Voltage transformation circuit and electronic equipment

Abstract

The invention discloses a voltage transformation circuit and electronic equipment, and belongs to the technical field of electronic equipment, and the voltage transformation circuit comprises a switch element, a sampling module, a first integrating circuit, a control module and a filtering unit, the sampling module determines a current parameter according to a sampling signal in a first time interval, carries out the amplification processing of the current parameter, and outputs the amplified current parameter; a sampling output signal associated with the amplified current parameter is kept to be output in a second time interval; the first integrating circuit carries out integration processing on sampling output signals in a first time interval and a second time interval, and the filtering unit filters an integration result of the first integrating circuit in the first time interval. The integral result of the first integral circuit on the sampling output signal in the second time interval is equal to the integral result of the ideal current waveform estimated according to the sampling signal in the first time interval in the first time interval and the second time interval; the control module outputs a control output signal according to the integration result of the first integration circuit in the conduction time.

Description

Technical Field

[0001] This application belongs to the field of electronic equipment technology, specifically relating to a transformer circuit and an electronic device. Background Technology

[0002] A transformer circuit, also known as a DC-DC converter, is commonly found in electronic devices. It converts DC voltage or current levels into the required output voltage to meet the operating voltage requirements of the electronic equipment. Techniques for regulating the output voltage of a transformer circuit include Pulse Frequency Modulation (PFM), which can be further divided into Fixed On Time and Fixed Off Time modes.

[0003] The Fix Off Time mode in related technologies generally controls the turn-off of switching elements by integral control based on the current waveform of the transformer circuit. However, in practice, factors such as parasitic capacitance and / or inductance can cause abnormal harmonics in the current waveform of the transformer circuit, resulting in deviations in the integral results formed based on the current waveform of the transformer circuit, which affects the control accuracy of the turn-off action of the switching elements in related technologies.

[0004] In some related technologies, the switching action of the switching element is generally controlled based on the integration of the historical average current value of the transformer circuit. Although the integration of the historical average current value can reduce the interference of abnormal harmonics to a certain extent, the historical average current value cannot accurately reflect the current waveform of the current transformer circuit, which will also affect the control accuracy of the switching action of the switching element in the related technologies. Summary of the Invention

[0005] This application aims to provide a transformer circuit and electronic device that can improve the control accuracy of the turn-off action of switching elements in practice.

[0006] To solve the above-mentioned technical problems, this application is implemented as follows:

[0007] In a first aspect, embodiments of this application propose a transformer circuit, including a switching element, a sampling module, a first integrating circuit, a control module, and a filtering unit. The input terminal of the sampling module is connected to the switching element, and the output terminal of the sampling module is connected to the input terminal of the first integrating circuit. The input terminal of the control module is connected to the output terminal of the first integrating circuit, and the output terminal of the control module is connected to the switching element. The filtering unit is connected to the first integrating circuit. The sampling module is used to receive a sampling signal, which represents the current magnitude of the switching element. The sampling module determines the current parameter based on the sampling signal within a first time interval, amplifies the current parameter, and maintains the output of a sampling output signal correlated with the amplified current parameter within a second time interval. The conduction time of the switching element includes the first time interval... The system consists of a first time interval and a second time interval, with the first time interval preceding the second time interval in sequence. A first integrating circuit is used to receive the sampled output signal and integrate the sampled output signal within the first and second time intervals. A filtering unit is used to filter out the integration result of the first integrating circuit within the first time interval. The integration result of the first integrating circuit on the sampled output signal within the second time interval is equal to the integration result of the ideal current waveform estimated based on the sampled signal within the first time interval within the first and second time intervals. The control module determines whether the integration result of the first integrating circuit within the conduction time is greater than or equal to the target integral amount. If so, it outputs a control output signal to the switching element to turn off the switching element; otherwise, it does not output a control output signal.

[0008] Secondly, embodiments of this application provide an electronic device including a transformer circuit and a load as described in the first aspect, wherein the load is connected to a switching element.

[0009] In the embodiments of this application, the transformer circuit is used to control the turn-off of the switching element by controlling the output signal. The filtering unit filters out the integration result of the first integrator circuit within the first time interval, reducing the interference of parasitic harmonics of the current waveform within the first time interval on the integration result. Since the sampling module maintains the output signal associated with the amplified current parameter within the second time interval, and the current parameter is amplified, the integration result of the first integrator circuit on the sampled output signal within the second time interval is equal to the integration result of the ideal current waveform estimated based on the sampled signal within the first time interval within both the first and second time intervals. Therefore, the amplified portion of the integration result within the second time interval can be used to compensate for the integration result within the first time interval filtered out by the filtering unit. This reduces the interference of parasitic harmonics of the current waveform within the first time interval on the integration result while ensuring the accuracy and completeness of the integration result of the first integrator circuit, thereby improving the turn-off control accuracy of the switching element. Furthermore, in this embodiment, the transformer circuit controls the switching element to turn off based on the sampled signal that represents the current of the switching element. Compared with the scheme that controls the switching element based on the integral result of the historical average current value, the transformer circuit in this embodiment controls the switching element to turn off more accurately and in accordance with the current operating condition of the switching element.

[0010] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0011] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0012] Figure 1 This is a partial structural schematic diagram of an electronic device in some embodiments of this application.

[0013] Figure 2 This is a schematic diagram of the switch control circuit in some embodiments of this application.

[0014] Figure 3 This is a schematic diagram of the ideal current waveform of the transformer circuit in some embodiments of this application.

[0015] Figure 4 This is a schematic diagram of the measured current waveform of the transformer circuit in some embodiments of this application.

[0016] Figure 5 This is a schematic diagram of the sampling unit in some embodiments of this application.

[0017] Figure 6This is a timing diagram of the transformer circuit in some embodiments of this application.

[0018] Figure 7 This is a schematic diagram of the integration results of the transformer circuit in some embodiments of this application.

[0019] Figure 8 This is a flowchart of a switch control method in some embodiments of this application.

[0020] Figure label:

[0021] 1. Electronic equipment; 2. Transformer circuit; 3. Control device; 10. Switch control circuit; 100. Sampling module; 110. Sampling unit; K1. First sub-switch; C1. First capacitor; 101. Amplifier circuit; K2. Second sub-switch; 120. Selector; 200. First integrator circuit; 201. First amplifier; C2. Second capacitor; K3. Third sub-switch; 300. Control module; 301. Comparator; 400. Filtering unit; K4. Fourth sub-switch; 500. Second integrator circuit; 501. Second amplifier; C3. Third capacitor; K5. Fifth sub-switch; 20. Switching element; 21. Gate; 31. Turn-off time controller; 32. Switch driving unit; 40. Energy storage element; 50. Resistor; 60. Diode; 70. Inductor; 80. Load. Detailed Implementation

[0022] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0023] The terms "first," "second," "third," "fourth," and "fifth" used in the specification and claims of this application may explicitly or implicitly include one or more of those features. Furthermore, the words "and / or" in the specification and claims indicate at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0024] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected," "linked," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0025] This application provides a transformer circuit and an electronic device.

[0026] A transformer circuit, also commonly referred to as a DC-DC converter, is an electronic circuit that converts a DC voltage or current level to another DC voltage or current level.

[0027] Optionally, transformer circuits can be classified into buck, boost, buck-boost, and isolated types according to their topology.

[0028] Optionally, the technology for regulating the output voltage of a transformer circuit can be divided into pulse width modulation (PWM) and pulse frequency modulation (PFM). Among them, PFM can be further divided into fixed on time mode and fixed off time mode.

[0029] In the embodiments of this application, the structure and control process of the transformer circuit will be illustrated using the Fix Off Time mode. Of course, in other embodiments, the transformer circuit can also be applied in a non-conflicting manner in the Fix On Time mode.

[0030] Alternatively, the transformer circuit can be applied to electronic devices.

[0031] For example, the electronic device may be at least one of a mobile phone, tablet computer, e-book, wearable device, and display screen. The specific type of electronic device is not limited in the embodiments of this application.

[0032] In related technologies, such as those employing Fix Off Time mode to regulate output voltage, the turn-off of switching elements is generally controlled based on the current waveform of the transformer circuit. However, in practice, due to the PCB (Printed Circuit Board) traces and the parasitic inductance and capacitance of the switching elements themselves, abnormal harmonics may appear in the current flowing through the transformer circuit when the switching element is turned on. This affects the control accuracy of controlling the turn-off of the switching element based on the current waveform of the transformer circuit.

[0033] Therefore, some embodiments of this application provide a transformer circuit and an electronic device.

[0034] Please see Figure 1 , Figure 1 An electronic device 1 is shown in some embodiments of this application.

[0035] Electronic device 1 includes transformer circuit 2 and load 80, with transformer circuit 2 connected to load 80.

[0036] The transformer circuit 2 includes a switch control circuit 10 and a switch element 20. The switch control circuit 10 is connected to the switch element 20, and the switch control circuit 10 can be used to control the switch element 20 to turn off.

[0037] Please see Figure 2 , Figure 2 A switch control circuit 10 is shown in some embodiments of this application.

[0038] like Figure 2 As shown, the switch control circuit 10 includes a sampling module 100, a first integrating circuit 200, a control module 300, and a filtering unit 400.

[0039] Specifically, the input terminal of the sampling module 100 is connected to the switching element 20, the output terminal of the sampling module 100 is connected to the input terminal of the first integrating circuit 200, the input terminal of the control module 300 is connected to the output terminal of the first integrating circuit 200, the output terminal of the control module 300 is connected to the switching element 20, and the filtering unit 400 is connected to the first integrating circuit 200.

[0040] The sampling module 100 is used to receive the sampling signal V1, which represents the current magnitude of the switching element 20. The sampling module 100 determines the current parameter based on the sampling signal V1 within a first time interval, amplifies the current parameter, and maintains the output of a sampling output signal V4 associated with the amplified current parameter within a second time interval. The conduction time of the switching element 20 includes both the first and second time intervals, with the first time interval sequentially preceding the second time interval.

[0041] The first integrating circuit 200 is used to receive the sampled output signal V4 and to integrate the sampled output signal V4 in the first time interval and the second time interval. The filtering unit 400 is used to filter out the integration result of the first integrating circuit 200 in the first time interval. The integration result of the first integrating circuit 200 on the sampled output signal V4 in the second time interval is equal to the integration result of the ideal current waveform estimated based on the sampled signal V1 in the first time interval in the first time interval and the second time interval.

[0042] The control module 300 is used to determine whether the integration result of the first integrating circuit 200 during the conduction time is greater than or equal to the target integration amount. If so, it outputs a control output signal V3 to the switching element 20 to turn off the switching element 20. If not, it does not output the control output signal V3.

[0043] In the embodiments of this application, the transformer circuit 2 is used to control the turn-off of the switching element 20 by controlling the output signal V3. The filtering unit 400 filters out the integration result of the first integrator circuit 200 within the first time interval, reducing the interference of parasitic harmonics of the current waveform within the first time interval on the integration result. Since the sampling module 100 maintains the output of the sampled output signal V4 associated with the amplified current parameter within the second time interval, the integration result of the first integrator circuit 200 on the sampled output signal V4 within the second time interval is equal to the integration result of the ideal current waveform estimated based on the sampled signal V1 within the first time interval within both the first and second time intervals, the amplified portion of the integration result within the second time interval can be used to compensate for the integration result within the first time interval filtered out by the filtering unit 400. This reduces the interference of parasitic harmonics of the current waveform within the first time interval on the integration result while ensuring the accuracy and completeness of the integration result of the first integrator circuit 200, thereby improving the turn-off control accuracy of the switching element 20. Furthermore, in this embodiment, the transformer circuit 2 controls the switching element 20 to turn off based on the sampling signal V1 related to the current of the switching element 20. Compared with the scheme that controls the switching based on the integral result of the historical average current value, the transformer circuit 2 in this embodiment controls the switching element 20 to turn off more in line with the current operating condition of the switching element 20, and the control accuracy of the switching element 20 is also higher.

[0044] For example, Figure 3 The ideal current waveform of transformer circuit 2 in some possible embodiments is shown. Figure 4 Measured current waveforms of transformer circuit 2 in some possible embodiments are shown. It is understood that the ideal current waveform estimated based on the sampled signal V1 within the first time interval could be as follows: Figure 3 The ideal current waveform is shown in the figure.

[0045] Combination Figure 3 and Figure 4 It is understandable that, compared to the ideal current waveform of transformer circuit 2, in Figure 4 The position of the dashed coil in the diagram illustrates the measured current waveform of transformer circuit 2, which is actually caused by abnormal harmonics generated by parasitic inductance 70 and / or capacitance.

[0046] In the embodiments of this application, the first time interval can be used as the time interval in which abnormal harmonics are generated in the measured current waveform. Thus, the sampling module 100 can input the sampling signal V1 corresponding to the abnormal harmonic portion of the measured current waveform of the transformer circuit 2 within the first time interval. The filtering unit 400 filters out the integration result of the first integrator circuit 200 within the first time interval, thereby reducing the interference of parasitic harmonics of the current waveform on the integration result within the first time interval. Furthermore, by using the sampling module 100 to determine the current parameter based on the sampling signal V1 within the first time interval, amplifying the current parameter, and maintaining the output of a sampling output signal V4 associated with the amplified current parameter within the second time interval, the first integrator circuit 200 integrates based on the sampling output signal V4 associated with the amplified current parameter within the second time interval. In this way, the integration result of the first integrator circuit 200 within the second time interval is correspondingly amplified to satisfy the condition that the integration result of the first integrator circuit 200 on the sampling output signal V4 within the second time interval is equal to the integration result of the ideal current waveform estimated based on the sampling signal V1 within the first time interval within both the first and second time intervals. Therefore, the amplified portion of the integral result in the second time interval can be used to compensate for the integral result in the first time interval that was filtered out by the filter unit 400. This reduces the interference of parasitic harmonics of the current waveform in the first time interval on the integral result, while ensuring the accuracy and integrity of the overall integral result of the first integrator circuit 200, thereby improving the turn-off control accuracy of the switching element 20.

[0047] In some embodiments of this application, optionally, the sampling module 100 determines the current parameter based on the sampled signal V1 within the first time interval by: the sampling module 100 determining the current parameter based on the sampled signal V1 at the end of the first time interval; the amplification factor k in the amplification process, the length t1 of the first time interval, and the length t2 of the second time interval satisfy: k = (t1 + t2) 2 / (2t1×t2).

[0048] By considering the magnification factor k, the length of the first time interval t1, and the length of the second time interval t2 in the magnification process, we can establish the formula k = (t1 + t2). 2The constraint relationship of / 2t1×t2 ensures that the integral result of the current parameter determined by the sampling signal V1 at the end of the first time interval in the second time interval is basically equal to the integral result of the ideal current waveform estimated by the sampling signal V1 in the first time interval in the first and second time intervals. This achieves the suppression of abnormal harmonic interference on the integral result and the compensation of the integral result in the first time interval.

[0049] In some embodiments of this application, optionally, the amplification factor k in the amplification process includes twice, and the length t2 of the second time interval is equal to the length t1 of the first time interval. This allows the amplified portion of the integrated result of the double-amplified current parameter in the second time interval to compensate for the filtered-out integrated result in the first time interval, thereby suppressing the interference of the parasitic component of the switching element 20 on the integrated result, while ensuring the accuracy of the overall integrated quantity of the first integrating circuit 200 and improving the control precision of the switching element 20.

[0050] Of course, this application is not limited to this. In other embodiments, the specific value of the amplification factor k and the ratio of the length t2 of the second time interval to the length t1 of the first time interval can be adjusted as needed, so that the sum of the integrals of the ideal current waveform of the transformer circuit 2 in the second time interval and the first time interval is approximately equal to the product of the integral of the sampled signal V1 at the end of the first time interval in the second time interval and the amplification factor k.

[0051] In some embodiments of this application, optionally, the conduction time of the switching element 20 may further include a third time interval, wherein the conduction time may specifically be the sum of the first time interval, the second time interval and the third time interval, and the third time interval is arranged sequentially after the second time interval.

[0052] The sampling module 100 is also used to output a sampling output signal V4 associated with the sampling signal V1 received in the third time interval based on the sampling signal V1 received in the third time interval, and the first integrator circuit 200 is also used to perform integration processing on the sampling output signal V4 received in the third time interval.

[0053] In this way, by integrating the sampled output signal V4 associated with the input sampled signal V1 within the third time interval using the first integrator circuit 200, the integrity and accuracy of the integration result of the first integrator circuit 200 during the conduction time of the switching element 20 can be achieved. Furthermore, the proportion of the second and first time intervals within the conduction time of the switching element can be coordinated by controlling the length of the third time interval. That is, the longer the third time interval, the shorter the length of the second and / or first time intervals can be. This allows for more flexible control over the length of the second and / or first time intervals, thereby helping to improve the amplification portion of the integration result within the second time interval and compensating for the integration result within the first time interval filtered out by the filter unit 400, thus improving the turn-off control accuracy of the switching element 20.

[0054] In general, the first integrating circuit 200 in this embodiment performs integration calculations by using pre-integration compensation (i.e., using the integration results in the second time interval to compensate for the filtered integration results in the first time interval) and post-integration superposition (i.e., superimposing the integration results in the third time interval with the integration results in the second time interval). This can better suppress the impact of parasitic components such as parasitic inductance and capacitance of the PCB traces and the switching element 20 itself on the control accuracy of the switching element 20.

[0055] By arranging the third time interval sequentially after the second time interval, the second time interval is closer to the first time interval. This reduces the amplification of the current parameter, thereby further improving the control accuracy of the integral compensation amount of the first time interval.

[0056] Of course, the embodiments of this application are not limited thereto. In other embodiments, the current parameter may also be the weighted value of the sampling signal V1 accessed by the sampling module 100 within the first time interval, or the current parameter may also be the average value of the sampling signal V1 accessed by the sampling module 100 within the first time interval, or the current parameter may also be the parameter of the sampling signal V1 accessed by the sampling module 100 at other times within the first time interval except for the end time. Accordingly, the constraint relationship between the amplification factor k, the length t1 of the first time interval, and the length t2 of the second time interval in the amplification process is not limited to k=(t1+t2). 2 / (2t1×t2), it can be understood that the constraints of the amplification factor k, the length of the first time interval t1, and the length of the second time interval t2 in the amplification process can vary according to the determination method of the current parameters. The integral result of the current parameters in the second time interval is basically equal to the integral result of the ideal current waveform estimated based on the sampling signal V1 in the first time interval in the first and second time intervals.

[0057] Optionally, the ideal current waveform is estimated based on the sampled signal V1 within the first time interval. For example, the estimated ideal current waveform can be determined based on the sampled signals V1 corresponding to the start and end times of the first time interval; or, for example, the estimated ideal current waveform can be determined based on one or more sampled signals V1 within the first time interval and a preset correction coefficient. It is understood that there are multiple ways to estimate the ideal current waveform based on the sampled signal V1 within the first time interval, and they will not be listed exhaustively here.

[0058] like Figure 2 As shown in some embodiments of this application, optionally, the sampling module 100 includes a sampling unit 110. The sampling unit 110 is connected to the switching element 20. The sampling unit 110 can be used to receive a sampling signal V1, determine the current parameter based on the received sampling signal V1, and amplify the current parameter.

[0059] For example, the current parameter may include the parameter corresponding to the sampling signal V1 accessed by the sampling unit 110 at the end of the first time interval. Of course, in other embodiments, the current parameter may also be the weighted value of the sampling signal V1 accessed by the sampling unit 110 within the first time interval, or the current parameter may also be the average value of the sampling signal V1 accessed by the sampling unit 110 within the first time interval, or the current parameter may also be the parameter of the sampling signal V1 accessed by the sampling unit 110 at other times within the first time interval besides the end time.

[0060] Please see Figure 5 , Figure 5 The sampling unit 110 in some embodiments of this application is shown.

[0061] like Figure 5 As shown, optionally, the sampling unit 110 may include a first sub-switch K1, a second sub-switch K2, a first capacitor C1, and an amplifier circuit 101. The first capacitor C1 is connected between the first sub-switch K1 and a reference potential; the input terminal of the amplifier circuit 101 is connected to the first sub-switch K1 and the first capacitor C1, and the output terminal of the amplifier circuit 101 is used to output the sampled output signal V4; the second sub-switch K2 is connected between the first sub-switch K1 and the reference potential.

[0062] Optionally, the reference potential may include, but is not limited to, the ground potential GND.

[0063] In this embodiment, when the second sub-switch K2 is open and the first sub-switch K1 is closed, the sampling signal V1 charges the first capacitor C1. The amplifier circuit 101 can amplify the current sampling signal V1 to output a sampled amplified signal Vf. Optionally, the amplification factor of the amplifier circuit 101 for the current sampling signal V1 can be preset or received in real time. The sampling module 100 is used to output a sampled output signal V4 based on the sampled amplified signal Vf. When the second sub-switch K2 is open and the first sub-switch K1 is open, the first capacitor C1 discharges, allowing the amplifier circuit 101 to maintain the output of the sampled amplified signal Vf for a period of time, for example, maintaining the output of the sampled amplified signal Vf during the second time interval. At this time, the amplifier circuit 101 maintains the output of the sampled amplified signal Vf in association with the sampling signal V1 received at the moment the first sub-switch K1 is open. Thus, this structure can correspondingly achieve: the sampling unit 110 amplifies the sampling signal V1 at the end of the first time interval by a preset factor and maintains the output of the sampled output signal V4 associated with the amplified current parameters during the second time interval.

[0064] like Figure 2 As shown in some embodiments of this application, the sampling module 100 may optionally include a selector 120.

[0065] Selector 120 has a first input terminal, a second input terminal, and an output terminal. The output terminal of selector 120 is connected to the input terminal of the first integrating circuit 200, the first input terminal is connected to the output terminal of the sampling unit 110, and the second input terminal is connected to the switching element 20 for receiving the sampling signal V1. The state of selector 120 is selectively selected between a state where the first input terminal and the output terminal are both on, and a state where the second input terminal and the output terminal are both on. Specifically, when the first input terminal and the output terminal are both on, selector 120 outputs a sampling output signal V4 associated with the amplified current parameter; and when the second input terminal and the output terminal are both on, it outputs a sampling output signal V4 associated with the sampling signal V1 received at the second input terminal.

[0066] By selecting one of the first input terminal and the second input terminal to be connected to the output terminal through selector 120, the sampling mode can be switched accordingly.

[0067] For example, selector 120 is used to input control signals (the control signals here can be referred to as...). Figure 2 and Figure 6 (understood as Φ3 signal), and based on the control signal, it switches to the state where the first input terminal and the output terminal of the selector 120 are connected within the second time interval; during the conduction time other than the second time interval, the selector 120 switches to the state where the second input terminal and the output terminal of the selector 120 are connected.

[0068] Optionally, the aforementioned other time intervals can be understood as the first time interval and the third time interval. In the second time interval, the first input terminal is connected to the output terminal, causing the selector 120 to output a sampled output signal V4 based on the sampled amplified signal Vf output by the sampling unit 110, which is then integrated by the first integrator circuit 200. In both the first and third time intervals, the second input terminal is connected to the output terminal, causing the selector 120 to output a sampled output signal V4 based on the sampled signal V1 input to the second input terminal, which is then integrated by the first integrator circuit 200. This design is simple, provides efficient switching between sampling modes, and improves the continuity of integration and the accuracy of the integration results at the first integrator circuit 200.

[0069] Of course, this application is not limited to this. In other embodiments, the sampling module 100 may not collect the sampling signal V1 during the first time interval; or, during the first time interval, the selector 120 may switch to a state where the first input terminal and the output terminal of the selector 120 are connected, so that the selector 120 also outputs the sampling output signal V4 associated with the amplified current parameter during the first time interval.

[0070] In some embodiments of this application, optionally, such as Figure 2 As shown, the first integrating circuit 200 includes a first amplifier 201, a second capacitor C2, and a third sub-switch K3. The input terminal of the first amplifier 201 is connected to the output terminal of the sampling module 100, and the output terminal of the first amplifier 201 is connected to the input terminal of the control module 300; the second capacitor C2 is connected between the output terminal of the first amplifier 201 and a reference potential; the third sub-switch K3 is connected between the output terminal of the first amplifier 201 and the reference potential. The reference potential here includes, but is not limited to, ground potential GND.

[0071] In this embodiment, when the third sub-switch K3 is opened, the first amplifier 201 can perform integration processing on the sampled output signal V4 or the sampled signal V1. When the third sub-switch K3 is closed, the first integration circuit 200 is reset to stop the integration processing.

[0072] In some embodiments of this application, optionally, such as Figure 2 As shown, the filter unit 400 includes a fourth sub-switch K4, which is connected between the output of the first amplifier 201 and a reference potential. This reference potential includes, but is not limited to, ground potential GND.

[0073] When the fourth sub-switch K4 is closed, the integration result during the period when the fourth sub-switch K4 is closed can be filtered out by the first integrator circuit 200. Therefore, by keeping the fourth sub-switch K4 closed during the first time interval and opening it at the end of the first time interval, the integration result of the first integrator circuit 200 during the first time interval can be filtered out.

[0074] In some embodiments of this application, optionally, such as Figure 2 As shown, the switch control circuit 10 also includes a second integrator circuit 500.

[0075] The input terminal of the second integrator circuit 500 is connected to the switching element 20, and the output terminal of the second integrator circuit 500 is connected to the input terminal of the control module 300. The second integrator circuit 500 is used to receive the average signal V2 and integrate the average signal V2. The integration result of the second integrator circuit 500 during the conduction time of the switching element 20 is used as the target integral quantity. Among them, the average signal V2 is used to represent the average current of the switching element 20.

[0076] Optionally, the average current can be the average current of the switching element 20 over a historical conduction period.

[0077] Of course, this application is not limited to this. In other embodiments, the second integrating circuit 500 may be omitted, and the target integration amount may be a preset value.

[0078] Optionally, the second integrating circuit 500 includes a second amplifier 501, a third capacitor C3, and a fifth sub-switch K5.

[0079] The input terminal of the second amplifier 501 is used to acquire the average signal V2, and the output terminal of the second amplifier 501 is connected to the input terminal of the control module 300; the third capacitor C3 is connected between the output terminal of the second amplifier 501 and the reference potential; the fifth sub-switch K5 is connected between the output terminal of the second amplifier 501 and the reference potential. The reference potential here includes, but is not limited to, the ground potential GND.

[0080] In this embodiment, when the fifth sub-switch K5 is open, the second amplifier 501 can perform integration processing on the average signal V2. When the fifth sub-switch K5 is closed, the second integration circuit 500 is reset to stop performing integration processing.

[0081] Optionally, one end of the second amplifier 501 and one end of the first amplifier 201 are both connected to a reference signal V0.

[0082] In some embodiments of this application, optionally, such as Figure 2As shown, the control module 300 includes a comparator 301, which is used to compare the integration result of the first integrator 200 during the conduction time of the switching element 20 with the target integration amount. When the integration result of the first integrator 200 during the conduction time of the switching element 20 is greater than or equal to the target integration amount, the comparator 301 outputs a control output signal V3. When the integration result of the first integrator 200 during the conduction time of the switching element 20 is less than the target integration amount, the comparator 301 does not output a control output signal V3.

[0083] In some embodiments of this application, optionally, the start time of the first time interval is synchronized with the start time of the switching element 20 being turned on.

[0084] This allows for more accurate suppression of the interference caused by the parasitic components of the switching element 20 on the integration result.

[0085] Of course, it is understood that the embodiments of this application are not limited thereto. In other embodiments, the start time of the first time interval may be slightly earlier than the time when the switching element 20 starts to conduct, or slightly later than the time when the switching element 20 starts to conduct.

[0086] In one specific embodiment of this application, such as Figure 1 As shown, the transformer circuit 2 may include a switch control circuit 10 and a switching element 20. Combined with... Figure 1 and Figure 2 It is understood that the switch control circuit 10 may include a sampling module 100, a first integrating circuit 200, a second integrating circuit 500, and a control module 300.

[0087] The sampling module 100 includes a selector 120 and a sampling unit 110, such as Figure 5 As shown, the sampling unit 110 includes a first sub-switch K1, a second sub-switch K2, a first capacitor C1, and an amplifier circuit 101. One end of the first sub-switch K1 is used to input the sampling signal V1, and the first capacitor C1 is connected between the other end of the first sub-switch K1 and a reference potential, which can be ground potential GND. The input terminal of the amplifier circuit 101 is connected to the other end of the first sub-switch K1 and the first capacitor C1, and the output terminal of the amplifier circuit 101 is used to output the sampled amplified signal Vf to the first input terminal of the selector 120. The second sub-switch K2 is connected between the other end of the first sub-switch K1 and the reference potential, which can be ground potential GND. The amplification factor of the amplifier circuit 101 for the sampling signal V1 can be twice. The lengths of the first time interval and the second time interval are equal. The second input terminal of the selector 120 is used to input the sampling signal V1, and the selector 120 is used to output a corresponding sampling output signal V4 based on the sampling signal V1 or the sampled amplified signal Vf.

[0088] The first integrating circuit 200 includes a first amplifier 201, a second capacitor C2, and a third sub-switch K3. The input terminal of the first amplifier 201 is connected to the sampling module 100, and the output terminal of the first amplifier 201 is connected to the control module 300; the second capacitor C2 is connected between the output terminal of the first amplifier 201 and a reference potential, which can be ground potential GND; the third sub-switch K3 is connected between the output terminal of the first amplifier 201 and the reference potential, which can be ground potential GND.

[0089] The second integrator circuit 500 includes a second amplifier 501, a third capacitor C3, and a fifth sub-switch K5. The input terminal of the second amplifier 501 is used to acquire the average signal V2, and the output terminal of the second amplifier 501 is connected to the control module 300; the third capacitor C3 is connected between the output terminal of the second amplifier 501 and the reference potential; the fifth sub-switch K5 is connected between the output terminal of the second amplifier 501 and the reference potential.

[0090] The second capacitor C2 of the first integrating circuit 200 and the third capacitor C3 of the second integrating circuit 500 both use the same value. The first amplifier 201 of the first integrating circuit 200 and the second amplifier 501 of the second integrating circuit 500 also use the same specifications.

[0091] The control signals for transformer circuit 2 include Φ1 signal, Φ2 signal and Φ3 signal.

[0092] Signals Φ2 and Φ3 can be high-level signals. Signals Φ2 and Φ3 are maintained at a high level for the same duration. Accordingly, the length of the second time interval is equal to the length of the first time interval.

[0093] The Φ2 and Φ3 signals can be arranged in a continuous and close sequence.

[0094] Combination Figure 2 The specific working principle of transformer circuit 2 can be understood as follows:

[0095] When transformer circuit 2 starts working, signal Φ1 is applied. The objects controlled by signal Φ1 can include the third sub-switch K3 and the fifth sub-switch K5, both of which disconnect in response to signal Φ1.

[0096] By disconnecting the third sub-switch K3, the first integrator circuit 200 begins integration based on the sampled output signal V4. Simultaneously, by disconnecting the fifth sub-switch K5, the second integrator circuit 500 begins integration based on the mean signal V2.

[0097] In order to reduce the interference of parasitic components of transformer circuit 2 on the integration result of the first integrator circuit 200, the fourth sub-switch K4 can be kept closed during the first time interval by using the Φ2 signal to filter out the integration result of the first integrator circuit 200 during the first time interval. The filtering out of the integration result of the first integrator circuit 200 during the first time interval means that the value of the integration result of the first integrator circuit 200 during the first time interval is 0.

[0098] The end time of the Φ2 signal corresponds to the end time of the first time interval. At this time, the fourth sub-switch K4 is opened to stop filtering the integral of the first integrating circuit 200. Simultaneously, the sampling unit 110 amplifies the sampled signal V1 at the end time of the first time interval by a factor of two. That is, the sampling unit 110 outputs a sampled amplified signal Vf to the selector 120, causing the selector 120 to output a sampled output signal V4, which is twice the sampled signal V1 at the end time of the first time interval.

[0099] The Φ3 signal immediately follows the Φ2 signal with a high-level output. At this time, the selector 120 responds to the Φ3 signal and continues to output the sampled output signal V4. The duration of the high-level signal Φ3 can be considered as the second time interval, allowing the selector 120 to continue outputting the sampled output signal V4 within this second time interval. Correspondingly, the first integrator circuit 200 performs an initial integration on the sampled output signal V4 within the second time interval. The result of this initial integration can be understood as the first sub-integral quantity. Since the sampled output signal V4 is a twice-amplified sampled signal V1, the first sub-integral quantity includes both the integral quantity within the second time interval (i.e., the duration of the high-level signal Φ3) and the compensation quantity for the integration compensation within the first time interval (i.e., the duration of the high-level signal Φ2).

[0100] After the high-level signal of Φ3 ends, selector 120 switches to the second input terminal and output terminal being connected. At this time, selector 120 outputs a sampled output signal V4 associated with the sampled signal V1 input to the second input terminal. The sampled output signal V4 corresponds to the sampled signal V1 without the double amplification processing. The third time interval can be defined as the time after the high-level signal of Φ3 ends. The first integrator circuit 200 performs a later integration on the sampled output signal V4 within the third time interval. The result of this later integration can be understood as the second sub-integral quantity. The second sub-integral quantity and the first sub-integral quantity are superimposed to form the integrated output signal. Of course, if the second and third time intervals are not consecutive, the integrated output signal can be further superimposed with an integral compensation amount corresponding to the time interval between the second and third time intervals, based on the second and first sub-integral quantities.

[0101] The control module 300 determines whether to output the control output signal V3 based on the superposition result of the second sub-integral quantity and the first sub-integral quantity and the target integral quantity. For example, the control module 300 is a comparator 301. The comparator 301 compares the superposition result of the second sub-integral quantity and the first sub-integral quantity with the target integral quantity. If the superposition result is greater than or equal to the target integral quantity, the control output signal V3 is output to control the switching element 20 to turn off; otherwise, the control output signal V3 is not output, and the switching element 20 remains open.

[0102] In this specific embodiment, by predicting abnormal harmonics, the generation time of the abnormal harmonics is corresponding to the first time interval, and the integral result within the first time interval is filtered out. The sampled signal V1 at the end of the second time interval and the amplified first time interval is used for integration to compensate for the integral result of the filtered first time interval, so as to form a control method of early integral compensation and late integral superposition, thereby improving the control accuracy of the switching element 20.

[0103] Combination Figure 5 The specific working principle of sampling unit 110 can be understood as follows:

[0104] The controlled object of the Φ1 signal may also include the second sub-switch K2.

[0105] When transformer circuit 2 starts working, signal Φ1 is applied. The second sub-switch K2 opens in response to signal Φ1.

[0106] The controlled object of the Φ2 signal may also include the first sub-switch K1. When the Φ2 signal is connected, the first sub-switch K1 closes in response to the Φ2 signal.

[0107] When the high level of the Φ2 signal ends, it corresponds to the end of the first time interval. At this time, the first sub-switch K1 is opened, the sampling unit 110 stops collecting new sampling signals V1, and the sampling unit 110 continues to amplify the sampling signal V1 at the end of the first time interval by two times and output it.

[0108] Figure 6 This is a timing diagram of transformer circuit 2 in this specific embodiment.

[0109] Wherein, V1 represents the sampling signal; V2 is indicated by a horizontal dashed line and represents the mean signal; Φ1, Φ2, and Φ3 represent logic signals used for control, respectively; V4 represents the sampling output signal; and GATE represents the gate signal used to turn off the switching element 20. The gate signal can be understood as the control output signal V3, or as the drive signal issued by the switch drive unit 32 in response to the control output signal V3.

[0110] In this process, the low level of the Φ1 signal controls both the third sub-switch K3 and the fifth sub-switch K5 to open, and the first integrator circuit 200 and the second integrator circuit 500 perform calculations simultaneously.

[0111] The high level of the Φ2 signal controls the fourth sub-switch K4 to close, so that in the first time interval (see reference) Figure 6 and Figure 7 (Understanding t1 in the text) The interference of the sampling signal V1 in the first time interval on the first integrator circuit 200 is filtered out.

[0112] The sampling module 100 acquires the sampling signal V1 within the first time interval corresponding to the high level of the Φ2 signal, and after the first time interval ends, it maintains the sampling signal V1 at the end of the first time interval and amplifies the sampling signal V1 at the end of the first time interval by two times before outputting it.

[0113] The high level of the Φ3 signal corresponds to the second time interval (see reference). Figure 6 and Figure 7 (Understanding t2 in the original text), where the high level of signal Φ3 is maintained for the same duration as the high level of signal Φ2, meaning the second time interval is equal in length to the first time interval, and the high levels of signals Φ3 and Φ2 are closely aligned in timing. Selector 120 responds to the high level of signal Φ3 to continue outputting the sampled output signal V4 during the second time interval. The first integrator circuit 200 integrates the sampled output signal V4 during the second time interval, and the integration result corresponds to the first sub-integral quantity. This first sub-integral quantity provides the integral quantity within the second time interval and the integral compensation quantity within the first time interval.

[0114] After the high level of the Φ3 signal ends, selector 120 is in the third time interval (see reference). Figure 6 and Figure 7 (Understanding t3 in the original text) Based on the input sampling signal V1, the first integrator circuit 200 outputs a sampled output signal V4. Within the third time interval, the first integrator circuit 200 performs subsequent integration on the sampled output signal V4, and the integration result corresponds to the second sub-integral quantity.

[0115] By superimposing the first sub-integral quantity and the second sub-integral quantity, the sum of the first sub-integral quantity and the second sub-integral quantity is compared with the target integral quantity. When the sum of the first sub-integral quantity and the second sub-integral quantity is greater than or equal to the target integral quantity, the comparator 301 outputs a control output signal V3 to control the switching element 20 to turn off.

[0116] When the switching element 20 is turned off, the Φ1 signal is reset to a high level to control the first capacitor C1, the second capacitor C2, and the third capacitor C3 of the transformer circuit 2 to be reset.

[0117] Figure 7This is a schematic diagram of the integration result of transformer circuit 2 in this specific embodiment.

[0118] like Figure 7 As shown, the area of ​​0dec represents the target integral quantity, i.e., A1; the area of ​​the dashed box B1 represents the integral quantity of the sampled signal V1 at the end of the first time interval in the second time interval; the area of ​​the two dashed boxes B1 represents the integral quantity of the sampled signal V1 at the end of the first time interval after being amplified by two times in the second time interval, i.e., the first sub-integral quantity; the area of ​​fgcb B2 represents the integral quantity of the sampled output signal V4 output by the selector 120 based on the input sampled signal V1 in the third time interval and the third time interval, i.e., the second sub-integral quantity.

[0119] During the first time interval, the integral of the sampled signal V1 is filtered out because the fourth sub-switch K4 is closed. Therefore, there is no integral in the first time interval, or it can be understood that the integral result in the first time interval is 0.

[0120] Within the second time interval, since the sampled signal V1 at the end time of the first time interval, which is magnified by two times, is integrated with the second time interval, the corresponding integration result is the first sub-integral (the first sub-integral is 2B1, i.e., the sum of B1 and B1). Among them, the areas of triangles s1 and s2 are approximately the same. Therefore, the area of ​​the first sub-integral 2B1 above the ab line can just compensate for the area below the ab line in the first time interval, so that the first sub-integral 2B1 can compensate for the integral in the first time interval.

[0121] The sum of 2B1 and B2 is compared with the target integral A1. When the sum of 2B1 and B2 is greater than or equal to A1, the control output signal V3 is output.

[0122] Please continue reading. Figure 1 In some embodiments of this application, the transformer circuit 2 may further include a turn-off time controller 31 and a switch drive unit 32; the input terminal of the turn-off time controller 31 is connected to the control module 300 of the transformer circuit 2, the output terminal of the turn-off time controller 31 is connected to the start input terminal of the switch drive unit 32, the reset input terminal of the switch drive unit 32 is connected to the turn-off time controller 31 and the control module 300, and the output terminal of the switch drive unit 32 is connected to the switch element 20.

[0123] The turn-off time controller 31 is used to calculate the preset turn-off duration starting from the turn-off time of the switching element 20; the switch drive unit 32 is used to control the turn-off and turn-on of the switching element 20 according to the control output signal V3 and the calculation result of the turn-off time controller 31.

[0124] Specifically, the turn-off time controller 31 starts timing from the turn-off moment of the switching element 20. When the timing duration is greater than or equal to the preset turn-off duration, the switch drive unit 32 controls the switching element 20 to turn on in response. When the control module 300 outputs the control output signal V3, the switch drive unit 32 can also respond to the control output signal V3 to turn off the switching element 20. This realizes the control of the turn-off and turn-on of the switching element 20.

[0125] Optionally, such as Figure 1 As shown, the transformer circuit 2 may specifically include a switching element 20 and a control device 3, wherein the switching control circuit 10, the off-time controller 31, and the switching drive unit 32 are all part of the control device 3. Furthermore, the transformer circuit 2 may also include an energy storage element 40, which can be an inductor or a capacitor. Thus, during the switching process of the switching element 20 controlled by the control device 3, the energy storage element 40 correspondingly switches between energy release and energy storage, thereby achieving the conversion of the DC voltage or current level to the DC voltage or current level required by the load 80.

[0126] Optionally, the switching element 20 can be a metal-oxide-semiconductor field-effect transistor (MOSFET), also commonly referred to as a MOS transistor. It is understood that the MOS transistor has a gate 21, a drain, and a source. The gate 21 is connected to the control device 3. Specifically, for example, the gate 21 is connected to the switch driving unit 32 of the control device 3. The switch driving unit 32 responds to the control output signal V3 by outputting a gate signal GATE to the gate 21. The gate signal GATE can be a low-level signal to turn off the switch 20 to be controlled.

[0127] Please continue reading. Figure 1 Embodiments of this application also provide an electronic device 1, which includes a transformer circuit 2 and a load 80. The load 80 is connected to the switching element 20 of the transformer circuit 2.

[0128] The transformer circuit 2 of the electronic device 1 can be the transformer circuit 2 in any of the above embodiments. Therefore, the transformer circuit 2 can be understood in a non-conflicting manner with reference to the transformer circuit 2 in any of the above embodiments, and will not be repeated here.

[0129] The electronic device 1 of this embodiment, by providing the transformer circuit 2 of any of the above embodiments, possesses the effects of any of the above embodiments.

[0130] Optionally, the electronic device 1 may be at least one of a mobile phone, tablet computer, e-book, wearable device, and display screen. The specific type of electronic device 1 is not limited in the embodiments of this application.

[0131] The following example will be an electronic device 1 with a light-emitting display. Of course, it is understood that electronic device 1 is not limited to electronic devices with light-emitting displays, but can also be an e-book, wearable device, etc.

[0132] Optionally, the light-emitting display electronic device 1 can be a light-emitting diode (LED) display screen or a liquid crystal display (LCD).

[0133] The electronic device 1, which is a light-emitting display, may specifically include a backlight driving circuit. See also... Figure 1 , Figure 1 The structure of at least a portion of the backlight driving circuit of electronic device 1 in some possible embodiments is illustrated.

[0134] The load 80 of the light-emitting display electronic device 1 can be a light-emitting element. The light-emitting element can be a light-emitting diode.

[0135] The light-emitting element is connected to one of the drain and source terminals of the switching element 20.

[0136] The electronic device 1 also includes a resistor 50, one end of which is connected to the other of the drain and source of the switching element 20, and the other end of which is connected to a reference potential, which may be ground potential GND.

[0137] The electronic device 1 also includes an inductor 70, which is connected in series between the light-emitting element and the switching element 20. By detecting the current in the resistor 50, the current flowing through the inductor 70 can be obtained accordingly.

[0138] The electronic device 1 also includes a diode 60, which is connected in parallel with the light-emitting element and the inductor 70.

[0139] The energy storage element 40 can be a capacitor. One end of the energy storage element 40 is connected to a reference potential, which can be ground potential GND. The other end of the energy storage element 40 is connected between an external signal and a light-emitting element.

[0140] The transformer circuit 2 of the control device 3 obtains a sampling signal V1 by detecting the current signal between the resistor 50 and the switching element 20. The off-time controller 31 has a built-in preset off-time OFF-Time, or can be connected to an external preset off-time OFF-Time. The second integrator circuit 500 is connected to the average signal V2. The gate 21 of the switching element 20 is connected to the switch drive unit 32, which responds to the control output signal V3 to turn off the switching element 20.

[0141] In this embodiment, the backlight driving circuit of the electronic device 1 can achieve a constant brightness of the light-emitting element by detecting and controlling the current flowing through the inductor 70. Specifically, for example, the electronic device 1 can adjust the supply current of the light-emitting element using the PFM (Fix Off Time) method.

[0142] like Figure 1 As shown, when the switching element 20 is turned on, in order to determine the off time of the switching element 20, the control device 3 detects the current flowing through the inductor 70 through the resistor 50 to collect a sampling signal V1 related to the detected current. The control device 3 performs integration on the sampling signal V1 and the average signal V2, and outputs a control output signal V3 based on the comparison result between the sampled output signal and the target output signal to turn off the switching element 20. When the switching element 20 is turned off, the off-time controller 31 controls the switching element 20 to turn on based on the preset off-time OFF-Time. The backlight driving circuit will cycle through the above operations to switch the switching element 20 on and off until the corresponding control target is achieved.

[0143] In this embodiment, the control device 3 uses a transformer circuit 2 to suppress the interference of parasitic components of the switching element 20 on the integration result, thereby improving the accuracy of the integration output signal. It also compares the integration output signal with the target integration signal to determine whether to output the control output signal V3. In this way, the historical control quantity and the current required control quantity are averaged, thereby improving the control accuracy of the switching element 20 to turn off and improving problems such as screen flickering of electronic device 1 caused by parasitic components.

[0144] like Figure 8 As shown, an embodiment of this application provides a control method for a transformer circuit, including the following steps:

[0145] Step S1: Input the sampling signal, determine the current parameter based on the sampling signal in the first time interval, amplify the current parameter, and maintain the output of the sampling output signal associated with the amplified current parameter in the second time interval. The conduction time of the switching element includes the first time interval and the second time interval, and the first time interval is arranged in time sequence before the second time interval.

[0146] Step S2: Integrate the sampled output signals in the first time interval and the second time interval. The filtering unit filters out the integration result of the first integrating circuit in the first time interval. The integration result of the first integrating circuit on the sampled output signals in the second time interval is equal to the integration result of the ideal current waveform estimated based on the sampled signals in the first time interval in the first time interval and the second time interval.

[0147] Step S3: Determine whether the integral result of the sampled output signal during the conduction time of the switching element is greater than or equal to the target integral. If yes, output a control output signal to the switching element to turn off the switching element. If no, do not output a control output signal.

[0148] It is understandable that steps S1, S2, and S3 do not limit the logical relationship between the steps of this control method. In fact, the sampling signal access process in step S1 and the process of integrating the sampled output signal within the same time interval in step S2 can be performed synchronously.

[0149] In the embodiments of this application, the first time interval can be used as the time interval in which abnormal harmonics are generated in the measured current waveform. This allows the sampling signal corresponding to the abnormal harmonic portion of the measured current waveform to be input within the first time interval. By filtering out the integration result within the first time interval, the interference of parasitic harmonics in the current waveform on the integration result within the first time interval is reduced. Furthermore, by determining the current parameters based on the sampling signals within the first time interval, the current parameters are amplified, and the output signal associated with the amplified current parameters is maintained within the second time interval. This allows integration within the second time interval based on the sampling output signal associated with the amplified current parameters. Thus, the integration result within the second time interval is amplified accordingly to satisfy the condition that the integration result of the first integrating circuit 200 on the sampling output signal V4 within the second time interval is equal to the integration result of the ideal current waveform estimated based on the sampling signal V1 within the first time interval within both the first and second time intervals. Therefore, the amplified portion of the integral result in the second time interval can be used to compensate for the integral result in the first time interval that was filtered out. This reduces the interference of parasitic harmonics of the current waveform in the first time interval on the integral result while ensuring the accuracy and completeness of the overall integral result, thereby improving the turn-off control precision of the switching element.

[0150] According to some embodiments of this application, optionally, the conduction time of the switching element further includes a third time interval; step S1 further includes:

[0151] Based on the sampled signals received within the third time interval, output a sampled output signal associated with the sampled signals received within the third time interval.

[0152] According to some embodiments of this application, optionally, the third time interval is arranged sequentially after the second time interval.

[0153] According to some embodiments of this application, optionally, the control method for the transformer circuit further includes the following steps:

[0154] The average signal is input and integrated. The integration result of the second integrator circuit is used as the target integral quantity. The average signal is used to represent the average current of the switching element.

[0155] Of course, this application is not limited to this. In other embodiments, the above steps may be omitted, and the target integral amount may be a preset value.

[0156] According to some embodiments of this application, optionally, the second time interval is arranged chronologically before the third time interval. This way, the second time interval is closer to the first time interval, which can improve the control accuracy of the integral compensation amount of the first time interval.

[0157] In some embodiments of this application, optionally, the start time of the first time interval is synchronized with the start time of the switching element's conduction. This can more accurately suppress interference from parasitic components of the switching element on the integration result.

[0158] Of course, it is understood that the embodiments of this application are not limited to this. In other embodiments, the start time of the first time interval may be slightly earlier or slightly later than the start time of the switching element, so that the first time interval can cover at least part of the time when abnormal harmonics are generated.

[0159] In some embodiments of this application, optionally, the magnitude of the preset multiplier is negatively correlated with the length of the second time interval. That is, the larger the preset multiplier, the shorter the length of the second time interval, which can more accurately compensate for the integral amount in the first time interval.

[0160] In some embodiments of this application, optionally, the preset multiplier includes two times, and the second time interval is equal to the first time interval. This ensures that the sampled signal at the end of the first time interval after being amplified by two times has an integral quantity in the second time interval that is approximately equal to the integral quantity to be compensated in the first time interval. This helps to suppress the interference of parasitic components of the switching element on the integration result, while reducing the deviation of the first sub-integral quantity, improving the accuracy of the integrated output signal, and thus improving the control precision of the switching element.

[0161] Of course, this application is not limited to this. In other embodiments, the specific value of the preset multiple and the ratio of the length of the second time interval to the length of the first time interval can be adjusted as needed, so that the sum of the integrals of the ideal current waveform of the transformer circuit in the second time interval and the first time interval is approximately equal to the product of the integral of the sampled signal at the end of the first time interval in the second time interval and the preset multiple.

[0162] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0163] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A voltage conversion circuit, characterized by, The variable voltage circuit comprises a switching element, a sampling module, a first integration circuit, a control module and a filtering unit, an input end of the sampling module is connected with the switching element, an output end of the sampling module is connected with an input end of the first integration circuit, an output end of the first integration circuit is connected with an input end of the control module, an output end of the control module is connected with the switching element, and the filtering unit is connected with the first integration circuit. The sampling module is used for accessing a sampling signal, the sampling signal is used for representing a current size of the switching element, the sampling module determines a current parameter according to the sampling signal in a first time interval, amplifies the current parameter, and keeps a sampling output signal associated with the amplified current parameter in a second time interval, wherein the on time of the switching element comprises the first time interval and the second time interval, and the first time interval is arranged in time sequence before the second time interval. The first integration circuit is used for accessing the sampling output signal and performing integration processing on the sampling output signal in the first time interval and the second time interval, wherein the filtering unit is used for filtering an integration result of the first integration circuit in the first time interval, and an integration result of the first integration circuit on the sampling output signal in the second time interval is equal to an integration result of an ideal current waveform estimated according to the sampling signal in the first time interval in the first time interval and the second time interval. The control module judges whether the integration result of the first integration circuit in the on time is greater than or equal to a target integration amount, if yes, outputs a control output signal for turning off the switching element to the switching element, and if not, does not output the control output signal.

2. The variable voltage circuit according to claim 1, wherein The sampling module determines the current parameter according to the sampling signal at the end of the first time interval. The amplification factor k in the amplification processing, the length t1 of the first time interval, and the length t2 of the second time interval satisfy: k=(t1+t2) 2 / (2t1×t2).

3. The variable voltage circuit according to claim 2, wherein The amplification multiple comprises two times, and the length of the second time interval is equal to the length of the first time interval.

4. The variable voltage circuit according to any one of claims 1 to 3, wherein The start time of the first time interval is synchronous with the time when the switching element starts to conduct.

5. The variable voltage circuit according to any one of claims 1 to 3, wherein The on time is a sum of the first time interval, the second time interval and a third time interval, the third time interval is arranged in time sequence after the second time interval; The sampling module is further used for outputting the sampling output signal associated with the sampling signal accessed in the third time interval according to the sampling signal accessed in the third time interval, and the first integration circuit further performs integration processing on the sampling output signal in the third time interval.

6. The transformer circuit according to any one of claims 1 to 3, characterized in that The sampling module comprises a sampling unit and a selector, the input end of the sampling unit is connected with the switch element, the selector has a first input end, a second input end and an output end, the output end of the selector is connected with the input end of the first integration circuit, the first input end is connected with the output end of the sampling unit, and the second input end is connected with the switch element; The sampling unit is used for accessing the sampling signal, determining the current parameter according to the accessed sampling signal, and amplifying the current parameter; The selector is used for outputting the sampling output signal associated with the amplified current parameter when the first input end and the output end of the selector are turned on, and outputting the sampling output signal associated with the sampling signal accessed by the second input end when the second input end and the output end of the selector are turned on.

7. The voltage conversion circuit according to claim 6, wherein The selector is used for accessing a control signal and switching to a state in which the first input end and the output end of the selector are turned on in the second time interval based on the control signal; In a time interval other than the second time interval in the on time, the selector is switched to a state in which the second input end and the output end of the selector are turned on.

8. The variable voltage circuit of claim 6, wherein, The sampling unit comprises a first sub-switch, a first capacitor, an amplification circuit, and a second sub-switch, the first capacitor is connected between the first sub-switch and a reference potential, the input end of the amplification circuit is connected with the first sub-switch and the first capacitor, the output end of the amplification circuit is used for outputting the sampling output signal, and the second sub-switch is connected between the first sub-switch and the reference potential.

9. The transformer circuit according to any one of claims 1 to 3, characterized in that The first integration circuit comprises a first amplifier, a second capacitor and a third sub-switch, the input end of the first amplifier is connected with the output end of the sampling module, the output end of the first amplifier is connected with the input end of the control module, the second capacitor is connected between the output end of the first amplifier and a reference potential, and the third sub-switch is connected between the output end of the first amplifier and the reference potential.

10. The voltage conversion circuit of claim 9, wherein, The filter unit comprises a fourth sub-switch, and the fourth sub-switch is connected between the output end of the first amplifier and a reference potential.

11. The transformer circuit according to any one of claims 1 to 3, characterized in that The second integration circuit is also included, the input end of the second integration circuit is connected with the switch element, the output end of the second integration circuit is connected with the input end of the control module, the second integration circuit is used for accessing a mean value signal and performing integration processing on the mean value signal, and the integration result of the second integration circuit in the on time is used as the target integration amount, wherein the mean value signal is used for representing the average current size of the switch element.

12. The transformer circuit according to any one of claims 1 to 3, characterized in that The application further comprises a turn-off time controller and a switch driving unit, an input end of the turn-off time controller is connected with the control module, an output end of the turn-off time controller is connected with an enabling input end of the switch driving unit, a reset input end of the switch driving unit is connected with the turn-off time controller and the control module, and an output end of the switch driving unit is connected with the switch element. The turn-off time controller is used for calculating a preset turn-off duration from a turn-off time of the switch element. The switch driving unit is used for controlling turn-off and turn-on of the switch element according to the control output signal and a calculation result of the turn-off time controller.

13. An electronic device, comprising: The application further comprises a load connected with the switch element.

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