistor, ⊿V BE is the difference between the bias voltage between the base and the emitter of the second transistor and the bias voltage between the base and the emitter of the first transistor, K is the Boltzmann constant, T is the absolute temperature, Q is the charge of the electron, β is the ratio of the collector current to the base current of the transistor, N is the ratio of the area occupied by the first transistor to the area occupied by the second transistor, and N>1.
5. The circuit according to claim 1, characterized in that The second end of the first triode or the third end of the second triode is connected to the current source, comprising: The second end of the first transistor is grounded through the current source, and the third end of the second transistor is connected to a power supply.
6. The circuit according to claim 5, characterized in that The first transistor and the second transistor are both PNP transistors, the first ends of the first transistor and the second transistor are both bases, the second ends of the first transistor and the second transistor are both collectors, and the third ends of the first transistor and the second transistor are both emitters.
7. The circuit according to claim 6, characterized in that The low voltage reference voltage signal satisfies: ΔV=VCC-VBG =VCC-(V1+V BE,Q1 ) =VCC-(VCC-V BE,Q2 -V R1 )-V BE,Q1 =V R1 +V BE,Q2 -V BE,Q1 in, but Wherein, ⊿V is the difference between the power supply voltage VCC and the low voltage reference voltage signal VBG, V1 is the voltage between the base and collector of the first transistor, V BE,Q1 is the bias voltage between the base and emitter of the first transistor, V BE,Q2 is the bias voltage between the base and emitter of the second transistor, R1 is the first resistor, R2 is the second resistor, V R1 is the voltage divided by the first resistor, ⊿V BE is the difference between the bias voltage between the base and the emitter of the second transistor and the bias voltage between the base and the emitter of the first transistor, K is the Boltzmann constant, T is the absolute temperature, Q is the electron charge, β is the ratio of the collector current to the base current of the transistor, N is the ratio of the area occupied by the first transistor to the area occupied by the second transistor, and N>1.
8. The circuit according to any one of claims 1 to 7, characterized in that: The second resistor is greater than the first resistor.
9. A chip, characterized in that: include: One or more low voltage reference voltage generating circuits as claimed in any one of claims 1 to 8.
10. An electronic device, characterized in that: include: One or more chips as claimed in claim 9.