Power supply circuit and electronic equipment

Abstract

The embodiment of the invention provides a power supply circuit and electronic equipment. The power supply circuit comprises a first switching power supply circuit and a second switching power supply circuit; the input end of the first switching power supply circuit and the input end of the second switching power supply circuit are connected in parallel to a direct-current power supply signal; the output end of the first switching power supply circuit and the output end of the second switching power supply circuit are connected in series to supply power to a load circuit; the first switching power supply circuit comprises a first switching module, and the first switching module is controlled by a first switching signal to conduct conduction control and / or turn-off control on an input direct-current power supply signal so as to at least adjust the output power of the first switching power supply circuit; the second switching power supply circuit comprises a second switching module, and the second switching module is controlled by a second switching signal to conduct conduction control and / or turn-off control on the input direct-current power supply signal so as to at least adjust the output power of the second switching power supply circuit; the ratio of the switching frequency of the first switching signal to the switching frequency of the second switching signal is greater than 10.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to a power supply circuit and electronic equipment. Background Art

[0002] Switching circuits usually use a pulse width modulation (PWM) voltage signal modulation strategy, which has the characteristics of high efficiency and fast dynamic response, and is widely used in fields such as instruments and equipment.

[0003] Due to its working characteristics, switching power supplies are prone to generate noise and ripples in the output signal. Ripple suppression is the focus of the design of switching power supplies, because ripples are caused by the basic working principle of switching power supplies and cannot be completely eliminated. Therefore, how to effectively suppress the ripple output of switching power supplies is an urgent problem to be solved. Summary of the invention

[0004] In view of this, an embodiment of the present disclosure provides a power supply circuit and an electronic device.

[0005] According to a first aspect of an embodiment of the present disclosure, a power supply circuit is provided, wherein the power supply circuit comprises a first switching power supply circuit and a second switching power supply circuit, wherein:

[0006] An input terminal of the first switching power supply circuit and an input terminal of the second switching power supply circuit are connected in parallel to a DC power supply signal;

[0007] The output end of the first switching power supply circuit and the output end of the second switching power supply circuit are connected in series to supply power to a load circuit;

[0008] Wherein, the first switching power supply circuit at least comprises a first switching module, and the first switching module is controlled by a first switching signal to perform on-control and / or off-control on an input DC power supply signal to at least adjust the output power of the first switching power supply circuit;

[0009] The second switching power supply circuit at least comprises a second switching module, and the second switching module is controlled by a second switching signal to perform on-control and / or off-control on an input DC power supply signal to at least adjust the output power of the second switching power supply circuit;

[0010] Wherein, the switching frequency of the first switching signal is greater than the switching frequency of the second switching signal.

[0011] In some embodiments, a ratio of a switching frequency of the first switching signal to a switching frequency of the second switching signal is greater than 10.

[0012] In some embodiments, a ratio of an output power of the first switching power circuit to an output power of the second switching power circuit is less than 1 / 10.

[0013] In some embodiments, the second switch module includes a chopper module, and the second switch power supply circuit further includes a transformer module and a rectifier module;

[0014] The chopping module is used to chop the DC power supply signal to obtain an alternating signal based on the control of the second switch signal.

[0015] The voltage transformation module is used to transform the alternating signal to obtain an alternating output signal;

[0016] The rectifier module is used to rectify the alternating output signal to obtain a direct current output signal.

[0017] In some embodiments, the second switching power supply circuit further includes an LLC resonance module.

[0018] The LLC resonance module is used to drive the switch MOS tube in the chopping module to perform zero voltage conduction and / or zero current shutdown.

[0019] In some embodiments, the LLC resonance module includes: a resonance capacitor, a resonance inductor and an excitation inductor, wherein:

[0020] The first end of the resonant capacitor is connected to the first output end of the chopping module;

[0021] The second end of the resonant capacitor is connected to the first end of the resonant inductor;

[0022] The second end of the resonant inductor, the first end of the excitation inductor and the first input end of the transformer module are connected;

[0023] The second end of the excitation inductor, the second input end of the voltage transformation module and the second output end of the chopping module are connected.

[0024] In some embodiments, the first switching power supply circuit includes one of the following:

[0025] Flyback switching power supply circuit;

[0026] Forward switching power supply circuit;

[0027] Push-pull switching power supply circuit.

[0028] In some embodiments, the first switch module includes a first switch MOS tube in the flyback switch power supply, and the flyback switch power supply circuit also includes a first isolation transformer, a first diode and a first capacitor; wherein,

[0029] The positive end of the DC power signal is connected to the first end of the primary winding of the first isolation transformer;

[0030] The control end of the first switch MOS tube is used to input a first switch signal, and the first end of the first switch MOS tube is connected to the second end of the primary winding of the first isolation transformer;

[0031] The first end of the first switch MOS tube is connected to the ground end of the DC power signal;

[0032] A first end of the secondary winding of the first isolation transformer is connected to the anode of the first diode;

[0033] The first end of the first capacitor is connected to the cathode of the first diode and serves as the forward output end of the flyback switching power supply circuit;

[0034] The second end of the secondary winding of the first isolation transformer is connected to the second end of the first capacitor and serves as the negative output end of the flyback switching power supply circuit;

[0035] The first end of the primary winding of the first isolation transformer and the second end of the secondary winding of the first isolation transformer are the same end.

[0036] In some embodiments, the first switch module includes: a second switch MOS tube in the forward switching power supply circuit, and the forward switching power supply circuit also includes: a second diode, a second isolation transformer, a third diode, a fourth diode, a first inductor and a second capacitor, wherein:

[0037] The first end of the primary winding of the second isolation transformer and the first end of the second primary winding of the second isolation transformer are connected to the positive end of the DC power signal;

[0038] The second end of the second primary winding of the second isolation transformer is connected to the cathode of the second diode;

[0039] The anode of the second diode and the second end of the second switch MOS tube are connected to the ground end of the DC power signal;

[0040] The control end of the second switch MOS tube is used to input a first switch signal, and the first end of the second switch MOS tube is connected to the second end of the primary winding of the second isolation transformer;

[0041] The first end of the first secondary winding of the second isolation transformer is connected to the anode of the third diode;

[0042] The cathode of the third diode, the cathode of the fourth diode and the first end of the first inductor are connected;

[0043] The second end of the first inductor is connected to the first end of the second capacitor and serves as a forward output end of the forward switching power supply circuit;

[0044] The second end of the first secondary winding of the second isolation transformer, the anode of the fourth diode and the second end of the second capacitor are connected and serve as the negative output end of the forward switching power supply circuit;

[0045] The first end of the primary winding of the second isolation transformer, the first end of the first secondary winding of the second isolation transformer, and the second end of the second secondary winding of the second isolation transformer are like-named ends.

[0046] In some embodiments, the first switch module includes: a third switch MOS tube and a fourth switch MOS tube in the push-pull switch power supply circuit; wherein,

[0047] The control end of the third switch MOS tube is used to input the first switch signal;

[0048] The control end of the fourth switch MOS tube is used to input the first switch signal;

[0049] The first end of the third switch MOS tube is connected to the positive end of the DC power signal;

[0050] The second end of the third switch MOS tube is connected to the first end of the fourth switch MOS tube and serves as the positive output end of the push-pull switch power supply circuit;

[0051] The second end of the fourth switch MOS tube is connected to the negative end of the DC power signal.

[0052] According to a second aspect of an embodiment of the present disclosure, an electronic device is provided. The electronic device includes the power supply circuit described in the first aspect.

[0053] The embodiment of the present disclosure discloses a power supply circuit and an electronic device, wherein the power supply circuit includes a first switching power supply circuit and a second switching power supply circuit, wherein the input end of the first switching power supply circuit and the input end of the second switching power supply circuit are connected in parallel to a DC power supply signal; the output end of the first switching power supply circuit and the output end of the second switching power supply circuit are connected in series to supply power to a load circuit; wherein the first switching power supply circuit includes at least a first switching module, and the first switching module is controlled by a first switching signal to conduct and / or shut down the input DC power supply signal to at least adjust the output power of the first switching power supply circuit; the second switching power supply circuit includes at least a second switching module, and the second switching module is controlled by a second switching signal to conduct and / or shut down the input DC power supply signal to at least adjust the output power of the second switching power supply circuit; wherein the ratio of the switching frequency of the first switching signal to the switching frequency of the second switching signal is greater than 10. In this way, by connecting the output end of the second switching power supply circuit with a higher switching frequency in series with the output end of the first switching power supply with a lower switching frequency, the ripple of the output end of the second switching power supply circuit is suppressed by utilizing the characteristic that the first switching power supply circuit has a higher response speed to the output voltage change, thereby improving the bandwidth of the power supply circuit and improving the stability of the output voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 is a schematic diagram of a power supply circuit structure according to an exemplary embodiment;

[0055] Figure 2 is a schematic diagram of a switching power supply circuit according to an exemplary embodiment;

[0056] Figure 3 is a schematic diagram of a second switch power supply circuit structure according to an exemplary embodiment;

[0057] Figure 4 is a schematic diagram of a second switch power supply circuit structure according to an exemplary embodiment;

[0058] Figure 5 is a schematic diagram of another power supply circuit structure according to an exemplary embodiment;

[0059] Figure 6 is a schematic diagram of another power supply circuit structure according to an exemplary embodiment;

[0060] Figure 7 is a schematic diagram of another power supply circuit structure according to an exemplary embodiment;

[0061] Figure 8 is a schematic diagram of another power supply circuit structure according to an exemplary embodiment. DETAILED DESCRIPTION

[0062] In order to make the technical solutions and beneficial effects of the present invention more clearly understandable, the following is a detailed description by listing specific embodiments. The drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application belongs.

[0063] The embodiments of the present disclosure are not exhaustive, but are only illustrative of some embodiments, and are not intended to be a specific limitation on the scope of protection of the present disclosure. In the absence of contradiction, each step in a certain embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, a solution after removing some steps in a certain embodiment can also be implemented as an independent embodiment, and the order of the steps in a certain embodiment can be arbitrarily exchanged. In addition, the optional implementation methods in a certain embodiment can be arbitrarily combined; in addition, the embodiments can be arbitrarily combined, for example, some or all of the steps of different embodiments can be arbitrarily combined, and a certain embodiment can be arbitrarily combined with the optional implementation methods of other embodiments.

[0064] In each embodiment of the present disclosure, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between the embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form a new embodiment based on their internal logical relationships.

[0065] The terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0066] In the embodiments of the present disclosure, unless otherwise specified, elements expressed in the singular form, such as "a", "an", "the", "above", "said", "aforementioned", "this", etc., may mean "one and only one", or "one or more", "at least one", etc. For example, when using articles such as "a", "an", "the" in English in translation, the noun after the article may be understood as a singular expression or a plural expression.

[0067] In the embodiments of the present disclosure, “plurality” refers to two or more.

[0068] In some embodiments, the terms "at least one", "one or more", "a plurality of", "multiple", etc. can be used interchangeably.

[0069] In some embodiments, "at least one of A and B", "A and / or B", "A in one case, B in another case", "A in one case, B in another case", etc., may include the following technical solutions according to the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed); in some embodiments, A and B (both A and B are executed). When there are more branches such as A, B, C, etc., the above is also similar.

[0070] In some embodiments, the recording method of "A or B" may include the following technical solutions according to the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed). When there are more branches such as A, B, C, etc., the above is also similar.

[0071] The prefixes such as "first" and "second" in the embodiments of the present disclosure are only used to distinguish different description objects, and do not constitute restrictions on the position, order, priority, value or content of the description objects. The statement of the description object refers to the description in the context of the claims or embodiments, and should not constitute redundant restrictions due to the use of prefixes. For example, if the description object is a "field", the ordinal number before the "field" in the "first field" and the "second field" does not limit the position or order between the "fields", and the "first" and "second" do not limit whether the "fields" they modify are in the same message, nor do they limit the order of the "first field" and the "second field". For another example, if the description object is a "level", the ordinal number before the "level" in the "first level" and the "second level" does not limit the priority between the "levels". For another example, the numerical value of the description object is not limited by the ordinal number, and can be one or more. Taking the "first device" as an example, the numerical value of the "device" can be one or more. In addition, the objects modified by different prefixes may be the same or different. For example, if the description object is "device", then the "first device" and the "second device" may be the same device or different devices, and their types may be the same or different. For another example, if the description object is "information", then the "first information" and the "second information" may be the same information or different information, and their contents may be the same or different.

[0072] In some embodiments, “including A”, “comprising A”, “used to indicate A”, and “carrying A” can be interpreted as directly carrying A or indirectly indicating A.

[0073] In some embodiments, terms such as “…”, “determine…”, “in the case of…”, “at the time of…”, “when…”, “if…”, “if…”, etc. can be used interchangeably.

[0074] In some embodiments, terms such as "greater than", "greater than or equal to", "not less than", "more than", "more than or equal to", "not less than", "higher than", "higher than or equal to", "not lower than", and "above" can be replaced with each other, and terms such as "less than", "less than or equal to", "not greater than", "less than", "less than or equal to", "no more than", "lower than", "lower than or equal to", "not higher than", and "below" can be replaced with each other.

[0075] In addition, each element, each row, or each column in the table of the embodiments of the present disclosure may be implemented as an independent embodiment, and the combination of any elements, any rows, and any columns may also be implemented as an independent embodiment.

[0076] It should be noted that the switch transistor in the embodiment of the present application can be an N-type transistor or a P-type transistor. For the N-type transistor, the on-level is a high level and the off-level is a low level. That is, when the gate of the N-type transistor is at a high level, the first end and the second end thereof are connected, and when the gate of the N-type transistor is at a low level, the first end and the second end thereof are disconnected. For the P-type transistor, the on-level is a low level and the off-level is a high level. That is, when the control end of the P-type transistor is at a low level, the first end and the second end thereof are connected, and when the control end of the P-type transistor is at a high level, the first end and the second end thereof are disconnected. In a specific implementation, the gate of each of the above-mentioned switch transistors serves as its control end. In the embodiment of the present application, the drain and the source are determined according to the transistor type: for the N-type transistor, the first end thereof can be used as the drain and the second end as the source; for the P-type transistor, the first end thereof can be used as the source and the second end as the drain. In addition, the on-level and the off-level in the embodiment of the present invention are both general terms. The on-level refers to any level that can turn on the transistor, and the off-level refers to any level that can turn off / off the transistor.

[0077] In the embodiment of the present application, the term "turning on the switching transistor" may refer to conduction between the first terminal and the second terminal of the switching transistor; the term "turning off the switching transistor" may refer to disconnection between the first terminal and the second terminal of the switching transistor.

[0078] In the embodiments of the present application, the term “connection” 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.

[0079] In the embodiments of the present application, unless otherwise specified, the switch transistor is described as an N-type transistor.

[0080] The present disclosure provides a power supply circuit 10, such as Figure 1 As shown, the power supply circuit 10 includes a first switching power supply circuit 11 and a second switching power supply circuit 12, wherein:

[0081] An input end of the first switching power supply circuit 11 and an input end of the second switching power supply circuit 12 are connected in parallel to a DC power supply signal;

[0082] The output end of the first switching power supply circuit 11 and the output end of the second switching power supply circuit 12 are connected in series to supply power to the load circuit;

[0083] The first switching power supply circuit 11 at least includes a first switching module, and the first switching module is controlled by a first switching signal to perform on-control and / or off-control on an input DC power supply signal to at least adjust the output power of the first switching power supply circuit 11;

[0084] The second switching power supply circuit 12 at least includes a second switching module, and the second switching module is controlled by a second switching signal to perform on-control and / or off-control on the input DC power supply signal to at least adjust the output power of the second switching power supply circuit 11;

[0085] Wherein, the switching frequency of the first switching signal is greater than the switching frequency of the second switching signal.

[0086] Here, the power circuit 10 may include a switching circuit for direct current to direct current (DC-DC) conversion.

[0087] The first switch power supply circuit 11 can adjust the output signal by at least turning on and off the input DC power supply signal through the first switch module. Here, the first switch module may include at least one switch, wherein the switch may be implemented by a switch MOS tube, etc. MOS tube is the abbreviation of Metal-Oxide-SemiconductorField-Effect Transistor (MOSFET).

[0088] The second switch power circuit 12 can adjust the output signal by at least turning on and off the input DC power signal through the second switch module. Here, the second switch module may include at least one switch, wherein the switch may be implemented by a switch MOS tube or the like.

[0089] For example, the first switching power supply circuit 11 and / or the second switching power supply circuit 12 can convert the input current power supply signal into an alternating voltage signal by turning on and off the switch, then transform the voltage through a transformer, and finally obtain an output signal through rectification and filtering.

[0090] In a possible implementation, the first switching power supply circuit 11 and the second switching power supply circuit 12 may respectively use the first switching signal and the second switching signal to control the on and off of the DC power supply signal input by their respective switches.

[0091] In a possible implementation, the first switching signal and the second switching signal are both PWM signals.

[0092] The working principle of the switching power supply circuit is shown as follows Figure 2 shown. Figure 2 The switching power supply circuit in the figure can represent the first switching power supply circuit 11 or the second switching power supply circuit 12. The switching power supply circuit adjusts the output signal by switching on and off the input DC power supply signal. The change of the load causes the change of the output signal (such as the output voltage signal and / or the output current signal). The sampling circuit can be used to sample the output signal (such as the output voltage signal) to obtain a sampling signal, and transmit the sample to the controller. The controller adjusts the output signal by adjusting the duty cycle of the switching signal based on the comparison between the sampling signal and the reference signal, thereby meeting the change of the load.

[0093] In a possible implementation, the first switching power supply circuit 11 and the second switching power supply circuit 12 may respectively have corresponding controllers.

[0094] In a possible implementation, the first switching power supply circuit 11 and the second switching power supply circuit 12 may use the same controller.

[0095] In a possible implementation, the second switching power supply circuit 12 may be a main power supply for supplying power to the load. The first switching power supply circuit 11 may be an auxiliary power supply for supplying power to the load. The output power of the second switching power supply circuit 12 is greater than the output power of the first switching power supply circuit 11.

[0096] Generally, a switching power supply with a larger output power can use a switching signal with a lower switching frequency. The reason is: on the one hand, the switching MOS tube of the switching power supply has a parasitic parameter C ds (drain-source parasitic capacitance) and C dg (Drain gate parasitic capacitance), when the bus voltage is high, the output voltage changes greatly in a short period of time, which will generate a relatively large pulse current, causing the voltage and current to form a large intersection on the switch tube, and the switching loss is relatively large. On the other hand, for isolated switching power supplies, the magnetizing and excitation process of the transformer is related to the power. The greater the power, the longer the magnetizing and excitation time, which will limit the increase in the switching frequency of the high-power switching power supply. Therefore, a switching power supply with a larger output power can use a switching signal with a lower switching frequency.

[0097] The reasons for the ripple of the actual output voltage signal of the switching power supply include: due to the existence of the equivalent series resistance (ESR) of the inductor, the inductor current ripple will form a voltage ripple on the ESR, and the process of charging and discharging the output capacitor will introduce ripple. When the input and output voltages and loads are constant, the ripple of the inductor current is inversely proportional to the switching frequency and inductance.

[0098] In a switching power supply, the ripple frequency of the output voltage signal is positively correlated with the switching frequency of the switching power supply. The dynamic response speed of the switching power supply is positively correlated with the switching frequency. Since the power of the second switching power supply circuit 12 is relatively large, the frequency of the second switching power supply circuit 12 is relatively low, and therefore, the dynamic response speed of the second switching power supply circuit 12 is relatively slow, that is, the second switching power supply circuit 12 responds slowly to the ripple of the output voltage signal of the second switching power supply circuit 12, and the ripple of the output voltage signal cannot be effectively suppressed.

[0099] Here, if Figure 1 As shown, the inputs of the first switching power supply circuit 11 and the second switching power supply circuit 12 are both connected to a DC power supply signal. The DC power supply signal may include a positive terminal and a ground terminal.

[0100] The output ends of the first switching power supply circuit 11 and the second switching power supply circuit 12 can be connected in series, for example, the forward output end of the first switching power supply circuit 11 is used as the forward output end of the power supply circuit 10, the reverse output end of the first switching power supply circuit 11 is connected to the forward output end of the second switching power supply circuit 12, and the reverse output end of the second switching power supply circuit 12 is used as the reverse output end of the power supply circuit 10. Alternatively, the forward output end of the second switching power supply circuit 12 is used as the forward output end of the power supply circuit 10, the reverse output end of the second switching power supply circuit 12 is connected to the forward output end of the first switching power supply circuit 11, and the reverse output end of the first switching power supply circuit 11 is used as the reverse output end of the power supply circuit 10.

[0101] In a possible implementation, the power supply circuit 10 includes N first switching power supply circuits 11 and M second switching power supply circuits 12, wherein N and M are positive integers greater than or equal to 1. The input end of each switching power supply circuit is connected to a DC power supply signal, and the output ends of each switching power supply circuit are connected in series.

[0102] In some embodiments, a ratio of a switching frequency of the first switching signal to a switching frequency of the second switching signal is greater than 10.

[0103] Here, the ratio of the switching frequency of the first switching signal to the switching frequency of the second switching signal is greater than 10. Since the switching frequency is positively correlated with the response speed of the switching power supply, the response speed of the first switching power supply circuit 11 is faster than that of the second switching power supply circuit 12. Since the output end of the first switching power supply circuit 11 is connected in series with the output end of the second switching power supply circuit 12, the first switching power supply circuit 11 can respond in time to the ripple of the second switching power supply circuit 12; that is, the ripple of the second switching power supply circuit 12 causes a sudden change in the output voltage signal of the first switching power supply circuit 11. Since the response speed of the first switching power supply circuit 11 is faster than that of the second switching power supply circuit 12, the first switching power supply circuit 11 can respond in time to the ripple generated at the output end of the second switching power supply circuit 12 (the voltages of the forward output end and the reverse output end change), so as to offset the ripple generated at the output end of the second switching power supply circuit 12.

[0104] For example, Figure 1 As shown, the forward output terminal of the first switching power supply circuit 11 serves as the forward output terminal +Vo of the power supply circuit 10, the reverse output terminal of the first switching power supply circuit 11 is connected to the forward output terminal of the second switching power supply circuit 12, and the reverse output terminal of the second switching power supply circuit 12 serves as the reverse output terminal -Vo of the power supply circuit 10. The reverse output terminal -Vo of the power supply circuit 10 can be a ground terminal. Therefore, when ripples are generated at the forward output terminal of the second switching power supply circuit 12, the voltage difference between the forward output terminal and the reverse output terminal of the first switching power supply circuit 11 changes. Since the switching frequency of the second switching power supply circuit 12 is relatively low, the response speed is relatively slow and the ripples cannot be suppressed in time. However, the switching frequency of the first switching power supply circuit 11 is relatively high, and the response speed is relatively fast. Therefore, its own output voltage can be adjusted relatively quickly to offset the ripples, thereby improving the output voltage stability of the output terminal +Vo of the power supply circuit 10.

[0105] In this way, by connecting the output end of the second switching power supply circuit 12 with a higher switching frequency in series with the output end of the first switching power supply circuit with a lower switching frequency, the ripple at the output end of the second switching power supply circuit 12 is suppressed by utilizing the characteristic that the first switching power supply circuit 11 has a higher response speed to the output voltage change, thereby improving the bandwidth of the power supply circuit 10 and improving the stability of the output voltage.

[0106] In some embodiments, a ratio of the output power of the first switching power supply circuit 11 to the output power of the second switching power supply circuit 12 is less than 1 / 10.

[0107] Here, since the first switching power supply circuit 11 needs to adopt a higher frequency, a first switching power supply circuit 11 with lower power can be adopted to reduce the switching loss of the switch in the first switching module and improve the efficiency of the power supply circuit 10.

[0108] In some embodiments, Figure 3 As shown, the second switch module includes a chopping module 121, and the second switch power supply circuit 12 also includes a transformer module 122 and a rectifier module 123; wherein the chopping module 121 is used to chop the DC power supply signal to obtain an alternating signal based on the control of the second switch signal, and the transformer module 122 is used to transform the alternating signal to obtain an alternating output signal; the rectifier module 123 is used to rectify the alternating output signal to obtain a DC output signal.

[0109] Here, since the second switch circuit requires a higher output power, the chopping module 121 can be used as follows: Figure 3 The full-bridge chopping method shown in FIG. 1 is used for chopping, and the rectifier module 123 can be used as follows: Figure 3 The full-bridge rectification method shown is used for rectification.

[0110] In a possible implementation, the chopping module 121 may also perform chopping in a half-bridge chopping manner.

[0111] In a possible implementation, the rectifier module 123 may also perform rectification using a half-bridge rectification method.

[0112] In a possible implementation, an input capacitor may be connected between the positive terminal Vbus of the DC power signal and the ground terminal GND.

[0113] In one possible implementation, Figure 3 As shown, an output capacitor may be connected between the positive output terminal and the negative output terminal of the power module to stabilize the DC output signal.

[0114] For example, Figure 3 As shown, the switch MOS transistors S1 to S4 constitute a chopping module 121. Among S1 to S4, S1 and S4 constitute a first path, and S2 and S3 constitute a second path. The first path and the second path are alternately turned on under the control of the first switch signal, so as to chop the DC power supply signal to obtain an alternating signal. The alternating signal can be converted by the transformer module 122 (such as Figure 3 The voltage is transformed by the isolating transformer (as shown) and rectified by the full-bridge rectifier module 123 composed of D1~D4 to obtain a DC output signal.

[0115] In some embodiments, Figure 4 As shown, the second switching power supply circuit 12 further includes an LLC resonance module 124,

[0116] The LLC resonance module 124 is used to drive the switch MOS tube in the chopping module 121 to perform zero voltage turn-on and / or zero current turn-off.

[0117] Here, L and C in the LLC resonance module represent inductance and capacitance respectively. The LLC resonance module may be a resonance circuit composed of at least two inductors and one capacitor.

[0118] During the switching process of the switching MOS tube in the second switching power supply circuit 12, if there is a high voltage between the drain and the source, it will cause current to flow through the switching MOS tube in the presence of a potential difference, resulting in greater energy consumption. The higher the switching frequency, the greater the proportion of the voltage and current crossing time in a switching cycle, thereby consuming a large amount of energy, reducing the transmission efficiency of the circuit, and also limiting the switching frequency of the power device.

[0119] Therefore, an LLC resonant module 124 may be added to the second switching power supply, where the LLC resonant module 124 may include: a resonant capacitor CR, a resonant inductor LR, and an excitation inductor LM. The LLC resonant module 124 generates a resonant current through resonance to adjust the voltage difference between the drain and the source when the switch MOS tube is turned on or off, thereby achieving zero voltage turn-on and / or zero current turn-off of the switch MOS tube, thereby reducing switching losses and improving the efficiency of the power supply circuit 10.

[0120] In some embodiments, Figure 4 As shown, the LLC resonance module 124 includes: a resonance capacitor CR, a resonance inductor LR and an excitation inductor LM, wherein the first end of the resonance capacitor CR is connected to the first output end of the chopping module 121;

[0121] The second end of the resonant capacitor CR is connected to the first end of the resonant inductor LR;

[0122] The second end of the resonant inductor LR, the first end of the excitation inductor LM and the first input end of the transformer module 122 are connected;

[0123] The second end of the excitation inductor LM, the second input end of the voltage transformation module 122 and the second output end of the chopping module 121 are connected.

[0124] The chopper circuit generates a fundamental current lagging behind the fundamental voltage in the LLC resonant module 124 by chopping a square wave voltage of a certain frequency, so that the current flows through the anti-parallel body diode of the switch MOS at the turn-on moment of the power device, thereby clamping the voltage across the drain and source of the power device to zero, reducing the voltage across the drain and source of the switch MOS tube to 0, achieving zero voltage turn-on and turn-off, and further achieving soft switching.

[0125] Here, the function of the LLC resonance module 124 is described by taking the zero voltage turn-on of the LLC resonance module 124 as an example. Figure 4 As shown, the explanation is given starting from the point where S2 and S3 are hard turned off and the four MOS switches S1-S4 are all turned off.

[0126] After S2 and S3 are hard-off, S 1- S4 are all turned off, and this process is hard shut-off. The circuit enters the dead zone state. The parasitic capacitances of the four MOS switches S1-S4 begin to transfer and exchange the energy therein under the action of the resonant current Ir. Since the impedance characteristic of the LLC resonant module 124 is inductive, the phase of the resonant current Ir lags behind the voltage, and the current direction remains in the negative direction. The clamping voltage of the parasitic diodes of S1 and S4 is released, and then the resonant current is continued through the parasitic diodes. The resonant current Ir flows through the S1 body diode -V bus -GND-S4 body diode, forming a loop current. In this process, because the current is forward-conducted in the body diodes of S1 and S4, the voltage of S1 and S4 drops to 0, which prepares for zero voltage switching. The resonant current Ir also flows through the body capacitance of S2 -Uin-S3's body capacitance to charge the capacitor, making the voltage difference between S2 and S3 Uin. S1 and S3 are turned on, the resonant current Ir changes to the positive direction, and current begins to flow through the switch tubes S1 and S3. At this time, the voltage of SI and S2 is 0 in the previous mode due to the resonant current Ir, so S1 and S4 are turned on with zero voltage. The zero voltage switching on and off of S1-S4 is similar to this, so I will not go into details here.

[0127] The LLC resonant module 124 is used to achieve zero voltage turn-on and / or zero voltage turn-off of the switch MOS tube, thereby reducing switching losses and improving the efficiency of the power supply circuit 10 .

[0128] In some embodiments, the first switching power supply circuit 11 includes one of the following:

[0129] Flyback switching power supply circuit 110;

[0130] Forward switching power supply circuit 120;

[0131] Push-pull switching power supply circuit 130 .

[0132] In a possible implementation, the first switch power circuit 11 may adopt the same circuit form as the second switch circuit. For example, the first switch power circuit 11 may also adopt a circuit form including a chopper module 121 , a resonance module, a transformer module 122 and a rectifier module 123 .

[0133] Since the first switch circuit requires a higher switching frequency and has a smaller output power, one of the flyback switch power supply circuit 110, the forward switch power supply circuit 120 and the push-pull switch power supply circuit 130 can be used to meet different requirements.

[0134] In some embodiments, Figure 5 As shown, the first switch module includes the first switch MOS tube in the flyback switch power supply, and the flyback switch power supply circuit 110 also includes a first isolation transformer T1, a first diode D1 and a first capacitor C1; wherein,

[0135] The DC power signal is connected to the first end of the primary winding of the first isolation transformer T1;

[0136] The control end of the first switch MOS tube is used to input a first switch signal, and the first end of the first switch MOS tube is connected to the second end of the primary winding of the first isolation transformer T1;

[0137] The first end of the first switch MOS tube is connected to the ground end of the DC power signal;

[0138] A first end of the secondary winding of the first isolation transformer T1 is connected to the anode of the first diode D1;

[0139] The first end of the first capacitor C1 is connected to the cathode of the first diode D1 and serves as the forward output end of the flyback switching power supply circuit 110;

[0140] The second end of the secondary winding of the first isolation transformer T1 is connected to the second end of the first capacitor C1 and serves as the negative output end of the flyback switching power supply circuit 110;

[0141] The first end of the primary winding of the first isolation transformer T1 and the second end of the secondary winding of the first isolation transformer T1 are the same end.

[0142] Specifically, Figure 5 As shown, when the first switch MOS tube is turned on, the working state of the primary winding is opposite to that of the secondary winding. When the first switch MOS tube is turned on, the first end of the primary winding is positive and the second end is negative, the first end of the secondary winding is negative and the second end is positive, the first diode D1 is cut off, and the primary winding stores energy; when the first switch MOS tube is turned off, due to the back electromotive force in the primary winding, energy needs to be released, the first end of the primary winding is negative and the second end is positive, the first end of the secondary winding is positive and the second end is negative, the first diode D1 is turned on to store energy in the first filter capacitor C1 and then output.

[0143] The flyback switching circuit can realize a switching power supply through a simple circuit to reduce the cost of the power supply circuit 10 .

[0144] In a possible implementation, an input capacitor CiL may be connected between the positive end of the DC power supply signal and the ground end to reduce the ripple of the input signal and improve the input stability. Figure 5 and Figure 6 As shown, the second power supply may have an LLC resonance module 124 or may not have a resonance module.

[0145] In some embodiments, Figure 7 As shown, the first switch module includes: the second switch MOS tube Q2 in the forward switching power supply circuit, and the forward switching power supply circuit 120 also includes: a second diode D2, a second isolation transformer T2, a third diode D3, a fourth diode D4, a first inductor L1 and a second capacitor C2, wherein,

[0146] The first end of the primary winding of the second isolation transformer T2 and the first end of the second primary winding of the second isolation transformer T2 are connected to the positive end of the DC power signal;

[0147] The second end of the second primary winding of the second isolation transformer T2 is connected to the cathode of the second diode D2;

[0148] The anode of the second diode D2 and the second end of the second switch MOS tube Q2 are connected to the ground end of the DC power signal;

[0149] The control end of the second switch MOS transistor Q2 is used to input a first switch signal, and the first end of the second switch MOS transistor Q2 is connected to the second end of the primary winding of the second isolation transformer T2;

[0150] The first end of the first secondary winding of the second isolation transformer T2 is connected to the anode of the third diode D3;

[0151] The cathode of the third diode D3, the cathode of the fourth diode D4 and the first end of the first inductor L1 are connected;

[0152] The second end of the first inductor L1 is connected to the first end of the second capacitor C2 and serves as a forward output end of the forward switching power supply circuit 120;

[0153] The second end of the first secondary winding of the second isolation transformer T2, the anode of the fourth diode D4 and the second end of the second capacitor C2 are connected and serve as the negative output end of the forward switching power supply circuit 120;

[0154] A first end of the primary winding N1 of the second isolation transformer T2 , a first end of the first secondary winding N2 of the second isolation transformer T2 , and a second end of the second secondary winding N3 of the second isolation transformer T2 are like-named ends.

[0155] In a possible implementation, the primary winding, the first secondary winding, and the second primary winding of the second isolation transformer T2 are on the same magnetic core.

[0156] Specifically, Figure 7 As shown, when the second switch MOS tube Q2 is turned on, the excitation current of the primary winding N1 magnetizes the magnetic core, and the first secondary winding N2 generates an induced current to charge the first inductor L1 and the second capacitor C2 through the third diode D3 to supply power to the load. The current generated by the second secondary winding N3 flowing out from the same-name end is cut off by the second diode D2. When the second switch MOS tube Q2 is turned off, the first inductor L1 and the second capacitor C2 release electric energy to continue to supply power to the load. The induced current flowing to the first secondary winding N2 is cut off by the third diode D3. The induced current generated by the second secondary winding N3 flowing into the same-name end can form a loop through the second diode D2, and the energy in the magnetic core can flow back to the power supply to complete the magnetic reset, so as to reduce the magnetic saturation of the second isolation transformer T2.

[0157] The output voltage and current accuracy of the forward switching power supply are very high, which can achieve very stable output and maintain a stable working state under various working conditions.

[0158] In some embodiments, Figure 8 As shown, the first switch module includes: a third switch MOS tube Q3 and a fourth switch MOS tube Q4 in the push-pull switch power supply circuit; wherein,

[0159] The control end of the third switch MOS tube Q3 is used to input the first switch signal;

[0160] The control end of the fourth switch MOS tube Q4 is used to input the first switch signal;

[0161] The first end of the third switch MOS tube Q3 is connected to the positive end of the DC power signal;

[0162] The second end of the third switch MOS transistor Q3 is connected to the first end of the fourth switch MOS transistor Q4 and serves as the positive output end of the push-pull switch power supply circuit 130;

[0163] The second end of the fourth switch MOS tube Q4 is connected to the negative end of the DC power signal.

[0164] Figure 8 In the push-pull switch circuit shown, the third switch MOS transistor Q3 and the fourth switch MOS transistor Q4 are switched alternately, thereby outputting electric energy to the load. Here, the second switch signal can adjust the output power by adjusting the duty cycle.

[0165] The push-pull switching circuit can realize a switching power supply through a simple circuit to reduce the cost of the power supply circuit 10 .

[0166] This embodiment further provides an electronic device, which includes the power supply circuit 10 provided in any of the above embodiments.

[0167] In a possible implementation, the electronic device may include a signal measuring device such as an oscilloscope and a signal source.

[0168] The implementation manner of the power supply circuit is as shown in any of the above embodiments and will not be repeated here.

[0169] The various embodiments or implementation methods in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0170] In the description of this specification, reference to "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0171] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A power supply circuit, characterized in that: The power supply circuit includes a first switching power supply circuit and a second switching power supply circuit, wherein: An input terminal of the first switching power supply circuit and an input terminal of the second switching power supply circuit are connected in parallel to a DC power supply signal; The output end of the first switching power supply circuit and the output end of the second switching power supply circuit are connected in series to supply power to a load circuit; Wherein, the first switching power supply circuit at least comprises a first switching module, and the first switching module is controlled by a first switching signal to perform on-control and / or off-control on an input DC power supply signal to at least adjust the output power of the first switching power supply circuit; The second switching power supply circuit at least comprises a second switching module, and the second switching module is controlled by a second switching signal to perform on-control and / or off-control on an input DC power supply signal to at least adjust the output power of the second switching power supply circuit; Wherein, the switching frequency of the first switching signal is greater than the switching frequency of the second switching signal.

2. The power supply circuit according to claim 1, characterized in that: A ratio of a switching frequency of the first switching signal to a switching frequency of the second switching signal is greater than 10.

3. The power supply circuit according to claim 1, characterized in that: A ratio of the output power of the first switching power supply circuit to the output power of the second switching power supply circuit is less than 1 / 10.

4. The power supply circuit according to claim 1, characterized in that: The second switch module includes a chopper module, and the second switch power supply circuit also includes a transformer module and a rectifier module; The chopping module is used to chop the DC power supply signal to obtain an alternating signal based on the control of the second switch signal. The voltage transformation module is used to transform the alternating signal to obtain an alternating output signal; The rectifier module is used to rectify the alternating output signal to obtain a direct current output signal.

5. The power supply circuit according to claim 4, characterized in that: The second switching power supply circuit further includes an LLC resonance module, The LLC resonance module is used to drive the switch MOS tube in the chopping module to perform zero voltage conduction and / or zero current shutdown.

6. The power supply circuit according to claim 5, characterized in that: The LLC resonance module includes: a resonance capacitor, a resonance inductor and an excitation inductor, wherein: The first end of the resonant capacitor is connected to the first output end of the chopping module; The second end of the resonant capacitor is connected to the first end of the resonant inductor; The second end of the resonant inductor, the first end of the excitation inductor and the first input end of the transformer module are connected; The second end of the excitation inductor, the second input end of the voltage transformation module and the second output end of the chopping module are connected.

7. The power supply circuit according to any one of claims 1 to 6, characterized in that: The first switching power supply circuit includes one of the following: Flyback switching power supply circuit; Forward switching power supply circuit; Push-pull switching power supply circuit.

8. The power supply circuit according to claim 7, characterized in that: The first switch module includes a first switch MOS tube in the flyback switch power supply, and the flyback switch power supply circuit also includes: a first isolation transformer, a first diode and a first capacitor; wherein, The positive end of the DC power signal is connected to the first end of the primary winding of the first isolation transformer; The control end of the first switch MOS tube is used to input a first switch signal, and the first end of the first switch MOS tube is connected to the second end of the primary winding of the first isolation transformer; The first end of the first switch MOS tube is connected to the ground end of the DC power signal; A first end of the secondary winding of the first isolation transformer is connected to the anode of the first diode; The first end of the first capacitor is connected to the cathode of the first diode and serves as the forward output end of the flyback switching power supply circuit; The second end of the secondary winding of the first isolation transformer is connected to the second end of the first capacitor and serves as the negative output end of the flyback switching power supply circuit; The first end of the primary winding of the first isolation transformer and the second end of the secondary winding of the first isolation transformer are the same end.

9. The power supply circuit according to claim 7, characterized in that: The first switch module includes: a second switch MOS tube in the forward switch power supply circuit, and the forward switch power supply circuit also includes: a second diode, a second isolation transformer, a third diode, a fourth diode, a first inductor and a second capacitor, wherein: The first end of the primary winding of the second isolation transformer and the first end of the second primary winding of the second isolation transformer are connected to the positive end of the DC power signal; The second end of the second primary winding of the second isolation transformer is connected to the cathode of the second diode; The anode of the second diode and the second end of the second switch MOS tube are connected to the ground end of the DC power signal; The control end of the second switch MOS tube is used to input a first switch signal, and the first end of the second switch MOS tube is connected to the second end of the primary winding of the second isolation transformer; The first end of the first secondary winding of the second isolation transformer is connected to the anode of the third diode; The cathode of the third diode, the cathode of the fourth diode and the first end of the first inductor are connected; The second end of the first inductor is connected to the first end of the second capacitor and serves as a forward output end of the forward switching power supply circuit; The second end of the first secondary winding of the second isolation transformer, the anode of the fourth diode and the second end of the second capacitor are connected and serve as the negative output end of the forward switching power supply circuit; The first end of the primary winding of the second isolation transformer, the first end of the first secondary winding of the second isolation transformer, and the second end of the second secondary winding of the second isolation transformer are like-named ends.

10. The power supply circuit according to claim 7, characterized in that: The switch module comprises: a third switch MOS tube and a fourth switch MOS tube in the push-pull switch power supply circuit; wherein, The control end of the third switch MOS tube is used to input the first switch signal; The control end of the fourth switch MOS tube is used to input the first switch signal; The first end of the third switch MOS tube is connected to the positive end of the DC power signal; The second end of the third switch MOS tube is connected to the first end of the fourth switch MOS tube and serves as the positive output end of the push-pull switch power supply circuit; The second end of the fourth switch MOS tube is connected to the negative end of the DC power signal.

11. An electronic device, characterized in that: The electronic device comprises: the power supply circuit according to any one of claims 1 to 10.

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