Flyback power supply circuit

Abstract

The utility model discloses a flyback power supply circuit. The flyback power supply circuit comprises a driving chip; the first end of the linear voltage stabilizing sub-circuit is electrically connected with the input power supply end, the second end of the linear voltage stabilizing sub-circuit is electrically connected with the power input end of the driving chip, the third end of the linear voltage stabilizing sub-circuit is electrically connected with the grounding end, and the linear voltage stabilizing sub-circuit is used for maintaining the potential of the power input end of the driving chip; the driving chip responds to the potential of the power supply input end of the driving chip and outputs a driving signal; the voltage transformation module comprises a primary winding and a secondary winding, the first end of the primary winding is electrically connected with the input power supply end, and the secondary winding is electrically connected with the output power supply end; and the switch module responds to enable level conduction of the driving signal output by the driving signal output end, and communicates the primary winding with the grounding end. According to the flyback power supply circuit provided by the embodiment of the invention, the conduction resistance of the switch module can be maintained in a better interval, so that the conduction loss of the switch module is reduced.

Description

Technical Field

[0001] The present application belongs to the field of power electronics technology, and in particular, relates to a flyback power supply circuit. Background Art

[0002] Typically, in existing household energy storage series, the flyback power supply circuit often cannot ensure that the power supply voltage is stabilized within a specific range when supplying power to the driver chip at the power supply end. Furthermore, because it is impossible to ensure that the voltage supplied to the driver chip is within a stable range, it is also impossible to ensure that the high level of the driver chip when emitting the PWM wave is within a stable range, so that the on-resistance of the transistor receiving the PWM wave cannot be maintained within the optimal range, resulting in increased conduction loss of the transistor and increased heat generation. Utility Model Content

[0003] An embodiment of the present application provides a flyback power supply circuit, which can stabilize the potential of the power input terminal of the driver chip in a specific range through a linear voltage stabilization sub-circuit, and further maintain the on-resistance of the switch module in a better range, thereby reducing the conduction loss of the switch module.

[0004] In a first aspect, an embodiment of the present application provides a flyback power supply circuit, which includes: a driver chip; a linear voltage regulator sub-circuit, a first end of the linear voltage regulator sub-circuit is electrically connected to an input power supply end, a second end of the linear voltage regulator sub-circuit is electrically connected to a power input end of the driver chip, a third end of the linear voltage regulator sub-circuit is electrically connected to a ground end, and the linear voltage regulator sub-circuit is used to maintain the potential of the power input end of the driver chip; the driver chip is used to output a drive signal in response to the potential of the power input end of the driver chip; a transformer module, the transformer module includes a primary winding and a secondary winding, a first end of the primary winding is electrically connected to the input power supply end, and a secondary winding is electrically connected to an output power supply end; a switch module, a control end of the switch module is electrically connected to a drive signal output end of the driver chip, a first end of the switch module is electrically connected to a ground end, a second end of the switch module is electrically connected to a second end of the primary winding, and the switch module is used to turn on in response to an enable level of a drive signal output from a drive signal output end, and connect the primary winding to the ground end.

[0005] According to the implementation of the first aspect of the present application, the linear voltage stabilization subcircuit includes: a first current limiting module, a first end of the first current limiting module is electrically connected to the input power supply end; a first charge and discharge module, a first end of the first charge and discharge module is electrically connected to the second end of the first current limiting module, and the second end of the first charge and discharge module is electrically connected to the ground end; a voltage stabilization module, a first end of the voltage stabilization module is electrically connected to the second end of the first charge and discharge module and the ground end; a transistor, a control end of the transistor is electrically connected to the second end of the voltage stabilization module, a first end of the transistor is electrically connected to the first end of the first charge and discharge module, and the second end of the transistor is electrically connected to the power input end of the driver chip; a second current limiting module, a first end of the second current limiting module is electrically connected to the first end of the transistor and the first end of the first charge and discharge module, and the second end of the second current limiting module is electrically connected to the control end of the transistor and the second end of the voltage stabilization module; a second charge and discharge module, a first end of the second charge and discharge module is electrically connected to the second end of the transistor and the power input end of the driver chip, and the second end of the second charge and discharge module is electrically connected to the first end of the voltage stabilization module and the ground end.

[0006] According to any of the aforementioned embodiments of the first aspect of the present application, the switch module includes a silicon carbide transistor.

[0007] According to any of the aforementioned embodiments of the first aspect of the present application, the transformer module includes a transformer, and the secondary winding includes a primary-secondary winding and a secondary-secondary winding; the first end of the primary winding of the transformer is electrically connected to the input power supply end, the second end of the primary winding is electrically connected to the second end of the switch module, the first end of the primary-secondary winding of the transformer is electrically connected to the ground end, the second end of the primary-secondary winding is electrically connected to the output power supply end, the first end of the secondary-secondary winding of the transformer is grounded, and the second end of the secondary-secondary winding is electrically connected to the fourth end of the linear voltage regulation sub-circuit.

[0008] According to any of the aforementioned embodiments of the first aspect of the present application, the flyback power supply circuit also includes: a first reverse cutoff module, the first end of the first reverse cutoff module is electrically connected to the second end of the main and secondary windings, and the second end of the first reverse cutoff module is electrically connected to the output power supply end; a first decoupling module, the first end of the first decoupling module is electrically connected to the second end of the first reverse cutoff module and the output power supply end, and the second end of the first decoupling module is electrically connected to the first end of the main and secondary windings and the ground end.

[0009] According to any of the aforementioned embodiments of the first aspect of the present application, the flyback power supply circuit also includes: a second reverse cutoff module, a first end of the second reverse cutoff module is electrically connected to the second end of the secondary winding, and a second end of the second reverse cutoff module is electrically connected to the fourth end of the linear voltage stabilization sub-circuit; a second decoupling module, a first end of the second decoupling module is electrically connected to the second end of the secondary winding and the fourth end of the linear voltage stabilization sub-circuit, and a second end of the second decoupling module is electrically connected to the ground end.

[0010] According to any of the aforementioned embodiments of the first aspect of the present application, the flyback power supply circuit also includes: a peak suppression sub-circuit, a first end of the peak suppression sub-circuit is electrically connected to the input power supply end and the first end of the primary winding, a second end of the peak suppression sub-circuit is electrically connected to the second end of the primary winding and the second end of the switch module, and the peak suppression sub-circuit is used to suppress the spike generated when the switch module is turned off.

[0011] According to any of the aforementioned embodiments of the first aspect of the present application, the spike suppression subcircuit includes: a third charge and discharge module, a first end of the third charge and discharge module is electrically connected to the input power supply end and the first end of the primary winding; a first voltage divider module, a first end of the first voltage divider module is electrically connected to the first end of the third charge and discharge module and the first end of the primary winding; a fourth reverse cutoff module, a first end of the fourth reverse cutoff module is electrically connected to the second end of the primary winding and the second end of the switch module, and a second end of the fourth reverse cutoff module is electrically connected to the second end of the third charge and discharge module and the second end of the first voltage divider module.

[0012] According to any of the aforementioned embodiments of the first aspect of the present application, the input power supply end includes a positive voltage DC input end and a negative voltage DC input end; the flyback power supply circuit also includes: a fourth charge and discharge module, a first end of the fourth charge and discharge module is electrically connected to the positive voltage DC input end, and a second end of the fourth charge and discharge module is electrically connected to the negative voltage DC input end.

[0013] According to any of the aforementioned embodiments of the first aspect of the present application, the flyback power supply circuit also includes: a first sampling module, a first end of the first sampling module is electrically connected to the input power supply end; a second sampling module, a first end of the second sampling module is electrically connected to the second end of the first sampling module and the feedforward compensation end of the driving chip, and the second end of the second sampling module is electrically connected to the ground end; a second voltage divider module, a first end of the second voltage divider module is electrically connected to the first end of the switch module, and the second end of the second voltage divider module is electrically connected to the ground end.

[0014] The flyback power supply circuit of the embodiment of the present application supplies power to the linear voltage stabilization subcircuit through the input power supply terminal, so that the linear voltage stabilization subcircuit stabilizes the input voltage in a specific range, and transmits the stable voltage to the driver chip through the power input terminal of the driver chip, so that the driver chip can send a stable drive signal through the drive signal output terminal to control the opening and closing of the switch module. Because the potential of the power input terminal is in a stable range, the high level of the drive signal is also in a stable range. By changing the linear voltage stabilization subcircuit, the high level potential of the drive signal can be in a more optimal range, so that the on-resistance of the switch module is maintained in a more optimal range, so that the conduction loss of the switch module is reduced and the heat is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0016] Figure 1 This is a circuit connection diagram of a flyback power supply circuit provided in an embodiment of the present application;

[0017] Figure 2 This is a circuit connection diagram of a linear voltage stabilization subcircuit provided in an embodiment of the present application;

[0018] Figure 3 is another circuit connection schematic diagram of the flyback power supply circuit provided in an embodiment of the present application;

[0019] Figure 4 This is another circuit connection diagram of the flyback power supply circuit provided in the embodiment of the present application. DETAILED DESCRIPTION

[0020] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0021] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0022] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0023] In the embodiments of the present application, the term “electrically connected” may refer to a direct electrical connection between two components, or may refer to an electrical connection between two components via one or more other components.

[0024] It is obvious to those skilled in the art that various modifications and changes can be made in the present application without departing from the spirit or scope of the present application. Therefore, the present application is intended to cover modifications and changes of the present application that fall within the scope of the corresponding claims (technical solutions for protection) and their equivalents. It should be noted that the implementation methods provided in the embodiments of the present application can be combined with each other without contradiction.

[0025] Before describing the technical solutions provided by the embodiments of the present application, in order to facilitate the understanding of the embodiments of the present application, the present application first specifically describes the problems existing in the related art:

[0026] Firstly, in the existing household energy storage series, the flyback power supply circuit often cannot ensure that the power supply voltage is stabilized in a specific range when supplying power to the driver chip at the power supply end. Furthermore, because it is impossible to ensure that the voltage supplied to the driver chip is in a stable range, it is also impossible to ensure that the high level of the driver chip when emitting the PWM wave is in a stable range, so that the on-resistance of the transistor receiving the PWM wave cannot be maintained in the optimal range, resulting in an increase in the conduction loss of the transistor.

[0027] Secondly, in the household energy storage series, due to the three-phase AC power supply, the upper limit of the flyback power supply input power supply is 1100V. The maximum drain-source voltage value of the current ordinary silicon metal oxide semiconductor (Si Metal-Oxide-Semiconductor, Si-MOS) is only 1500V. If used in the flyback power supply with 1100V input conditions, the voltage stress of a single Si-MOS will exceed the standard.

[0028] The solution in the related art is to use a double-tube series flyback topology. However, the need for two main power Si-MOS and the increase in driving electrical appliances will increase material costs; and because the two main power Si-MOS will require two isolated drive circuits, the transformer will require two primary windings, which increases the design difficulty.

[0029] In order to solve the above technical problems, an embodiment of the present application provides a flyback power supply circuit that can solve the above technical problems.

[0030] Figure 1 is a circuit diagram of a flyback power supply circuit provided in an embodiment of the present application, such as Figure 1 As shown, the flyback power supply circuit 100 may include a driving chip 110 , a linear voltage stabilization sub-circuit 120 , a voltage transformation module 130 and a switch module 140 .

[0031] The first end of the linear voltage stabilization subcircuit 120 is electrically connected to the input power supply terminal VIN, the second end of the linear voltage stabilization subcircuit 120 is electrically connected to the power input terminal VCC of the driver chip 110, and the third end of the linear voltage stabilization subcircuit 120 is electrically connected to the ground terminal GND. The linear voltage stabilization subcircuit 120 is used to maintain the potential of the power input terminal VCC of the driver chip 110. For details on how the linear voltage stabilization subcircuit 120 stabilizes the potential of the power input terminal VCC, see Figure 2 Partial detailed explanation.

[0032] The driving chip 110 is used for outputting a driving signal in response to the potential of the power input terminal VCC of the driving chip 110 .

[0033] It should be noted that the driver chip 110 should be selected such that there is a linear relationship between the driving voltage of the driving signal and the potential of the power input terminal VCC. In this way, because the potential of the power input terminal VCC is stable (due to the linear voltage stabilization subcircuit), and the potential of the power output terminal VCC is a relatively constant value with the high level of the driving signal, the driving signal output by the driver chip according to the potential of the power input terminal VCC is also stable in the high level stage.

[0034] The transformer module 130 includes a primary winding N P and the secondary winding N S , primary winding N P The first end is electrically connected to the input power supply terminal VIN, and the secondary winding N S Electrically connected to the output power supply terminal VOUT.

[0035] The transformer module 130 can be used to convert the primary winding N p The voltage of the primary winding N p and the secondary winding N S The turns ratio is the required output voltage.

[0036] The control end of the switch module 140 is electrically connected to the drive signal output end GD of the driver chip 110, the first end of the switch module 140 is electrically connected to the ground end GND, and the second end of the switch module 140 is electrically connected to the primary winding N PThe switch module 140 is used to respond to the enable level of the drive signal output by the drive signal output terminal GD to turn on the primary winding N P Connected to the ground terminal GND.

[0037] The switch module 140 includes but is not limited to the NMOS transistor Q2 .

[0038] In some specific embodiments, the driver chip 110 includes but is not limited to L6565D, and the switch module 140 includes but is not limited to a silicon carbide transistor (SiC-MOS). In this case, the maximum drain-source voltage value (Drain-Source Voltage, Vds) of the SiC-MOS can reach 1700V, which can meet the voltage stress requirements of the single-tube flyback topology under 1100V input conditions, solving the problem of excessive voltage stress easily caused by a single Si-MOS, and only one switch module is needed instead of two tubes in series, which reduces the design difficulty and material cost.

[0039] The flyback power supply circuit 100 of the embodiment of the present application supplies power to the linear voltage stabilization subcircuit 120 through the input power supply terminal VIN, so that the linear voltage stabilization subcircuit 120 stabilizes the input voltage in a specific range, and transmits the stable voltage to the driver chip 110 through the power input terminal VCC of the driver chip 110, so that the driver chip 110 can send a stable drive signal through the drive signal output terminal GD to control the opening and closing of the switch module 140. Because the potential of the power input terminal VCC is in a stable range, the high level of the drive signal is also in a stable range. By changing the linear voltage stabilization subcircuit 120, the high level potential of the drive signal can be in a more optimal range, so that the on-resistance of the switch module is maintained in a more optimal range, so that the conduction loss of the switch module 140 is reduced and the heat is reduced.

[0040] Figure 2 is another circuit connection diagram of the flyback power supply circuit provided in the embodiment of the present application, such as Figure 2 As shown, in some embodiments, the linear voltage stabilization subcircuit 120 may include a first current limiting module 201 , a first charge and discharge module 202 , a voltage stabilization module 203 , a transistor 204 , a second current limiting module 205 and a second charge and discharge module 206 .

[0041] The first end of the first current limiting module 201 is electrically connected to the input power supply terminal VIN. The first end of the first charge and discharge module 202 is electrically connected to the second end of the first current limiting module 201, and the second end of the first charge and discharge module 202 is electrically connected to the ground terminal GND. The first end of the voltage stabilizing module 203 is electrically connected to the second end of the first charge and discharge module 202 and the ground terminal GND.

[0042] In some specific embodiments, the first current limiting module 201 is specifically used to limit the current when the input power supply end VIN is supplied with high voltage. The first current limiting module 201 includes but is not limited to the first resistor R1, the first charge and discharge module 202 includes but is not limited to the first capacitor C1, and the voltage stabilizing module 203 includes but is not limited to the voltage stabilizing diode ZD1. The anode of the voltage stabilizing diode ZD1 is electrically connected to the ground end GND, and the cathode of the voltage stabilizing diode ZD1 is electrically connected to the control end of the transistor 204.

[0043] The control end of transistor 204 is electrically connected to the second end of voltage stabilizing module 203, the first end of transistor 204 is electrically connected to the first end of first charging and discharging module 202, and the second end of transistor 204 is electrically connected to the power input end of driving chip. In some specific embodiments, transistor 204 includes but is not limited to NPN transistor Q1.

[0044] The first end of the second current limiting module 205 is electrically connected to the first end of the transistor 204 and the first end of the first charge and discharge module 202, and the second end of the second current limiting module 205 is electrically connected to the control end of the transistor 204 and the second end of the voltage stabilizing module 203. In some specific embodiments, the second current limiting module 205 includes but is not limited to a second resistor R2, and the second resistor R2 is used as a current limiting resistor in the linear voltage stabilizing sub-circuit 120.

[0045] The first end of the second charge and discharge module 206 is electrically connected to the second end of the transistor 204 and the power input end of the driving chip, and the second end of the second charge and discharge module 206 is electrically connected to the first end of the voltage stabilizing module 203 and the ground end. In some specific embodiments, the second charge and discharge module 206 includes but is not limited to a second capacitor C2.

[0046] Figure 2 The transistor 204 is an NPN transistor Q1, and the voltage stabilizing module 203 is a voltage stabilizing diode ZD1. The selection of the voltage stabilizing diode ZD1 determines the voltage stabilizing value of the linear voltage stabilizing subcircuit 120. For example, the voltage stabilizing diode ZD1 is selected as a 20V voltage stabilizing diode. In actual use, the NPN transistor Q1 is often turned on at 0.5V, and the voltage of the power input terminal VCC is about 19.5V.

[0047] Figure 3 is another circuit connection diagram of the flyback power supply circuit provided in the embodiment of the present application, such as Figure 3 As shown, the transformer module 130 includes a transformer T1, a secondary winding N S Including main and secondary windings N S1 and the secondary winding N S2 ; The primary winding N of transformer T1 P The first end of the primary winding N is electrically connected to the input power supply terminal VIN. PThe second end of the transformer T1 is electrically connected to the second end of the switch module. S1 The first end of the primary winding is electrically connected to the ground terminal GND, and the secondary winding N S1 The second end of the transformer T1 is electrically connected to the output power supply terminal VOUT, and the secondary winding N S2 The first end of the secondary winding N is grounded. S2 The second end of is electrically connected to the fourth end of the linear voltage regulation sub-circuit 120.

[0048] Among them, the secondary winding N of transformer T1 S2 The function is to supply power to the linear voltage regulator sub-circuit, and further supply power to the driver chip 110.

[0049] The circuit works as follows: when the machine is started, the input power supply terminal supplies power to the linear voltage regulator subcircuit 120, which can be based on Figure 2 The circuit structure of the linear voltage stabilization subcircuit 120 stabilizes the voltage of the power input terminal VCC of the driver chip 110 in a specific range. Furthermore, the driver chip 110 sends a drive signal through the drive signal output terminal GD, and the high level stage of the drive signal is also stabilized in a specific range. Exemplarily, when the voltage of VCC is stabilized at 19.5V, the drive voltage of the drive signal is about 16.5V. The switch module 140 is turned on to directly drive the control transformer T1. When the transformer T1 starts working, the secondary winding N of the transformer T1 S2 The linear voltage regulator subcircuit is powered, and further the driver chip 110 is powered.

[0050] Figure 3 The primary winding N P The first end is shown as the same name end, in the primary winding N P When the first end is the same name end, the main and secondary windings N S1 The second end is the same name end, the secondary winding N S2 The second end of the same name.

[0051] Continue to see Figure 3 In some embodiments, the flyback power supply circuit 100 may further include: a first reverse cutoff module 301 , a first decoupling module 302 , a second reverse cutoff module 303 and a second decoupling module 304 .

[0052] The first terminal of the first reverse cut-off module 301 is connected to the primary and secondary windings N S1 The second end of the first reverse cut-off module 301 is electrically connected to the output power supply end.

[0053] The first end of the first decoupling module 302 is electrically connected to the second end of the first reverse cutoff module 301 and the output power supply end VOUT, and the second end of the first decoupling module 302 is electrically connected to the primary and secondary windings NS1 The first end and the ground end GND are electrically connected.

[0054] The first terminal of the second reverse cut-off module 303 is connected to the secondary winding N S2 The second end of the second reverse cut-off module 303 is electrically connected to the fourth end of the linear voltage stabilization sub-circuit 120.

[0055] The first terminal of the second decoupling module 304 is connected to the secondary winding N S2 The second end of the second decoupling module 304 is electrically connected to the fourth end of the linear voltage stabilization sub-circuit 120, and the second end of the second decoupling module 304 is electrically connected to the ground end GND.

[0056] In some specific embodiments, the first reverse cutoff module 301 includes but is not limited to a first diode D1, the second reverse cutoff module 303 includes but is not limited to a second diode D2, the first decoupling module 302 includes but is not limited to a third capacitor C3, and the second decoupling module includes but is not limited to a fourth capacitor C4.

[0057] The first reverse cutoff module 301 and the first decoupling module 302 are used to filter out interference so that the primary and secondary windings N S1 The output voltage is more stable, and the interference is filtered out by cutting off the main and secondary windings N through the first reverse cut-off module 301. S1 The first decoupling module 302 performs noise reduction processing on the induced reverse voltage.

[0058] The second reverse cutoff module 303 and the second decoupling module 304 also filter out interference, so that the secondary winding N S2 The output voltage is more stable. The interference filtering principle is the same as the interference filtering principle of the first reverse cutoff module 301 and the first decoupling module 302, which will not be described in detail here.

[0059] Continue to see Figure 3 In some embodiments, the flyback power supply circuit 100 may further include: a peak suppression subcircuit 310 .

[0060] The first terminal of the peak suppression sub-circuit 310 is connected to the input power supply terminal VIN and the primary winding N P The first end of the peak suppression sub-circuit 310 is electrically connected to the primary winding N P The second end of the switch module 140 is electrically connected to the second end of the switch module 140, and the peak suppression sub-circuit 310 is used to suppress the spike generated when the switch module 140 is turned off.

[0061] In some embodiments, the peak suppression subcircuit 310 may include: a third charging and discharging module 311 , a first voltage dividing module 312 , and a fourth reverse cutoff module 313 .

[0062] The first end of the third charge and discharge module 311 is connected to the input power supply end VIN and the primary winding N P The first end of the first voltage dividing module 312 is electrically connected to the first end of the third charge and discharge module 311 and the primary winding N P The first end is electrically connected to the

[0063] The first end of the fourth reverse cut-off module 313 is connected to the primary winding N P The second end of the fourth reverse cut-off module 313 is electrically connected to the second end of the third charge and discharge module 311 and the second end of the first voltage dividing module 312 .

[0064] In some specific embodiments, the third charging and discharging module 311 includes but is not limited to a fifth capacitor C5, the first voltage dividing module 312 includes but is not limited to a third resistor R3, and the fourth reverse cutoff module 313 includes but is not limited to a third diode D3.

[0065] Figure 4 is another circuit connection diagram of the flyback power supply circuit provided in the embodiment of the present application, such as Figure 4 As shown, the input power supply terminal VIN includes a positive voltage DC input terminal DC+ and a negative voltage DC input terminal DC-; the flyback power supply circuit 100 may further include: a fourth charging and discharging module 401.

[0066] A first end of the fourth charge and discharge module 401 is electrically connected to the positive voltage DC input terminal DC+, and a second end of the fourth charge and discharge module 401 is electrically connected to the negative voltage DC input terminal DC-.

[0067] In some specific embodiments, the fourth charge and discharge module 401 includes but is not limited to a sixth capacitor C6.

[0068] Continue to see Figure 4 The flyback power supply circuit 100 may further include: a first sampling module 402 , a second sampling module 403 and a second voltage dividing module 404 .

[0069] A first terminal of the first sampling module 402 is electrically connected to the input power supply terminal VIN.

[0070] A first end of the second sampling module 403 is electrically connected to a second end of the first sampling module 402 and a feedforward compensation end VFF of the driving chip, and a second end of the second sampling module 403 is electrically connected to a ground end GND.

[0071] The first sampling module 402 and the second sampling module 403 are used to sample the branch currents and provide feedforward compensation for the chip.

[0072] A first end of the second voltage dividing module 404 is electrically connected to a first end of the switch module 140 , and a second end of the second voltage dividing module 404 is electrically connected to a ground end GND.

[0073] In some specific embodiments, the first sampling module 402 may include a fourth resistor R4, the second sampling module 403 may include a fifth resistor R5, and the second voltage dividing module 404 may include a sixth resistor R6.

[0074] Exemplarily, in terms of device selection implementation, the switch module 140 can be SiC-MOS, and the driver chip can be an L6565D chip. In order to ensure that the SiC-MOS has a relatively low drain-source on-state resistance (Rds) when it is turned on, the drive voltage VOH (the drive voltage VOH is the high-level voltage output by the drive signal output terminal GD of the driver chip 110) must be controlled within a narrow range. The SiC-MOS that can be selected is IV2Q171R0T3 of Zhanxin Electronics, and the recommended drive voltage VOH is 15V to 18V.

[0075] Since the driving voltage VOH of the L6565D chip is related to the voltage of the power input terminal VCC of the chip, and the two are relatively constant values, the linear voltage stabilization subcircuit 120 can stabilize the value of the power input terminal VCC of the chip in a specific range, and further stabilize VOH in a range. When the voltage stabilization module 203 selects the voltage stabilization value of the first voltage stabilizing diode ZD1 as 20V, the power is supplied through the first resistor R1 when the power is started, and the linear voltage stabilization subcircuit 120 stabilizes VCC at about 19.5V. When VCC = 19.5V, the driving voltage VOH is about 16.5, so that the driving voltage can directly drive SiC-MOS (switch module 140). Thus, the single-tube flyback SiC-MOS driving circuit design is realized.

[0076] It should be understood that the specific structures of the circuits provided in the drawings of the embodiments of the present application are merely examples and are not intended to limit the present application. In addition, the above embodiments provided in the present application may be combined with each other if there is no contradiction.

[0077] It should be clear that each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. According to the embodiments described above in this application, these embodiments do not describe all the details in detail, nor do they limit the application to only the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the application, so that technicians in the relevant technical field can make good use of the application and the modified use based on the application. The application is only limited by the claims and their full scope and equivalents.

[0078] Those skilled in the art should understand that the above embodiments are exemplary rather than restrictive. Different technical features appearing in different embodiments can be combined to achieve beneficial effects. Based on the study of the drawings, the specification and the claims, those skilled in the art should be able to understand and implement other variations of the disclosed embodiments. In the claims, the term "comprising" does not exclude other structures; the quantity involves "one" but does not exclude multiple; the terms "first" and "second" are used to indicate names rather than to indicate any specific order. Any figure marks in the claims should not be understood as limiting the scope of protection. The appearance of certain technical features in different dependent claims does not mean that these technical features cannot be combined to achieve beneficial effects.

Claims

1. A flyback power supply circuit, characterized in that: include: Driver chip; A linear voltage stabilizing subcircuit, wherein a first end of the linear voltage stabilizing subcircuit is electrically connected to an input power supply end, a second end of the linear voltage stabilizing subcircuit is electrically connected to a power input end of the driver chip, a third end of the linear voltage stabilizing subcircuit is electrically connected to a ground end, and the linear voltage stabilizing subcircuit is used to maintain a potential at the power input end of the driver chip; The driving chip is used to output a driving signal in response to the potential of the power input terminal of the driving chip; A transformer module, the transformer module comprising a primary winding and a secondary winding, a first end of the primary winding being electrically connected to the input power supply end, and the secondary winding being electrically connected to the output power supply end; A switch module, wherein the control end of the switch module is electrically connected to the drive signal output end of the drive chip, the first end of the switch module is electrically connected to the ground end, the second end of the switch module is electrically connected to the second end of the primary winding, and the switch module is used to be turned on in response to the enable level of the drive signal output by the drive signal output end, so as to connect the primary winding to the ground end.

2. The flyback power supply circuit according to claim 1, characterized in that: The linear voltage stabilization subcircuit comprises: A first current limiting module, wherein a first end of the first current limiting module is electrically connected to the input power supply end; a first charging and discharging module, wherein a first end of the first charging and discharging module is electrically connected to a second end of the first current limiting module, and a second end of the first charging and discharging module is electrically connected to a ground end; A voltage stabilizing module, wherein a first end of the voltage stabilizing module is electrically connected to a second end of the first charging and discharging module and the ground end; A transistor, wherein a control end of the transistor is electrically connected to a second end of the voltage stabilizing module, a first end of the transistor is electrically connected to a first end of the first charging and discharging module, and a second end of the transistor is electrically connected to a power input end of the driving chip; a second current limiting module, wherein a first end of the second current limiting module is electrically connected to a first end of the transistor and a first end of the first charge and discharge module, and a second end of the second current limiting module is electrically connected to a control end of the transistor and a second end of the voltage stabilizing module; A second charging and discharging module, wherein a first end of the second charging and discharging module is electrically connected to a second end of the transistor and a power input end of the driving chip, and a second end of the second charging and discharging module is electrically connected to a first end of the voltage stabilizing module and the ground end.

3. The flyback power supply circuit according to claim 1 or 2, characterized in that: The switch module includes a silicon carbide transistor.

4. The flyback power supply circuit according to claim 1, characterized in that: The transformer module includes a transformer, and the secondary winding includes a primary secondary winding and a secondary secondary winding; The first end of the primary winding of the transformer is electrically connected to the input power supply end, the second end of the primary winding is electrically connected to the second end of the switch module, the first end of the primary and secondary windings of the transformer is electrically connected to the ground end, the second end of the primary and secondary windings is electrically connected to the output power supply end, the first end of the secondary and secondary windings of the transformer is grounded, and the second end of the secondary and secondary windings is electrically connected to the fourth end of the linear voltage regulation sub-circuit.

5. The flyback power supply circuit according to claim 4, characterized in that: The flyback power supply circuit also includes: A first reverse cutoff module, wherein a first end of the first reverse cutoff module is electrically connected to a second end of the primary and secondary windings, and a second end of the first reverse cutoff module is electrically connected to the output power supply end; A first decoupling module, wherein a first end of the first decoupling module is electrically connected to a second end of the first reverse cutoff module and the output power supply end, and a second end of the first decoupling module is electrically connected to a first end of the primary and secondary windings and a ground end.

6. The flyback power supply circuit according to claim 4, characterized in that: The flyback power supply circuit also includes: a second reverse cutoff module, wherein a first end of the second reverse cutoff module is electrically connected to a second end of the secondary winding, and a second end of the second reverse cutoff module is electrically connected to a fourth end of the linear voltage stabilization sub-circuit; A second decoupling module, wherein a first end of the second decoupling module is electrically connected to a second end of the secondary winding and a fourth end of the linear voltage stabilizing subcircuit, and a second end of the second decoupling module is electrically connected to a ground end.

7. The flyback power supply circuit according to claim 4, characterized in that: The flyback power supply circuit also includes: A spike suppression subcircuit, wherein the first end of the spike suppression subcircuit is electrically connected to the input power supply end and the first end of the primary winding, the second end of the spike suppression subcircuit is electrically connected to the second end of the primary winding and the second end of the switch module, and the spike suppression subcircuit is used to suppress the spike generated when the switch module is turned off.

8. The flyback power supply circuit according to claim 7, characterized in that: The spike suppression subcircuit comprises: A third charging and discharging module, wherein a first end of the third charging and discharging module is electrically connected to the input power supply end and the first end of the primary winding; a first voltage dividing module, wherein a first end of the first voltage dividing module is electrically connected to a first end of the third charging and discharging module and a first end of the primary winding; A fourth reverse cutoff module, wherein a first end of the fourth reverse cutoff module is electrically connected to a second end of the primary winding and a second end of the switch module, and a second end of the fourth reverse cutoff module is electrically connected to a second end of the third charge and discharge module and a second end of the first voltage divider module.

9. The flyback power supply circuit according to claim 1, characterized in that: The input power supply terminal includes a positive voltage DC input terminal and a negative voltage DC input terminal; the flyback power supply circuit also includes: A fourth charge and discharge module, wherein a first end of the fourth charge and discharge module is electrically connected to the positive voltage DC input end, and a second end of the fourth charge and discharge module is electrically connected to the negative voltage DC input end.

10. The flyback power supply circuit according to claim 1, characterized in that: The flyback power supply circuit also includes: A first sampling module, wherein a first end of the first sampling module is electrically connected to the input power supply end; a second sampling module, wherein a first end of the second sampling module is electrically connected to a second end of the first sampling module and a feedforward compensation end of the driving chip, and a second end of the second sampling module is electrically connected to a ground end; A second voltage dividing module, wherein a first end of the second voltage dividing module is electrically connected to the first end of the switch module, and a second end of the second voltage dividing module is electrically connected to the ground end.

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