A multi-channel output power supply circuit

Abstract

The present application provides a multi-channel output power supply circuit. The multi-channel output power supply circuit includes a first switch tube M1, a regulating circuit and an output circuit; the current input end of the first switch tube M1 is connected to the input voltage VIN; the emitter of the first transistor Q1 is connected to the current output end of the first switch tube M1, the second transistor Q2 is grounded, and the first transistor Q1 and the second transistor Q2 are both connected by diodes; the first output end of the output circuit is connected to the current output end of the first switch tube M1, so as to be connected to the power supply end through the first switch tube M1, so that the first output end has voltage output capability and current output capability; the second output end of the output circuit is connected to the first node J1 between the first resistor R1 and the second resistor R2, and under the action of the regulating circuit, the current flowing through the second resistor R2, the third resistor R3 and the second transistor Q2 remains unchanged, so that the second output end only has voltage output capability. The multi-channel output power supply circuit of the present invention has a multi-channel output function.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply circuits, and in particular to a multi-channel output power supply circuit. Background Art

[0002] In the prior art, the power supply circuit inside the chip usually has only a single output. When the application scenario requires multiple outputs, a separate power supply circuit needs to be set for each output. In particular, when the power supply circuit only needs to provide a stable voltage output without providing current output capability, an additional independent power supply circuit still needs to be set. This design method not only significantly increases the power consumption of the chip circuit, but also leads to an increase in the chip size and overall complexity, which is not conducive to efficient integration and optimized design. Summary of the invention

[0003] An embodiment of the present invention provides a multi-output power supply circuit, which has multiple outputs and can provide outputs with both current and voltage capabilities, or provide outputs with no current capability but only voltage capability, thereby reducing the power consumption of the chip circuit and reducing the size of the chip circuit.

[0004] According to one aspect of the present invention, a multi-channel output power supply circuit is provided, comprising a first switch tube M1, a regulating circuit and an output circuit, wherein a current input terminal of the first switch tube M1 is connected to an input voltage VIN of a power supply terminal, and a control terminal of the first switch tube M1 is connected to a node B of the regulating circuit;

[0005] The output circuit comprises a first transistor Q1, a first resistor R1, a second resistor R2, a third resistor R3 and a second transistor Q2 which are connected in sequence, the emitter of the first transistor Q1 is connected to the current output end of the first switch tube M1, the second transistor Q2 is grounded, and the first transistor Q1 and the second transistor Q2 are both connected in diode mode;

[0006] The first output end of the output circuit is connected to the current output end of the first switch tube M1 to be connected to the power supply end through the first switch tube M1, so that the first output end has voltage output capability and current output capability;

[0007] The second output end of the output circuit is connected to the first node J1 between the first resistor R1 and the second resistor R2, and under the action of the adjustment circuit, the current flowing through the second resistor R2, the third resistor R3 and the second transistor Q2 remains unchanged, so that the second output end only has voltage output capability.

[0008] In a possible implementation, the regulating circuit includes a third transistor Q3 and a fourth transistor Q4, a second switch tube M2 and a third switch tube M3 connected in sequence;

[0009] The base of the third transistor Q3 is connected to the second node J2 between the second resistor R2 and the third resistor R3, and the emitter of the third transistor Q3 is connected to the current input terminal of the second switch tube M2;

[0010] The base of the fourth transistor Q4 is connected to the first node J1, and the current output terminal of the third switch tube M3 is grounded.

[0011] In a possible implementation, the regulating circuit further includes a fourth resistor R4, a fifth resistor R5 and a fourth switch tube M4;

[0012] One end of the fourth resistor R4 is connected to the collector of the fourth transistor Q4, and the other end is connected to the current output end of the fourth switch tube M4;

[0013] The control end of the fourth switch tube M4 is connected to the current output end of the fourth switch tube M4, and the current input end of the fourth switch tube M4 is connected to the input voltage VIN;

[0014] One end of the fifth resistor R5 is connected to the current output end of the fourth switch tube M4 , and the other end is connected to the collector of the third transistor Q3 .

[0015] In a possible implementation, the regulating circuit further includes a first current mirror structure, which is connected to the power supply end and has a first output end, a second output end, and a third output end;

[0016] The first output end of the first current mirror structure is grounded through the fifth switch tube M5 and the sixth resistor R6 in sequence, the second output end of the first current mirror structure is grounded through the sixth switch tube M6 and the seventh resistor R7 in sequence, the control end of the fifth switch tube M5 is respectively connected to the current input end of the fifth switch tube M5 and the control end of the sixth switch tube M6, and the current input end of the sixth switch tube M6 is also connected to the control end of the first switch tube M1;

[0017] The regulating circuit further includes a seventh switch tube M7 and an eighth switch tube M8, wherein a current input end of the seventh switch tube M7 is connected to a current input end of the eighth switch tube M8 and a third output end of the first current mirror structure, a current output end of the seventh switch tube M7 is connected to a current output end of the fifth switch tube M5, and a control end of the seventh switch tube M7 is connected to a collector of the fourth triode Q4;

[0018] The current output end of the eighth switch tube M8 is connected to the current output end of the sixth switch tube M6 , and the control end of the eighth switch tube M8 is connected to the collector of the third triode Q3 .

[0019] In a possible implementation, the first current mirror structure includes a ninth switch tube M9, a tenth switch tube M10, and an eighth resistor R8 connected in sequence, an eleventh switch tube M11 and a twelfth switch tube M12 connected in sequence, a thirteenth switch tube M13 and a fourteenth switch tube M14 connected in sequence, a fifteenth switch tube M15 and a sixteenth switch tube M16 connected in sequence, and a seventeenth switch tube M17 and an eighteenth switch tube M18 connected in sequence;

[0020] The current input terminals of the ninth switch tube M9, the eleventh switch tube M11, the thirteenth switch tube M13, the fifteenth switch tube M15 and the seventeenth switch tube M17 are all connected to the input voltage VIN, and the control terminals are all connected to the current output terminal of the tenth switch tube M10;

[0021] The control ends of the tenth switch tube M10, the twelfth switch tube M12, the fourteenth switch tube M14, the sixteenth switch tube M16 and the eighteenth switch tube M18 are all connected to the end of the eighth resistor R8 away from the tenth switch tube M10;

[0022] The current output end of the fourteenth switch tube M14 serves as the first output end of the first current mirror structure, the current output end of the sixteenth switch tube M16 serves as the second output end of the first current mirror structure, and the current output end of the twelfth switch tube M12 serves as the third output end of the first current mirror structure.

[0023] In a possible implementation, the regulating circuit further includes a first capacitor C1, one end of the first capacitor C1 is connected to the control end of the first switch tube M1, and the other end is connected to the base of the second transistor Q2 and grounded.

[0024] In a possible implementation, the regulating circuit further includes an RC circuit in which a capacitor and a resistor are connected in series, one end of the RC circuit is connected to the control end of the first switch tube M1, and the other end is connected to the base of the second transistor Q2 and grounded.

[0025] In a possible implementation, the fourth resistor R4 has a resistance value equal to that of the fifth resistor R5, and the sixth resistor R6 has a resistance value equal to that of the seventh resistor R7;

[0026] The number ratio of the fourth transistor Q4 to the third transistor Q3 is 1:A, where A≥1.

[0027] In a possible implementation, the first output terminal voltage V1 of the output circuit satisfies the following formula:

[0028] ;

[0029] The second output terminal voltage V2 of the output circuit satisfies the following formula:

[0030] ;

[0031] Wherein, VBE represents the voltage difference between the base and emitter of the first transistor Q1 and the second transistor Q2, and Vt represents the thermal voltage of the transistor;

[0032] By matching the parameters of A, R1, R2 and R3, the first output terminal voltage V1 and the second output terminal voltage V2 of the output circuit are not affected by temperature.

[0033] In a possible implementation, the resistance of the first resistor R1 is equal to the sum of the resistances of the second resistor R2 and the third resistor R3.

[0034] In a possible implementation, the regulating circuit further includes a second current mirror structure and a first current source I1 connected to the power supply terminal;

[0035] The second current mirror structure includes a ninth resistor R9, a nineteenth switch tube M19 and a twentieth switch tube M20 connected in sequence, a twenty-first switch tube M21 and a twenty-second switch tube M22 connected in sequence, and the second switch tube M2 and the third switch tube M3 connected in sequence, and the ninth resistor R9 is connected to the first current source I1;

[0036] The current output terminals of the 20th switch tube M20, the third switch tube M3 and the 22nd switch tube M22 are all grounded, and the control terminals are all connected to the current input terminal of the 19th switch tube M19;

[0037] The control ends of the nineteenth switch tube M19 , the second switch tube M2 and the twenty-first switch tube M21 are connected to each other and to the output end of the first current source I1 , and the twenty-first switch tube M21 is connected to the eighth resistor R8 .

[0038] In a possible implementation, the multi-output power supply circuit also includes a startup circuit, which is configured to ensure that the voltage difference between the base and the emitter of the third transistor Q3 and the fourth transistor Q4 is greater than the forward conduction voltage drop of the transistor, so that the third transistor Q3 and the fourth transistor Q4 are smoothly turned on.

[0039] In a possible implementation, the startup circuit includes a twenty-third switch tube M23, a twenty-fourth switch tube M24, and a twenty-fifth switch tube M25;

[0040] The twenty-third switch tube M23 and the twenty-fourth switch tube M24 are both diode-connected, the current output end of the twenty-third switch tube M23 is grounded, the current input end of the twenty-third switch tube M23 is connected to the current output end of the twenty-fourth switch tube M24, the current input end of the twenty-fourth switch tube M24 is connected to the current output end of the eighteenth switch tube M18, the twenty-fourth switch tube M24 is connected to the control end of the twenty-fifth switch tube M25, the current output end of the twenty-fifth switch tube M25 is connected to the first node J1, and the current input end of the twenty-fifth switch tube M25 is connected to the input voltage VIN.

[0041] According to the scheme of the embodiment of the present invention, the power supply circuit provides two different types of outputs through the design of the first output terminal and the second output terminal. The first output terminal is connected to the power supply terminal through the first switch tube M1, so that the current output to the load comes from the power supply terminal, and the current output to the load does not affect the size of the regulating current IO in the output circuit. Therefore, the first output terminal has both voltage output capability and current output capability, which can meet the load requirements that require voltage drive and current drive at the same time. At the same time, by making the current flowing through the second resistor R2, the third resistor R3 and the second triode Q2 in the output circuit remain constant, therefore, if the second output terminal outputs current to the load, it will inevitably lead to an increase in the regulating current IO, thereby causing the voltage V1 of the first output terminal to increase, so that the voltage V1 of the first output terminal is no longer stably output, so it is necessary to ensure that the second output terminal cannot provide current output capability, and only has voltage output capability. This design can flexibly adapt to different power requirements, not only expands the scope of application of the power supply circuit, but also effectively reduces the power consumption of the chip circuit, and significantly reduces the chip volume through integrated design.

[0042] Furthermore, in the embodiment of the present application, by providing a startup circuit, it can be ensured that the base voltage of the fourth transistor Q4 is at least VGS, and the base voltage of the third transistor Q3 is at least close to VGS, so that the third transistor Q3 and the fourth transistor Q4 are smoothly turned on.

[0043] In addition, in the embodiment of the present application, by matching the parameters of A, R1, R2 and R3, the first output terminal voltage V1 and the second output terminal voltage V2 of the output circuit can be unaffected by temperature.

[0044] 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

[0045] 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.

[0046] Figure 1 A schematic circuit structure diagram of a multi-output power supply circuit according to an embodiment of the present invention is shown;

[0047] Figure 2 A schematic circuit structure diagram of a multi-output power supply circuit according to another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0048] 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.

[0049] Figure 1 FIG. 1 shows a schematic circuit structure diagram of a multi-channel output power supply circuit according to an embodiment of the present invention. Figure 1 As shown, the multi-channel output power supply circuit includes a first switch tube M1, a regulating circuit and an output circuit. The current input end of the first switch tube M1 is connected to the input voltage VIN of the power supply end, and the control end of the first switch tube M1 is connected to the B node of the regulating circuit. The output circuit includes a first transistor Q1, a first resistor R1, a second resistor R2, a third resistor R3 and a second transistor Q2 connected in sequence. The emitter of the first transistor Q1 is connected to the current output end of the first switch tube M1, and the second transistor Q2 is grounded. The first transistor Q1 and the second transistor Q2 are both connected in a diode manner. The first output end of the output circuit is connected to the current output end of the first switch tube M1 to be connected to the power supply end through the first switch tube M1, so that the first output end has voltage output capability and current output capability. The second output end of the output circuit is connected to the first node J1 between the first resistor R1 and the second resistor R2, and under the action of the regulating circuit, the current flowing through the second resistor R2, the third resistor R3 and the second transistor Q2 remains unchanged, so that the second output end only has voltage output capability.

[0050] The power supply circuit provides two different types of outputs through the design of the first output terminal and the second output terminal. The first output terminal is connected to the power supply terminal through the first switch tube M1, so that the current output to the load comes from the power supply terminal, and the current output to the load does not affect the size of the regulating current IO in the output circuit. Therefore, the first output terminal has both voltage output capability and current output capability, which can meet the load requirements that require both voltage drive and current drive. At the same time, by making the current flowing through the second resistor R2, the third resistor R3 and the second triode Q2 in the output circuit remain constant, therefore, if the second output terminal outputs current to the load, it will inevitably cause the regulating current IO to increase, thereby causing the voltage V1 of the first output terminal to increase, so that the voltage V1 of the first output terminal is no longer stably output, so it is necessary to ensure that the second output terminal cannot provide current output capability, and only has voltage output capability. This design can flexibly adapt to different power requirements, not only expands the scope of application of the power supply circuit, but also effectively reduces the power consumption of the chip circuit, and significantly reduces the chip volume through integrated design.

[0051] Figure 2 FIG. 2 shows a schematic circuit structure diagram of a multi-channel output power supply circuit according to another embodiment of the present invention. Figure 2 As shown, the regulating circuit includes a third triode Q3 and a fourth triode Q4, a second switch tube M2 and a third switch tube M3 connected in sequence. The base of the third triode Q3 is connected to the second node J2 between the second resistor R2 and the third resistor R3, and the emitter of the third triode Q3 is connected to the current input end of the second switch tube M2. The base of the fourth triode Q4 is connected to the first node J1, and the current output end of the third switch tube M3 is grounded. Since the base of the third triode Q3 is connected to the second node J2 and the base of the fourth triode Q4 is connected to the first node J1, when the third triode Q3 and the fourth triode Q4 are turned on, the current flowing through the second resistor R2, the third resistor R3 and the second triode Q2 remains unchanged through the feedback mechanism of the regulating circuit. In some embodiments, the number ratio of the fourth triode Q4 to the third triode Q3 is 1:A, A≥1.

[0052] In some embodiments, the regulating circuit further includes a fourth resistor R4, a fifth resistor R5 and a fourth switch tube M4. One end of the fourth resistor R4 is connected to the collector of the fourth triode Q4, and the other end is connected to the current output end of the fourth switch tube M4. The control end of the fourth switch tube M4 is connected to the current output end of the fourth switch tube M4, and the current input end of the fourth switch tube M4 is connected to the input voltage VIN. One end of the fifth resistor R5 is connected to the current output end of the fourth switch tube M4, and the other end is connected to the collector of the third triode Q3. In one embodiment, the fourth resistor R4 and the fifth resistor R5 have the same resistance.

[0053] In some embodiments, the regulating circuit also includes a first current mirror structure. The first current mirror structure is connected to the power supply end and has a first output end, a second output end and a third output end. The first output end of the first current mirror structure is grounded through the fifth switch tube M5 and the sixth resistor R6 in sequence. The second output end of the first current mirror structure is grounded through the sixth switch tube M6 and the seventh resistor R7 in sequence. The control end of the fifth switch tube M5 is respectively connected to the current input end of the fifth switch tube M5 and the control end of the sixth switch tube M6. The current input end of the sixth switch tube M6 is also connected to the control end of the first switch tube M1, that is, the current input end of the sixth switch tube M6 is connected to the B node. In one embodiment, the resistance of the sixth resistor R6 is equal to that of the seventh resistor R7.

[0054] The regulating circuit also includes a seventh switch tube M7 and an eighth switch tube M8, wherein the current input end of the seventh switch tube M7 is connected to the current input end of the eighth switch tube M8 and the third output end of the first current mirror structure, the current output end of the seventh switch tube M7 is connected to the current output end of the fifth switch tube M5, and the control end of the seventh switch tube M7 is connected to the collector of the fourth triode Q4. The current output end of the eighth switch tube M8 is connected to the current output end of the sixth switch tube M6, and the control end of the eighth switch tube M8 is connected to the collector of the third triode Q3.

[0055] In some embodiments, the first current mirror structure includes a ninth switch tube M9, a tenth switch tube M10 and an eighth resistor R8 connected in sequence, an eleventh switch tube M11 and a twelfth switch tube M12 connected in sequence, a thirteenth switch tube M13 and a fourteenth switch tube M14 connected in sequence, a fifteenth switch tube M15 and a sixteenth switch tube M16 connected in sequence, and a seventeenth switch tube M17 and an eighteenth switch tube M18 connected in sequence. The current input terminals of the ninth switch tube M9, the eleventh switch tube M11, the thirteenth switch tube M13, the fifteenth switch tube M15 and the seventeenth switch tube M17 are all connected to the input voltage VIN, and the control terminals are all connected to the current output terminal of the tenth switch tube M10. The control terminals of the tenth switch tube M10, the twelfth switch tube M12, the fourteenth switch tube M14, the sixteenth switch tube M16 and the eighteenth switch tube M18 are all connected to the end of the eighth resistor R8 away from the tenth switch tube M10. The current output end of the fourteenth switch tube M14 serves as the first output end of the first current mirror structure, the current output end of the sixteenth switch tube M16 serves as the second output end of the first current mirror structure, and the current output end of the twelfth switch tube M12 serves as the third output end of the first current mirror structure. The design of the first current mirror structure realizes high-precision current replication and distribution through multi-stage series connection, precise matching of switch tubes and resistor networks, and provides flexible multi-channel output and dynamic adjustment capabilities.

[0056] When the circuit is just powered on, the current in the third transistor Q3 and the fourth transistor Q4 is small, so at this time, the voltage drop across the fourth resistor R4 and the fifth resistor R5 is small. At this time, if the fourth switch tube M4 does not exist, the fourth resistor R4 and the fifth resistor R5 are directly connected to the input voltage VIN, then the terminal voltage of the fourth resistor R4 and the fifth resistor R5 far from the input voltage will be larger, close to the input voltage VIN, resulting in a larger control terminal voltage of the seventh switch tube M7 and the eighth switch tube M8, making the seventh switch tube M7 and the eighth switch tube M8 unable to conduct. Therefore, at this time, the fourth switch tube M4 is set in the circuit, so that the terminal voltage of the fourth resistor R4 and the fifth resistor R5 close to the input voltage VIN is VIN-VGS. And by Figure 2 It can be seen that when the control terminal voltage of the seventh switch tube M7 and the eighth switch tube M8 is less than VIN-2VDS-VGS, they can be smoothly turned on, and because the VDS at both ends of the eleventh switch tube M11 and the twelfth switch tube M12 are small after they are turned on, therefore, when the fourth switch tube M4 is set in the circuit, it can ensure that the terminal voltage of the fourth resistor R4 and the fifth resistor R5 is far away from the input voltage, that is, the control terminal voltage of the seventh switch tube M7 and the eighth switch tube M8 is less than VIN-2VDS-VGS, so that the seventh switch tube M7 and the eighth switch tube M8 are smoothly turned on.

[0057] In some embodiments, the thirteenth switch tube M13 and the fourteenth switch tube M14 constitute the first branch of the first current mirror, and the fifteenth switch tube M15 and the sixteenth switch tube M16 constitute the second branch of the first current mirror. The current ratio flowing through the first branch and the second branch is set to 1:1. The current ratio of the first branch to the second branch is set to 1:1, and the resistance values ​​of the sixth resistor R6 and the seventh resistor R7 are set to be equal, which can significantly enhance the symmetry, accuracy and stability of the current output, while simplifying the circuit design process and reducing power consumption. In addition, in actual circuit design, the ratio of the current mirror branch is usually determined by the device size (such as the transistor width-to-length ratio W / L). The design fixed to 1:1 allows the sizes of the thirteenth switch tube M13 and the fifteenth switch tube M15, the fourteenth switch tube M14 and the sixteenth switch tube M16 to remain consistent, simplifying the device parameter matching process and reducing the design complexity.

[0058] In some embodiments, the regulating circuit further includes a first capacitor C1. One end of the first capacitor C1 is connected to the control end of the first switch tube M1, and the other end is connected to the base of the second transistor Q2 and grounded. During the operation of the circuit, load changes or other transient interferences may cause fluctuations in the voltage of the B node. The control end of the first switch tube M1 is directly connected to the B node, and its switching state is controlled by the change of the B node voltage. If the B node voltage is unstable, it will lead to uncertainty in the working state of the first switch tube M1, and the phenomenon of increased noise or decreased output performance may occur. The first capacitor C1 can be used as an element for storing charge in a short time. When the B node voltage increases, the first capacitor C1 absorbs excess charge. When the B node voltage decreases, the first capacitor C1 releases the stored charge, thereby smoothing the voltage fluctuation of the B node. Therefore, the first capacitor C1 ensures the accuracy of the control signal by compensating the B node voltage, thereby ensuring the stable operation of the first switch tube M1. In other embodiments, the first capacitor C1 can be replaced by an RC circuit in which a capacitor and a resistor are connected in series.

[0059] In some embodiments, the regulating circuit further includes a second current mirror structure and a first current source I1 connected to the power supply terminal. The second current mirror structure includes a ninth resistor R9, a nineteenth switch tube M19 and a twentieth switch tube M20 connected in sequence, a twenty-first switch tube M21 and a twenty-second switch tube M22 connected in sequence, and a second switch tube M2 and a third switch tube M3 connected in sequence, and the ninth resistor R9 is connected to the first current source I1. The current output ends of the twentieth switch tube M20, the third switch tube M3 and the second switch tube M22 are all grounded, and the control ends are all connected to the current input end of the nineteenth switch tube M19. The control ends of the nineteenth switch tube M19, the second switch tube M2 and the twenty-first switch tube M21 are connected and connected to the output end of the first current source I1, and the twenty-first switch tube M21 is connected to the eighth resistor R8. The use of the second current mirror structure can ensure the high consistency and accuracy of current replication.

[0060] In some embodiments, the multi-channel output power supply circuit further includes a startup circuit. The startup circuit is configured to ensure that the base voltage of the fourth transistor Q4 is at least VGS, and the base voltage of the third transistor Q3 is at least close to VGS, so that the third transistor Q3 and the fourth transistor Q4 are smoothly turned on. The startup circuit includes a twenty-third switch tube M23, a twenty-fourth switch tube M24, and a twenty-fifth switch tube M25. The twenty-third switch tube M23 and the twenty-fourth switch tube M24 are both diode-connected, the current output end of the twenty-third switch tube M23 is grounded, the current input end of the twenty-third switch tube M23 is connected to the current output end of the twenty-fourth switch tube M24, the current input end of the twenty-fourth switch tube M24 is connected to the current output end of the eighteenth switch tube M18, the twenty-fourth switch tube M24 is connected to the control end of the twenty-fifth switch tube M25, the current output end of the twenty-fifth switch tube M25 is connected to the first node J1, and the current input end of the twenty-fifth switch tube M25 is connected to the input voltage VIN. In some embodiments, the twenty-third switch tube M23 and the twenty-fourth switch tube M24 have the same parameters.

[0061] The working principle of the multi-channel output power supply circuit is:

[0062] After the circuit is powered on, the first current source I1 generates a pull-up current, which pulls up the control terminal voltages of the 20th switch tube M20, the 3rd switch tube M3, and the 22nd switch tube M22 through the 9th resistor R9, and the 20th switch tube M20, the 3rd switch tube M3, and the 22nd switch tube M22 are turned on. At this time, the voltages of the current output terminals of the 19th switch tube M19, the 2nd switch tube M2, and the 21st switch tube M21 are pulled down by the 20th switch tube M20, the 3rd switch tube M3, and the 22nd switch tube M22, respectively. At the same time, the pull-up current pulls up the control terminal voltages of the 19th switch tube M19, the 2nd switch tube M2, and the 21st switch tube M21 are turned on. At this time, the control terminal voltages of the ninth switch tube M9, the eleventh switch tube M11, the thirteenth switch tube M13, the fifteenth switch tube M15 and the seventeenth switch tube M17 are pulled down through the eighth resistor R8, the twenty-first switch tube M21 and the twenty-second switch tube M22. Since the current input terminal voltages of the ninth switch tube M9, the eleventh switch tube M11, the thirteenth switch tube M13, the fifteenth switch tube M15 and the seventeenth switch tube M17 are the input voltage VIN, that is, the power supply voltage, the ninth switch tube M9, the eleventh switch tube M11, the thirteenth switch tube M13, the fifteenth switch tube M15 and the seventeenth switch tube M17 are turned on. At this time, the ninth switch tube M9, the eleventh switch tube M11, the thirteenth switch tube M13, the fifteenth switch tube M15 and the seventeenth switch tube M17 respectively pull up the current input terminal voltages of the tenth switch tube M10, the twelfth switch tube M12, the fourteenth switch tube M14, the sixteenth switch tube M16 and the eighteenth switch tube M18. At the same time, the control terminal voltages of the tenth switch tube M10, the twelfth switch tube M12, the fourteenth switch tube M14, the sixteenth switch tube M16 and the eighteenth switch tube M18 are pulled down through the twenty-first switch tube M21 and the twenty-second switch tube M22. Therefore, the tenth switch tube M10, the twelfth switch tube M12, the fourteenth switch tube M14, the sixteenth switch tube M16 and the eighteenth switch tube M18 are turned on.

[0063] Afterwards, the power supply voltage pulls up the voltage of the control terminal and the current input terminal of the twenty-fourth switch tube M24 through the seventeenth switch tube M17 and the eighteenth switch tube M18. At the same time, the twenty-third switch tube M23 and the twenty-fourth switch tube M24 are both diode-connected. At this time, since the input voltage VIN is greater than the sum of the voltage differences between the current input terminal and the control terminal of the twenty-third switch tube M23 and the twenty-fourth switch tube M24, 2VGS, at this time, the twenty-third switch tube M23 and the twenty-fourth switch tube M24 are both turned on. Therefore, according to the circuit structure, the control terminal voltage of the twenty-fourth switch tube M24 is equal to 2VGS, that is, the control terminal voltage of the twenty-fifth switch tube M25 is equal to 2VGS. Therefore, at this time, when the current output terminal voltage of the twenty-fifth switch tube M25 is less than VGS, the twenty-fifth switch tube M25 is turned on, and the current output terminal voltage of the twenty-fifth switch tube M25 is clamped at VGS. When the voltage at the current output terminal of the twenty-fifth switch tube M25 is greater than VGS, the twenty-fifth switch tube M25 is not turned on, but the base voltage of the fourth triode Q4 is greater than VGS. Therefore, the startup circuit provided in the present application can ensure that the base voltage of the fourth triode Q4 is at least VGS, and the base voltage of the third triode Q3 is at least close to VGS, that is, to ensure that the voltage difference between the base and the emitter of the third triode Q3 and the fourth triode Q4 is greater than the forward conduction voltage drop of the triode. The forward conduction voltage drop of the triode is generally 0.7V, and VGS is generally greater than 0.7V, and can be selected as 1.2V. Furthermore, since the fourth triode Q4 and the third triode Q3 are grounded through the second switch tube M2 and the third switch tube M3, and after the second switch tube M2 and the third switch tube M3 are turned on, the VDS at both ends thereof is small. Therefore, at this time, when the base voltage of the fourth triode Q4 is at least VGS and the base voltage of the third triode Q3 is at least close to VGS, the fourth triode Q4 and the third triode Q3 can be smoothly turned on, and the circuit thus completes the startup process.

[0064] After the fourth transistor Q4 and the third transistor Q3 are turned on, the control terminal voltage of the fourth switch tube M4 is pulled down through the fourth resistor R4, the fourth transistor Q4, the second switch tube M2 and the third switch tube M3, and the fourth switch tube M4 is turned on. Therefore, current flows through the fourth transistor Q4 and the third transistor Q3. At this time, since the ratio of the number of the fourth transistor Q4 to the number of the third transistor Q3 is 1:A, and when the circuit is just powered on, the base voltage of the fourth transistor Q4 is very small compared with the base voltage of the third transistor Q3, at this time, the number ratio of the transistors has a greater impact on the current flowing through the transistors. Therefore, the current IC1 flowing through the fourth transistor Q4 is less than the current IC2 flowing through the third transistor Q3, and since the fourth resistor R4 and the fifth resistor R5 have equal resistance values, the voltage drop across the fourth resistor R4 is less than the voltage drop across the fifth resistor R5. Since the fourth resistor R4 is connected to one end of the fifth resistor R5, it can be obtained that the control terminal voltage of the seventh switch tube M7 connected to the fourth resistor R4 is greater than the control terminal voltage of the eighth switch tube M8 connected to the fifth resistor R5. Since the seventh switch tube M7 is connected to the current input end of the eighth switch tube M8, the voltage difference between the current input end and the control end of the seventh switch tube M7 is less than the voltage difference between the current input end and the control end of the eighth switch tube M8. Therefore, the current flowing through the eighth switch tube M8 is greater than the current flowing through the seventh switch tube M7. At this time, since the sixth resistor R6 and the seventh resistor R7 have the same resistance value, it can be obtained that the voltage drop across the sixth resistor R6 is less than the voltage drop across the seventh resistor R7, so it can be obtained that the current output terminal voltage of the fifth switch tube M5 is less than the current output terminal voltage of the sixth switch tube M6. The fifth switch tube M5 is connected to the control end of the sixth switch tube M6, so the voltage difference between the control end and the current output end of the sixth switch tube M6 is less than the voltage difference between the control end and the current output end of the fifth switch tube M5. Therefore, at this time, the current flowing through the fifth switch tube M5 is greater than the current flowing through the sixth switch tube M6. Figure 2From the circuit structure, it can be seen that the thirteenth switch tube M13, the fourteenth switch tube M14, the fifteenth switch tube M15 and the sixteenth switch tube M16 are two branches of the current mirror, and the ratio of the current flowing through the two branches is set to 1:1. In addition, since the current mirror branch formed by the thirteenth switch tube M13 and the fourteenth switch tube M14 is connected in series with the fifth switch tube M5, the current of the current mirror branch formed by the fifteenth switch tube M15 and the sixteenth switch tube M16 flows to the connection node B between the control end of the first switch tube M1 and the current input end of the sixth switch tube M6. Therefore, the current flowing through the fifth switch tube M5 is equal to the current of the current mirror branch. Therefore, it can be obtained that the current flowing into the B node is equal to the current flowing through the fifth switch tube M5, and the current flowing out of the B node is equal to the current flowing through the fifth switch tube M5. The current is equal to the current flowing through the sixth switch tube M6. Therefore, the voltage of the B node is pulled up, that is, the voltage of the control terminal of the first switch tube M1 is pulled up to be close to the power supply voltage. At the same time, the current output terminal of the first switch tube M1 is grounded through the first transistor Q1, the first resistor R1, the second resistor R2, the third resistor R3 and the second transistor Q2. The power supply voltage is obviously much larger than the voltage difference VBE between the base and the emitter of the first transistor Q1 plus the voltage difference VBE between the base and the emitter of the second transistor Q2 plus the voltage difference VGS between the control terminal and the current output terminal of the first switch tube M1. Therefore, the first switch tube M1 is turned on. At this time, the first switch tube M1, the first transistor Q1, the first resistor R1, the second resistor R2, the third resistor R3 and the second transistor Q2 are connected to the ground. A regulating current IO is generated in the branch composed of the resistor R3 and the second transistor Q2. As the regulating current IO increases, the base voltage of the fourth transistor Q4 and the base voltage of the third transistor Q3 both gradually increase, and the base voltage of the fourth transistor Q4 becomes larger and larger relative to the base voltage of the third transistor Q3. Therefore, the voltage difference VBE1 between the base and the emitter of the fourth transistor Q4 becomes larger and larger relative to the voltage difference VBE2 between the base and the emitter of the third transistor Q3. In addition, the influence of the voltage difference between the base and the emitter of the transistor on the current is greater than the influence of the number of transistors connected in parallel on the current. Therefore, it can be obtained that as the regulating current IO increases, the current IC1 flowing through the fourth transistor Q4 gradually becomes larger than the current IC1 flowing through the third transistor Q3. The current IC2 flows through the fourth resistor R4, and since the fourth resistor R4 and the fifth resistor R5 have the same resistance value, the voltage drop across the fourth resistor R4 is greater than the voltage drop across the fifth resistor R5. Since the fourth resistor R4 is connected to one end of the fifth resistor R5, it can be obtained that the control terminal voltage of the seventh switch tube M7 connected to the fourth resistor R4 is less than the control terminal voltage of the eighth switch tube M8 connected to the fifth resistor R5. Since the seventh switch tube M7 is connected to the current input end of the eighth switch tube M8, the voltage difference between the current input end and the control end of the seventh switch tube M7 is greater than the voltage difference between the current input end and the control end of the eighth switch tube M8. Therefore, the current flowing through the eighth switch tube M8 is less than the current flowing through the seventh switch tube M7. At this time,Since the sixth resistor R6 and the seventh resistor R7 have the same resistance value, it can be obtained that the voltage drop across the sixth resistor R6 is greater than the voltage drop across the seventh resistor R7, and thus it can be obtained that the voltage at the current output terminal of the fifth switch tube M5 is greater than the voltage at the current output terminal of the sixth switch tube M6. In addition, the fifth switch tube M5 is connected to the control terminal of the sixth switch tube M6, so the voltage difference between the control terminal and the current output terminal of the sixth switch tube M6 is greater than the voltage difference between the control terminal and the current output terminal of the fifth switch tube M5. Therefore, at this time, the current flowing through the fifth switch tube M5 is less than the current flowing through the sixth switch tube M6. At this time, according to, Figure 2 It can be seen from the circuit structure that the thirteenth switch tube M13, the fourteenth switch tube M14, the fifteenth switch tube M15 and the sixteenth switch tube M16 are two branches of the current mirror, and the ratio of the current flowing through the two branches is set to 1:1. In addition, since the current mirror branch formed by the thirteenth switch tube M13 and the fourteenth switch tube M14 is connected in series with the fifth switch tube M5, the current of the current mirror branch formed by the fifteenth switch tube M15 and the sixteenth switch tube M16 flows to the connection node B between the control end of the first switch tube M1 and the current input end of the sixth switch tube M6. Therefore, the current flowing through the fifth switch tube M5 is equal to the current of the current mirror branch. Therefore, it can be obtained that the current flowing into the B node is equal to the current flowing through the fifth switch tube M5, and the current flowing out of the B node is equal to the current flowing through the sixth switch tube M6. Therefore, the voltage of the B node is pulled down, that is, the voltage of the control end of the first switch tube M1 is pulled down. At this time, by setting the parameters of the seventh resistor R7 and the current flowing through the sixth switch tube M6 in advance, the terminal voltage of the seventh resistor R7 is lower than the voltage difference VBE between the base and the emitter of the first transistor Q1 plus the voltage difference VBE between the base and the emitter of the second transistor Q2 plus the voltage difference VGS between the control end and the current output end of the first switch tube M1. Therefore, when the voltage at the B node is pulled low, the first switch tube M1 is turned off, the base voltage of the fourth transistor Q4 and the base voltage of the third transistor Q3 are both reduced, and the current IC1 flowing through the fourth transistor Q4 is smaller than the current IC2 flowing through the third transistor Q3, and the circuit enters the next cycle process.

[0065] It can be seen that when the regulating circuit enters a stable working state, that is, when the power supply circuit works normally, the current IC1 flowing through the fourth transistor Q4 is equal to the current IC2 flowing through the third transistor Q3. At the same time, it can be seen from the circuit structure that VBE1=VBE2+VR2, where VR2 is the voltage difference across the second resistor R2, and VR2=IO×R2. At this time, combined with the transistor current formula, it can be obtained: , it can be seen that the adjustment current , where Vt is the thermal voltage and R2 is the resistance of the second resistor.

[0066] Therefore, the first output voltage , the second output voltage At this time, first, the first transistor Q1 and the second transistor Q2 are designed to have exactly the same parameters. Therefore, VBE3 of the first transistor Q1 is equal to VBE4 of the second transistor Q2, 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 A, R1, R2 and R3 with appropriate parameters, the first output voltage V1 and the second output voltage V2 can be made unaffected by temperature, thereby improving the accuracy of the output voltage. In a preferred embodiment, the resistance of the first resistor R1 is designed to be equal to the sum of the resistances of the second resistor R2 and the third resistor R3. At this time, the obtained first output voltage V1 is twice the second output voltage V2. At the same time, the second output voltage V2 is designed to be greater than VGS, thereby ensuring that when the regulation circuit enters a stable working state, the twenty-fifth switch tube M25 is in an off state and will not affect the normal operation of the circuit.

[0067] 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.

[0068] 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 multi-channel output power supply circuit, characterized in that: It includes a first switch tube M1, a regulating circuit and an output circuit, wherein the current input end of the first switch tube M1 is connected to the input voltage VIN of the power supply end, and the control end of the first switch tube M1 is connected to the B node of the regulating circuit; The output circuit comprises a first transistor Q1, a first resistor R1, a second resistor R2, a third resistor R3 and a second transistor Q2 which are connected in sequence, the emitter of the first transistor Q1 is connected to the current output end of the first switch tube M1, the second transistor Q2 is grounded, and the first transistor Q1 and the second transistor Q2 are both connected in diode mode; The first output end of the output circuit is connected to the current output end of the first switch tube M1 to be connected to the power supply end through the first switch tube M1, so that the first output end has voltage output capability and current output capability; The second output end of the output circuit is connected to the first node J1 between the first resistor R1 and the second resistor R2, and under the action of the regulating circuit, the current flowing through the second resistor R2, the third resistor R3 and the second transistor Q2 remains unchanged, so that the second output end has only voltage output capability; The regulating circuit includes a third triode Q3 and a fourth triode Q4, a second switch tube M2 and a third switch tube M3 connected in sequence; The base of the third transistor Q3 is connected to the second node J2 between the second resistor R2 and the third resistor R3, and the emitter of the third transistor Q3 is connected to the current input terminal of the second switch tube M2; The base of the fourth transistor Q4 is connected to the first node J1, and the current output terminal of the third switch tube M3 is grounded; The regulating circuit also includes a fourth resistor R4, a fifth resistor R5 and a fourth switch tube M4; One end of the fourth resistor R4 is connected to the collector of the fourth transistor Q4, and the other end is connected to the current output end of the fourth switch tube M4; The control end of the fourth switch tube M4 is connected to the current output end of the fourth switch tube M4, and the current input end of the fourth switch tube M4 is connected to the input voltage VIN; One end of the fifth resistor R5 is connected to the current output end of the fourth switch tube M4 , and the other end is connected to the collector of the third transistor Q3 .

2. The multi-output power supply circuit according to claim 1, characterized in that: The regulating circuit further includes a first current mirror structure, which is connected to the power supply terminal and has a first output terminal, a second output terminal and a third output terminal; The first output end of the first current mirror structure is grounded through the fifth switch tube M5 and the sixth resistor R6 in sequence, the second output end of the first current mirror structure is grounded through the sixth switch tube M6 and the seventh resistor R7 in sequence, the control end of the fifth switch tube M5 is respectively connected to the current input end of the fifth switch tube M5 and the control end of the sixth switch tube M6, and the current input end of the sixth switch tube M6 is also connected to the control end of the first switch tube M1; The regulating circuit further includes a seventh switch tube M7 and an eighth switch tube M8, wherein a current input end of the seventh switch tube M7 is connected to a current input end of the eighth switch tube M8 and a third output end of the first current mirror structure, a current output end of the seventh switch tube M7 is connected to a current output end of the fifth switch tube M5, and a control end of the seventh switch tube M7 is connected to a collector of the fourth triode Q4; The current output end of the eighth switch tube M8 is connected to the current output end of the sixth switch tube M6 , and the control end of the eighth switch tube M8 is connected to the collector of the third triode Q3 .

3. The multi-output power supply circuit according to claim 2, characterized in that: The first current mirror structure includes a ninth switch tube M9, a tenth switch tube M10 and an eighth resistor R8 connected in sequence, an eleventh switch tube M11 and a twelfth switch tube M12 connected in sequence, a thirteenth switch tube M13 and a fourteenth switch tube M14 connected in sequence, a fifteenth switch tube M15 and a sixteenth switch tube M16 connected in sequence, and a seventeenth switch tube M17 and an eighteenth switch tube M18 connected in sequence; The current input terminals of the ninth switch tube M9, the eleventh switch tube M11, the thirteenth switch tube M13, the fifteenth switch tube M15 and the seventeenth switch tube M17 are all connected to the input voltage VIN, and the control terminals are all connected to the current output terminal of the tenth switch tube M10; The control ends of the tenth switch tube M10, the twelfth switch tube M12, the fourteenth switch tube M14, the sixteenth switch tube M16 and the eighteenth switch tube M18 are all connected to the end of the eighth resistor R8 away from the tenth switch tube M10; The current output end of the fourteenth switch tube M14 serves as the first output end of the first current mirror structure, the current output end of the sixteenth switch tube M16 serves as the second output end of the first current mirror structure, and the current output end of the twelfth switch tube M12 serves as the third output end of the first current mirror structure.

4. The multi-output power supply circuit according to any one of claims 1 to 3, characterized in that: The regulating circuit further includes a first capacitor C1 , one end of which is connected to the control end of the first switch tube M1 , and the other end of which is connected to the base of the second transistor Q2 and grounded.

5. The multi-output power supply circuit according to any one of claims 1 to 3, characterized in that: The regulating circuit further includes an RC circuit in which a capacitor and a resistor are connected in series, one end of the RC circuit is connected to the control end of the first switch tube M1 , and the other end is connected to the base of the second transistor Q2 and grounded.

6. The multi-output power supply circuit according to claim 2 or 3, characterized in that: The fourth resistor R4 has the same resistance as the fifth resistor R5, and the sixth resistor R6 has the same resistance as the seventh resistor R7; The number ratio of the fourth transistor Q4 to the third transistor Q3 is 1:A, where A≥1.

7. The multi-output power supply circuit according to claim 6, characterized in that: The first output terminal voltage V1 of the output circuit satisfies the following formula: ； The second output terminal voltage V2 of the output circuit satisfies the following formula: ； Wherein, VBE represents the voltage difference between the base and emitter of the first transistor Q1 and the second transistor Q2, and Vt represents the thermal voltage of the transistor; By matching the parameters of A, R1, R2 and R3, the first output terminal voltage V1 and the second output terminal voltage V2 of the output circuit are not affected by temperature.

8. The multi-output power supply circuit according to claim 7, characterized in that: The resistance of the first resistor R1 is equal to the sum of the resistances of the second resistor R2 and the third resistor R3.

9. The multi-output power supply circuit according to any one of claims 3 and 7-8, characterized in that: The regulating circuit also includes a second current mirror structure and a first current source I1 connected to the power supply terminal; The second current mirror structure includes a ninth resistor R9, a nineteenth switch tube M19 and a twentieth switch tube M20 connected in sequence, a twenty-first switch tube M21 and a twenty-second switch tube M22 connected in sequence, and the second switch tube M2 and the third switch tube M3 connected in sequence, and the ninth resistor R9 is connected to the first current source I1; The current output terminals of the 20th switch tube M20, the third switch tube M3 and the 22nd switch tube M22 are all grounded, and the control terminals are all connected to the current input terminal of the 19th switch tube M19; The control ends of the nineteenth switch tube M19 , the second switch tube M2 and the twenty-first switch tube M21 are connected to each other and to the output end of the first current source I1 , and the twenty-first switch tube M21 is connected to the eighth resistor R8 .

10. The multi-output power supply circuit according to any one of claims 3 and 7-8, characterized in that: It also includes a starting circuit, which is configured to ensure that the voltage difference between the base and the emitter of the third transistor Q3 and the fourth transistor Q4 is greater than the forward conduction voltage drop of the transistor, so that the third transistor Q3 and the fourth transistor Q4 are smoothly turned on.

11. The multi-output power supply circuit according to claim 10, characterized in that: The startup circuit includes a twenty-third switch tube M23, a twenty-fourth switch tube M24 and a twenty-fifth switch tube M25; The twenty-third switch tube M23 and the twenty-fourth switch tube M24 are both diode-connected, the current output end of the twenty-third switch tube M23 is grounded, the current input end of the twenty-third switch tube M23 is connected to the current output end of the twenty-fourth switch tube M24, the current input end of the twenty-fourth switch tube M24 is connected to the current output end of the eighteenth switch tube M18, the twenty-fourth switch tube M24 is connected to the control end of the twenty-fifth switch tube M25, the current output end of the twenty-fifth switch tube M25 is connected to the first node J1, and the current input end of the twenty-fifth switch tube M25 is connected to the input voltage VIN.

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