A small-volume, high-stability power supply circuit

Abstract

The present application provides a power supply circuit with small volume and high stability, and relates to the technical field of power supply circuit. The power supply circuit includes an internal power supply circuit, a regulating circuit and an internal compensation circuit, the internal power supply circuit is connected to a high power supply voltage VIN, and outputs a low power supply voltage VR and a reference voltage VB; in the regulating circuit, the high power supply voltage VIN is grounded through the first switch tube M1, the first resistor R1, the second resistor R2 and the third resistor R3 in sequence, the control end of the first switch tube M1 is connected to the A node of the control module, the control module is connected between the second resistor R2 and the third resistor R3, and the output end of the power supply circuit is connected to the current output end of the first switch tube M1; the internal compensation circuit includes a second switch tube M2 and a first capacitor C1, the high voltage end of the first capacitor C1 is connected to the current output end of the second switch tube M2, and the low voltage end is connected to the B node of the control module. The power supply circuit of the present application can meet the requirements of small volume and high stability at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply circuits, and in particular to a power supply circuit with small volume and high stability. Background Art

[0002] The power supply circuit in the prior art usually requires multiple input voltages, including but not limited to a high power supply voltage, a low power supply voltage, and a reference voltage. In this configuration, the high power supply voltage is usually provided by an external power supply, and the low power supply voltage and the reference voltage are usually generated inside the power supply circuit. Therefore, the power supply circuit usually needs to be configured with at least two independent power supply circuits to provide the low power supply voltage and the reference voltage, thereby increasing the volume of the power supply circuit. At the same time, the output voltage of the power supply circuit in the prior art usually relies on an external voltage stabilizing capacitor for voltage stabilization, but the volume of the external voltage stabilizing capacitor is usually positively correlated with the size of the output voltage. Therefore, if it is necessary to ensure the stability of the output voltage, a capacitor with a larger volume needs to be used, which makes it difficult for the power supply circuit to take into account the requirements of small volume and high stability. Summary of the invention

[0003] The embodiment of the present invention provides a power supply circuit with small volume and high stability, and the power supply circuit can simultaneously meet the requirements of small volume and high stability.

[0004] According to a first aspect of the present invention, there is provided a power supply circuit with a small volume and high stability, comprising an internal power supply circuit, a regulating circuit and an internal compensation circuit, wherein the internal power supply circuit is connected to a high power supply voltage VIN and outputs a low power supply voltage VR and a reference voltage VB;

[0005] In the regulation circuit, the high power supply voltage VIN, the low power supply voltage VR and the reference voltage VB are all connected to the control module, and the control module is grounded, and the high power supply voltage VIN is grounded through the first switch tube M1, the first resistor R1, the second resistor R2 and the third resistor R3 in sequence; the control end of the first switch tube M1 is connected to the A node of the control module, the control module is connected between the second resistor R2 and the third resistor R3, and the output end of the power supply circuit is connected to the current output end of the first switch tube M1;

[0006] The internal compensation circuit includes a second switch tube M2 and a first capacitor C1, the current output end of the second switch tube M2 is connected to the D node of the control module, the control end of the second switch tube M2 is connected between the first resistor R1 and the second resistor R2, the low supply voltage VR is connected to the current input end of the second switch tube M2, the high voltage end of the first capacitor C1 is connected to the current output end of the second switch tube M2, and the low voltage end of the first capacitor C1 is connected to the B node of the control module.

[0007] In a possible implementation, in the control module, the high power supply voltage VIN is grounded through the third switch tube M3 and the first current mirror structure in sequence, and the current output end of the third switch tube M3 is connected to the A node of the control module; the high power supply voltage VIN is also grounded through the fourth switch tube M4 and the first current mirror structure in sequence;

[0008] The control end of the fourth switch tube M4 is connected to the control end of the third switch tube M3 and is merged into the current output end of the fourth switch tube M4.

[0009] In a possible implementation, the regulating circuit includes a fifth switch tube M5 and a sixth switch tube M6;

[0010] A current input terminal of the fifth switch tube M5 is connected to a current output terminal of the third switch tube M3, the current output terminal is grounded through the first current mirror structure, and a control terminal is connected to the low power supply voltage VR;

[0011] The current input end of the sixth switch tube M6 is connected to the current output end of the fourth switch tube M4 , the current output end is grounded through the first current mirror structure, and the control end is connected to the low power supply voltage VR.

[0012] In a possible implementation, the control module includes a second current mirror structure, a seventh switch tube M7 and an eighth switch tube M8, the second current mirror structure has a first output end, and the low power supply voltage VR is connected to the second current mirror structure;

[0013] The current output end of the seventh switch tube M7 is connected to the B node between the fifth switch tube M5 and the first input end of the first current mirror structure, the reference voltage VB is connected to the control end of the seventh switch tube M7, and the B node is connected to the low voltage end of the first capacitor C1;

[0014] The current output end of the eighth switch tube M8 is connected to the C node between the sixth switch tube M6 and the second input end of the first current mirror structure, the control end of the eighth switch tube M8 is connected between the second resistor R2 and the third resistor R3, and the current input end of the eighth switch tube M8 is connected to the current input end of the seventh switch tube M7 and is incorporated into the first output end of the second current mirror structure.

[0015] In a possible implementation, the regulating circuit further includes a first current source I1; the second current mirror structure includes a ninth switch tube M9, a tenth switch tube M10 and an eleventh switch tube M11;

[0016] The low power supply voltage VR is grounded through the eleventh switch tube M11 and the first current source I1 in sequence, and is also grounded through the tenth switch tube M10 and the first current mirror structure in sequence, and the low power supply voltage VR is connected to the current input terminal of the ninth switch tube M9;

[0017] The current output end of the ninth switch tube M9 serves as the first output end of the second current mirror structure, and the control ends of the ninth switch tube M9, the tenth switch tube M10 and the eleventh switch tube M11 are connected and merged into the current output end of the eleventh switch tube M11.

[0018] In a possible implementation, the first current mirror structure includes a twelfth switch tube M12, a thirteenth switch tube M13, a fourteenth switch tube M14 and a fifteenth switch tube M15;

[0019] The current input end of the twelfth switch tube M12 is connected to the current output end of the tenth switch tube M10, the current input end of the thirteenth switch tube M13 serves as the second input end of the first current mirror structure, the current input end of the fourteenth switch tube M14 serves as the first input end of the first current mirror structure, the current input end of the fifteenth switch tube M15 is connected to the current output end of the second switch tube M2, and the current input end of the fifteenth switch tube M15 serves as the D node of the control module;

[0020] The current output ends of the twelfth switch tube M12, the thirteenth switch tube M13, the fourteenth switch tube M14 and the fifteenth switch tube M15 are all grounded, and the control ends of the twelfth switch tube M12, the thirteenth switch tube M13, the fourteenth switch tube M14 and the fifteenth switch tube M15 are connected and merged into the current input end of the twelfth switch tube M12.

[0021] In a possible implementation, in the first current mirror structure, the current ratio of the twelfth switch tube M12, the thirteenth switch tube M13, the fourteenth switch tube M14 and the fifteenth switch tube M15 is M:1:1:N;

[0022] The fourth switch tube M4 and the third switch tube M3 form a 1:1 current mirror structure.

[0023] In a possible implementation, in the internal power supply circuit, the high power supply voltage VIN is grounded through the sixteenth switch tube M16, the fourth resistor R4, the first transistor Q1 and the seventeenth switch tube M17 in sequence, and the high power supply voltage VIN is also grounded through the eighteenth switch tube M18, the second transistor Q2, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the third transistor Q3 in sequence, and the current output end of the sixteenth switch tube M16 is connected to the control end of the sixteenth switch tube M16;

[0024] The internal power supply circuit further includes an eighth resistor R8 and a fourth transistor Q4, one end of the eighth resistor R8 is connected to the current output end of the sixteenth switch tube M16, and the other end is connected to the collector of the fourth transistor Q4, the emitter of the fourth transistor Q4 is connected between the first transistor Q1 and the seventeenth switch tube M17, and the base of the fourth transistor Q4 is connected between the sixth resistor R6 and the seventh resistor R7;

[0025] The low power supply voltage end of the internal power supply circuit is connected between the eighteenth switch tube M18 and the second transistor Q2, the reference voltage end of the internal power supply circuit is connected to the F node between the fifth resistor R5 and the sixth resistor R6, and the base of the first transistor Q1 is connected to the F node.

[0026] In a possible implementation, the ratio of the number of the first transistor Q1 to the number of the fourth transistor Q4 is 1:K;

[0027] The fourth resistor R4 and the eighth resistor R8 have the same resistance value;

[0028] The parameters of the second transistor Q2 and the third transistor Q3 are the same.

[0029] In a possible implementation, the low supply voltage VR output by the low supply voltage terminal satisfies the following formula:

[0030]

[0031] The reference voltage VB output by the reference voltage terminal satisfies the following formula:

[0032]

[0033] Wherein, VBE represents the voltage difference between the base and the emitter of the second transistor Q2 and the third transistor Q3, and Vt represents the thermal voltage of the transistor.

[0034] In a possible implementation, the parameters of K, the fifth resistor R5, the sixth resistor R6 and the seventh resistor R7 in the internal power supply circuit are matched so that the output low power supply voltage VR and the reference voltage VB are not affected by temperature.

[0035] In a possible implementation, in the internal power supply circuit, the high power supply voltage VIN is further grounded through the twenty-first switch tube M21, the nineteenth switch tube M19, and the ninth resistor R9 in sequence; the high power supply voltage VIN is further grounded through the twenty-first switch tube M21, the twentieth switch tube M20, and the tenth resistor R10 in sequence;

[0036] The control end of the nineteenth switch tube M19 is connected between the fourth resistor R4 and the first transistor Q1 , and the control end of the twentieth switch tube M20 is connected between the eighth resistor R8 and the fourth transistor Q4 .

[0037] In a possible implementation, in the internal power supply circuit, the high power supply voltage VIN is further grounded through the twenty-second switch tube M22, the twenty-third switch tube M23, and the ninth resistor R9 in sequence; the high power supply voltage VIN is further grounded through the twenty-fourth switch tube M24, the twenty-fifth switch tube M25, and the tenth resistor R10 in sequence;

[0038] The control ends of the twenty-third switch tube M23 and the twenty-fifth switch tube M25 are connected and merged into the current input end of the twenty-third switch tube M23, and the control end of the eighteenth switch tube M18 is connected to the E node between the twenty-fourth switch tube M24 and the twenty-fifth switch tube M25.

[0039] In a possible implementation, in the internal power supply circuit, the high power supply voltage VIN is also connected to ground via the second current source I2 and the twenty-sixth switch tube M26 in sequence; the high power supply voltage VIN is also connected to ground via the twenty-seventh switch tube M27 and the twenty-eighth switch tube M28 in sequence;

[0040] The control ends of the twenty-sixth switch tube M26, the seventeenth switch tube M17 and the twenty-eighth switch tube M28 are connected and merged into the current input end of the twenty-sixth switch tube M26.

[0041] In a possible implementation, in the internal power supply circuit, the high power supply voltage VIN is also connected to ground via the twenty-ninth switch tube M29, the thirtieth switch tube M30, and the thirty-first switch tube M31 in sequence; the high power supply voltage VIN is also connected to the F node via the thirty-second switch tube M32;

[0042] Control ends of the twenty-ninth switch tube M29, the twenty-fourth switch tube M24, the twenty-second switch tube M22, the twenty-first switch tube M21 and the twenty-seventh switch tube M27 are connected and merged into the current output end of the twenty-seventh switch tube M27;

[0043] The control ends of the 30th switch tube M30 and the 32nd switch tube M32 are connected and merged into the current input end of the 30th switch tube M30, and the 31st switch tube M31 adopts a diode connection method.

[0044] In a possible implementation, the second transistor Q2 and the third transistor Q3 are both connected by diodes.

[0045] The ninth resistor R9 and the tenth resistor R10 have the same resistance value;

[0046] The currents flowing through the twenty-second switch tube M22 and the twenty-fourth switch tube M24 are 1:1.

[0047] In a possible implementation, the resistance of the fifth resistor R5 is equal to the sum of the resistances of the sixth resistor R6 and the seventh resistor R7.

[0048] In a possible implementation, after the internal power supply circuit works normally, the reference voltage VB is greater than VGS to ensure that the thirty-second switch tube M32 is in an off state, wherein the VGS is the voltage difference between the current output end and the control end of the thirtieth switch tube M30 and the thirty-first switch tube M31.

[0049] According to the solution of the embodiment of the present invention, by setting an internal compensation circuit, it is ensured that during the startup of the circuit, the output voltage VOUT at the output end of the power supply circuit will not overshoot upward, and that after the circuit is normally operated, when the output voltage VOUT suddenly decreases, the output voltage VOUT will not overshoot downward, and when the output voltage VOUT suddenly increases, the output voltage VOUT will not overshoot upward, thereby improving the stability of the output voltage VOUT. Therefore, the power supply circuit in the present invention only needs to use a small-volume external compensation capacitor. At the same time, the internal power supply circuit of the power supply circuit can provide a low power supply voltage VR and a reference voltage VB at the same time, so only one power supply circuit is required to obtain these two output voltages, thereby effectively reducing the volume of the power supply circuit. Therefore, the power supply circuit of the embodiment of the present application can simultaneously meet the requirements of small volume and high stability.

[0050] Furthermore, in the embodiment of the present application, the sixth switch tube M6 and the fifth switch tube M5 play a role in isolating high voltage, so that Figure 1The devices below the sixth switch tube M6 and the fifth switch tube M5 can all be low-voltage devices, thereby further reducing the volume of the power supply circuit.

[0051] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0053] Figure 1 A schematic circuit structure diagram of a small-volume, high-stability power supply circuit according to an embodiment of the present invention is shown;

[0054] Figure 2 A schematic circuit diagram showing a small-volume, high-stability power supply circuit according to another embodiment of the present invention

[0055] Figure 3 A schematic structural diagram of a power supply circuit with small volume and high stability according to another embodiment of the present invention is shown;

[0056] Figure 4 A schematic structural diagram of an internal power supply circuit according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0057] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0058] Figure 1 FIG. 1 is a schematic circuit diagram of a power supply circuit with a small volume and high stability according to an embodiment of the present invention. Figure 1As shown, the power supply circuit includes an internal power supply circuit, a regulating circuit and an internal compensation circuit. The internal power supply circuit is connected to a high power supply voltage VIN, and outputs a low power supply voltage VR and a reference voltage VB. In the regulating circuit, the high power supply voltage VIN, the low power supply voltage VR and the reference voltage VB are all connected to the control module, and the control module is grounded, and the high power supply voltage VIN is grounded through the first switch tube M1, the first resistor R1, the second resistor R2 and the third resistor R3 in sequence; the control end of the first switch tube M1 is connected to the A node of the control module, the control module is connected between the second resistor R2 and the third resistor R3, and the output end of the power supply circuit is connected to the current output end of the first switch tube M1. The internal compensation circuit includes a second switch tube M2 and a first capacitor C1, the current output end of the second switch tube M2 is connected to the D node of the control module, the control end of the second switch tube M2 is connected between the first resistor R1 and the second resistor R2, the low power supply voltage VR is connected to the current input end of the second switch tube M2, the high voltage end of the first capacitor C1 is connected to the current output end of the second switch tube M2, and the low voltage end of the first capacitor C1 is connected to the B node of the control module.

[0059] Figure 2 FIG. 2 shows a schematic circuit structure diagram of a small-volume, high-stability power supply circuit according to another embodiment of the present invention. Figure 2 As shown, in some embodiments, the regulation circuit further includes a first voltage regulator diode D1 , one end of which is connected to the high power supply voltage VIN, and the other end of which is connected to the control end of the first switch tube M1 .

[0060] In some embodiments, in the control module, the high supply voltage VIN is grounded through the third switch tube M3 and the first current mirror structure in sequence, and the current output end of the third switch tube M3 is connected to the A node of the control module.

[0061] In some embodiments, the regulating circuit further includes a fifth switch tube M5, the current input end of the fifth switch tube M5 is connected to the current output end of the third switch tube M3, the current output end is connected to the first current mirror structure, and the control end is connected to the low power supply voltage VR. In this embodiment, the low voltage end of the first capacitor C1 is connected to the B node between the fifth switch tube M5 and the first input end of the first current mirror structure. The fifth switch tube M5 plays a role in isolating the high voltage, so that Figure 2 All devices below the fifth switch tube M5 can be low-voltage devices, thereby reducing the size of the power supply circuit.

[0062] The power supply circuit is provided with an internal compensation circuit to ensure that during the startup of the circuit, the output voltage VOUT at the output end of the power supply circuit will not overshoot upward, and to ensure that after the circuit is operating normally, when the output voltage VOUT suddenly decreases, the output voltage VOUT will not overshoot downward, and when the output voltage VOUT suddenly increases, the output voltage VOUT will not overshoot upward, thereby improving the stability of the output voltage VOUT. At the same time, the internal power supply circuit of the power supply circuit can provide a low power supply voltage VR and a reference voltage VB at the same time, so only one power supply circuit is required to obtain these two output voltages, thereby effectively reducing the volume of the power supply circuit. Therefore, the power supply circuit of the embodiment of the present application can simultaneously meet the requirements of small volume and high stability.

[0063] The working principle of the internal compensation circuit in the embodiment of the present application is as follows:

[0064] When the circuit is powered on and just started, the current output end of the second switch tube M2 is pulled down through the switch tube connected to the second switch tube M2 in the first current mirror structure 1. After that, the output voltage VOUT gradually increases so that the voltage of the control end of the second switch tube M2 gradually increases to be greater than its conduction threshold, and the second switch tube M2 is turned on. At this time, the low power supply voltage VR charges the high voltage end of the first capacitor C1 through the second switch tube M2, and the low voltage end of the first capacitor C1 generates an internal compensation current flowing into the B node. At this time, since the current flowing from the B node to the switch tube connected to the B node in the first current mirror structure 1 is a fixed value, therefore, when the low voltage end of the first capacitor C1 generates an internal compensation current flowing into the B node, the current flowing from the A node into the fifth switch tube M5 must be reduced, thereby reducing the rate at which the voltage of the control end of the first switch tube M1 is pulled down. Therefore, the output voltage VOUT will not rise suddenly, ensuring that the output voltage VOUT will not overshoot upward during the startup of the circuit, thereby improving the stability of the output voltage VOUT.

[0065] When the circuit works normally, the output voltage VOUT is always in a high level state, the second switch tube M2 is always in an on state, and the voltage difference between the control end and the current output end of the second switch tube M2 is always VGS. Therefore, when the voltage at the control end of the second switch tube M2 changes, the voltage at the current output end of the second switch tube M2 (that is, the voltage at the high voltage end of the first capacitor C1) also changes in the same way.

[0066] Therefore, when the circuit is working normally, if the output voltage VOUT suddenly increases, the regulating circuit will adjust the current flowing from the third switch tube M3 to the A node to be greater than the current flowing from the A node to the fifth switch tube M5, thereby raising the voltage of the A node, and the first switch tube M1 is always in the off state, and the output voltage VOUT decreases. However, since the regulating circuit has a response time, it will not completely turn off the first switch tube M1 so quickly. At this time, due to the existence of the internal compensation circuit, when the output voltage VOUT suddenly increases, the control terminal voltage of the second switch tube M2 also suddenly increases, and the high-voltage terminal voltage of the first capacitor C1 increases accordingly, and the low-voltage terminal voltage of the first capacitor C1 increases accordingly. An internal compensation current is generated to flow into the B node. At this time, since the current flowing from the B node to the switch tube connected to the B node in the first current mirror structure 1 is a fixed value, when the internal compensation current is generated at the low-voltage end of the first capacitor C1 and flows into the B node, the current flowing from the A node to the fifth switch tube M5 will inevitably decrease. Therefore, at this time, the current flowing from the third switch tube M3 to the A node will immediately be greater than the current flowing from the A node to the fifth switch tube M5, thereby quickly raising the A node voltage, and the first switch tube M1 is quickly turned off, ensuring that when the output voltage VOUT suddenly increases, the output voltage VOUT will not have a large overshoot upward, thereby improving the stability of the output voltage VOUT.

[0067] When the circuit is working normally, if the output voltage VOUT suddenly decreases, the regulating circuit will adjust the current flowing from the third switch tube M3 to the A node to be smaller than the current flowing from the A node to the fifth switch tube M5, thereby lowering the voltage of the A node, and the first switch tube M1 is always in the on state, and the output voltage VOUT increases. However, since the regulating circuit has a response time, it will not completely turn on the first switch tube M1 so quickly. At this time, due to the existence of the internal compensation circuit, when the output voltage VOUT suddenly decreases, the control terminal voltage of the second switch tube M2 also suddenly decreases, and the high-voltage terminal voltage of the first capacitor C1 decreases accordingly, and the internal compensation current flows to the B node. Into the low-voltage end of the first capacitor C1, at this time, since the current flowing from the B node to the switch tube connected to the B node in the first current mirror structure 1 is a fixed value, therefore, after the B node generates an internal compensation current flowing into the low-voltage end of the first capacitor C1, the current flowing from the A node to the fifth switch tube M5 will inevitably increase. Therefore, at this time, the current flowing from the third switch tube M3 into the A node will immediately be less than the current flowing from the A node to the fifth switch tube M5, thereby quickly lowering the A node voltage, and the first switch tube M1 is quickly turned on, ensuring that when the output voltage VOUT suddenly decreases, the output voltage VOUT will not have a large overshoot downward, thereby improving the stability of the output voltage VOUT.

[0068] In some embodiments, the power supply circuit further includes an external compensation circuit, which includes a second capacitor C2. One end of the second capacitor C2 is connected to the output end of the power supply circuit, and the other end is grounded. The second capacitor C2 of this embodiment, as an external compensation capacitor, can reduce the fluctuation of the output voltage VOUT and stabilize the output voltage VOUT. At the same time, since the embodiment of the present application improves the stability of the output voltage VOUT by setting an internal compensation circuit, the second capacitor C2 can adopt a small volume capacitor. Therefore, the power supply circuit in the embodiment of the present application only needs to use a small volume external compensation capacitor, which can simultaneously meet the requirements of small volume and high stability of the power supply circuit.

[0069] In some embodiments, in the control module, the high supply voltage VIN is also grounded in sequence through the fourth switch tube M4 and the first current mirror structure 1. The control end of the fourth switch tube M4 is connected to the control end of the third switch tube M3 and is incorporated into the current output end of the fourth switch tube M4. In some embodiments, the fourth switch tube M4 and the third switch tube M3 form a 1:1 current mirror structure.

[0070] In some embodiments, the regulating circuit further includes a sixth switch tube M6, the current input end of the sixth switch tube M6 is connected to the current output end of the fourth switch tube M4, the current output end is connected to the first current mirror structure, and the control end is connected to the low power supply voltage VR. The sixth switch tube M6 plays a role in isolating the high voltage, so that Figure 2 All devices below the sixth switch tube M6 can be low-voltage devices, thereby reducing the volume of the power supply circuit.

[0071] The control module also includes a second current mirror structure 2, a seventh switch tube M7 and an eighth switch tube M8. The second current mirror structure 2 has a first output terminal, and the low power supply voltage VR is connected to the second current mirror structure 2. The current output terminal of the seventh switch tube M7 is connected to the B node, and the reference voltage VB is connected to the control terminal of the seventh switch tube M7. The current output terminal of the eighth switch tube M8 is connected to the C node between the sixth switch tube M6 and the second input terminal of the first current mirror structure 1, the control terminal of the eighth switch tube M8 is connected between the second resistor R2 and the third resistor R3, and the current input terminal of the eighth switch tube M8 is connected to the current input terminal of the seventh switch tube M7 and is incorporated into the first output terminal of the second current mirror structure 2.

[0072] In some embodiments, the second current mirror structure 2 includes a ninth switch tube M9, a tenth switch tube M10, and an eleventh switch tube M11. The low power supply voltage VR is connected to ground through the eleventh switch tube M11 and the first current source I1 in sequence, and the low power supply voltage VR is also connected to ground through the tenth switch tube M10 and the first current mirror structure 1 in sequence, and the low power supply voltage VR is connected to the current input end of the ninth switch tube M9. The current output end of the ninth switch tube M9 serves as the first output end of the second current mirror structure 2, and the control ends of the ninth switch tube M9, the tenth switch tube M10, and the eleventh switch tube M11 are connected and merged into the current output end of the eleventh switch tube M11.

[0073] In some embodiments, the first current mirror structure 1 includes a twelfth switch tube M12, a thirteenth switch tube M13, a fourteenth switch tube M14, and a fifteenth switch tube M15. The current input end of the twelfth switch tube M12 is connected to the current output end of the tenth switch tube M10, the current input end of the thirteenth switch tube M13 serves as the second input end of the first current mirror structure 1, the current input end of the fourteenth switch tube M14 serves as the first input end of the first current mirror structure 1, the current input end of the fifteenth switch tube M15 is connected to the current output end of the second switch tube M2, and the current input end of the fifteenth switch tube M15 serves as the D node of the control module. The current output ends of the twelfth switch tube M12, the thirteenth switch tube M13, the fourteenth switch tube M14, and the fifteenth switch tube M15 are all grounded, and the control ends of the twelfth switch tube M12, the thirteenth switch tube M13, the fourteenth switch tube M14, and the fifteenth switch tube M15 are connected and merged into the current input end of the twelfth switch tube M12.

[0074] In some embodiments, in the first current mirror structure 1 , the current ratio of the twelfth switch tube M12 , the thirteenth switch tube M13 , the fourteenth switch tube M14 , and the fifteenth switch tube M15 is M:1:1:N.

[0075] The working principle of the small-volume and high-stability power supply circuit of the embodiment of the present application is as follows:

[0076] When the circuit is powered on, the high power supply voltage VIN is input into the internal power supply circuit, and the internal power supply circuit generates the low power supply voltage VR and the reference voltage VB. At this time, the first current source I1 generates the first current, and the first current pulls down the control terminal voltage of the eleventh switch tube M11, the tenth switch tube M10 and the ninth switch tube M9, while the current input terminal voltage of the eleventh switch tube M11, the tenth switch tube M10 and the ninth switch tube M9 is pulled up by the low power supply voltage VR, so the eleventh switch tube M11, the tenth switch tube M10 and the ninth switch tube M9 are turned on. At this time, the control terminal voltages of the twelfth switch tube M12, the thirteenth switch tube M13, the fourteenth switch tube M14 and the fifteenth switch tube M15 are pulled up to the low power supply voltage VR by the tenth switch tube M10, and the current output terminals of the twelfth switch tube M12, the thirteenth switch tube M13, the fourteenth switch tube M14 and the fifteenth switch tube M15 are grounded. Therefore, the twelfth switch tube M12, the thirteenth switch tube M13, the fourteenth switch tube M14 and the fifteenth switch tube M15 are turned on. At this time, the voltage at the current output end of the sixth switch tube M6 is pulled down by the thirteenth switch tube M13, the voltage at the current output end of the fifth switch tube M5 is pulled down by the fourteenth switch tube M14, and the voltage at the control end of the sixth switch tube M6 and the fifth switch tube M5 is pulled up by the low power supply voltage VR, and the sixth switch tube M6 and the fifth switch tube M5 are turned on. Therefore, at this time, the voltage at the control end of the fourth switch tube M4 and the third switch tube M3 is pulled down by the sixth switch tube M6 and the thirteenth switch tube M13, and the voltage at the current input end of the fourth switch tube M4 and the third switch tube M3 is the high power supply voltage VIN. Therefore, the fourth switch tube M4 and the third switch tube M3 are turned on.

[0077] At this time, it can be known from the above analysis that when the circuit is just powered on, the internal power supply circuit generates a reference voltage VB, and the reference voltage VB is input to the control end of the seventh switch tube M7. Since the output voltage VOUT is almost 0 when the circuit is just powered on, the voltage at the control end of the eighth switch tube M8 is also almost 0. In addition, since the voltages at the current input ends of the seventh switch tube M7 and the eighth switch tube M8 are pulled up to the low power supply voltage VR through the ninth switch tube M9, the conduction margin of the seventh switch tube M7 is smaller than the conduction margin of the eighth switch tube M8 at the initial stage of power-on. The current flowing from the seventh switch tube M7 into the B node is less than the current flowing from the eighth switch tube M8 into the C node, and because the thirteenth switch tube M13 and the fourteenth switch tube M14 form a 1:1 current mirror, the current flowing from the B node into the fourteenth switch tube M14 is equal to the current flowing from the C node into the thirteenth switch tube M13. Therefore, at this time, it can be obtained that the current flowing from the fifth switch tube M5 into the B node is greater than the current flowing from the sixth switch tube M6 into the C node. Since the fourth switch tube M4 and the third switch tube M3 form a 1:1 current mirror, at this time, combined with Figure 1It can be seen that the current flowing from the sixth switch tube M6 into the C node is equal to the current flowing from the fourth switch tube M4 into the sixth switch tube M6, and is equal to the current flowing from the third switch tube M3 into the A node, and the current flowing from the fifth switch tube M5 into the B node is equal to the current flowing from the A node into the fifth switch tube M5, so it can be obtained that the current flowing from the third switch tube M3 into the A node is less than the current flowing from the A node into the fifth switch tube M5, therefore, the A node voltage is pulled down, the first switch tube M1 is turned on, and the output voltage VOUT increases. Therefore, the control terminal voltage of the eighth switch tube M8 also increases. When the control terminal voltage of the eighth switch tube M8 increases to be greater than the reference voltage VB, the conduction margin of the seventh switch tube M7 is converted to be greater than the conduction margin of the eighth switch tube M8, and the current flowing from the seventh switch tube M7 into the B node is greater than the current flowing from the eighth switch tube M8 into the C node. At this time, combined with the above analysis, it can be obtained that the current flowing from the fifth switch tube M5 into the B node is less than the current flowing from the sixth switch tube M6 into the C node, and the current flowing from the third switch tube M3 into the A node is greater than the current flowing from the A node into the fifth switch tube M5. Therefore, the voltage of the A node is pulled up, the first switch tube M1 is turned off, and the output voltage VOUT is reduced. Therefore, the control terminal voltage of the eighth switch tube M8 is also reduced. When the control terminal voltage of the eighth switch tube M8 is reduced to less than the reference voltage VB, the circuit enters the next cycle.

[0078] Therefore, when the circuit enters a stable working state, the control terminal voltage of the eighth switch tube M8 is equal to the reference voltage VB, that is, , so now we can get, .

[0079] Figure 3 A schematic structural diagram of a power supply circuit with small volume and high stability according to yet another embodiment of the present invention is shown. Figure 4 FIG. 2 shows a schematic structural diagram of an internal power supply circuit according to an embodiment of the present invention. Figure 3 and Figure 4As shown, in the internal power supply circuit, the high power supply voltage VIN is connected to the ground through the sixteenth switch tube M16, the fourth resistor R4, the first transistor Q1 and the seventeenth switch tube M17 in sequence, and the high power supply voltage VIN is also connected to the ground through the eighteenth switch tube M18, the second transistor Q2, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the third transistor Q3 in sequence, and the current output end of the sixteenth switch tube M16 is connected to the control end of the sixteenth switch tube M16. The internal power supply circuit also includes an eighth resistor R8 and a fourth transistor Q4, one end of the eighth resistor R8 is connected to the current output end of the sixteenth switch tube M16, and the other end is connected to the collector of the fourth transistor Q4, the emitter of the fourth transistor Q4 is connected between the first transistor Q1 and the seventeenth switch tube M17, and the base of the fourth transistor Q4 is connected between the sixth resistor R6 and the seventh resistor R7. The low power supply voltage terminal of the internal power supply circuit is connected between the eighteenth switch tube M18 and the second transistor Q2, the reference voltage terminal of the internal power supply circuit is connected to the F node between the fifth resistor R5 and the sixth resistor R6, and the base of the first transistor Q1 is connected to the F node.

[0080] In some embodiments, the number ratio of the first triode Q1 to the fourth triode Q4 is 1:K. The fourth resistor R4 and the eighth resistor R8 have the same resistance. The parameters of the second triode Q2 and the third triode Q3 are the same. The second triode Q2 and the third triode Q3 are both diode-connected.

[0081] In the internal power supply circuit of the present embodiment, the low power supply voltage end of the internal power supply circuit is connected to the high power supply voltage end through the eighteenth switch tube M18, and the current outputted by the low power supply voltage end to the regulating circuit all comes from the high power supply voltage end, and the current outputted to the regulating circuit does not affect the magnitude of the second current IO generated in the branch composed of the eighteenth switch tube M18, the second transistor Q2, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the third transistor Q3, so the low power supply voltage end has current capacity. The reference voltage end is connected to the high power supply voltage end through the fifth resistor R5, the second transistor Q2 and the eighteenth switch tube M18, and since the current flowing through the sixth resistor R6, the seventh resistor R7 and the third transistor Q3 is unchanged, at this time, if the reference voltage end outputs current to the regulating circuit, the second current IO will inevitably increase, thereby making the low power supply voltage VR too large, so the reference voltage end must not have current capacity.

[0082] When the internal power supply circuit works normally, the current IC1 flowing through the first transistor Q1 is equal to the current IC2 flowing through the fourth transistor Q4. At the same time, according to the circuit structure of the internal power supply circuit, VBE1=VBE4+VR6, where VR6 is the voltage difference across the sixth resistor R6, and VR6=IO×R6. At this time, combined with the transistor current formula, it can be obtained: , it can be seen that the second current , where Vt is the thermal voltage and R6 is the resistance of the sixth resistor.

[0083] Therefore, the output low supply voltage , the output reference voltage At this time, first, since the second transistor Q2 and the third transistor Q3 are transistors with exactly the same parameters, it can be obtained that the VBE2 of the second transistor Q2 is equal to the VBE3 of the third transistor Q3, recorded as VBE, therefore, , Secondly, the VBE of the transistor is a negative temperature parameter, and the thermal voltage Vt of the transistor is a positive temperature parameter. Therefore, by matching the parameters of K, R5, R6 and R7 appropriately, the output low power supply voltage VR and the reference voltage VB can be made unaffected by temperature, so that the internal power supply circuit can generate two power supply voltages and improve the accuracy of the power supply voltage.

[0084] In some embodiments, in the internal power supply circuit, the high power supply voltage VIN is also connected to ground through the twenty-first switch tube M21, the nineteenth switch tube M19 and the ninth resistor R9 in sequence; the high power supply voltage VIN is also connected to ground through the twenty-first switch tube M21, the twentieth switch tube M20 and the tenth resistor R10 in sequence. The control end of the nineteenth switch tube M19 is connected between the fourth resistor R4 and the first transistor Q1, and the control end of the twentieth switch tube M20 is connected between the eighth resistor R8 and the fourth transistor Q4.

[0085] In some embodiments, the ninth resistor R9 and the tenth resistor R10 have the same resistance.

[0086] When the internal power supply circuit is just powered on, the current in the first transistor Q1 and the fourth transistor Q4 is small, so at this time, the voltage drop across the fourth resistor R4 and the eighth resistor R8 is small. At this time, if the sixteenth switch tube M16 does not exist, the fourth resistor R4 and the eighth resistor R8 are directly connected to the high power supply voltage VIN, then the terminal voltage of the fourth resistor R4 and the eighth resistor R8 far from the high power supply voltage VIN will be larger, close to the high power supply voltage VIN, resulting in a large control terminal voltage of the nineteenth switch tube M19 and the twentieth switch tube M20, so that the nineteenth switch tube M19 and the twentieth switch tube M20 cannot be turned on. Therefore, at this time, the sixteenth switch tube M16 is set in the internal power supply circuit, so that the terminal voltage of the fourth resistor R4 and the eighth resistor R8 close to the high power supply voltage VIN is VIN-VGS, and by Figure 4It can be seen that when the control terminal voltage of the nineteenth switch tube M19 and the twentieth switch tube M20 is less than VIN-VDS-VGS, they can be smoothly turned on, and because the VDS at both ends of the twenty-first switch tube M21 is small after it is turned on, therefore, when the sixteenth switch tube M16, the fourth resistor R4 and the eighth resistor R8 are set in the circuit, it can be ensured that the fourth resistor R4 and the eighth resistor R8 are far away from the terminal voltage of the high power supply voltage VIN, that is, the control terminal voltage of the nineteenth switch tube M19 and the twentieth switch tube M20 is less than VIN-VDS-VGS, so that the nineteenth switch tube M19 and the twentieth switch tube M20 can be smoothly turned on.

[0087] In some embodiments, in the internal power supply circuit, the high power supply voltage VIN is also connected to ground through the twenty-second switch tube M22, the twenty-third switch tube M23 and the ninth resistor R9 in sequence; the high power supply voltage VIN is also connected to ground through the twenty-fourth switch tube M24, the twenty-fifth switch tube M25 and the tenth resistor R10 in sequence. The control ends of the twenty-third switch tube M23 and the twenty-fifth switch tube M25 are connected and merged into the current input end of the twenty-third switch tube M23, and the control end of the eighteenth switch tube M18 is connected to the E node between the twenty-fourth switch tube M24 and the twenty-fifth switch tube M25.

[0088] In some embodiments, the ratio of the current flowing through the twenty-second switch tube M22 and the current flowing through the twenty-fourth switch tube M24 is 1:1.

[0089] In some embodiments, in the internal power supply circuit, the high power supply voltage VIN is also connected to ground through the second current source I2 and the twenty-sixth switch tube M26 in sequence; the high power supply voltage VIN is also connected to ground through the twenty-seventh switch tube M27 and the twenty-eighth switch tube M28 in sequence. The control ends of the twenty-sixth switch tube M26, the seventeenth switch tube M17 and the twenty-eighth switch tube M28 are connected and merged into the current input end of the twenty-sixth switch tube M26.

[0090] In some embodiments, in the internal power supply circuit, the high power supply voltage VIN is also connected to the ground through the twenty-ninth switch tube M29, the thirtieth switch tube M30 and the thirty-first switch tube M31 in sequence; the high power supply voltage VIN is also connected to the F node through the thirty-second switch tube M32. The control ends of the twenty-ninth switch tube M29, the twenty-fourth switch tube M24, the twenty-second switch tube M22, the twenty-first switch tube M21 and the twenty-seventh switch tube M27 are connected and merged into the current output end of the twenty-seventh switch tube M27. The control ends of the thirtieth switch tube M30 and the thirty-second switch tube M32 are connected and merged into the current input end of the thirtieth switch tube M30, and the thirty-first switch tube M31 adopts a diode connection method.

[0091] In some embodiments, the resistance of the fifth resistor R5 is equal to the sum of the resistances of the sixth resistor R6 and the seventh resistor R7.

[0092] The working principle of this internal power supply circuit is as follows:

[0093] After the circuit is powered on, the second current source I2 generates a third current, and the third current pulls up the control terminal voltage of the twenty-sixth switch tube M26, the seventeenth switch tube M17, and the twenty-eighth switch tube M28, and the twenty-sixth switch tube M26, the seventeenth switch tube M17, and the twenty-eighth switch tube M28 are turned on. At this time, the twenty-eighth switch tube M28 pulls down the control terminal voltage of the twenty-seventh switch tube M27, the twenty-first switch tube M21, the twenty-second switch tube M22, the twenty-fourth switch tube M24, and the twenty-ninth switch tube M29, and the twenty-seventh switch tube M27, the twenty-first switch tube M21, the twenty-second switch tube M22, the twenty-fourth switch tube M24, and the twenty-ninth switch tube M29 are turned on.

[0094] Afterwards, the high power supply voltage VIN pulls up the voltage of the control terminal and the current input terminal of the 30th switch tube M30 through the 29th switch tube M29. Figure 4 It can be seen that the thirty-first switch tube M31 and the thirtieth switch tube M30 are diode-connected. At this time, since the high power supply voltage VIN is greater than the sum of the voltage differences between the current output terminals and the control terminals of the thirty-first switch tube M31 and the thirtieth switch tube M30, 2VGS, at this time, the thirty-first switch tube M31 and the thirtieth switch tube M30 are both turned on. Therefore, from the specific circuit structure of the internal power supply circuit, it can be obtained that the control terminal voltage of the 30th switch tube M30 is equal to 2VGS, that is, the control terminal voltage of the thirty-second switch tube M32 is equal to 2VGS. Therefore, at this time, when the current output terminal voltage of the thirty-second switch tube M32 is less than VGS, the thirty-second switch tube M32 is turned on to clamp the current output terminal voltage of the thirty-second switch tube M32 at VGS. When the voltage at the current output end of the thirty-second switch tube M32 is greater than VGS, although the thirty-second switch tube M32 is not turned on, at this time, the base voltage of the first transistor Q1 is greater than VGS. Therefore, the 30th switch tube M30 to the thirty-second switch tube M32 provided in the present application can ensure that the base voltage of the first transistor Q1 is at least VGS, and the base voltage of the fourth transistor Q4 is at least close to VGS. Since the first transistor Q1 and the fourth transistor Q4 are grounded through the seventeenth switch tube M17, and after the seventeenth switch tube M17 is turned on, the VDS at both ends is small. Therefore, at this time, when the base voltage of the first transistor Q1 is at least VGS, and the base voltage of the fourth transistor Q4 is at least close to VGS, the first transistor Q1 and the fourth transistor Q4 can be smoothly turned on, and the internal power supply circuit completes the startup process.

[0095] After the first transistor Q1 and the fourth transistor Q4 are turned on, the control terminal voltage of the sixteenth switch tube M16 is pulled down through the fourth resistor R4, the first transistor Q1 and the seventeenth switch tube M17, and the sixteenth switch tube M16 is turned on, so current flows through the first transistor Q1 and the fourth transistor Q4. At this time, since the ratio of the number of the first transistor Q1 to the number of the fourth transistor Q4 is 1:K, and when the circuit is just powered on, the base voltage of the first transistor Q1 and the base voltage of the fourth transistor Q4 are very small, at this time, the number ratio of the transistors has a greater impact on the current flowing through the transistors, so the current IC1 flowing through the first transistor Q1 is less than the current IC2 flowing through the fourth transistor Q4. Since the fourth resistor R4 and the eighth resistor R8 have the same resistance value, the voltage drop across the fourth resistor R4 is smaller than the voltage drop across the eighth resistor R8. Since the fourth resistor R4 is connected to one end of the eighth resistor R8, it can be obtained that the control terminal voltage of the nineteenth switch tube M19 connected to the fourth resistor R4 is greater than the control terminal voltage of the twentieth switch tube M20 connected to the eighth resistor R8. Since the nineteenth switch tube M19 is connected to the current input terminal of the twentieth switch tube M20, the voltage difference between the current input terminal and the control terminal of the nineteenth switch tube M19 is smaller than the voltage difference between the current input terminal and the control terminal of the twentieth switch tube M20. Therefore, the current flowing through the twentieth switch tube M20 is greater than the voltage of the nineteenth switch tube M19. The current flowing through the ninth switch tube M19, at this time, since the ninth resistor R9 and the tenth resistor R10 have the same resistance value, it can be obtained that the voltage drop across the tenth resistor R10 is greater than the voltage drop across the ninth resistor R9, so it can be obtained that the voltage at the current output end of the twenty-third switch tube M23 is less than the voltage at the current output end of the twenty-fifth switch tube M25, and the twenty-third switch tube M23 is connected to the control end of the twenty-fifth switch tube M25, therefore, the voltage difference between the control end and the current output end of the twenty-fifth switch tube M25 is less than the voltage difference between the control end and the current output end of the twenty-third switch tube M23, so at this time, the current flowing through the twenty-third switch tube M23 is greater than the current flowing through the twenty-fifth switch tube M25. At this time, by Figure 4From the circuit structure, it can be seen that since the currents flowing through the twenty-second switch tube M22 and the twenty-fourth switch tube M24 are equal, it can be obtained that the current flowing into the E node from the twenty-fourth switch tube M24 is equal to the current flowing through the twenty-third switch tube M23, and the current flowing out of the E node is equal to the current flowing through the twenty-fifth switch tube M25. Therefore, the current flowing into the E node is greater than the current flowing out of the E node, and the voltage of the E node is pulled up, that is, the voltage of the control terminal of the eighteenth switch tube M18 is pulled up to close to the high power supply voltage VIN. At the same time, the current output end of the eighteenth switch tube M18 is grounded through the second transistor Q2, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the third transistor Q3, and the high power supply voltage VIN is obviously much larger than the voltage difference VBE between the base and the emitter of the second transistor Q2 plus the voltage difference VBE between the base and the emitter of the third transistor Q3 plus the voltage difference VGS between the control end and the current output end of the eighteenth switch tube M18. Therefore, the eighteenth switch tube M18 is turned on. At this time, the eighteenth switch tube M18, the second transistor Q2, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the third transistor Q3 are connected to the ground. The second current IO is generated in the branch composed of the resistor R5, the sixth resistor R6, the seventh resistor R7 and the third transistor Q3. As the second current IO increases, the base voltage of the first transistor Q1 and the base voltage of the fourth transistor Q4 both gradually increase, and the base voltage of the first transistor Q1 becomes larger and larger relative to the base voltage of the fourth transistor Q4. Therefore, the voltage difference VBE1 between the base and the emitter of the first transistor Q1 becomes larger and larger relative to the voltage difference VBE4 between the base and the emitter of the fourth transistor Q4, and the voltage difference VBE4 between the base and the emitter of the transistor becomes larger and larger. The influence of the voltage difference on the current is greater than the influence of the number of transistors connected in parallel on the current. Therefore, at this time, it can be obtained that as the second current IO increases, the current IC1 flowing through the first transistor Q1 gradually becomes greater than the current IC2 flowing through the fourth transistor Q4. At this time, combined with the above analysis, it can be seen that the current flowing into the E node is less than the current flowing out of the E node, and the E node voltage is pulled down, that is, the control terminal voltage of the eighteenth switch tube M18 is pulled down. At this time, by setting the parameters of the tenth resistor R10 and the current flowing through the twenty-fifth switch tube M25 in advance, the terminal voltage of the tenth resistor R10 is The voltage is lower than the voltage difference VBE between the base and the emitter of the second transistor Q2 plus the voltage difference VBE between the base and the emitter of the third transistor Q3 plus the voltage difference VGS between the control end and the current output end of the eighteenth switch tube M18. Therefore, when the E node voltage is pulled low, the eighteenth switch tube M18 is turned off, the second current IO decreases, the base voltage of the first transistor Q1 and the base voltage of the fourth transistor Q4 both decrease, and the current IC1 flowing through the first transistor Q1 is smaller than the current IC2 flowing through the fourth transistor Q4, and the circuit enters the next cycle.

[0096] Therefore, when the internal power supply circuit works normally, the current IC1 flowing through the first transistor Q1 is equal to the current IC2 flowing through the fourth transistor Q4; and when the internal power supply circuit works normally, the reference voltage VB output by the internal power supply circuit is designed to be greater than VGS, thereby ensuring that the thirty-second switch tube M32 is in the off state and will not affect the size of the two power supply voltages output by the internal power supply circuit.

[0097] In summary, the power supply circuit of the embodiment of the present application only uses one internal power supply circuit to obtain two power supply voltages, thereby further reducing the size of the power supply circuit.

[0098] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0099] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A small-volume, high-stability power supply circuit, characterized in that: It includes an internal power supply circuit, a regulating circuit and an internal compensation circuit, wherein the internal power supply circuit is connected to a high power supply voltage VIN and outputs a low power supply voltage VR and a reference voltage VB; In the regulation circuit, the high power supply voltage VIN, the low power supply voltage VR and the reference voltage VB are all connected to the control module, and the control module is grounded, and the high power supply voltage VIN is grounded through the first switch tube M1, the first resistor R1, the second resistor R2 and the third resistor R3 in sequence; the control end of the first switch tube M1 is connected to the A node of the control module, the control module is connected between the second resistor R2 and the third resistor R3, and the output end of the power supply circuit is connected to the current output end of the first switch tube M1; The internal compensation circuit includes a second switch tube M2 and a first capacitor C1, the current output end of the second switch tube M2 is connected to the D node of the control module, the control end of the second switch tube M2 is connected between the first resistor R1 and the second resistor R2, the low power supply voltage VR is connected to the current input end of the second switch tube M2, the high voltage end of the first capacitor C1 is connected to the current output end of the second switch tube M2, and the low voltage end of the first capacitor C1 is connected to the B node of the control module; In the control module, the high power supply voltage VIN is grounded through the third switch tube M3 and the first current mirror structure in sequence, and the current output end of the third switch tube M3 is connected to the A node of the control module; the high power supply voltage VIN is also grounded through the fourth switch tube M4 and the first current mirror structure in sequence; The control end of the fourth switch tube M4 is connected to the control end of the third switch tube M3 and is incorporated into the current output end of the fourth switch tube M4; The regulating circuit includes a fifth switch tube M5 and a sixth switch tube M6; A current input terminal of the fifth switch tube M5 is connected to a current output terminal of the third switch tube M3, the current output terminal is grounded through the first current mirror structure, and a control terminal is connected to the low power supply voltage VR; The current input end of the sixth switch tube M6 is connected to the current output end of the fourth switch tube M4 , the current output end is grounded through the first current mirror structure, and the control end is connected to the low power supply voltage VR.

2. The power supply circuit according to claim 1, characterized in that: The control module includes a second current mirror structure, a seventh switch tube M7 and an eighth switch tube M8, the second current mirror structure has a first output end, and the low power supply voltage VR is connected to the second current mirror structure; The current output end of the seventh switch tube M7 is connected to the B node between the fifth switch tube M5 and the first input end of the first current mirror structure, and the reference voltage VB is connected to the control end of the seventh switch tube M7; The current output end of the eighth switch tube M8 is connected to the C node between the sixth switch tube M6 and the second input end of the first current mirror structure, the control end of the eighth switch tube M8 is connected between the second resistor R2 and the third resistor R3, and the current input end of the eighth switch tube M8 is connected to the current input end of the seventh switch tube M7 and is incorporated into the first output end of the second current mirror structure.

3. The power supply circuit according to claim 2, characterized in that: The regulating circuit further includes a first current source I1; the second current mirror structure includes a ninth switch tube M9, a tenth switch tube M10 and an eleventh switch tube M11; The low power supply voltage VR is grounded through the eleventh switch tube M11 and the first current source I1 in sequence, and is also grounded through the tenth switch tube M10 and the first current mirror structure in sequence, and the low power supply voltage VR is connected to the current input terminal of the ninth switch tube M9; The current output end of the ninth switch tube M9 serves as the first output end of the second current mirror structure, and the control ends of the ninth switch tube M9, the tenth switch tube M10 and the eleventh switch tube M11 are connected and merged into the current output end of the eleventh switch tube M11.

4. The power supply circuit according to claim 3, characterized in that: The first current mirror structure includes a twelfth switch tube M12, a thirteenth switch tube M13, a fourteenth switch tube M14 and a fifteenth switch tube M15; The current input end of the twelfth switch tube M12 is connected to the current output end of the tenth switch tube M10, the current input end of the thirteenth switch tube M13 serves as the second input end of the first current mirror structure, the current input end of the fourteenth switch tube M14 serves as the first input end of the first current mirror structure, the current input end of the fifteenth switch tube M15 is connected to the current output end of the second switch tube M2, and the current input end of the fifteenth switch tube M15 serves as the D node of the control module; The current output ends of the twelfth switch tube M12, the thirteenth switch tube M13, the fourteenth switch tube M14 and the fifteenth switch tube M15 are all grounded, and the control ends of the twelfth switch tube M12, the thirteenth switch tube M13, the fourteenth switch tube M14 and the fifteenth switch tube M15 are connected and merged into the current input end of the twelfth switch tube M12.

5. The power supply circuit according to claim 4, characterized in that: In the first current mirror structure, the current ratio of the twelfth switch tube M12, the thirteenth switch tube M13, the fourteenth switch tube M14 and the fifteenth switch tube M15 is M:1:1:N; The fourth switch tube M4 and the third switch tube M3 form a 1:1 current mirror structure.

6. The power supply circuit according to any one of claims 1 to 5, characterized in that: In the internal power supply circuit, the high power supply voltage VIN is grounded through the sixteenth switch tube M16, the fourth resistor R4, the first transistor Q1 and the seventeenth switch tube M17 in sequence, and the high power supply voltage VIN is also grounded through the eighteenth switch tube M18, the second transistor Q2, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the third transistor Q3 in sequence, and the current output end of the sixteenth switch tube M16 is connected to the control end of the sixteenth switch tube M16; The internal power supply circuit further includes an eighth resistor R8 and a fourth transistor Q4, one end of the eighth resistor R8 is connected to the current output end of the sixteenth switch tube M16, and the other end is connected to the collector of the fourth transistor Q4, the emitter of the fourth transistor Q4 is connected between the first transistor Q1 and the seventeenth switch tube M17, and the base of the fourth transistor Q4 is connected between the sixth resistor R6 and the seventh resistor R7; The low power supply voltage end of the internal power supply circuit is connected between the eighteenth switch tube M18 and the second transistor Q2, the reference voltage end of the internal power supply circuit is connected to the F node between the fifth resistor R5 and the sixth resistor R6, and the base of the first transistor Q1 is connected to the F node.

7. The power supply circuit according to claim 6, characterized in that: The number ratio of the first transistor Q1 to the fourth transistor Q4 is 1:K; The fourth resistor R4 and the eighth resistor R8 have the same resistance value; The parameters of the second transistor Q2 and the third transistor Q3 are the same.

8. The power supply circuit according to claim 7, characterized in that: The low power supply voltage VR output by the low power supply voltage terminal satisfies the following formula: The reference voltage VB output by the reference voltage terminal satisfies the following formula: Wherein, VBE represents the voltage difference between the base and the emitter of the second transistor Q2 and the third transistor Q3, and Vt represents the thermal voltage of the transistor.

9. The power supply circuit according to claim 8, characterized in that: By matching the parameters of K, the fifth resistor R5, the sixth resistor R6 and the seventh resistor R7 in the internal power supply circuit, the output low power supply voltage VR and the reference voltage VB are not affected by the temperature.

10. The power supply circuit according to any one of claims 7 to 9, characterized in that: In the internal power supply circuit, the high power supply voltage VIN is also connected to ground via the twenty-first switch tube M21, the nineteenth switch tube M19 and the ninth resistor R9 in sequence; the high power supply voltage VIN is also connected to ground via the twenty-first switch tube M21, the twentieth switch tube M20 and the tenth resistor R10 in sequence; The control end of the nineteenth switch tube M19 is connected between the fourth resistor R4 and the first transistor Q1 , and the control end of the twentieth switch tube M20 is connected between the eighth resistor R8 and the fourth transistor Q4 .

11. The power supply circuit according to claim 10, characterized in that: In the internal power supply circuit, the high power supply voltage VIN is also connected to ground via the twenty-second switch tube M22, the twenty-third switch tube M23 and the ninth resistor R9 in sequence; the high power supply voltage VIN is also connected to ground via the twenty-fourth switch tube M24, the twenty-fifth switch tube M25 and the tenth resistor R10 in sequence; The control ends of the twenty-third switch tube M23 and the twenty-fifth switch tube M25 are connected and merged into the current input end of the twenty-third switch tube M23, and the control end of the eighteenth switch tube M18 is connected to the E node between the twenty-fourth switch tube M24 and the twenty-fifth switch tube M25.

12. The power supply circuit according to claim 11, characterized in that: In the internal power supply circuit, the high power supply voltage VIN is also connected to the ground through the second current source I2 and the twenty-sixth switch tube M26 in sequence; the high power supply voltage VIN is also connected to the ground through the twenty-seventh switch tube M27 and the twenty-eighth switch tube M28 in sequence; The control ends of the twenty-sixth switch tube M26, the seventeenth switch tube M17 and the twenty-eighth switch tube M28 are connected and merged into the current input end of the twenty-sixth switch tube M26.

13. The power supply circuit according to claim 12, characterized in that: In the internal power supply circuit, the high power supply voltage VIN is also connected to the ground through the twenty-ninth switch tube M29, the thirtieth switch tube M30 and the thirty-first switch tube M31 in sequence; the high power supply voltage VIN is also connected to the F node through the thirty-second switch tube M32; Control ends of the twenty-ninth switch tube M29, the twenty-fourth switch tube M24, the twenty-second switch tube M22, the twenty-first switch tube M21 and the twenty-seventh switch tube M27 are connected and merged into the current output end of the twenty-seventh switch tube M27; The control ends of the 30th switch tube M30 and the 32nd switch tube M32 are connected and merged into the current input end of the 30th switch tube M30, and the 31st switch tube M31 adopts a diode connection method.

14. The power supply circuit according to any one of claims 11 to 13, characterized in that: The second transistor Q2 and the third transistor Q3 are both connected by diodes. The ninth resistor R9 and the tenth resistor R10 have the same resistance value; The currents flowing through the twenty-second switch tube M22 and the twenty-fourth switch tube M24 are 1:

1.

15. The power supply circuit according to any one of claims 11 to 13, characterized in that: The resistance of the fifth resistor R5 is equal to the sum of the resistances of the sixth resistor R6 and the seventh resistor R7.

16. The power supply circuit according to any one of claims 7 to 9 and 11 to 13, characterized in that: After the internal power supply circuit works normally, the reference voltage VB is greater than VGS to ensure that the thirty-second switch tube M32 is in the off state, wherein VGS is the voltage difference between the current output terminal and the control terminal of the thirtieth switch tube M30 and the thirty-first switch tube M31.

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