A Zener reference voltage source circuit and microprocessor chip

Abstract

The embodiments of the present application provide a Zener reference voltage source circuit and a microprocessor chip. The Zener reference voltage source circuit includes: a voltage generating circuit, a current generating circuit and a core circuit, wherein the input end of the voltage generating circuit is electrically connected to the first voltage end, the first output end of the voltage generating circuit is electrically connected to the input end of the current generating circuit, and the output end of the current generating circuit is electrically connected to the input end of the core circuit; the current generating circuit includes a first current mirror structure, and the core circuit includes a second current mirror structure, a transistor and a Zener diode connected in series, and the first current mirror structure and the second current mirror structure form a first current mirror circuit. The technical solution of the embodiments of the present application improves the power supply suppression capability of the Zener reference voltage source circuit and enables the Zener reference voltage source circuit to have a lower temperature drift.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of electronic technology, and in particular to a Zener reference voltage source circuit and a microprocessor chip. Background Art

[0002] A voltage reference is a highly stable voltage source used as a voltage reference in a circuit. With the continuous increase in the scale of integrated circuits, especially the development of system-on-chip (SoC) technology, voltage references have become an indispensable basic circuit module in large-scale and ultra-large-scale integrated circuits and nearly all digital and analog systems.

[0003] A voltage reference provides a reference voltage for series voltage regulators, analog-to-digital (A / D) converters, and digital-to-analog (D / A) converters. It also serves as a regulated power supply or excitation source for most sensors. Integrated circuits often require a voltage reference, and its accuracy determines the accuracy of the IC's output voltage.

[0004] Conventional voltage references can include traditional bandgap reference circuits or traditional Zener reference circuits. Traditional bandgap reference circuits have high temperature drift. High-order temperature compensation complicates the bandgap reference circuit's circuit structure and increases its circuit area, so Zener reference circuits are often preferred. However, traditional Zener reference circuits have poor power supply rejection and high temperature drift. Summary of the Invention

[0005] In view of this, embodiments of the present application provide a Zener reference voltage source circuit and a microprocessor chip, which are used to ensure that the Zener reference voltage source circuit has strong power supply rejection capability and low temperature drift.

[0006] In a first aspect, an embodiment of the present application provides a Zener reference voltage source circuit, comprising: a voltage generating circuit, a current generating circuit, and a core circuit, wherein an input terminal of the voltage generating circuit is electrically connected to a first voltage terminal, a first output terminal of the voltage generating circuit is electrically connected to an input terminal of the current generating circuit, and an output terminal of the current generating circuit is electrically connected to an input terminal of the core circuit;

[0007] The current generating circuit includes a first current mirror structure, the core circuit includes a second current mirror structure, a transistor and a Zener diode connected in series, and the first current mirror structure and the second current mirror structure form a first current mirror circuit;

[0008] The voltage generating circuit is configured to generate a first output voltage under the control of a first voltage provided by the first voltage terminal, and output the first output voltage;

[0009] The current generating circuit is configured to generate a first reference current under the control of the first output voltage, and mirror the first reference current to the core circuit through the first current mirror circuit, so that the core circuit obtains a second reference current;

[0010] The core circuit is used to generate a reference voltage with zero temperature characteristics under the control of the second reference current.

[0011] In a second aspect, an embodiment of the present application provides a microprocessor chip, comprising: the Zener reference voltage source circuit described in the first aspect.

[0012] In the technical solution provided in the embodiment of the present application, the current generating circuit includes a first current mirror structure, and the core circuit includes a second current mirror structure, a transistor and a Zener diode connected in series. The first current mirror structure and the second current mirror structure form a first current mirror circuit. The current generating circuit mirrors the first reference current to the core circuit through the first current mirror circuit. The first current mirror circuit can improve the power supply rejection ratio, thereby improving the power supply rejection capability of the Zener reference voltage source circuit; the first current mirror circuit mirrors the first reference current to the core circuit, and after compensation by the first reference current, the Zener reference voltage source circuit has a lower temperature drift, thereby improving the stability of the Zener reference voltage source circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0014] Figure 1 Schematic diagram of the structure of a bandgap reference circuit in the related art;

[0015] Figure 2 Schematic diagram of the structure of a Zener reference circuit in the related art;

[0016] Figure 3a A schematic structural diagram of a Zener reference voltage source circuit provided in an embodiment of the present application;

[0017] Figure 3b A schematic structural diagram of another Zener reference voltage source circuit provided in an embodiment of the present application;

[0018] Figure 4 A schematic diagram of the specific structure of a Zener reference voltage source circuit provided in an embodiment of the present application;

[0019] Figure 5A schematic diagram of the structure of a microprocessor chip provided in an embodiment of the present application. DETAILED DESCRIPTION

[0020] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0021] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0022] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0023] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the associated objects.

[0024] Figure 1 Schematic diagram of the structure of the bandgap reference circuit in the related art, such as Figure 1As shown, the bandgap reference circuit may include an operational amplifier A1, a resistor R6, a resistor R7, a resistor R8, a transistor Q7, and a transistor Q8. The transistor Q7 and the transistor Q8 are both bipolar junction transistors (BJTs). A first end of the resistor R6 and a first end of the resistor R7 are electrically connected and electrically connected to the output terminal of the operational amplifier A1, a second end of the resistor R6 is electrically connected to the non-inverting input terminal D of the operational amplifier A1, a second end of the resistor R7 is electrically connected to the inverting input terminal E of the operational amplifier A1, a first end of the resistor R8 is electrically connected to the inverting input terminal E, a second end of the resistor R8 is electrically connected to the collector of the transistor Q8, a base of the transistor Q8 is electrically connected to the collector, an emitter of the transistor Q8 is electrically connected to the ground terminal GND, a base and collector of the transistor Q7 are electrically connected and electrically connected to the non-inverting input terminal D, and an emitter of the transistor Q7 is electrically connected to the ground terminal GND. If the two transistors Q7 and Q8 operate at unequal current densities, the difference in base-emitter voltage between the two transistors Q7 and Q8 is proportional to the absolute temperature. Operational amplifier A1 clamps the voltage of the non-inverting input terminal D and the inverting input terminal E so that the voltage of the non-inverting input terminal D is equal to the voltage of the inverting input terminal E. The positive temperature coefficient voltage falls on resistor R3, that is, the current on resistor R3 is a positive temperature coefficient current. The positive temperature coefficient voltage of resistors R3 and R2 and the negative temperature coefficient voltage of transistor Q8 constitute the reference voltage V REF .

[0025] Figure 2 FIG. 1 is a schematic diagram of the structure of a Zener reference circuit in the related art, such as Figure 2 As shown, the Zener reference circuit may include a current source, a transistor Q9 and a Zener diode D5, wherein the base and collector of the transistor Q9 are electrically connected and electrically connected to the reference voltage terminal, the emitter of the transistor Q9 is electrically connected to the cathode of the Zener diode D5, the anode of the Zener diode D5 is electrically connected to the ground terminal GND, and the output terminal of the current source is electrically connected to the reference voltage terminal. Figure 2 As shown, the Zener diode D5 has a positive temperature coefficient voltage, and the transistor Q9 has a negative temperature coefficient voltage. The positive temperature coefficient voltage of the Zener diode D5 and the negative temperature coefficient voltage of the transistor Q9 are added together to obtain a zero temperature coefficient reference voltage V REF And output the reference voltage V through the reference voltage terminal REF .

[0026] The bandgap reference circuits used in related art exhibit high temperature drift. Implementing high-order temperature compensation complicates the circuit structure, increases the circuit area, and places high demands on matching during circuit layout design. The Zener reference circuits used in related art also lack load capability and have poor power supply rejection.

[0027] In order to solve the above-mentioned technical problems existing in the related art, the embodiments of the present application provide a Zener reference voltage source circuit and a microprocessor chip.

[0028] Figure 3a A schematic diagram of the structure of a Zener reference voltage source circuit provided in an embodiment of the present application is shown in FIG. Figure 3a As shown, the Zener reference voltage source circuit includes a voltage generating circuit 11, a current generating circuit 12, and a core circuit 13. The input terminal of the voltage generating circuit 11 is electrically connected to the first voltage terminal avddH, the first output terminal of the voltage generating circuit 11 is electrically connected to the input terminal of the current generating circuit 12, and the output terminal of the current generating circuit 12 is electrically connected to the input terminal of the core circuit 13. The voltage generating circuit 11 is used to generate a first output voltage under the control of the first voltage provided by the first voltage terminal avddH, and output the first output voltage. The current generating circuit 12 is used to generate a first reference current under the control of the first output voltage, and mirror the first reference current to the core circuit 13 so that the core circuit 13 obtains a second reference current. The core circuit 13 is used to generate a reference voltage with zero temperature characteristics under the control of the second reference current.

[0029] In an embodiment of the present application, the current generating circuit includes a first current mirror structure, and the core circuit includes a second current mirror structure, a transistor, and a Zener diode connected in series. The first current mirror structure and the second current mirror structure form a first current mirror circuit. Specifically, the current generating circuit 12 is configured to mirror the first reference current to the core circuit 13 via the first current mirror circuit. For example, the current generating circuit 12 can mirror the first reference current to the core circuit 13 at a certain ratio via the first current mirror circuit, so that the core circuit 13 obtains the second reference current.

[0030] Among them, as follows Figure 4 As shown, the transistor may include a sixth transistor Q6, and the Zener diode may include a fourth Zener diode D4; the first current mirror structure may include a fourth switch tube M4 and a fifth switch tube M5, and the second current mirror structure may include a sixth switch tube M6 and a seventh switch tube M7.

[0031] like Figure 3a As shown, in one possible implementation, the Zener reference voltage source circuit further includes a buffer circuit 14. The input end of the buffer circuit 14 is electrically connected to the second output end of the voltage generating circuit 11 and the output end of the core circuit 13. The voltage generating circuit 11 is further configured to generate a second output voltage under the control of the first voltage and output the second output voltage to the buffer circuit 14. The core circuit 13 is further configured to output the reference voltage to the buffer circuit 14. The buffer circuit 14 is configured to amplify the second output voltage and the reference voltage.

[0032] In the embodiment of the present application, the buffer circuit 14 can amplify and output the second output voltage from the voltage generating circuit 11 and the reference voltage from the core circuit 13. The amplification of the second output voltage and the reference voltage does not change the waveforms of the second output voltage and the reference voltage. The buffer circuit 14 can be used to improve the driving capability of the Zener reference voltage source circuit, so that the Zener reference voltage source circuit has load carrying capacity and can drive large loads.

[0033] Figure 3b A schematic diagram of another Zener reference voltage source circuit provided in an embodiment of the present application is shown in FIG. Figure 3b As shown, the Zener reference voltage source circuit includes a voltage generating circuit 11, a current generating circuit 12, and a core circuit 13. The input terminal of the voltage generating circuit 11 is electrically connected to the first voltage terminal avddH, the first output terminal of the voltage generating circuit 11 is electrically connected to the input terminal of the current generating circuit 12, and the output terminal of the current generating circuit 12 is electrically connected to the input terminal of the core circuit 13. The voltage generating circuit 11 is used to generate a first output voltage under the control of the first voltage provided by the first voltage terminal avddH, and output the first output voltage. The current generating circuit 12 is used to generate a first reference current under the control of the first output voltage, and mirror the first reference current to the core circuit 13 so that the core circuit 13 obtains a second reference current. The core circuit 13 is used to generate a reference voltage with zero temperature characteristics under the control of the second reference current.

[0034] like Figure 3b As shown, in one possible implementation, the Zener reference voltage source circuit further includes a reference voltage divider circuit 15, the input end of which is electrically connected to the voltage output end of the core circuit 13. The reference voltage divider circuit 15 is used to divide the reference voltage to generate a reference sub-voltage. In the embodiment of the present application, the reference voltage is divided by the reference voltage divider circuit 15 so that the generated reference sub-voltage can meet the reference voltage requirements of different circuits.

[0035] like Figure 3b As shown, in one possible implementation, the Zener reference voltage source circuit further includes a buffer circuit 14. The input of the buffer circuit 14 is electrically connected to the second output of the voltage generating circuit 11 and the output of the reference voltage divider circuit 15. The voltage generating circuit 11 is further configured to generate a second output voltage under the control of the first voltage and output the second output voltage to the buffer circuit 14. The reference voltage divider circuit 15 is further configured to output multiple reference sub-voltages to the buffer circuit 14. The buffer circuit 14 is configured to amplify the second output voltage and the multiple reference sub-voltages.

[0036] In the embodiment of the present application, buffer circuit 14 amplifies and outputs the second output voltage from voltage generating circuit 11 and the reference sub-voltage from reference voltage divider circuit 15. The amplification of the second output voltage and the reference voltage does not change the waveforms of the second output voltage and the reference sub-voltage. Buffer circuit 14 can be used to improve the driving capability of the Zener reference voltage source circuit, enabling the Zener reference voltage source circuit to have a load-carrying capacity and drive large loads.

[0037] In the technical solution provided in the embodiment of the present application, the current generating circuit includes a first current mirror structure, the core circuit includes a second current mirror structure, a transistor and a Zener diode connected in series, the first current mirror structure and the second current mirror structure form a first current mirror circuit, the current generating circuit mirrors the first reference current to the core circuit through the first current mirror circuit, the power supply rejection ratio can be improved by the first current mirror circuit, thereby improving the power supply rejection capability of the Zener reference voltage source circuit; the first current mirror circuit mirrors the first reference current to the core circuit, and after compensation by the first reference current, the Zener reference voltage source circuit has a lower temperature drift, thereby improving the stability of the Zener reference voltage source circuit. In the embodiment of the present application, a buffer circuit is provided in the Zener reference voltage source circuit, and the buffer circuit can improve the driving capability of the Zener reference voltage source circuit, so that the Zener reference voltage source circuit has load carrying capacity and can drive large loads. In the embodiment of the present application, the Zener reference voltage source circuit formed by the voltage generating circuit, the current generating circuit and the core circuit has a low temperature drift, avoiding the use of a high-order temperature compensation module, thereby reducing the complexity of the circuit structure and reducing the area of ​​the circuit and layout; the Zener reference voltage source circuit can generate a fixed reference voltage under higher voltage input and a wider power supply range, has load capacity, and improves the power supply rejection ratio of the reference voltage.

[0038] Figure 4 A schematic diagram of the specific structure of a Zener reference voltage source circuit provided in an embodiment of the present application is shown in FIG. Figure 3a 、 Figure 3b and Figure 4As shown, the voltage generating circuit 11 includes a first resistor R1, a first transistor Q1, a first Zener diode D1, a first switch M1, a second resistor R2, and a second Zener diode D2. A first end of the first resistor R1 is electrically connected to a first voltage terminal avddH, and a second end of the first resistor R1 is electrically connected to a first node A; a base and a collector of the first transistor Q1 are electrically connected and electrically connected to the first node A, an emitter of the first transistor Q1 is electrically connected to the cathode of the first Zener diode D1; an anode of the first Zener diode D1 is electrically connected to the second voltage terminal; a control end of the first switch M1 is electrically connected to the first node A, a first end of the first switch M1 is electrically connected to the first voltage terminal avddH, and a second end of the first switch M1 is electrically connected to a third voltage terminal avdd; a first end of the second resistor R2 is electrically connected to the third voltage terminal avdd, a second end of the second resistor R2 is electrically connected to the cathode of the second Zener diode D2, and an anode of the second Zener diode D2 is electrically connected to the second voltage terminal.

[0039] like Figure 4 As shown, in a possible implementation, the voltage generating circuit 11 further includes a second capacitor C2, a first end of the second capacitor C2 is electrically connected to the third voltage end avdd, and a second end of the second capacitor C2 is electrically connected to the second voltage end.

[0040] like Figure 4 As shown, in a possible implementation, the voltage generating circuit 11 further includes a first capacitor C1, a first end of the first capacitor C1 is electrically connected to the cathode of the first Zener diode D1, and a second end of the first capacitor C1 is electrically connected to the second voltage end.

[0041] like Figure 4 As shown, the first voltage terminal avddH may be a power supply voltage terminal, for example, the voltage of the first voltage terminal avddH may be a first voltage, which may be a high-level voltage; the second voltage terminal may be a low voltage terminal, for example, the voltage of the second voltage terminal may be a second voltage, which may be a low-level voltage or a ground voltage. Figure 4 As shown, the voltage of the second voltage terminal is the ground voltage, that is, the second voltage terminal can be the ground terminal GND.

[0042] like Figure 4 As shown, the substrate terminal of the first switch transistor M1 is electrically connected to the second terminal. The first switch transistor M1 includes an N-type metal-oxide-semiconductor (NMOS) transistor, the control terminal of the first switch transistor M1 is the gate, the first terminal of the first switch transistor M1 is the drain, and the second terminal of the first switch transistor M1 is the source. The source and substrate terminals of the first switch transistor M1 are electrically connected.

[0043] like Figure 4As shown, in one possible implementation, the current generating circuit 12 includes a second switch M2, a third switch M3, a third transistor Q3, a fourth transistor Q4, a third Zener diode D3, a fourth switch M4, a fifth switch M5, a fifth resistor R5, a fifth transistor Q5, and a trimming resistor module Rs. The second switch M2, the third switch M3, the fourth switch M4, and the fifth switch M5 form a second current mirror circuit. A first terminal of the second switch M2 is electrically connected to a first voltage terminal avddH, a first terminal of the fourth switch M4 is electrically connected to the first voltage terminal avddH, a control terminal of the second switch M2 is electrically connected to a control terminal of the fourth switch M4; a first terminal of the third switch M3 is electrically connected to a second terminal of the second switch M2, a second terminal of the third switch M3 is electrically connected to a second node B, a first terminal of the fifth switch M5 is electrically connected to a second terminal of the fourth switch M4, a second terminal of the fifth switch M5 is electrically connected to a first terminal of the fifth resistor R5, and a control terminal of the third switch M3 is electrically connected to a control terminal of the fifth switch M5. The base and collector of the third transistor Q3 are electrically connected and electrically connected to the second node B, the emitter of the third transistor Q3 is electrically connected to the emitter of the fourth transistor Q4, the base and collector of the fourth transistor Q4 are electrically connected and electrically connected to the cathode of the third Zener diode D3, and the anode of the third Zener diode D3 is electrically connected to the second voltage terminal; the second end of the fifth resistor R5 is electrically connected to the collector of the fifth transistor Q5, the base of the fifth transistor Q5 is electrically connected to the second node B, the emitter of the fifth transistor Q5 is electrically connected to the first end of the trimming resistor module Rs, and the second end of the trimming resistor module Rs is electrically connected to the second voltage terminal.

[0044] The voltage of the third voltage terminal avdd generated by the voltage generating circuit 11 is a low voltage, which can be used as a trimming control signal of the trimming resistor module Rs.

[0045] like Figure 4As shown, the substrate terminals of the second, third, fourth, and fifth switching transistors M2, M3, M4, and M5 are all connected to the first terminal, and the substrate terminals of the second and fourth switching transistors M2 and M4 are all electrically connected to the first power supply terminal avddH. The second, third, fourth, and fifth switching transistors M2, M3, M4, and M5 may include P-type metal-oxide-semiconductor (PMOS) transistors, and the control terminals of the second, third, fourth, and fifth switching transistors M2, M3, M4, and M5 are gates. The first terminals of the second, third, fourth, and fifth switching transistors M2, M3, M4, and M5 are sources, and the second terminals of the second, third, fourth, and fifth switching transistors M2, M3, M4, and M5 are drains. The sources and substrate terminals of the second, third, fourth, and fifth switching transistors M2, M3, M4, and M5 are electrically connected.

[0046] like Figure 4 As shown, in one possible implementation, the Zener reference voltage source circuit further includes a startup circuit for powering on the Zener reference voltage source circuit. The startup circuit may include a third resistor R3, a second transistor Q2, a first resistor R1, a first transistor Q1, and a first Zener diode D1. A first end of the third resistor R3 is electrically connected to the first voltage terminal avddH, and a second end of the third resistor R3 is electrically connected to the collector of the second transistor Q2. The base of the second transistor Q2 is electrically connected to the first node A, and the emitter of the second transistor Q2 is electrically connected to the second node B. The voltage generating circuit 11 and the startup circuit reuse the branch formed by the first resistor R1, the first transistor Q1, and the first Zener diode D1. Therefore, the voltage generating circuit 11 and the startup circuit have a shared circuit.

[0047] like Figure 4 As shown, after the first voltage terminal avddH is powered on, the first voltage terminal avddH is loaded with the first voltage. The branch formed by the first resistor R1, the first transistor Q1, and the first Zener diode D1 generates current to begin operation, raising the voltage at the first node A. Since the third transistor Q3 is not operating and the current flowing through the third transistor Q3 is zero, the voltage at the second node B is low. Under the control of the voltage at the second node B, the second transistor Q2 is turned on to begin operation. Current flows through the third resistor R3 and the second transistor Q2 to the branch formed by the second switch M2, the third switch M3, the third transistor Q3, the fourth transistor Q4, and the third Zener diode D3, causing the branch formed by the second switch M2, the third switch M3, the third transistor Q3, the fourth transistor Q4, and the third Zener diode D3 to begin operation. Ultimately, the voltage at the second node B is raised to a value greater than the voltage at the first node A, causing the second transistor Q2 to turn off, shutting down the startup circuit, and completing the power-up of the Zener reference voltage source circuit.

[0048] In the embodiment of the present application, the voltage generating circuit 11 and the starting circuit have a common circuit, and an ingenious and reasonable circuit design is utilized to save circuit area, thereby saving costs.

[0049] like Figure 4 As shown, in one possible implementation, the core circuit 13 includes a sixth switch M6, a seventh switch M7, a sixth transistor Q6, and a fourth Zener diode D4. The fourth switch M4, the fifth switch M5, the sixth switch M6, and the seventh switch M7 form a first current mirror circuit. A first terminal of the sixth switch M6 is electrically connected to the first voltage terminal avddH, a second terminal of the sixth switch M6 is electrically connected to the first terminal of the seventh switch M7, and a control terminal of the sixth switch M6 is electrically connected to the control terminal of the fourth switch M5. A second terminal of the seventh switch M7 is electrically connected to the voltage output terminal of the core circuit 13, and a control terminal of the seventh switch M7 is electrically connected to the control terminal of the fifth switch M5. An emitter of the sixth transistor Q6 is electrically connected to the voltage output terminal of the core circuit 13, a base and collector of the sixth transistor Q6 are electrically connected and are electrically connected to the cathode of the fourth Zener diode D4, and an anode of the fourth Zener diode D4 is electrically connected to the second voltage terminal.

[0050] like Figure 4 As shown, the substrate terminals of the sixth and seventh switching transistors M6 and M7 are both connected to the first terminal, and the substrate terminal of the sixth switching transistor M6 is electrically connected to the first power supply terminal avddH. The sixth and seventh switching transistors M6 and M7 may include P-type MOS transistors, with the control terminals of the sixth and seventh switching transistors M6 and M7 serving as gates, the first terminals of the sixth and seventh switching transistors M6 and M7 serving as sources, and the second terminals of the sixth and seventh switching transistors M6 and M7 serving as drains. The sources and substrate terminals of the sixth and seventh switching transistors M6 and M7 are electrically connected.

[0051] like Figure 4 As shown, in one possible implementation, the Zener reference voltage source circuit further includes an eighth switch transistor M8 and a ninth switch transistor M9. The sixth switch transistor M6, the seventh switch transistor M7, the eighth switch transistor M8, and the ninth switch transistor M9 form a third current mirror circuit. A first terminal of the eighth switch transistor M8 is electrically connected to the first voltage terminal avddH, a second terminal of the eighth switch transistor M8 is electrically connected to the first terminal of the ninth switch transistor M9, and a control terminal of the eighth switch transistor M8 is electrically connected to the control terminal of the sixth switch transistor M6. A second terminal of the ninth switch transistor M9 is electrically connected to the current output terminal of the core circuit 13, and a control terminal of the ninth switch transistor M9 is electrically connected to the control terminal of the seventh switch transistor M7.

[0052] like Figure 4As shown, the substrate terminals of the eighth and ninth switching transistors M8 and M9 are electrically connected to the first terminal, and the substrate terminal of the eighth switching transistor M8 is electrically connected to the first power supply terminal avddH. The eighth and ninth switching transistors M8 and M9 may comprise P-type MOS transistors, wherein the control terminals of the eighth and ninth switching transistors M8 and M9 serve as gates, the first terminals of the eighth and ninth switching transistors M8 and M9 serve as sources, and the second terminals of the eighth and ninth switching transistors M8 and M9 serve as drains. The sources and substrate terminals of the eighth and ninth switching transistors M8 and M9 are electrically connected.

[0053] like Figure 4 As shown, the first transistor Q1 , the third transistor Q3 and the fifth transistor Q5 are all NPN transistors, and the fourth transistor Q4 and the sixth transistor Q6 are all PNP transistors.

[0054] like Figure 4 As shown, in the embodiment of the present application, the gate of the second switch tube M2, the gate of the fourth switch tube M4, and the gate of the sixth switch tube M6 are electrically connected, the source of the second switch tube M2, the source of the fourth switch tube M4, and the source of the sixth switch tube M6 are electrically connected, and the gate of the third switch tube M3, the gate of the fifth switch tube M5, and the gate of the sixth switch tube M7 are electrically connected. Therefore, the first current mirror circuit, the second current mirror circuit, and the third current mirror circuit are cascode current mirror circuits. It should be noted that: Figure 4 The “V1” shown in the figure indicates that the gates of the second switch tube M2, the fourth switch tube M4, and the sixth switch tube M6 may have the same voltage V1, that is, the gates of the second switch tube M2, the fourth switch tube M4, and the sixth switch tube M6 are electrically connected; Figure 4 The “V2” shown in the figure indicates that the gates of the third switch tube M3, the fifth switch tube M5 and the seventh switch tube M7 may have the same voltage V2, that is, the gates of the third switch tube M3, the fifth switch tube M5 and the seventh switch tube M7 are electrically connected.

[0055] The following combination Figure 4 The working principle of the Zener reference voltage source circuit provided in the embodiment of the present application is described in detail.

[0056] like Figure 4As shown, in the voltage generating circuit 11, after the first voltage terminal avddH is powered on, the first voltage terminal avddH is loaded with the first voltage, and the branch formed by the first resistor R1, the first transistor Q1 and the first Zener diode D1 is turned on to start working. The voltage of the first node A (that is, the voltage of the control terminal of the first switch tube M1) is raised to Vbe. The voltage Vbe of the first node A is the sum of the voltage of the first transistor Q1 and the voltage of the first Zener diode D1. Therefore, the voltage of the third voltage terminal avdd is the difference between the voltage of the first node A and the threshold voltage of the first switch tube M1, that is: V avdd =V be -V th，M1 =(V be，Q1 +V D1 )-V th，M1 , where V avdd is the voltage of the third voltage terminal avdd, V be is the voltage of the first node A, V th，M1 is the threshold voltage of the first switch tube M1, V be，Q1 is the voltage of the first transistor Q1, V D1 The first output voltage is the voltage of the first node A, and the second output voltage is the voltage of the third voltage terminal avdd.

[0057] like Figure 4 As shown, in a possible implementation, the second resistor R2 may be a current limiting resistor. The third voltage terminal avdd may abnormally increase the voltage V of the third voltage terminal avdd in a no-load state. avdd Therefore, a second resistor R2 and a second Zener diode D2 are added to the voltage generating circuit 11. When the voltage V avdd When the voltage V of the third voltage terminal avdd is abnormally pulled high, the second resistor R2 and the second Zener diode D2 can be used to reduce the voltage V avdd Pull it low, thus ensuring the safety of the subsequent circuit.

[0058] like Figure 4 As shown, after the first voltage terminal avddH is powered on, the base voltage of the fifth transistor Q5 is greater than the emitter voltage, and the fifth transistor Q5 starts to work. Since the fifth transistor Q5 and the third transistor Q3 are both NPN transistors, and the base of the fifth transistor Q5 is electrically connected to the base of the third transistor Q3, V be，Q3 =V be，Q5 , so the emitter voltage of the fifth transistor Q5 is equal to the emitter voltage of the third transistor Q3, and the emitter voltage of the third transistor Q3 is equal to the sum of the voltage of the fourth transistor Q4 and the voltage of the third Zener diode D3. Then the first reference current generated by the current generating circuit 12 is: I Q=V be，Q5 / R S =V be，Q3 / R S =(V D3 +V be，Q4 ) / R S , where I Q is the first reference current, V be，Q5 is the voltage of the fifth transistor Q5, V be，Q3 is the voltage of the third transistor Q3, V D3 is the voltage of the third Zener diode D3, V be，Q4 is the voltage of the fourth transistor Q4, R S The first reference current I generated by the current generating circuit 12 is Q It is the current in the branch formed by the fourth switch tube M4, the fifth switch tube M5, the fifth resistor R5, the fifth transistor Q5 and the trimming resistor module Rs.

[0059] The current generating circuit 12 can convert the first reference current I Q The current of the branch formed by the sixth switch tube M6, the seventh switch tube M7, the sixth transistor Q6 and the fourth Zener diode D4 is the second reference current. REF The accuracy of the current generating circuit 12 requires the first reference current I Q The first reference current I of the current generating circuit 12 remains unchanged when the voltage and temperature change. Q The formula is: when V D3 and V be，Q4 When the sum remains unchanged, the output reference voltage V REF The voltage of the third node C is the reference voltage V REF In other words, the reference voltage V REF The voltage of the third node C is the same as the voltage of the fourth transistor Q4. be，Q4 The voltage V of the third Zener diode D3 D3 The third Zener diode D3 has a positive temperature coefficient of voltage V D3 , the fourth transistor Q4 has a negative temperature coefficient voltage V D3 , therefore, the positive temperature coefficient voltage V D3 and negative temperature coefficient voltage V D3 Adding them together can get a reference voltage V with zero temperature coefficient REF , reference voltage VREF Has zero temperature characteristics.

[0060] like Figure 4 As shown, the reference voltage V REF =V D4 +V be，Q6 , where V D4 is the voltage of the fourth Zener diode D4, V be，Q6 The voltage of the fourth Zener diode D4 has a positive temperature coefficient, and the voltage of the sixth transistor Q6 has a negative temperature coefficient. Therefore, the voltage of the fourth Zener diode D4 and the voltage of the sixth transistor Q6 are added to obtain a reference voltage V with a zero temperature coefficient. REF , thereby reducing the temperature drift of the Zener reference voltage source circuit.

[0061] The temperature coefficient of the transistor has a certain degree of nonlinearity. The method of correcting the temperature characteristics of the transistor is also relatively simple. Just select Figure 4 The resistor type of the resistor of the trimming resistor module Rs can be used. It has been verified that the resistor type of the trimming resistor module Rs in the embodiment of the present application can adopt a resistor type whose resistance decreases as the temperature increases, so the test current ipbias output by the core circuit 13 will increase to a certain extent as the temperature increases. The core circuit 13 can use the third current mirror circuit (sixth switch tube M6, seventh switch tube M7, eighth switch tube M8 and ninth switch tube M9) to mirror the second reference current of the core circuit 13 to the branch formed by the eighth switch tube M8 and the ninth switch tube M9 according to a certain ratio, and output the test current ipbias through the current output end electrically connected to the ninth switch tube M9. The test current ipbias can be used to test whether the current of the current generating circuit 12 is normal during subsequent tests, and it can be determined whether the trimming resistor module Rs needs to be trimmed based on the test current ipbias. The test current ipbias will increase to a certain extent as the temperature increases. Through the third current mirror circuit, the second reference current in the branch formed by the sixth switch tube M6, the seventh switch tube M7, the sixth transistor Q6 and the fourth Zener diode D4 in the core circuit 13 is mirrored according to a certain ratio to the branch formed by the eighth switch tube M8 and the ninth switch tube M9, and the test current ipbias is output through the current output end electrically connected to the ninth switch tube M9. The type of the trimming resistor module Rs is adjusted by the test current ipbias, and a suitable resistor type is selected to correct the temperature characteristics of the transistor, which can further improve the temperature characteristics of the transistor, thereby generating a Zener reference voltage source circuit with a lower temperature coefficient and higher precision.

[0062] like Figure 4 As shown, in a possible implementation, the third current mirror circuit and the first current mirror circuit can perform current mirroring in the same proportion.

[0063] like Figure 4 As shown, in a possible implementation, the reference voltage divider circuit 15 includes a resistor voltage divider circuit Rm, a first end of the resistor voltage divider circuit Rm is electrically connected to the voltage output end of the core circuit 13, and a second end of the resistor voltage divider circuit Rm is electrically connected to the second voltage end; the resistor voltage divider circuit Rm is used to divide the reference voltage to generate multiple reference sub-voltages; the resistor voltage divider circuit Rm has multiple voltage divider output ends, and the voltage divider output ends are used to output corresponding reference sub-voltages. For example, Figure 4 The reference sub-voltages outputted by the multiple voltage divider output terminals may include va1, va2, ..., van and vb1, vb2, ..., vbn. Assuming that the reference voltage is 5V, the resistor voltage divider circuit Rm divides the reference voltage 5V into multiple reference sub-voltages, wherein the reference sub-voltage va1 = 4V, the reference sub-voltage van = 3V, the reference sub-voltage vb1 = 2V, the reference sub-voltage vbn = 1.25V, etc., and outputs the reference sub-voltages val, van, vbl and vbn through the corresponding voltage divider output terminals. The reference voltage values ​​required by different circuits may be different. The reference voltage divider circuit 15 in the embodiment of the present application can divide the reference voltage through the resistor voltage divider circuit Rm and output different reference sub-voltages, so that the reference voltage divider circuit 15 can output different reference sub-voltages to circuits with different reference voltage requirements, thereby meeting the reference voltage requirements of different circuits.

[0064] like Figure 4 As shown, in the embodiment of the present application, the trimming resistor module Rs and the resistor voltage divider circuit Rm both include a resistor string formed by multiple resistors. The trimming resistor module Rs and the resistor voltage divider circuit Rm have different functions. The trimming resistor module Rs is used to trim the resistance, and the resistor voltage divider circuit Rm is used to output the reference sub-voltage generated after voltage division. However, the voltage at the first end of the trimming resistor module Rs and the voltage at the first end of the resistor voltage divider circuit Rm are the same, that is, V RS =V C =V REF .

[0065] The Zener reference voltage source circuit provided in the embodiment of the present application is a Zener reference circuit with low temperature drift and high power supply rejection ratio.

[0066] In the embodiment of the present application, the Zener reference voltage source circuit has a low temperature drift, avoiding the use of a high-order temperature compensation module, thereby reducing the complexity of the circuit structure and reducing the area of ​​the circuit and layout. The Zener reference voltage source circuit in the embodiment of the present application reduces the requirements for matching in the layout design. In the Zener reference voltage source circuit provided in the embodiment of the present application, the structure of the core circuit is relatively simple, thereby making the long-term stability performance of the Zener reference voltage source circuit better.

[0067] In the embodiment of the present application, it can be seen from the simulation results that the temperature drift coefficient of the reference voltage output by the reference voltage source is very low, that is, the output reference voltage changes little with temperature, and the power supply suppression effect is improved, and the power supply suppression effect is good.

[0068] In the embodiment of the present application, the Zener reference voltage source circuit adopts the BCD process, so that a fixed reference voltage can be generated under the condition of higher voltage input and wider power supply range. In the embodiment of the present application, a Zener diode and a transistor are connected in series, and then a first reference current I is generated. Q Compensation ensures low temperature drift in the Zener voltage reference circuit. This low temperature drift eliminates the need for high-order temperature compensation modules, thus reducing circuit and layout area. Due to the simple core circuit structure, the overall Zener voltage reference circuit exhibits excellent long-term stability.

[0069] In the embodiment of the present application, a first reference current I is generated in a branch formed by the fourth switch tube M4, the fifth switch tube M5, the fifth resistor R5, the fifth transistor Q5 and the trimming resistor module Rs. Q Due to the high input impedance of the collector of the fifth transistor Q5 and the cascode current mirror structure of the second switch tube M2 to the seventh switch tube M7, the first reference current I Q With a high power supply rejection ratio, the first reference current I Q The current is mirrored to the core circuit through the common-source common-gate current mirror (M2-M7), thereby further improving the power supply rejection ratio of the output reference voltage.

[0070] Figure 5 A schematic diagram of the structure of a microprocessor chip provided in an embodiment of the present application is shown in FIG. Figure 5 As shown, the microprocessor chip may include a Zener reference voltage source circuit. For a detailed description of the Zener reference voltage source circuit, please refer to the above Figure 3a 、 Figure 3b or Figure 4 The description of the Zener reference voltage source circuit in the illustrated embodiment will not be repeated here.

[0071] In the embodiments of the present application, the microprocessor chip includes but is not limited to a microcontroller unit (MCU), a DSP, a microprocessor (MPU), a central processing unit (CPU), and the like, which can process digital signals, analog signals, or perform signal control functions, instruction processing, and calculation functions, and other micro central control chips and system-on-chip chips.

[0072] In the technical solution of the microprocessor chip provided in the embodiment of the present application, the current generating circuit includes a first current mirror structure, the core circuit includes a second current mirror structure, a transistor and a Zener diode connected in series, the first current mirror structure and the second current mirror structure form a first current mirror circuit, the current generating circuit mirrors the first reference current to the core circuit through the first current mirror circuit, the power supply rejection ratio can be improved by the first current mirror circuit, thereby improving the power supply rejection capability of the Zener reference voltage source circuit; the first current mirror circuit mirrors the first reference current to the core circuit, and after compensation by the first reference current, the Zener reference voltage source circuit has a lower temperature drift, thereby improving the stability of the Zener reference voltage source circuit. In the embodiment of the present application, a buffer circuit is provided in the Zener reference voltage source circuit, and the buffer circuit can improve the driving capability of the Zener reference voltage source circuit, so that the Zener reference voltage source circuit has load carrying capacity and can drive large loads.

[0073] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A Zener reference voltage source circuit, characterized in that: include: a voltage generating circuit, a current generating circuit, and a core circuit, wherein the input terminal of the voltage generating circuit is electrically connected to the first voltage terminal, the first output terminal of the voltage generating circuit is electrically connected to the input terminal of the current generating circuit, and the output terminal of the current generating circuit is electrically connected to the input terminal of the core circuit; The current generating circuit includes a first current mirror structure, the core circuit includes a second current mirror structure, a transistor and a Zener diode connected in series, and the first current mirror structure and the second current mirror structure form a first current mirror circuit; The voltage generating circuit is configured to generate a first output voltage under the control of the first voltage provided by the first voltage terminal, and output the first output voltage; The current generating circuit is configured to generate a first reference current under the control of the first output voltage, and mirror the first reference current to the core circuit through the first current mirror circuit, so that the core circuit obtains a second reference current; The core circuit is configured to generate a reference voltage with zero temperature characteristics under the control of the second reference current; The Zener reference voltage source circuit further includes: a buffer circuit, wherein an input end of the buffer circuit is electrically connected to the second output end of the voltage generating circuit and the output end of the core circuit; The voltage generating circuit is further configured to generate a second output voltage under the control of the first voltage, and output the second output voltage to the buffer circuit; The core circuit is further configured to output the reference voltage to the buffer circuit; The buffer circuit is configured to amplify the second output voltage and the reference voltage; or The Zener reference voltage source circuit further includes: a reference voltage divider circuit, wherein an input end of the reference voltage divider circuit is electrically connected to a voltage output end of the core circuit; The reference voltage divider circuit is used to divide the reference voltage to generate a plurality of reference sub-voltages; The Zener reference voltage source circuit further includes: a buffer circuit, wherein an input terminal of the buffer circuit is electrically connected to the second output terminal of the voltage generating circuit and the output terminal of the reference voltage divider circuit; The voltage generating circuit is further configured to generate a second output voltage under the control of the first voltage, and output the second output voltage to the buffer circuit; The reference voltage divider circuit is further configured to output the plurality of reference sub-voltages to the buffer circuit; The buffer circuit is used to amplify the second output voltage and the multiple reference sub-voltages.

2. The Zener reference voltage source circuit according to claim 1, wherein: The voltage generating circuit includes: a first resistor, a first transistor, a first Zener diode, a first switch tube, a second resistor and a second Zener diode; A first end of the first resistor is electrically connected to the first voltage terminal, and a second end of the first resistor is electrically connected to a first node; The base and collector of the first transistor are electrically connected and electrically connected to the first node, and the emitter of the first transistor is electrically connected to the cathode of the first Zener diode; The anode of the first Zener diode is electrically connected to the second voltage terminal; The control terminal of the first switch tube is electrically connected to the first node, the first terminal of the first switch tube is electrically connected to the first voltage terminal, and the second terminal of the first switch tube is electrically connected to the third voltage terminal; A first end of the second resistor is electrically connected to the third voltage end, a second end of the second resistor is electrically connected to the cathode of the second Zener diode, and an anode of the second Zener diode is electrically connected to the second voltage end.

3. The Zener reference voltage source circuit according to claim 2, wherein: The Zener reference voltage source circuit further includes a startup circuit for powering on the Zener reference voltage source circuit; The startup circuit includes: a third resistor, a second transistor, the first resistor, the first transistor and the first Zener diode; A first end of the third resistor is electrically connected to the first voltage terminal, and a second end of the third resistor is electrically connected to the collector of the second transistor; The base of the second transistor is electrically connected to the first node, and the emitter of the second transistor is electrically connected to the second node.

4. The Zener reference voltage source circuit according to claim 2, wherein: The voltage generating circuit further includes: a first capacitor and a second capacitor; A first terminal of the first capacitor is electrically connected to the cathode of the first Zener diode, and a second terminal of the first capacitor is electrically connected to the second voltage terminal; A first terminal of the second capacitor is electrically connected to the third voltage terminal, and a second terminal of the second capacitor is electrically connected to the second voltage terminal.

5. The Zener reference voltage source circuit according to claim 1, wherein: The current generating circuit further includes: a second switch tube, a third switch tube, a third transistor, a fourth transistor, a third Zener diode, a fifth resistor, a fifth transistor, and a trimming resistor module; the first current mirror structure includes the fourth switch tube and the fifth switch tube; the second switch tube, the third switch tube, the fourth switch tube, and the fifth switch tube form a second current mirror circuit; The first end of the second switch tube is electrically connected to the first voltage end, the first end of the fourth switch tube is electrically connected to the first voltage end, and the control end of the second switch tube is electrically connected to the control end of the fourth switch tube; a first end of the third switch transistor electrically connected to the second end of the second switch transistor, a second end of the third switch transistor electrically connected to the second node, a first end of the fifth switch transistor electrically connected to the second end of the fourth switch transistor, a second end of the fifth switch transistor electrically connected to the first end of the fifth resistor, and a control end of the third switch transistor electrically connected to a control end of the fifth switch transistor; The base and collector of the third transistor are electrically connected and electrically connected to the second node, the emitter of the third transistor is electrically connected to the emitter of the fourth transistor, the base and collector of the fourth transistor are electrically connected and electrically connected to the cathode of the third Zener diode, and the anode of the third Zener diode is electrically connected to the second voltage terminal; The second end of the fifth resistor is electrically connected to the collector of the fifth transistor, the base of the fifth transistor is electrically connected to the second node, the emitter of the fifth transistor is electrically connected to the first end of the trimming resistor module, and the second end of the trimming resistor module is electrically connected to the second voltage end.

6. The Zener reference voltage source circuit according to claim 5, wherein: The resistor type of the trimming resistor module is a resistor type whose resistance decreases as the temperature increases.

7. The Zener reference voltage source circuit according to claim 5, wherein: The transistor includes a sixth transistor, the Zener diode includes a fourth Zener diode, the second current mirror structure includes a sixth switch tube and a seventh switch tube, and the fourth switch tube, the fifth switch tube, the sixth switch tube, and the seventh switch tube form the first current mirror circuit; The first end of the sixth switch tube is electrically connected to the first voltage end, the second end of the sixth switch tube is electrically connected to the first end of the seventh switch tube, and the control end of the sixth switch tube is electrically connected to the control end of the fourth switch tube; The second end of the seventh switch tube is electrically connected to the voltage output end of the core circuit, and the control end of the seventh switch tube is electrically connected to the control end of the fifth switch tube; The emitter of the sixth transistor is electrically connected to the voltage output end of the core circuit, the base and collector of the sixth transistor are electrically connected and electrically connected to the cathode of the fourth Zener diode, and the anode of the fourth Zener diode is electrically connected to the second voltage end.

8. The Zener reference voltage source circuit according to claim 7, wherein: The Zener reference voltage source circuit further includes: an eighth switching tube and a ninth switching tube, wherein the sixth switching tube, the seventh switching tube, the eighth switching tube and the ninth switching tube form a third current mirror circuit; The first end of the eighth switch tube is electrically connected to the first voltage end, the second end of the eighth switch tube is electrically connected to the first end of the ninth switch tube, and the control end of the eighth switch tube is electrically connected to the control end of the sixth switch tube; The second end of the ninth switch tube is electrically connected to the current output end of the core circuit, and the control end of the ninth switch tube is electrically connected to the control end of the seventh switch tube.

9. The Zener reference voltage source circuit according to claim 1, wherein: The reference voltage divider circuit includes a resistance voltage divider circuit, a first end of the resistance voltage divider circuit is electrically connected to the voltage output end of the core circuit, and a second end of the resistance voltage divider circuit is electrically connected to the second voltage end; The resistor voltage divider circuit is used to divide the reference voltage to generate a plurality of reference sub-voltages; The resistor voltage divider circuit has a plurality of output ports, and the output ports are used to output the corresponding reference sub-voltages.

10. A microprocessor chip, characterized in that: include: The Zener reference voltage source circuit according to any one of claims 1 to 9.

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