Power supply output adjusting circuit and power supply system

Abstract

The utility model provides a power supply output adjusting circuit and a power supply system. The power supply output adjusting circuit comprises a voltage reference sub-circuit which comprises a first output end used for outputting a first voltage; the sampling sub-circuit comprises a second output end for outputting a second voltage; the negative feedback sub-circuit comprises a first input end, a second input end and a third output end used for outputting a control level according to the first voltage and the second voltage, and the first output end is connected with the first input end; the second output end is connected with the second input end; the dummy load comprises a control end for accessing a control level, a first end connected to the power supply output end, and a second end grounded. When the external load connected with the power supply is smaller than the minimum load of the power supply, the overall load of the power supply works together by the dummy load and the external load, so that the overall load is equal to the minimum load of the power supply; and when the external load of the power supply is greater than or equal to the minimum load of the power supply, the dummy load is in a cut-off state and does not participate in work to improve the conversion efficiency of the power supply.

Description

Technical Field

[0001] This utility model relates to the field of power supply design technology, specifically to a power output regulation circuit and power supply system. Background Technology

[0002] In power supply design, to prevent the power supply's output voltage from exceeding the target output voltage (or the designed expected output value) when the load is light, a dummy load is usually incorporated into the power supply to ensure a stable output voltage. Currently, a resistor is commonly used as this dummy load. However, in this case, if the resistance value is too small, the power supply's output voltage will still exceed the expected output voltage; if the resistance value is too large, the resistor acts as a load, reducing the power supply's efficiency. Utility Model Content

[0003] In view of the shortcomings of the existing technology, this utility model provides a power output regulation circuit and power system.

[0004] In a first aspect, in some embodiments, the present invention provides a power output regulation circuit comprising: a voltage reference sub-circuit, a negative feedback sub-circuit, a dummy load, and a sampling sub-circuit; wherein; the voltage reference sub-circuit includes a first output terminal for outputting a first voltage; the first voltage has a constant voltage value; the sampling sub-circuit includes a second output terminal for outputting a second voltage; the second voltage is determined by the output voltage of the power output terminal; the negative feedback sub-circuit includes a first input terminal, a second input terminal, and a third output terminal for outputting a control level according to the first voltage and the second voltage, wherein the first output terminal is connected to the first input terminal; the second output terminal is connected to the second input terminal; the dummy load includes a control terminal for connecting the control level, a first terminal connected to the power output terminal, and a second terminal grounded.

[0005] In some embodiments, the voltage reference subcircuit includes a Zener diode and a first resistor; the Zener diode and the first resistor are connected to a first node serving as the first output terminal; the first resistor is connected between the power output terminal and the first node; and the Zener diode is connected between the first node and ground.

[0006] In some embodiments, the resistance value of the first resistor is determined by the operating current of the Zener diode.

[0007] In some embodiments, the sampling sub-circuit includes a second resistor and a third resistor; the second resistor and the third resistor are connected to a second node serving as the second output terminal; the second resistor is connected between the power output terminal and the second node; and the third resistor is connected between the second node and ground.

[0008] In some embodiments, the resistance value of the third resistor is determined by the first voltage output by the voltage reference sub-circuit, the second resistor, and the target output voltage of the power supply.

[0009] In some embodiments, the negative feedback sub-circuit includes an operational amplifier; the operational amplifier includes a first input terminal, a second input terminal, and a third output terminal; the operational amplifier also includes a grounded first terminal and a second terminal connected to the power output terminal.

[0010] In some embodiments, the power output regulation circuit further includes a capacitor; the capacitor is connected in parallel with the operational amplifier between the power output terminal and ground.

[0011] In some embodiments, the dummy load includes one of the following: a transistor or a MOSFET.

[0012] In some embodiments, the power output regulation circuit further includes a fourth resistor and a fifth resistor, wherein the fourth resistor is connected between the third output terminal of the negative feedback sub-circuit and the control terminal of the dummy load; and the fifth resistor is connected between the power output terminal and the control terminal of the dummy load.

[0013] Secondly, in some embodiments, the present invention provides a power supply system, the power supply system including a power supply circuit and a power output regulation circuit as described in any of the above claims.

[0014] By incorporating a dummy load into the power output regulation circuit and power system, and by operating the dummy load in the amplification region when the external load is light, acting as a variable load alongside the external load to ensure the overall load equals the power supply's minimum load, thus enabling the power supply to output a stable and desired value, the system achieves this. Conversely, when the external load is heavy, the dummy load operates in the off state, not participating in the operation, thereby improving the power supply's conversion efficiency. In this way, when the load is light, the dummy load acts as the power supply load, ensuring a stable output voltage; while when the load is heavy, the dummy load operates in the off state, improving the power supply's conversion efficiency. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A schematic diagram of the power output regulation circuit provided in one embodiment of this utility model;

[0017] Figure 2 This is a schematic diagram of an exemplary power output regulation circuit of this utility model. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0019] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified. In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to implement and use this utility model. In the following description, details are set forth for illustrative purposes. It should be understood that those skilled in the art will recognize that this utility model can be implemented without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid unnecessary detail that would obscure the description of this utility model. Therefore, this utility model is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0020] Firstly, such as Figure 1As shown, in some embodiments, the present invention provides a power output regulation circuit 100, which may include a voltage reference sub-circuit 101, a negative feedback sub-circuit 102, a dummy load 103, and a sampling sub-circuit 104. The voltage reference sub-circuit 101 may include a first output terminal for outputting a first voltage; the first voltage has a constant voltage value. The sampling sub-circuit 104 may include a second output terminal for outputting a second voltage; the second voltage is determined by the output voltage of the power output terminal. The negative feedback sub-circuit 102 may include a first input terminal, a second input terminal, and a third output terminal for outputting a control level based on the first voltage and the second voltage, wherein the first output terminal is connected to the first input terminal; the second output terminal is connected to the second input terminal. The dummy load 103 may include a control terminal for connecting the control level, a first terminal connected to the power output terminal, and a second terminal grounded.

[0021] like Figure 2 As shown, as an example, the voltage reference sub-circuit 101 may include a Zener diode ZD1 and a first resistor R1; the Zener diode ZD1 and the first resistor R1 are connected to a first node N1, which serves as the first output terminal; the first resistor R1 is connected between the power output terminal VCC and the first node N1; the Zener diode ZD1 is connected between the first node N1 and ground GND. The resistance value of the first resistor R1 is determined by the operating current of the Zener diode ZD1.

[0022] It should be noted that the Zener diode ZD1 achieves its voltage regulation function through reverse breakdown, and its core operating region is the reverse breakdown region. When the reverse voltage reaches the breakdown voltage, the Zener diode enters the breakdown state, at which point the current changes drastically but the voltage across its terminals remains stable. Therefore, in this invention, the voltage across the Zener diode is used as a reference voltage for subsequent feedback of the power supply's output voltage. It should be understood that a Zener diode operates within a certain current range; in other words, the Zener diode has minimum and maximum current limits. For the Zener diode to operate normally, the corresponding operating current cannot be less than the minimum limit nor exceed the maximum limit. Otherwise, the Zener diode will not be able to start or will burn out. Therefore, in such cases… Figure 2 In the adjustment circuit shown, the first resistor R1 is used as a protection element for the Zener diode ZD1, limiting the current flowing through the Zener diode ZD1 to not exceed its operating current range. Conversely, the resistance value of the first resistor R1 can be calculated based on the operating current range of the Zener diode ZD1.

[0023] like Figure 2As shown, as an example, the sampling sub-circuit 104 may include a second resistor R2 and a third resistor R3; the second resistor R2 and the third resistor R3 are connected to a second node N2, which serves as the second output terminal; the second resistor R2 is connected between the power supply output terminal and the second node; the third resistor R3 is connected between the second node N2 and ground GND. The resistance value of the third resistor is determined by the first voltage output from the voltage reference sub-circuit, the second resistor, and the target output voltage of the power supply.

[0024] It should be noted that the function of the sampling sub-circuit 104 is to acquire the feedback voltage used for the output voltage of the feedback power supply. For example... Figure 2 As shown, as an example, the sampling sub-circuit 104 can be a voltage divider circuit, including a second resistor R2 and a third resistor R3 connected in series, and uses the voltage of the second node N2 as the feedback voltage, i.e., the second voltage.

[0025] In practical applications, when the output voltage at the power supply output terminal is the target output voltage, the second voltage output by the acquisition sub-circuit should be equal to the first voltage output by the voltage reference sub-circuit. Based on this, after determining the value of the target output voltage and the value of the first voltage, the ratio between the second resistor R2 and the third resistor R3 can be calculated; then, based on the selected resistance value of the second resistor R2, the resistance value of the third resistor R3 can be calculated. That is, the resistance value of the third resistor R3 is determined by the first voltage output by the voltage reference sub-circuit, the second resistor R2, and the target output voltage of the power supply.

[0026] like Figure 2 As shown, as an example, the negative feedback sub-circuit 102 may include an operational amplifier U1; the operational amplifier U1 may include a first input terminal, a second input terminal, and a third output terminal; the operational amplifier U1 may also include a first terminal grounded (GND) and a second terminal connected to the power output terminal VCC. The power output regulation circuit 100 may also include a capacitor C1; the capacitor C1 is connected in parallel with the operational amplifier U1 between the power output terminal VCC and ground (GND).

[0027] It should be noted that the operational amplifier U1 can be a high-gain, directly coupled differential input voltage amplifier. Its core function is to perform mathematical operations (such as addition, subtraction, integration, differentiation, etc.) and signal processing through an external feedback network, making it a fundamental module of modern analog electronic circuits. In this invention, the operational amplifier U1 can be a single-supply comparator, used to input a first voltage from the first node N1 and a second voltage from the second node N2, and to compare the magnitudes of the first and second voltages. The second voltage is related to the output voltage of the power supply output terminal. Specifically, when the second voltage is greater than or equal to the first voltage, the operational amplifier U1 can output a control level with a first level; when the second voltage is less than the first voltage, the operational amplifier U1 can output a control level with a second level, where the first and second levels have different values. The capacitor C1 can form an LC low-pass filter with the equivalent inductance of the line to suppress high-frequency noise and prevent transient currents generated during rapid switching of the operational amplifier from coupling to the power supply network, thus avoiding interference to its circuitry.

[0028] Here, the dummy load 103 may include one of the following: a transistor or a MOSFET. The transistor may be of NPN or PNP type; the MOSFET is a metal-oxide-semiconductor field-effect transistor.

[0029] like Figure 2 As shown, as an example, the dummy load 103 can be a transistor Q1, and the transistor Q1 can be a PNP transistor, including a control terminal connected to a control level, a first terminal connected to the power output terminal VCC, and a second terminal connected to ground GND. Based on this, in such... Figure 2In the power output regulation circuit shown, in one scenario, operational amplifier U1 outputs a first-level control level when the second voltage is greater than or equal to the first voltage. This first level can be high. Under this high-level control, transistor Q1 is cut off. This indicates that the external load connected to the power supply is relatively heavy, requiring transistor Q1 to be disconnected, thus preventing Q1 from acting as a dummy load and improving the power supply's conversion efficiency. In another scenario, operational amplifier U1 outputs a second-level control level when the second voltage is less than the first voltage. This second level can be low. Under the low-level control, transistor Q1 operates in the amplification region, acting as a variable resistor (or variable load). This indicates that the external load connected to the power supply is relatively light, requiring transistor Q1 to operate in the amplification region, working together with the external load to ensure the overall load of the power supply equals its minimum load, stabilizing the power supply output at the target output voltage, and ensuring that V+ = V- of operational amplifier U1. It should be noted that the minimum load of the power supply can refer to the minimum power requirement needed to maintain normal stable output characteristics, usually expressed in current or power. The minimum load setting of this power supply is used to ensure stable operation under light load or no-load conditions, preventing the output voltage from deviating from the nominal range or causing abnormal behavior. In this embodiment, transistor Q1 is used to operate in the amplification region to maintain stable power output when the external load connected to the power supply is light.

[0030] like Figure 2 As shown, as an example, the power output regulation circuit 100 may further include a fourth resistor R4 and a fifth resistor R5, wherein the fourth resistor is connected between the third output terminal of the negative feedback sub-circuit and the control terminal of the dummy load; and the fifth resistor is connected between the power output terminal and the control terminal of the dummy load.

[0031] It should be noted that the fourth resistor R4 can limit current. When transistor Q1 is turned on, the fifth resistor R5, together with transistor Q1, allows transistor Q1 to operate in the amplification region.

[0032] The power output regulation circuit described above uses a dummy load (transistor Q1). When the external load connected to the power supply is light, the dummy load operates in the amplification region, acting as a variable load to work together with the external load, ensuring the overall load equals the power supply's minimum load, thus enabling the power supply to output a stable, desired value. When the external load is heavy, the dummy load operates in the off state, not participating in the operation, thereby improving the power supply's conversion efficiency. In this way, when the load is light, the dummy load acts as the power supply load, ensuring a stable output voltage; while when the load is heavy, the dummy load operates in the off state, improving the power supply's conversion efficiency.

[0033] Secondly, in some embodiments, the present invention provides a power supply system, which includes a power supply circuit and a power output regulation circuit as described in any of the preceding claims. The power supply circuit can refer to a circuit in a circuit system that provides stable and reliable electrical energy to other circuits or devices. As an example, the power supply circuit can be, but is not limited to, a switching power supply circuit, such as a buck or boost converter circuit.

[0034] By using the power supply system described above, a dummy load (e.g., transistor Q1) is set up. When the external load connected to the power supply is relatively light, the dummy load operates in the amplification region, acting as a variable load to work together with the external load, ensuring the overall load equals the minimum load of the power supply, thus enabling the power supply to output a stable and desired output value. When the external load connected to the power supply is relatively heavy, the dummy load operates in the cutoff state, not participating in the operation, thereby improving the power supply's conversion efficiency. In this way, when the load connected to the power supply is light, the dummy load acts as the power supply load to ensure a stable output voltage; while when the load connected to the power supply is heavy, the dummy load operates in the cutoff state, improving the power supply's conversion efficiency. This allows the power supply circuit to provide suitable voltages for different types of connected loads.

[0035] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed descriptions of other embodiments above, which will not be repeated here.

[0036] The power output regulation circuit and power system provided by this utility model have been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

[0037] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

Claims

1. A power supply output regulation circuit, characterized by comprising: The power supply output regulating circuit comprises: a voltage reference sub-circuit, a negative feedback sub-circuit, a dummy load and a sampling sub-circuit; wherein; the voltage reference sub-circuit comprises a first output end for outputting a first voltage; the first voltage has a constant voltage value; the sampling sub-circuit comprises a second output end for outputting a second voltage; the second voltage is determined by an output voltage of a power supply output end; the negative feedback sub-circuit comprises a first input end, a second input end and a third output end for outputting a control level according to the first voltage and the second voltage, wherein the first output end is connected to the first input end; the second output end is connected to the second input end; the dummy load comprises a control end for connecting to the control level, a first end connected to the power supply output end and a second end connected to ground.

2. The power supply output adjustment circuit according to claim 1, characterized by, The voltage reference sub-circuit comprises a voltage stabilizing diode and a first resistor; the voltage stabilizing diode and the first resistor are connected to a first node as the first output end; the first resistor is connected between the power supply output end and the first node; the voltage stabilizing diode is connected between the first node and ground.

3. The power supply output adjustment circuit according to claim 2, characterized by, The resistance value of the first resistor is determined by the working current of the voltage stabilizing diode.

4. The power supply output adjustment circuit according to claim 1, characterized by, The sampling sub-circuit comprises a second resistor and a third resistor; the second resistor and the third resistor are connected to a second node as the second output end; the second resistor is connected between the power supply output end and the second node; the third resistor is connected between the second node and ground.

5. The power supply output adjustment circuit according to claim 4, wherein The resistance value of the third resistor is determined by the first voltage output by the voltage reference sub-circuit, the second resistor and the target output voltage of the power supply.

6. The power supply output adjustment circuit according to claim 1, wherein The negative feedback sub-circuit comprises an operational amplifier; the operational amplifier comprises the first input end, the second input end and the third output end; the operational amplifier further comprises a first end connected to ground and a second end connected to the power supply output end.

7. The power supply output adjustment circuit according to claim 6, wherein The power supply output regulating circuit further comprises a capacitor; the capacitor is connected in parallel with the operational amplifier between the power supply output end and ground.

8. The power supply output adjustment circuit according to claim 1, wherein The dummy load comprises one of a triode and an MOS tube.

9. The power supply output adjustment circuit according to claim 1, wherein The power supply output regulating circuit further comprises a fourth resistor and a fifth resistor, wherein the fourth resistor is connected between the third output end of the negative feedback sub-circuit and the control end of the dummy load; the fifth resistor is connected between the power supply output end and the control end of the dummy load.

10. A power supply system characterized by comprising: The power supply system comprises a power supply circuit and the power supply output regulating circuit according to any one of claims 1 to 9.

Images