Low-power-consumption low-output-voltage reference circuit and chip

Abstract

The invention relates to a low-power-consumption low-output-voltage reference circuit and a chip, and aims to solve the problems of low-voltage output, high power consumption and circuit complexity. The circuit comprises a temperature complementation circuit, an output voltage regulation circuit, an error amplifier and a power output circuit. The temperature complementation circuit counteracts the influence of temperature drift by accurately controlling a current source and a voltage-stabilized power supply, and ensures stable work in a low-voltage environment. The output voltage regulating circuit regulates the voltage at the positive input end of the error amplifier by switching internal resistance, so that the output reference voltage is stabilized. Through the optimization, the circuit can provide stable reference voltage under lower power supply voltage, and is particularly suitable for modern low-power-consumption and high-integration-level chip design. The low-voltage band-gap reference circuit solves the problem that a traditional band-gap reference circuit depends on high supply voltage, is suitable for a low-voltage environment and meets the requirements of modern electronic equipment.

Description

Technical Field

[0001] The present invention relates to the field of integrated circuits, and particularly to a low-power and low-output voltage reference circuit and a chip. Background Art

[0002] In the prior art, voltage reference circuits are widely used to provide a stable reference voltage as the reference voltage source of an electronic system. Traditional voltage reference circuits usually rely on bandgap reference circuits and use techniques such as temperature compensation and current source mirroring to ensure the stability of the output voltage. However, as the power supply voltage gradually decreases, when many traditional voltage reference circuits operate in a low-voltage environment, they face the following problems:

[0003] Problem of low-voltage output: In modern low-voltage chip designs, the power supply voltage is often lower than the operating requirements of traditional voltage reference circuits. For example, the operating voltages of many chips have dropped to 1.8V, 1.2V or even lower, while traditional bandgap reference circuits usually require a higher power supply voltage (such as 2.5V or higher) to operate stably, resulting in the inability to meet the requirements of low-voltage application scenarios.

[0004] Problem of high power consumption: Although various optimization means have been adopted in the design of existing voltage reference circuits to reduce power consumption, for application scenarios with extremely strict low-power requirements, the existing circuits are still difficult to meet their extreme power consumption requirements. Especially in some highly integrated systems, excessive power consumption not only increases battery consumption but also causes the temperature of the system to rise, affecting stability and reliability.

[0005] Problems of circuit complexity and integration: In order to meet the requirements of low power consumption and low voltage, the designs of many existing voltage reference circuits are very complex and have low integration, making it difficult to be implemented on small-sized and highly integrated chips. Such problems of design complexity and low integration not only increase the design and manufacturing costs but also make it difficult to ensure the reliability and stability of the circuit. Summary of the Invention

[0006] The present invention provides a low-power and low-output voltage reference circuit and a chip. To solve the above problems, the present invention adopts the following technical solutions:

[0007] A low-power and low-output-voltage reference circuit, comprising a temperature complementary circuit, an output voltage regulation circuit, an error amplifier and a power output circuit; the temperature complementary circuit is used to cancel the influence of temperature drift on voltage output and provide a reference current; the output voltage regulation circuit is respectively connected to the temperature complementary circuit and the positive input terminal of the error amplifier, and is used to adjust the voltage at the positive input terminal of the error amplifier by switching an internal resistor; the output terminal of the error amplifier is connected to the power output circuit; the power output circuit is connected to the negative input terminal of the error amplifier and outputs a reference voltage through a voltage output terminal.

[0008] Further, the temperature compensation circuit includes a voltage regulation branch, a mirror current source branch, a bandgap branch and a reverse protection branch; the voltage regulation branch is respectively connected to the mirror current source branch and the bandgap branch; the mirror current source branch is respectively connected to the bandgap branch and the reverse protection branch; the reverse protection branch is respectively connected to the output voltage regulation circuit and the positive input terminal of the error amplifier;

[0009] The voltage regulation branch includes a PNP transistor Q1 and an NPN transistor Q7; the emitter of the PNP transistor Q1 is connected to the power supply voltage terminal through a bias, the base is respectively connected to the collector of the PNP transistor Q2 and the collector of the NPN transistor Q1, and the collector is connected to the voltage output terminal; the base of the NPN transistor Q7 is respectively connected to the collector of the NPN transistor Q9 and the collector of the PNP transistor Q4, and the emitter is connected to the voltage output terminal;

[0010] The mirror current source branch includes PNP transistors Q2, Q3, Q4, Q5, Q6 and a resistor R1; the emitters of the PNP transistors Q2, Q3, Q4, Q5 and Q2 are all connected to the power supply voltage terminal through a bias, and the bases are commonly connected; the collector of the PNP transistor Q3 is connected to one end of the resistor R1; the collector of the PNP transistor Q5 is respectively connected to one end of a resistor R5, one end of a resistor R7 and the collector of an NPN transistor Q11; the collector of the PNP transistor Q6 is respectively connected to the collector and the base of an NPN transistor Q13; the other end of the resistor R1 is connected to the voltage output terminal;

[0011] The bandgap branch includes NPN transistor Q9, NPN transistor Q11, PNP transistor Q12, resistor R2, resistor R5, resistor R6, resistor R7, resistor R8, resistor R9, resistor R10, and resistor R11; the base of the NPN transistor Q9 is connected to one end of the resistor R5, and the emitter is connected to the voltage output terminal; the base of the NPN transistor Q11 is connected to one end of the resistor R6, and the emitter is connected to the voltage output terminal; the other end of the resistor R6 is respectively connected to the other end of the resistor R7 and one end of the resistor R8; the other end of the resistor R8 is respectively connected to one end of the resistor R9 and the base of the PNP transistor Q12; the emitter of the PNP transistor Q12 is connected to one end of the resistor R11, and the collector is connected to the other end of the resistor R9 and one end of the resistor R10; the other end of the resistor R10 is connected to the voltage output terminal; the other end of the resistor R11 is connected to the power supply voltage terminal through a bias.

[0012] The reverse protection branch includes NPN transistor Q13 and PNP transistor Q14; the emitter of the NPN transistor Q13 is respectively connected to the emitter of the PNP transistor Q14 and the positive input terminal of the error amplifier; the collector and the base of the PNP transistor Q14 are commonly connected and connected to the voltage output terminal.

[0013] Further, the output voltage regulating circuit includes a first voltage regulating branch, a second voltage regulating branch, a third voltage regulating branch, and a fourth voltage regulating branch that are connected in parallel with each other;

[0014] The first voltage regulating branch includes resistor R21, resistor R22, and switch V1. The resistor R21 and resistor R22 are connected in parallel. One end of the resistor R21 and resistor R22 is connected to the positive input terminal of the error amplifier, and the other end is grounded through the series-connected switch V1; the second voltage regulating branch includes resistor R14 and switch V2. One end of the resistor R14 is connected to the positive input terminal of the error amplifier, and the other end of the resistor R14 is grounded through the series-connected switch V2;

[0015] The third voltage regulating branch includes resistor R15, resistor R16, and switch V3. The resistor R15 and resistor R16 are connected in series. One end of the resistor R15 is connected to the positive input terminal of the error amplifier, and one end of the resistor R16 is grounded through the series-connected switch V3; the fourth voltage regulating branch includes resistor R17, resistor R18, resistor R19, resistor R20, and switch V4. The resistor R17, resistor R18, resistor R19, and resistor R20 are connected in series in sequence. One end of the resistor R17 is connected to the positive input terminal of the error amplifier, and one end of the resistor R20 is grounded through the series-connected switch V4.

[0016] Further, the power output circuit includes an NPN transistor Q15, a PNP transistor Q16, a PNP transistor Q17, and a resistor R12;

[0017] The emitters of the PNP transistor Q16 and the PNP transistor Q17 are connected to the power supply voltage terminal, and the bases are connected in common; the collector of the PNP transistor Q16 is connected to the collector of the NPN transistor Q15; the collector of the PNP transistor Q17 is connected to the voltage output terminal.

[0018] Preferably, the emitter area ratio of the NPN transistor Q9 and the NPN transistor Q11 is 32:1.

[0019] The present invention also provides a chip integrating the foregoing low-power and low-output voltage reference circuit.

[0020] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0021] 1. Improvement of the low-voltage output problem: The design of the temperature compensation circuit can offset the influence of temperature drift on voltage output. By using precise current sources and stable voltage sources, it can operate stably at a lower power supply voltage. In particular, the temperature compensation circuit can still ensure the accuracy of the reference voltage when the power supply voltage is low. This makes the circuit suitable for modern low-voltage applications and solves the problem of the dependence of traditional bandgap reference circuits on higher power supply voltages.

[0022] 2. Improvement of the high-power consumption problem: In the design of this circuit, multiple optimization means are adopted to reduce power consumption, including using low-power transistor structures and fine current control. The mirror current source branch in the temperature compensation circuit can reduce power consumption and stably provide a reference current under low-voltage conditions. The mirror current source circuit can efficiently generate the required current in a low-voltage environment, reducing the overall power consumption.

[0023] 3. Improvement of the circuit complexity and integration problem: To solve the problems of circuit design complexity and low integration, the present application integrates multiple functional circuits into a compact structure through modular circuit design. This not only improves the integration but also reduces the circuit complexity and area, which is beneficial to implementation on a small-sized chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the circuit principle block diagram of the embodiment of the present invention;

[0025] Figure 2 is the circuit diagram of the low-power and low-output voltage reference circuit of the embodiment of the present invention.

[0026] In the above-mentioned drawings: 1. Temperature complementary circuit; 2. Output voltage regulation circuit; 3. Error amplifier; 4. Power output circuit. Detailed implementation manners

[0027] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings. The example implementation manners can be implemented in various forms and should not be construed as being limited to the examples described herein; on the contrary, these implementation manners are provided so that the present invention will be more comprehensive and complete, and the concept of the example implementation manners will be fully conveyed to those skilled in the art. In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0028] This embodiment provides a low-power and low-output voltage reference circuit, which includes a temperature complementary circuit 1, an output voltage regulation circuit 2, an error amplifier 3, and a power output circuit 4. The circuit principle block diagram of this embodiment is as Figure 1 shown. The temperature complementary circuit 1 is used to offset the influence of temperature drift on voltage output and provide a reference current I REF ; the output voltage regulation circuit 2 is respectively connected to the temperature complementary circuit 1 and the positive input terminal of the error amplifier 3, and is used to adjust the voltage V REF at the positive input terminal of the error amplifier 3 by switching internal resistors; the output terminal of the error amplifier 3 is connected to the power output circuit 4; the power output circuit 4 is connected to the negative input terminal of the error amplifier 3 and outputs a reference voltage V OUT through a voltage output terminal.

[0029] The negative input terminal of the error amplifier 3 is connected to the power output circuit, that is, the working mode of the error amplifier 3 is a follower, and it will adjust the output voltage V OUT through a negative feedback mechanism to ensure that V OUT = V REF .

[0030] The circuit diagram of the low-power and low-output voltage reference circuit of this embodiment is as Figure 2 shown. Among them, the temperature compensation circuit 1 includes a voltage stabilization branch, a mirror current source branch, a bandgap branch, and a reverse protection branch; the voltage stabilization branch is respectively connected to the mirror current source branch and the bandgap branch; the mirror current source branch is respectively connected to the bandgap branch and the reverse protection branch; the reverse protection branch is respectively connected to the output voltage regulation circuit 2 and the positive input terminal of the error amplifier 3.

[0031] The voltage stabilizing branch includes PNP transistor Q1 and NPN transistor Q7; the emitter of PNP transistor Q1 is connected to the power supply voltage terminal through a bias, the base is respectively connected to the collector of PNP transistor Q2 and the collector of NPN transistor Q1, and the collector is connected to the voltage output terminal; the base of NPN transistor Q7 is respectively connected to the collector of NPN transistor Q9 and the collector of PNP transistor Q4, and the emitter is connected to the voltage output terminal.

[0032] The mirror current source branch includes PNP transistors Q2, Q3, Q4, Q5, Q6 and resistor R1; the emitters of PNP transistors Q2, Q3, Q4, Q5 and PNP transistor Q2 are all connected to the power supply voltage terminal through a bias, and the bases are commonly connected. The collector of PNP transistor Q3 is connected to one end of resistor R1; the collector of PNP transistor Q5 is respectively connected to one end of resistor R5, one end of resistor R7 and the collector of NPN transistor Q11.

[0033] The bandgap branch includes NPN transistors Q9, Q11, PNP transistor Q12, resistors R2, R5, R6, R7, R8, R9, R10 and R11; the collector of PNP transistor Q6 is respectively connected to the collector and base of NPN transistor Q13; the other end of resistor R1 is connected to the voltage output terminal.

[0034] The reverse protection branch includes NPN transistor Q13 and PNP transistor Q14. The base of NPN transistor Q9 is connected to one end of resistor R5, and the emitter is connected to the voltage output terminal; the base of NPN transistor Q11 is connected to one end of resistor R6, and the emitter is connected to the voltage output terminal; the other end of resistor R6 is respectively connected to the other end of resistor R7 and one end of resistor R8; the other end of resistor R8 is respectively connected to one end of resistor R9 and the base of PNP transistor Q12; the emitter of PNP transistor Q12 is connected to one end of resistor R11, the collector is connected to the other end of resistor R9 and one end of resistor R10; the other end of resistor R10 is connected to the voltage output terminal; the other end of resistor R11 is connected to the power supply voltage terminal through a bias.

[0035] The emitter of NPN transistor Q13 is respectively connected to the emitter of PNP transistor Q14 and the positive input terminal of error amplifier 3; the collector and base of PNP transistor Q14 are commonly connected and connected to the voltage output terminal.

[0036] In this embodiment, the output voltage regulating circuit 2 includes a first voltage regulating branch, a second voltage regulating branch, a third voltage regulating branch and a fourth voltage regulating branch that are connected in parallel with each other.

[0037] The first voltage regulation branch includes resistor R21, resistor R22 and switch V1. Resistors R21 and R22 are connected in parallel. One end of resistors R21 and R22 is connected to the positive input terminal of error amplifier 3, and the other end is grounded through the series-connected switch V1. The second voltage regulation branch includes resistor R14 and switch V2. One end of resistor R14 is connected to the positive input terminal of error amplifier 3, and the other end of resistor R14 is grounded through the series-connected switch V2.

[0038] The third voltage regulation branch includes resistor R15, resistor R16 and switch V3. Resistors R15 and R16 are connected in series. One end of resistor R15 is connected to the positive input terminal of error amplifier 3, and one end of resistor R16 is grounded through the series-connected switch V3. The fourth voltage regulation branch includes resistor R17, resistor R18, resistor R19, resistor R20 and switch V4. Resistors R17, R18, R19 and R20 are connected in series in sequence. One end of resistor R17 is connected to the positive input terminal of error amplifier 3, and one end of resistor R20 is grounded through the series-connected switch V4.

[0039] In this embodiment, the power output circuit 4 includes NPN transistor Q15, PNP transistor Q16, PNP transistor Q17 and resistor R12.

[0040] The emitters of PNP transistor Q16 and PNP transistor Q17 are connected to the power supply voltage terminal, and their bases are connected together. The collector of PNP transistor Q16 is connected to the collector of NPN transistor Q15. The collector of PNP transistor Q17 is connected to the voltage output terminal.

[0041] In this embodiment, the emitter area ratio of NPN transistor Q9 and NPN transistor Q11 is 32:1. Under the same V BE , their emitter currents will also be distributed in a ratio of 32:1. By controlling their current ratio, a stable temperature compensation voltage is generated to achieve temperature stability.

[0042] The temperature complementary circuit 1 superimposes the output current I REF through its internal mirror current source branch. The current I REF is:

[0043]

[0044] I REF passes through the output voltage regulation circuit 2 to obtain the voltage V REF . The output voltage regulation circuit 2 adjusts the voltage at the positive input terminal of the error amplifier 3 by appropriately switching the voltage regulation branch. V REF can pass through any one of the first voltage regulation branch, the second voltage regulation branch, the third voltage regulation branch and the fourth voltage regulation branch of the output voltage regulation circuit 2.REF = V1 / V2 / V3 / V4. The corresponding relationship is:

[0045] When V REF = V1:

[0046]

[0047] When V REF = V2:

[0048] V REF = V 2 = I REF ·R 14 ;

[0049] When V REF = V3:

[0050] V REF = V 3 = I REF ·(R 15 + R 16 );

[0051] When V REF = V4:

[0052] V REF = V 4 = I REF ·(R 17 + R 18 + R 19 + R 20 );

[0053] Through the follower of error amplifier 3, V OUT = V REF . Q15 and Q17 form a composite transistor to drive the load. The low potential of the circuit is V OUT , which is equivalent to a floating ground. The whole circuit only needs the VIN voltage to be 1.4V higher than the VOUT voltage to work.

[0054] The present invention utilizes the temperature complementary circuit 1 to obtain a fixed current I REF , which has good low temperature drift characteristics. The integrated resistors in the output voltage regulation circuit 2 have the characteristics of low temperature drift and high precision, which can avoid the disadvantages of uncontrollable temperature drift and insufficient precision caused by external resistors. The current I REF flows through the resistor to obtain a V REF with low temperature drift and high precision. Through the follower characteristic of the error amplifier 3, V OUT is output. The V OUT can be freely switched through the integrated resistors in the output voltage regulation circuit 2.Voltage value. It realizes a voltage output lower than 1.25V. And the circuit structure is simple and the function is simple, thus improving the circuit reliability and reducing the power consumption.

[0055] This embodiment also includes a chip. The integrated low-power and low-output voltage reference circuit includes a temperature complementary circuit 1, an output voltage regulation circuit 2, an error amplifier 3, and a power output circuit 4. The present invention integrates multiple functional circuits into a compact structure through modular circuit design. This not only improves the integration degree, but also reduces the circuit complexity and area, which is beneficial to implementation on a small-sized chip.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A low power consumption and low output voltage reference circuit, characterized in that: It includes a temperature complementary circuit, an output voltage regulating circuit, an error amplifier and a power output circuit; The temperature complementary circuit is used to offset the influence of temperature drift on voltage output and provide reference current; The output voltage regulating circuit is connected to the temperature complementary circuit and the positive input terminal of the error amplifier respectively, and is used to adjust the voltage of the positive input terminal of the error amplifier by switching the internal resistor; The output end of the error amplifier is connected to the power output circuit; The power output circuit is connected to the negative input terminal of the error amplifier and outputs a reference voltage through a voltage output terminal.

2. The low power consumption and low output voltage reference circuit according to claim 1, characterized in that: The temperature compensation circuit comprises a voltage stabilization branch, a mirror current source branch, a bandgap branch and a reverse protection branch; The voltage stabilizing branch is connected to the mirror current source branch and the bandgap branch respectively; the mirror current source branch is connected to the bandgap branch and the reverse protection branch respectively; the reverse protection branch is connected to the output voltage regulating circuit and the positive input terminal of the error amplifier respectively; The voltage stabilizing branch includes a PNP transistor Q1 and an NPN transistor Q7; the emitter of the PNP transistor Q1 is connected to the power supply voltage terminal through a bias, the base is respectively connected to the collector of the PNP transistor Q2 and the collector of the NPN transistor Q1, and the collector is connected to the voltage output terminal; the base of the NPN transistor Q7 is respectively connected to the collector of the NPN transistor Q9 and the collector of the PNP transistor Q4, and the emitter is connected to the voltage output terminal; The mirror current source branch includes PNP transistor Q2, PNP transistor Q3, PNP transistor Q4, PNP transistor Q5, PNP transistor Q6 and resistor R1; the emitters of the PNP transistors Q2, PNP transistor Q3, PNP transistor Q4, PNP transistor Q5 and PNP transistor Q2 are all connected to the power supply voltage end through bias, and the bases are connected in common; the collector of the PNP transistor Q3 is connected to one end of the resistor R1; the collector of the PNP transistor Q5 is respectively connected to one end of the resistor R5, one end of the resistor R7 and the collector of the NPN transistor Q11; the collector of the PNP transistor Q6 is respectively connected to the collector and base of the NPN transistor Q13; the other end of the resistor R1 is connected to the voltage output end; The bandgap branch includes an NPN transistor Q9, an NPN transistor Q11, a PNP transistor Q12, a resistor R2, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10 and a resistor R11; the base of the NPN transistor Q9 is connected to one end of the resistor R5, and the emitter is connected to the voltage output end; the base of the NPN transistor Q11 is connected to one end of the resistor R6, and the emitter is connected to the voltage output end; the other end of the resistor R6 is respectively connected to the other end of the resistor R7 and one end of the resistor R8; the other end of the resistor R8 is respectively connected to one end of the resistor R9 and the base of the PNP transistor Q12; the emitter of the PNP transistor Q12 is connected to one end of the resistor R11, and the collector is connected to the other end of the resistor R9 and one end of the resistor R10; the other end of the resistor R10 is connected to the voltage output end; the other end of the resistor R11 is connected to the power supply voltage end through a bias; The reverse protection branch includes an NPN transistor Q13 and a PNP transistor Q14; the emitter of the NPN transistor Q13 is respectively connected to the emitter of the PNP transistor Q14 and the positive input terminal of the error amplifier; the collector and base of the PNP transistor Q14 are connected in parallel and connected to the voltage output terminal.

3. The low power consumption and low output voltage reference circuit according to claim 1, characterized in that: The output voltage regulation circuit comprises a first voltage regulation branch, a second voltage regulation branch, a third voltage regulation branch and a fourth voltage regulation branch connected in parallel with each other; The first voltage regulation branch includes a resistor R21, a resistor R22 and a switch V1, wherein the resistor R21 and the resistor R22 are arranged in parallel, one end of the resistor R21 and the resistor R22 is connected to the positive input end of the error amplifier, and the other end is grounded through the switch V1 connected in series; The second voltage regulation branch includes a resistor R14 and a switch V2, one end of the resistor R14 is connected to the positive input end of the error amplifier, and the other end of the resistor R14 is grounded through the series switch V2; The third voltage regulation branch includes a resistor R15, a resistor R16 and a switch V3, wherein the resistor R15 and the resistor R16 are arranged in series, one end of the resistor R15 is connected to the positive input end of the error amplifier, and one end of the resistor R16 is grounded through the series switch V3; The fourth voltage regulation branch includes a resistor R17, a resistor R18, a resistor R19, a resistor R20 and a switch V4. The resistor R17, the resistor R18, the resistor R19 and the resistor R20 are connected in series in sequence. One end of the resistor R17 is connected to the positive input end of the error amplifier, and one end of the resistor R20 is grounded through the series switch V4.

4. The low power consumption and low output voltage reference circuit according to claim 1, characterized in that: The power output circuit includes an NPN transistor Q15, a PNP transistor Q16, a PNP transistor Q17 and a resistor R12; The emitters of the PNP transistor Q16 and the PNP transistor Q17 are connected to the power supply voltage terminal, and the bases are connected in common; the collector of the PNP transistor Q16 is connected to the collector of the NPN transistor Q15; and the collector of the PNP transistor Q17 is connected to the voltage output terminal.

5. The low power consumption and low output voltage reference circuit according to claim 2, characterized in that: The emitter area ratio of the NPN transistor Q9 and the NPN transistor Q11 is 32:

1.

6. A chip, characterized in that: The low-power consumption and low-output voltage reference circuit as claimed in any one of claims 1 to 5 is integrated.

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