Constant voltage control circuit and electronic equipment

Abstract

This application provides a constant voltage control circuit and electronic device, relating to the field of electronic power. The constant voltage control circuit includes a sampling circuit, a driving circuit, a signal output circuit, and a voltage feedback circuit. The driving circuit receives a sampled electrical signal output from the sampling circuit and outputs a driving signal based on the magnitude relationship between the sampled electrical signal and a reference electrical signal. The signal output circuit is connected to the sampling circuit and the driving circuit, and outputs a load voltage signal based on the sampled electrical signal and the driving signal. The voltage feedback circuit generates a voltage feedback signal based on the load voltage signal. The voltage feedback signal adjusts the reference electrical signal from a first reference voltage to a second reference voltage, so that the load voltage signal output by the signal output circuit is within a preset voltage range. The embodiments of this application aim to improve the voltage accuracy of the power module output voltage, reduce the cost of the power module, and improve the stability of the power module.

Description

Technical Field

[0001] This application relates to the field of electronic power, and in particular to a constant voltage control circuit and electronic device. Background Technology

[0002] Electronic devices typically include a power supply module. Existing power supply modules generally adjust the output voltage by using a resistor-based voltage divider feedback to the feedback pin (FB) of the power chip, thereby dynamically adjusting the output voltage. However, existing power supply modules have a reverse voltage at their output that is higher than the module's output voltage. When an external voltage is applied, the power supply module cannot effectively dissipate this large amount of energy, which may cause the sampled output voltage value to rise as the output voltage increases, resulting in lower output voltage accuracy. Summary of the Invention

[0003] The main objective of this application is to provide a constant voltage control circuit and electronic device, which aims to improve the voltage accuracy of the power module output voltage, reduce the cost of the power module, and improve the stability of the power module.

[0004] In a first aspect, this application provides a constant voltage control circuit for constant voltage control of a power supply module. The constant voltage control circuit includes a sampling circuit, a driving circuit, a signal output circuit, and a voltage feedback circuit. The sampling circuit is used to acquire a sampled electrical signal output by the power supply module. The driving circuit is connected to the sampling circuit and is used to receive the sampled electrical signal and output a driving signal according to the magnitude relationship between the sampled electrical signal and a reference electrical signal. The signal output circuit is connected to the sampling circuit and the driving circuit and is used to output a load voltage signal according to the sampled electrical signal and the driving signal. The voltage feedback circuit is connected to the signal output circuit and the driving circuit and is used to generate a voltage feedback signal according to the load voltage signal. The voltage feedback signal is used to adjust the reference electrical signal from a first reference voltage to a second reference voltage so that the load voltage signal output by the signal output circuit is within a preset voltage range.

[0005] Secondly, this application also provides an electronic device, which includes a power supply module and a constant voltage control circuit as described above, wherein the constant voltage control circuit is used to perform constant voltage control on the power supply module.

[0006] This application provides a constant voltage control circuit and electronic device. The constant voltage control circuit includes a sampling circuit, a driving circuit, a signal output circuit, and a voltage feedback circuit. The sampling circuit acquires a sampled electrical signal output by the power module. The driving circuit is connected to the sampling circuit and receives the sampled electrical signal, outputting a driving signal based on the magnitude relationship between the sampled electrical signal and a reference electrical signal. The signal output circuit is connected to both the sampling circuit and the driving circuit and outputs a load voltage signal based on the sampled electrical signal and the driving signal. The voltage feedback circuit is connected to both the signal output circuit and the driving circuit and generates a voltage feedback signal based on the load voltage signal. The voltage feedback signal adjusts the reference electrical signal from a first reference voltage to a second reference voltage, so that the load voltage signal output by the signal output circuit is within a preset voltage range. This constant voltage control circuit can achieve constant voltage control of the power module through hardware, thereby improving the voltage accuracy of the power module's output voltage, reducing the cost of the power module, and improving the stability of the power module. Attached Figure Description

[0007] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 A schematic block diagram of a constant voltage control circuit provided in an embodiment of this application;

[0009] Figure 2 A schematic circuit diagram of a constant voltage control circuit provided for an embodiment of this application;

[0010] Figure 3 A schematic block diagram of another constant voltage control circuit provided in an embodiment of this application;

[0011] Figure 4 A schematic circuit diagram of another constant voltage control circuit provided in an embodiment of this application;

[0012] Figure 5 A schematic block diagram of an electronic device provided in an embodiment of this application;

[0013] Figure label:

[0014] 1000. Electronic devices;

[0015] 100. Constant voltage control circuit; 10. Sampling circuit; 20. Drive circuit; 30. Signal output circuit; 40. Voltage feedback circuit; 200. Power supply module. Detailed Implementation

[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0017] In commonly used power modules, voltage output adjustment typically uses resistor-based voltage divider feedback fed into the feedback pin (FB) of the power chip to dynamically adjust the output voltage. However, obtaining an accurate voltage value and achieving a high dynamic response when an external voltage is applied to the output port presents a challenge.

[0018] Specifically, the voltage divider feedback resistor feeds the current voltage back to the differential amplifier, and the internal hardware processes the data to control the switching degree of the power switch transistor, thereby enabling the voltage to be output on demand. At that time, when there was an external voltage backflow, the power module could not dissipate the large amount of external energy; at the same time, using software to detect the external backflow voltage and adjust the output voltage precisely was slow.

[0019] To address the aforementioned issues, this application provides a constant voltage control circuit and electronic device. The constant voltage control circuit is used to perform constant voltage control on the power module, aiming to improve the voltage accuracy of the power module's output voltage, reduce the cost of the power module, and improve the stability of the power module.

[0020] Please refer to Figure 1 , Figure 1 This is a schematic block diagram of a constant voltage control circuit 100 provided in an embodiment of this application.

[0021] like Figure 1 As shown, the constant voltage control circuit 100 includes a sampling circuit 10, a driving circuit 20, a signal output circuit 30, and a voltage feedback circuit 40. The sampling circuit 10 is used to acquire the sampled electrical signal output by the power supply module 200, wherein the sampled electrical signal can be obtained by sampling at the output port of the power supply module 200. The driving circuit 20 is connected to the sampling circuit 10, and is used to receive the sampled electrical signal and output a driving signal according to the magnitude relationship between the sampled electrical signal and the reference electrical signal. Specifically, when the sampled electrical signal is greater than the reference electrical signal, the driving circuit 20 outputs a first driving signal; when the sampled electrical signal is not greater than the reference electrical signal, the driving circuit 20 outputs a second driving signal.

[0022] The signal output circuit 30 is connected to the sampling circuit 10 and the driving circuit 20. The signal output circuit 30 is used to output a load voltage signal based on the sampled electrical signal and the driving signal. The load voltage signal is used to represent the voltage corresponding to the load. The voltage feedback circuit 40 is connected to the signal output circuit 30 and the driving circuit 20. The voltage feedback circuit 40 is used to generate a voltage feedback signal based on the load voltage signal.

[0023] The voltage feedback signal is used to adjust the reference electrical signal from a first reference voltage to a second reference voltage, so that the load voltage signal output by the signal output circuit 30 is within a preset voltage range. The first reference voltage is an initially provided standard voltage value, and the second reference voltage is a standard voltage value calculated by adding the voltage feedback signal. The preset voltage range can be any voltage range suitable for the load operation, and is not specifically limited here.

[0024] The constant voltage control circuit 100 of this application first compares the magnitude relationship between the sampled electrical signal and the first reference voltage through the drive circuit 20 to generate a corresponding drive signal, thereby causing the signal output circuit 30 to output a corresponding voltage to the load. Then, the voltage feedback circuit 40 detects the voltage of the load and generates a corresponding voltage feedback signal, and adjusts the first reference voltage to the second reference voltage through the voltage feedback signal to generate a corresponding drive signal, thereby controlling the load voltage signal output by the signal output circuit 30 to be within a preset voltage range.

[0025] For example, when there is external voltage backflow at the output port of the power supply device or the sampling electrical signal output by the power module 200 is greater than the expected voltage value, the drive circuit 20 outputs a corresponding drive signal according to the relationship between the sampling electrical signal and the first reference voltage to control a larger voltage output to the load. At this time, the voltage feedback circuit 40 detects the load voltage signal and generates a voltage feedback signal, and increases the first reference voltage to the second reference voltage through the voltage feedback signal. Thus, the drive circuit 20 outputs a corresponding drive signal according to the relationship between the sampling electrical signal and the second reference voltage to control a more suitable voltage output to the load, thereby controlling the load voltage signal output by the signal output circuit 30 to be within the preset voltage range.

[0026] Please refer to Figure 2 , Figure 2 This is a schematic circuit diagram of a constant voltage control circuit 100 provided in an embodiment of this application. In some embodiments, the signal output circuit 30 includes a first switch Q1 and a first resistor R1. The control terminal of the first switch Q1 is connected to the drive circuit 20, the first terminal of the first switch Q1 is connected to the sampling circuit 10, the first terminal of the first resistor R1 is connected to the second terminal of the first switch Q1, the second terminal of the first resistor R1 is grounded, and the first resistor R1 is also connected to the voltage feedback circuit 40.

[0027] The first switching transistor Q1 can be a transistor or MOSFET or other device with switching characteristics, and the first resistor R1 can be a load resistor. The load voltage signal can be obtained by detecting the voltage difference across the first resistor R1.

[0028] For example, the first switching transistor Q1 is an NMOS transistor. The gate of the first switching transistor Q1 is connected to the driving circuit 20, the source of the first switching transistor Q1 is grounded, and the drain of the first switching transistor Q1 is connected to the sampling circuit 10. That is, the drain of the first switching transistor Q1 is used to receive the sampling electrical signal output by the power supply module 200. The first switching transistor Q1 can be controlled to a certain degree of turn-on according to the driving signal output by the driving circuit 20, thereby ensuring that the load voltage signal output by the signal output circuit 30 is within a preset voltage range and that the load current is within a specific load current range.

[0029] The load current range can be any current interval, and is set according to the actual situation, without specific limitation here. This application adjusts the turn-on degree of the NMOS transistor to dissipate the load on the sampling electrical signal output by the power module 200, thereby controlling the load voltage signal within the desired range.

[0030] In some embodiments, the driving circuit 20 includes a first comparator U1. The non-inverting input of the first comparator U1 is connected to the sampling circuit 10, the inverting input of the first comparator U1 is connected to the first preset power supply and voltage feedback circuit 40, and the output of the first comparator U1 is connected to the control terminal of the first switch Q1. The first comparator U1 is used to output a first driving signal when the sampled electrical signal is greater than the reference electrical signal to drive the first switch Q1 to turn on, and is also used to output a second driving level signal when the sampled electrical signal is not greater than the reference electrical signal to drive the first switch Q1 to turn off.

[0031] The first comparator U1 can be a voltage comparator, which is an electronic component that compares the voltages at two input terminals and outputs different voltage results at the output terminal. The first preset power supply is used to provide a reference electrical signal. In order to make the load voltage signal output the desired set value, the voltage value of the first preset power supply can be any value, and there is no specific limitation here. The first drive level signal can be a high level signal, and the second drive level signal can be a low level signal.

[0032] Specifically, when the sampled electrical signal is greater than the reference electrical signal, the first comparator U1 outputs a first drive signal to drive the first switch Q1 to turn on; when the sampled electrical signal is not greater than the reference electrical signal, the first comparator U1 outputs a second drive level signal to drive the first switch Q1 to turn off.

[0033] It should be noted that when the sampled electrical signal is greater than the reference electrical signal, since the sampled electrical signal is fixed, the magnitude of the reference electrical signal can be changed according to the voltage feedback signal. Generally speaking, the larger the voltage corresponding to the drive signal, the greater the opening degree of the first switch Q1, the greater the load current, and the greater the voltage obtained through the first resistor R1. Therefore, the opening degree of the first switch Q1 can be controlled according to the voltage magnitude of the reference electrical signal, thereby ensuring that the load voltage signal output by the signal output circuit 30 is within the preset voltage range.

[0034] For example, if the voltage value of the sampled electrical signal is 5V and the first reference voltage is 2V, then the first comparator U1 outputs a first drive signal, and the voltage value of the first drive signal is the voltage difference between the sampled electrical signal and the first reference voltage, which is 3V. At this time, the first switch Q1 is more open, therefore the load voltage signal output by the signal output circuit 30 is also larger. If the voltage value of the sampled electrical signal is 5V and the second reference voltage is 3V, then the first comparator U1 outputs a first drive signal, and the voltage value of the first drive signal is the voltage difference between the sampled electrical signal and the first reference voltage, which is 2V. At this time, the first switch Q1 is less open, therefore the load voltage signal output by the signal output circuit 30 is also smaller, thus ensuring that the load voltage signal output by the signal output circuit 30 is within the preset voltage range.

[0035] In some embodiments, the driving circuit 20 further includes a second resistor R2 and a first diode D1. The first end of the second resistor R2 is connected to the output terminal of the first comparator U1, and the second end of the second resistor R2 is connected to the signal output circuit 30. The second resistor R2 is used to limit the current of the driving signal output by the driving circuit 20. The anode of the first diode D1 is grounded, and the cathode of the first diode D1 is connected to the second end of the first resistor R1. The first diode D1 is used to protect the first switching transistor Q1.

[0036] Among them, the first diode D1 is a Zener diode. By connecting the Zener diode in parallel to the gate of the NMOS transistor, it limits the gate voltage, thereby limiting the turn-on degree (load current) of the NMOS transistor within a certain range and playing a protective role.

[0037] In some embodiments, the driving circuit 20 further includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6. The first end of the third resistor R3 is connected to the sampling circuit 10, and the second end of the third resistor R3 is connected to the non-inverting input of the first comparator U1. The third resistor R3 is used to limit the current of the sampled electrical signal. The first end of the fourth resistor R4 is connected to a first preset power supply. The first end of the fifth resistor R5 is connected to the second end of the fourth resistor R4, and the second end of the fifth resistor R5 is connected to the voltage feedback circuit 40. The first end of the sixth resistor R6 is connected to the second end of the fourth resistor R4, and the second end of the sixth resistor R6 is connected to the inverting input of the first comparator U1. The sixth resistor R6 is used to limit the current of the reference electrical signal.

[0038] Among them, the third resistor R3 is used to limit the current of the sampled electrical signal, the fourth resistor R4 and the fifth resistor R5 serve as voltage dividers, and the sixth resistor R6 is used to limit the current of the reference electrical signal.

[0039] In some embodiments, the inverting input of the first comparator U1 is used as the input of the reference electrical signal, which is obtained by differential calculation of the voltage value corresponding to the first preset power supply and the voltage value corresponding to the voltage feedback signal.

[0040] Specifically, when the non-inverting input of the first comparator U1 first receives the sampling electrical signal output by the power module 200, or when the voltage feedback signal is zero, the reference electrical signal can be considered as the voltage value corresponding to the first preset power supply; when the voltage feedback signal is not zero, the reference electrical signal is obtained by differential calculation processing of the voltage value corresponding to the first preset power supply and the voltage value corresponding to the voltage feedback signal.

[0041] The reference electrical signal is obtained by differential calculation of the voltage value corresponding to the first preset power supply and the voltage value corresponding to the voltage feedback signal, which can be expressed by the following formula:

[0042]

[0043] Among them, V U1 V1 is the voltage value corresponding to the reference electrical signal, and V is the voltage value corresponding to the first preset power supply. U2 This refers to the voltage value corresponding to the voltage feedback signal output by the voltage feedback circuit 40. and These are the weighting coefficients for the adder values ​​input to the inverting input of the first comparator U1.

[0044] Specifically, when there is external voltage backflow at the port or the sampling electrical signal output by the power module 200 is greater than the expected voltage value, the non-inverting input value of the first comparator U1 is greater than the inverting input value. Because the open-loop gain of the operational amplifier is large, the difference between the non-inverting input of the first comparator U1 will be amplified and approach the positive power supply voltage value. At this moment, the first switching transistor Q1 is fully turned on and connected to ground. At the same time, the sampling voltage through the first resistor R1 will be proportionally amplified and output to the inverting input of the first comparator U1, thereby forming the operational amplifier negative feedback control logic, so that the voltage is controlled within the expected range set by the parameters corresponding to the first preset power supply and within the specific load current range.

[0045] In some embodiments, the voltage feedback circuit 40 includes a first amplifier U2, the non-inverting input terminal of the first amplifier U2 is connected to the first end of the first resistor R1, the inverting input terminal of the first amplifier U2 is connected to the second end of the first resistor R1, and the output terminal of the first amplifier U2 is connected to the driving circuit 20. The first amplifier U2 is used to amplify the load voltage signal to generate the voltage feedback signal.

[0046] The first amplifier U2 is used to sample the voltage difference of the first resistor R1 to obtain the load voltage signal, and amplify the load voltage signal to generate a voltage feedback signal. If the current through the first resistor R1 is small, the induced voltage will be relatively small. If it is sent directly to the drive circuit 20 without amplification, the purpose will not be achieved. At the same time, the first amplifier U2 has an impedance isolation function for the preceding and following circuits.

[0047] Specifically, the voltage feedback circuit 40 also includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, and a first capacitor C1. The first end of the seventh resistor R7 is grounded, and the second end of the seventh resistor R7 is connected to the non-inverting input terminal of the first amplifier U2. The first end of the eighth resistor R8 is connected to the first end of the first resistor R1, and the second end of the eighth resistor R8 is connected to the second end of the seventh resistor R7. The seventh resistor R7 and the eighth resistor R8 serve as a voltage divider.

[0048] The first terminal of the ninth resistor R9 is connected to the second terminal of the first resistor R1, and the second terminal of the ninth resistor R9 is connected to the inverting input terminal of the first amplifier U2. The ninth resistor R9 serves as a current limiter. The first terminal of the tenth resistor R10 is connected to the inverting input terminal of the first amplifier U2, and the second terminal of the tenth resistor R10 is connected to the output terminal of the first amplifier U2. The first terminal of the first capacitor C1 is connected to the inverting input terminal of the first amplifier U2, and the second terminal of the first capacitor C1 is connected to the output terminal of the first amplifier U2. That is, the first capacitor C1 and the tenth resistor R10 are connected in parallel. The tenth resistor R10 and the first capacitor C1 serve as a low-pass filter.

[0049] Specifically, the voltage feedback signal output by the first amplifier U2 at this time can be expressed by the formula:

[0050]

[0051] Among them, V U2 Here, I represents the voltage value corresponding to the voltage feedback signal output by the voltage feedback circuit 40, and I represents the load current of the first switching transistor Q1. This represents the voltage amplification ratio of the first amplifier U2.

[0052] In some embodiments, the sampling circuit 10 is used to sample the voltage of the power module 200. In this application, the power module 200 has been simplified and only has an input terminal (VIN) and an output terminal (VOUT). The eleventh resistor R11 is the equivalent DC resistance of the entire output link.

[0053] Specifically, the sampling circuit 10 samples the output terminal (VOUT) of the power module 200 to obtain a sampled electrical signal.

[0054] like Figure 3 As shown, in some embodiments, the constant voltage control circuit 100 further includes a voltage processing circuit connected to the sampling circuit 10 and the drive circuit 20. The voltage processing circuit is used to perform signal amplification processing on the sampled electrical signal output by the power module 200.

[0055] It should be noted that if the sampling electrical signal output by the power module 200 is not downsampled and the original value is directly input to the differential circuit, it will not be able to match the voltage input parameter of the inverting input terminal of the first comparator U1.

[0056] like Figure 4 As shown, in some embodiments, the voltage processing circuit includes a second amplifier U3, the non-inverting input terminal of the second amplifier U3 is connected to the sampling circuit 10, the inverting input terminal of the second amplifier U3 is grounded, and the output terminal of the second amplifier U3 is connected to the driving circuit 20.

[0057] Specifically, the voltage processing circuit also includes a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, and a second capacitor C2. The output terminal of the second amplifier U3 is connected to the non-inverting input terminal of the first comparator U1. The first terminal of the twelfth resistor R12 is grounded, and the second terminal of the twelfth resistor R12 is connected to the non-inverting input terminal of the first amplifier U2. The first terminal of the thirteenth resistor R13 is connected to the sampling circuit 10, and the second terminal of the thirteenth resistor R13 is connected to the second terminal of the twelfth resistor R12. The twelfth resistor R12 and the thirteenth resistor R13 serve as a voltage divider.

[0058] The first terminal of the fourteenth resistor R14 is grounded, and the second terminal of the fourteenth resistor R14 is connected to the inverting input terminal of the second amplifier U3. The fourteenth resistor R14 serves as a current limiter. The first terminal of the fifteenth resistor R15 is connected to the inverting input terminal of the second amplifier U3, and the second terminal of the fifteenth resistor R15 is connected to the output terminal of the second amplifier U3. The first terminal of the second capacitor C2 is connected to the inverting input terminal of the second amplifier U3, and the second terminal of the second capacitor C2 is connected to the output terminal of the second amplifier U3. That is, the second capacitor C2 and the fifteenth resistor R15 are connected in parallel. The fifteenth resistor R15 and the second capacitor C2 serve as low-pass filters.

[0059] Specifically, at this time, the voltage value V output by the second amplifier U3 is... OUT_ZO This can be expressed by the formula:

[0060]

[0061] Among them, V U3 The voltage value output by the voltage processing circuit. This is the voltage reduction factor for the second amplifier U3.

[0062] The constant voltage control circuit 100 of this application can first compare the magnitude relationship between the sampled electrical signal and the first reference voltage through the drive circuit 20 to generate a corresponding drive signal, thereby causing the signal output circuit 30 to output a corresponding voltage to the load. Then, the voltage feedback circuit 40 detects the voltage of the load and generates a corresponding voltage feedback signal, and adjusts the first reference voltage to the second reference voltage through the voltage feedback signal to generate a corresponding drive signal, thereby controlling the load voltage signal output by the signal output circuit 30 to be within a preset voltage range.

[0063] Specifically, the relationships between the parameters of the constant voltage control circuit 100 can be made as follows:

[0064]

[0065] This allows the drive signal output by the drive circuit to control the opening degree of the first switch Q1, thereby ensuring that the load voltage signal output by the signal output circuit 30 is within a preset voltage range and that the load current is within a specific load current range.

[0066] like Figure 5 As shown, Figure 5 This is a schematic block diagram of an electronic device 1000 provided in an embodiment of this application. The electronic device 1000 includes a power module 200 and a constant voltage control circuit 100, which is used to perform constant voltage control on the power module 200.

[0067] The constant voltage control circuit 100 can be referred to as follows: Figures 1 to 4 The example configuration is as follows: the constant voltage control circuit 100 includes a sampling circuit 10, a driving circuit 20, a signal output circuit 30, and a voltage feedback circuit 40. The specific configuration of the constant voltage control circuit 100 can be found in the corresponding embodiments described in this application specification, which will not be repeated here. The electronic device 1000 provided in this application embodiment can achieve constant voltage control of the power module 200 through hardware, thereby improving the voltage accuracy of the power module 200 output, reducing the cost of the power module 200, and improving the stability of the power module 200.

[0068] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly, referring to direct connection or indirect connection through an intermediate medium, and can refer to the internal connection of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0069] The foregoing disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described above. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0070] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0071] The above embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of protection of this application. Any non-substantial changes and substitutions made by those skilled in the art based on this application shall fall within the scope of protection claimed by this application.

Claims

1. A constant voltage control circuit, characterized in that, The constant voltage control circuit is used for constant voltage control of the power module, and includes: A sampling circuit is used to acquire the sampled electrical signal output by the power module; A driving circuit is connected to the sampling circuit. The driving circuit is used to receive the sampled electrical signal and output a driving signal according to the magnitude relationship between the sampled electrical signal and the reference electrical signal. A signal output circuit is connected to the sampling circuit and the driving circuit, and the signal output circuit is used to output a load voltage signal according to the sampled electrical signal and the driving signal; A voltage feedback circuit is connected to the signal output circuit and the drive circuit, and the voltage feedback circuit is used to generate a voltage feedback signal based on the load voltage signal. The voltage feedback signal is used to adjust the reference electrical signal from the first reference voltage to the second reference voltage so that the load voltage signal output by the signal output circuit is within a preset voltage range.

2. The constant voltage control circuit according to claim 1, characterized in that, The signal output circuit includes: A first switching transistor, the control terminal of the first switching transistor is connected to the driving circuit, and the first terminal of the first switching transistor is connected to the sampling circuit; The first resistor has its first end connected to the second end of the first switching transistor, and its second end is grounded.

3. The constant voltage control circuit according to claim 2, characterized in that, The driving circuit includes: A first comparator has its non-inverting input connected to the sampling circuit, its inverting input connected to a first preset power supply and the voltage feedback circuit, and its output connected to the control terminal of the first switching transistor. The first comparator is used to output a first driving signal to drive the first switching transistor to turn on when the sampled electrical signal is greater than the reference electrical signal, and to output a second driving level signal to drive the first switching transistor to turn off when the sampled electrical signal is not greater than the reference electrical signal.

4. The constant voltage control circuit according to claim 3, characterized in that, The driving circuit also includes: The second resistor has a first end connected to the output of the first comparator and a second end connected to the signal output circuit. The second resistor is used to limit the current of the drive signal output by the drive circuit. The first diode has its anode grounded and its cathode connected to the second terminal of the first resistor. The first diode is used to protect the first switching transistor.

5. The constant voltage control circuit according to claim 3, characterized in that, The inverting input of the first comparator serves as the input of the reference electrical signal, which is obtained by differential calculation of the voltage value corresponding to the first preset power supply and the voltage value corresponding to the voltage feedback signal.

6. The constant voltage control circuit according to claim 3, characterized in that, The driving circuit also includes: The third resistor has a first end connected to the sampling circuit and a second end connected to the non-inverting input of the first comparator. The third resistor is used to limit the current of the sampled electrical signal. The fourth resistor, the first end of which is connected to the first preset power supply; The fifth resistor has its first end connected to the second end of the fourth resistor, and its second end connected to the voltage feedback circuit. The sixth resistor has its first end connected to the second end of the fourth resistor, and its second end connected to the inverting input of the first comparator. The sixth resistor is used to limit the current of the reference signal.

7. The constant voltage control circuit according to claim 2, characterized in that, The voltage feedback circuit includes: A first amplifier has its non-inverting input connected to the first end of the first resistor, its inverting input connected to the second end of the first resistor, and its output connected to the driving circuit. The first amplifier is used to amplify the load voltage signal to generate the voltage feedback signal.

8. The constant voltage control circuit according to claim 1, characterized in that, The constant voltage control circuit also includes: A voltage processing circuit is connected to the sampling circuit and the driving circuit. The voltage processing circuit is used to perform signal amplification processing on the sampled electrical signal output by the power module.

9. The constant voltage control circuit according to claim 8, characterized in that, The voltage processing circuit includes: The second amplifier has its non-inverting input connected to the sampling circuit, its inverting input grounded, and its output connected to the driving circuit.

10. An electronic device, characterized in that, The electronic device includes a power module and a constant voltage control circuit as described in any one of claims 1-9, wherein the constant voltage control circuit is used to perform constant voltage control on the power module.

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