A switching converter

Abstract

The application discloses a switching converter, comprising a voltage offset circuit and a voltage clamping circuit, the voltage offset circuit is used for adding an offset voltage proportional to the negative current in the inductive element to the current detection circuit, so that the current detection circuit can detect the negative current in the power circuit. At the same time, the voltage clamping circuit can also clamp the minimum voltage of the error signal at the preset reference voltage when the voltage at the output end is greater than the set voltage, ensuring that the subsequent circuit can work normally. Through the above two aspects, the switching converter of the embodiment can normally stabilize the voltage when the external power supply transmits energy to the output end, and at the same time, the energy is transmitted to the input end for storage through at least one switching element and the inductive element in the power circuit, so that the energy is not wasted, and the efficiency of the switching converter is improved.

Description

Technical Field

[0001] This invention relates to the field of electronic circuit technology, and more specifically to a switching converter. Background Technology

[0002] Modern portable electronic devices are typically powered by a battery, which serves as direct current (DC) for the various electronic components within the device. However, these components often have different voltage requirements, so such devices usually employ one or more voltage converters that reduce the nominal voltage associated with the power supply to a voltage suitable for the different electronic components.

[0003] Existing voltage converters typically employ either linear regulators or switching converters. In a linear regulator, the output voltage is regulated by adjusting passive components (such as variable resistors) to control the continuous flow of current from the voltage source to the load. A switching converter controls the output voltage by switching the current on and off. It typically uses one or more switches, along with inductors and capacitors, to store and transfer energy to the load. The regulator adjusts the voltage delivered to the load by controlling the on and off states of the switching elements, thereby controlling the amount of electricity delivered through the inductor in the form of discontinuous current pulses. The inductor and capacitor convert the delivered current pulses into a stable load current to regulate the load voltage. Finally, the output voltage is regulated by adjusting the on and off times of the switching elements based on feedback signals representing the output voltage and load current.

[0004] Current-mode switching converters offer excellent linearity and load transient signal rejection, and provide good current limiting capabilities during fault conditions (such as output short circuits), making them widely used. Many current-mode DC-DC converters monitor the inductor current and compare it to the peak inductor current to determine when to disconnect the main switching element, thereby eliminating excessive current delivery.

[0005] Existing switching converters can only achieve unidirectional energy transfer, that is, energy transfer can only be achieved from the input terminal to the load terminal. When external energy is supplied to the load terminal, the output voltage will exceed the set voltage, causing the output of the op-amp in the switching converter to be 0, resulting in the switching converter failing to work properly. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a switching converter that can operate normally when external energy is supplied to the load end, thereby realizing reverse energy storage from the load end to the input end.

[0007] According to an embodiment of the present invention, a switching converter is provided, comprising: an input terminal for receiving an input voltage; an output terminal connected to a load for providing an output voltage; a power circuit connected to the input terminal and the output terminal, the power circuit employing at least one inductor and at least one switching element to regulate the current supplied to the load; a current detection circuit for obtaining a current sampling signal characterizing the inductor current of the at least one inductor; a voltage offset circuit for adding an offset voltage proportional to the negative current in the at least one inductor to the current detection circuit; a voltage clamping circuit for comparing an error signal characterizing the output voltage with a preset reference voltage to obtain a clamping voltage; and a conduction time control circuit for comparing a superimposed signal of the current sampling signal and a ramp compensation signal with the clamping voltage to control a first time period of the at least one switching element, during which the inductor current flows in the at least one inductor to store energy in the at least one inductor.

[0008] Optionally, the clamping voltage is not lower than the voltage value of the preset reference voltage.

[0009] Optionally, the switching converter further includes a timer for providing a clock signal to the power circuit to control a second time period of the at least one switching element, during which energy is transferred from the at least one inductive element to the output or input terminal.

[0010] Optionally, the switching converter further includes: an error amplifier, whose non-inverting input is used to receive a reference voltage, and whose inverting input is used to receive a feedback voltage of the output voltage, for comparing the feedback voltage with the reference voltage to generate the error signal.

[0011] Optionally, the current detection circuit includes: a sampling resistor for sampling the inductor current in the power circuit; and a current amplifier for generating a sensing voltage across the sampling resistor to obtain the current sampling signal.

[0012] Optionally, the voltage offset circuit includes a bias voltage source, one end of which is connected to the non-inverting input of the current amplifier, and the other end is connected to one end of the sampling resistor.

[0013] Optionally, the conduction time control circuit includes: a PWM comparator, whose non-inverting input is used to receive the superimposed signal of the current sampling signal and the ramp compensation signal, whose inverting input is used to receive the clamping voltage, and whose output is used to output a reset signal that controls the turn-off time of the at least one switching element.

[0014] Optionally, the power circuit can be selected from buck topology, boost topology, or buck-boost topology.

[0015] Optionally, the switching converter is a synchronous switching converter or an asynchronous switching converter.

[0016] The switching converter of this invention has the following beneficial effects: The voltage offset circuit adds an offset voltage proportional to the negative current in the inductor to the current detection circuit, enabling the current detection circuit to detect the negative current in the power circuit. Simultaneously, the voltage clamping circuit clamps the minimum voltage of the error signal to a preset reference voltage when the output voltage exceeds a set voltage, ensuring the normal operation of subsequent circuits. Through these two aspects, the switching converter of this embodiment can effectively regulate voltage when an external power supply transmits energy to the output. Furthermore, by transferring this energy to the input for storage through at least one switching element and an inductor in the power circuit, this energy is not wasted, thus improving the efficiency of the switching converter. Attached Figure Description

[0017] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings.

[0018] Figure 1 A schematic circuit diagram of a conventional switching converter is shown.

[0019] Figure 2 A schematic block diagram of a switching converter according to an embodiment of the present invention is shown;

[0020] Figure 3 A schematic circuit diagram of a switching converter according to an embodiment of the present invention is shown;

[0021] Figure 4 This diagram shows a voltage waveform of the switching converter operating under reverse energy storage according to an embodiment of the present invention.

[0022] Figure 5a and 5b Two simulation diagrams of the switching converter according to an embodiment of the present invention are shown respectively. Detailed Implementation

[0023] The invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale. Furthermore, some well-known parts may not be shown in the drawings.

[0024] Many specific details of the invention, such as the structure, materials, dimensions, processing methods, and techniques of the components, are described below to provide a clearer understanding of the invention. However, as those skilled in the art will understand, the invention may be implemented without following these specific details.

[0025] It should be understood that, in the following description, "circuit" refers to a conductive loop consisting of at least one element or sub-circuit connected by an electrical or electromagnetic link. When an element or circuit is said to be "connected" to another element or "connected" between two nodes, it can be directly coupled or connected to the other element, or there may be intermediate elements. The connection between elements can be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected" to another element, it means that there are no intermediate elements between them.

[0026] In the context of this application, when a transistor is in an "off" state, it blocks current and / or conducts essentially no current. Conversely, when a transistor is in an "on" state, it conducts current significantly. For example, in one embodiment, a high-voltage transistor includes an N-channel metal-oxide-semiconductor (NMOS) field-effect transistor (FET), wherein a high voltage is provided between a first terminal (i.e., the drain) and a second terminal (i.e., the source) of the transistor. In some embodiments, an integrated controller circuit can be used to drive a power switch when regulating the energy supplied to a load. Additionally, for the purposes of this disclosure, "ground" or "ground potential" as used herein refers to a reference voltage or potential relative to which all other voltages or potentials of an electronic circuit or integrated circuit (IC) are defined or measured.

[0027] Figure 1 This illustrates a conventional switching converter, such as Figure 1 As shown, the switching converter 100 includes a power circuit 110, an error amplifier OP1, a current amplifier Comp1, a PWM comparator Comp2, a timer 140, and a sampling resistor Rs.

[0028] The power circuit 110 is connected between the input and output terminals and uses at least one inductor and at least one switching element to regulate the current supplied to the load connected to the output terminal, thereby providing a stable and continuous output voltage Vout to the load according to the input voltage Vin.

[0029] The switching converter 100 also includes voltage divider resistors R1 and R2, which are connected in series between the output terminal and ground. The intermediate node between them is used to provide a feedback voltage VFB for the output voltage Vout. The error amplifier OP1 has an inverting input connected to the feedback voltage VFB, a non-inverting input receiving a reference voltage VREF, and an output for outputting an error signal Vea for outputting the difference (or error) between the feedback voltage VFB and the reference voltage VREF.

[0030] One end of the sampling resistor Rs is connected to the input terminal, and the other end is connected to the switching element in the power circuit 110. The current amplifier Comp1 has a non-inverting input terminal and an inverting input terminal connected across the sampling resistor Rs. The current amplifier Comp1 obtains a current sampling signal Vsen that characterizes the inductor current in the power circuit 110 by generating a sensing voltage across the sampling resistor Rs.

[0031] The switching converter 100 is configured to use peak current to control the operation of the power circuit 110 in continuous conduction mode (CCM). Specifically, each switching cycle includes a turn-on period Ton and a turn-off period Toff. During the turn-on period Ton, current from the input flows through the inductor and switching elements, allowing energy to be stored in the at least one inductor. In peak current control mode, the duration of the turn-on period Ton is controlled using a suitable feedback control loop based on the voltage sensed at the sampling resistor Rs. For example, the PWM comparator Comp2 has a non-inverting input that receives a superposition signal Vsum of a current sampling signal Vsen and a ramp compensation signal Vsaw, an inverting input that receives the error signal Vea, and a reset signal RSET for outputting the comparison result of the error signal Vea and the superposition signal Vsum, to control the duration of the turn-on period Ton based on the comparison result.

[0032] During the off-time period Toff, energy previously stored in the inductor is transferred to the load. Specifically, the duration of the off-time period Toff can be fixed. For example, timer 140 is used to provide an internal clock for the switching timing of the circuit to control the off-time period Toff of at least one of its switching elements.

[0033] Traditional switching converters 100 can only provide unidirectional energy transfer, meaning current can only flow from the input to the output, and the current in the inductor is always greater than zero throughout the switching cycle. However, for some highly capacitive loads, due to the capacitive characteristics of the load, they do not actually consume much power during the charging phase. Most of the energy absorbed during the charging phase is stored in the load's capacitance. During the discharging phase, this energy is transferred to the output of the switching converter 100, causing the output voltage Vout to rise. Consequently, the feedback voltage VFB exceeds the reference voltage VREF, and the switching converter 100 cannot operate normally. This results in the energy being discharged from the load's capacitance to ground or the negative power supply, causing energy waste.

[0034] Figure 2 A schematic block diagram of a switching converter according to an embodiment of the present invention is shown. Figure 2 As shown, the switching converter 200 includes a power circuit 210, a current detection circuit 220, a voltage offset circuit 230, a timer 240, an error amplifier circuit 250, a voltage clamping circuit 260, an on-time control circuit 270, and a feedback circuit 280.

[0035] The power circuit 210 includes one or more switching elements and filter elements (e.g., inductors and / or capacitors), which are configured to regulate the power transfer from the input to the output of the switching converter in response to a switching drive signal, so as to convert the input voltage Vin into a stable and continuous output voltage Vout.

[0036] In some embodiments, according to the topology classification of the power circuit 210, the switching converter 200 can be classified as a buck converter, a boost converter, a flyback converter, and a buck-boost converter.

[0037] The switching converter 200 is configured to use peak current to control the operation of the power circuit 210 in continuous conduction mode (CCM). Specifically, each switching cycle includes a turn-on time period Ton and a turn-off time period Toff. During the turn-on time period Ton, current from the input flows through the inductor and the switching element, allowing energy to be stored in the at least one inductor. During the turn-off time period Toff, the energy previously stored in the inductor is transferred to the load or the input.

[0038] The current detection circuit 220 is used to obtain a current sampling signal Vsen characterizing the inductor current of at least one inductor element in the power circuit 210 by detecting the current flowing through at least one inductor element during the conduction time period Ton. The sampling can be implemented using a sampling resistor, a current transformer, or a current mirror, etc. Furthermore, the current detection circuit 220 can also estimate the current flowing through the inductor element and obtain the current sampling signal Vsen by sampling the current flowing through each switching element.

[0039] The voltage offset circuit 230 is connected to the current detection circuit 220 and is used to add an offset voltage Vos proportional to the negative current in the at least one inductor to the current detection circuit 220, so that the current detection circuit 220 can detect the negative current in the at least one inductor and output a valid current sampling signal Vsen.

[0040] Timer 240 is used to provide internal switching timing for the circuit. For example, the duration of the off-time period Toff of the switching converter 200 in this embodiment can be fixed, and the duration of the off-time period Toff is controlled by the clock signal SET provided by timer 240.

[0041] Feedback circuit 280 is connected between the output of switching converter 200 and ground to provide feedback voltage VFB for the output voltage Vout. Error amplifier circuit 250 compares the feedback voltage VFB with the reference voltage VREF1 and obtains the error signal Vea based on the difference or error between the two.

[0042] The voltage clamping circuit 260 is used to compare the error signal Vea with a preset reference voltage VREF2, and obtain a clamping voltage Vc based on the comparison result. In some embodiments, the main function of the voltage clamping circuit 260 is to clamp the minimum voltage of the error signal Vea. That is, when the voltage value of the error signal Vea is greater than the voltage value of the reference voltage VREF2, the clamping voltage Vc is equal to the error signal Vea; when the voltage value of the error signal Vea is less than the voltage value of the reference voltage VREF2, the clamping voltage Vc is equal to the reference voltage VREF2. In other words, the obtained clamping voltage Vc will never be lower than the preset reference voltage VREF2.

[0043] The on-time control circuit 270 is used to compare the superimposed signal Vsum of the current sampling signal Vsen and the slope compensation signal Vsaw with the clamping voltage Vc, and obtain a reset signal RSET based on the comparison result to control the on-time period Ton of at least one switching element.

[0044] Compared to traditional switching converters, the voltage offset circuit 230 in the switching converter 200 adds an offset voltage proportional to the negative current in the inductor to the current detection circuit 220. This allows the current detection circuit 220 to detect the negative current in the power circuit 210, i.e., the current direction is from the output terminal to the input terminal. Furthermore, the voltage clamping circuit 260 can clamp the minimum voltage of the error signal to a preset reference voltage when the output voltage exceeds a set voltage, ensuring the normal operation of the subsequent on-time control circuit 270. Through these two configurations, the switching converter 200 of this embodiment can operate normally when an external power supply transfers energy to the output terminal. This energy is then transferred to the input terminal for storage through at least one switching element and inductor element in the power circuit 210, ensuring that this energy is not wasted and improving the efficiency of the switching converter.

[0045] Figure 3 A schematic circuit diagram of a switching converter according to an embodiment of the present invention is shown. In this embodiment, the power circuit 210 is implemented using a buck topology and includes a power switch M1, a rectifier switch M2, and an inductor L. The first terminal of the power switch M1 is connected to the input voltage Vin, and the second terminal is connected to the first terminal of the rectifier switch M2. The second terminal of the rectifier switch M2 is grounded. The common terminal of the power switch M1 and the rectifier switch M2 forms a switching node. The first terminal of the inductor L is connected to this switching node, and the second terminal is connected to the output voltage Vout. The power switch M1 and the rectifier switch M2 can be any controllable semiconductor switching device, such as a metal-oxide-semiconductor field-effect transistor (MOSFET) or an insulated-gate bipolar transistor (IGBT).

[0046] It should be noted that although a MOSFET is used as a switching element in this embodiment, any other suitable switching element of any type can be used without departing from the principles of the invention. Furthermore, although this embodiment is described using a synchronous buck converter, the invention is not limited thereto; it is equally applicable to asynchronous buck converters. Those skilled in the art can also use a rectifier diode instead of the rectifier switch M2 in the above embodiment.

[0047] In some other embodiments, the power circuit 210 further includes a logic module that can implement the system's logic control functions, process the logic signals of each module controlling the operating state of the switching elements M1 to M2, and generate switch drive signals to provide to the switching elements M1 to M2. The logic module may also include a pulse width modulator (PWM) circuit or any other suitable circuit capable of controlling the duty cycle of the power switches M1 to M2.

[0048] In some embodiments, the current sensing circuit 220 includes a sampling resistor Rs and a current amplifier Comp1. The sampling resistor Rs is connected between the input voltage Vin and the first terminal of the power switch M1. The current amplifier Comp1 has a non-inverting input, an inverting input, and an output. Its non-inverting input is connected to the first terminal of the sampling resistor Rs, and its inverting input is connected to the second terminal of the sampling resistor Rs. When the power switch M1 is turned on, the inductor current flows through the sampling resistor Rs, generating a sense voltage across it. This sense voltage is approximately equal to the product of the inductor current and the value of the sampling resistor. This voltage is then amplified by the current amplifier Comp1 to obtain the current sampling signal Vsen.

[0049] In some embodiments, the voltage offset circuit 230 may include a bias voltage source, one end of which is connected to the non-inverting input of the current amplifier Comp1 and the other end of which is connected to the first end of the sampling resistor Rs, thereby providing an offset voltage Vos at the non-inverting input of the current amplifier Comp1.

[0050] In some embodiments, the error amplifier circuit 250 includes an error amplifier OP1, which has a non-inverting input, an inverting input, and an output. The non-inverting input receives a reference voltage VREF1, and the inverting input receives a feedback voltage VFB of the output voltage Vout. The error amplifier OP1 is adapted to compare the feedback voltage VFB with the reference voltage VREF1 and generate an error signal Vea at the output. Generally, a compensation network consisting of resistors and capacitors is provided between the output of the error amplifier OP1 and the reference ground. Figure 3 (Not shown in the image). Although Figure 3 The embodiment shown uses error amplifier OP1 to implement error amplifier circuit 250, but those skilled in the art will know that other suitable analog or digital circuits are also applicable, as long as they can achieve the error amplification function.

[0051] In some embodiments, the on-time control circuit 270 may include a PWM comparator Comp2. The PWM comparator Comp2 has a non-inverting input, an inverting input, and an output. Its non-inverting input is coupled to the output of the voltage clamping circuit 260 to receive the clamping voltage Vc, and its inverting input is used to receive the superimposed signal Vsum of the current sampling signal Vsen and the slope compensation signal Vsaw. The PWM comparator Comp2 is adapted to compare the clamping voltage Vc with the superimposed signal Vsum, and generate a reset signal RSET when the two intersect. The reset signal RSET is used to control the off-time of the power switch M1.

[0052] In some embodiments, the feedback circuit 280 includes voltage divider resistors R1 and R2 connected in series between the output terminal and ground, with the intermediate node between them used to provide the feedback voltage VFB of the output voltage Vout.

[0053] Figure 4 This diagram illustrates the voltage waveform of the switching converter operating under reverse energy storage according to an embodiment of the present invention. Figure 4 The diagram shows the voltage waveforms of the superimposed signal Vsum (formulated from the inductor current IL, clock signal SET, current sampling signal Vsen, and slope compensation signal Vsaw) and the reset signal RSET. Figure 4 As shown, when external energy is injected into the output, a voltage offset is added to the current detection circuit. Therefore, the current detection circuit outputs a voltage of 0, corresponding to a negative current value, and the clamping voltage Vc is clamped to the reference voltage VREF2. At the beginning of each switching cycle, timer 240 provides a narrow-pulse clock signal SET to the logic circuit. The logic circuit turns on the power switch M1 and turns off the rectifier switch M2 according to the received clock signal SET. This makes the voltage across inductor L approximately Vin-Vout, and the current through inductor L (i.e., inductor current IL) increases linearly, with a larger amount of current being delivered to the input. When the superposition signal Vsum of the current sampling signal Vsen and the slope compensation signal Vsaw exceeds the voltage at the inverting input of the PWM comparator Comp2 (i.e., the reference voltage VREF2), the PWM comparator Comp2 provides a reset signal RSET to the logic circuit to turn off the power switch M1 and turn on the rectifier switch M2. This causes the voltage across the inductor 221 to change to -Vout, resulting in a decrease in the inductor current IL until the next clock signal SET turns the power switch M1 on again and turns off the rectifier switch M2.

[0054] Figure 5a and 5b Two simulation diagrams of the switching converter according to an embodiment of the present invention are shown respectively. Figure 5a The diagram shows the waveforms of the input voltage Vin, output voltage Vout, inductor current IL, and current source I1 during the simulation process. Figure 5b The diagram shows waveforms of the switching node Lx, input voltage Vin, output voltage Vout, inductor current IL, and current source I1 during the simulation. Current source I1 simulates an external power supply, providing current to the output of the switching converter. Figure 5a and 5bAs shown, when the output voltage Vout stabilizes, the inductor current in the switching converter of this embodiment becomes a negative current, that is, the direction of the inductor current changes from the output terminal to the input terminal. Therefore, the switching converter of this embodiment can normally regulate voltage when an external energy source provides energy to the output terminal, and can also transfer energy from the load terminal to the input terminal for energy storage.

[0055] In summary, the switching converter of this embodiment includes a voltage offset circuit and a voltage clamping circuit. The voltage offset circuit adds an offset voltage proportional to the negative current in the inductor to the current detection circuit, enabling the current detection circuit to detect the negative current in the power circuit. Simultaneously, the voltage clamping circuit clamps the minimum voltage of the error signal to a preset reference voltage when the output voltage exceeds a set voltage, ensuring the normal operation of subsequent circuits. Through these two aspects, the switching converter of this embodiment can effectively regulate voltage when an external power supply transmits energy to the output. Furthermore, by transferring this energy to the input for storage through at least one switching element and an inductor in the power circuit, this energy is not wasted, thus improving the efficiency of the switching converter.

[0056] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0057] As described above, these embodiments of the present invention do not exhaustively cover all details, nor do they limit the invention to the specific embodiments described. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to effectively utilize the invention and its modifications. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A switching converter, comprising: The input terminal receives the input voltage. Connect to the output terminal of the load to provide the output voltage; A power circuit connected to the input and output terminals, wherein the power circuit employs at least one inductor and at least one switching element to regulate the current supplied to the load; A current detection circuit is used to obtain a current sampling signal characterizing the inductor current of the at least one inductor element; A voltage offset circuit is used to apply an offset voltage to the current detection circuit that is proportional to the negative current in the at least one inductive element. A voltage clamping circuit is used to compare an error signal characterizing the output voltage with a preset reference voltage to obtain a clamping voltage. as well as A conduction time control circuit is used to compare the superimposed signal of the current sampling signal and the ramp compensation signal with the clamping voltage to control a first time period of the at least one switching element, during which the inductor current flows in the at least one inductor element to store energy in the at least one inductor element.

2. The switching converter according to claim 1, wherein, The clamping voltage is not lower than the preset reference voltage.

3. The switching converter according to claim 1, further comprising: A timer is used to provide a clock signal to the power circuit to control a second time period of the at least one switching element, during which energy is transferred from the at least one inductive element to the output or input terminal.

4. The switching converter according to claim 1, further comprising: An error amplifier has a non-inverting input terminal for receiving a reference voltage and an inverting input terminal for receiving a feedback voltage of the output voltage. The feedback voltage is compared with the reference voltage to generate the error signal.

5. The switching converter according to claim 1, wherein, The current detection circuit includes: A sampling resistor is used to sample the inductor current in the power circuit; and A current amplifier obtains the current sampling signal by generating a sensing voltage across the sampling resistor.

6. The switching converter according to claim 5, wherein, The voltage offset circuit includes a bias voltage source, one end of which is connected to the non-inverting input terminal of the current amplifier, and the other end is connected to one end of the sampling resistor.

7. The switching converter according to claim 1, wherein, The on-time control circuit includes: The PWM comparator has a non-inverting input terminal for receiving the superimposed signal of the current sampling signal and the slope compensation signal, an inverting input terminal for receiving the clamping voltage, and an output terminal for outputting a reset signal that controls the turn-off time of the at least one switching element.

8. The switching converter according to claim 1, wherein, The power circuit can be selected from buck topology, boost topology, or buck-boost topology.

9. The switching converter according to claim 1, wherein, The switching converter is either a synchronous switching converter or an asynchronous switching converter.

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