Modulation method and circuit of LLC conversion circuit, and electronic equipment

Abstract

The invention discloses a modulation method and circuit of an LLC conversion circuit, and electronic equipment, and is applied to charge modulation of a resonant conversion circuit, and the modulation method comprises the steps: obtaining the power supply output of the resonant conversion circuit; obtaining an output control signal by using an error signal between the power supply output and a target reference signal; generating a drive control signal using the output control signal; detecting whether the output control signal is in a dynamic threshold interval; wherein the second comparison threshold value of the lower limit value of the dynamic threshold value interval is in negative correlation with the output control signal; in response to the fact that the output control signal is smaller than the second comparison threshold value, carrying out wave sealing on the driving control signal until the output control signal is larger than the first comparison threshold value; and the driving control signal is sent to the resonant conversion circuit to adjust the power supply output. Through the mode, the modulation method of the LLC conversion circuit can realize full-load adaptive control through the dynamic hysteresis threshold value and a natural wave stopping mechanism, and the requirement of stability in a full-load range is effectively met.

Description

Technical Field

[0001] This application relates to the field of circuit control technology, and in particular to modulation methods and circuits for LLC converter circuits, and electronic equipment. Background Technology

[0002] In recent years, resonant converters have been widely used in industrial power supplies, data centers, and other fields due to their high efficiency, high power density, and soft-switching characteristics. To improve the dynamic performance of resonant converters, charge control mode has been introduced into the topology of resonant converters, which achieves rapid regulation of the output voltage by directly adjusting the charge in the resonant cavity.

[0003] However, the charge control mode has inherent drawbacks under light load or no-load conditions: due to its fast response speed, the Burst mode is more sensitive to triggering, which is not conducive to modulating output ripple; the high bandwidth of charge control makes it extremely sensitive to small disturbances. Under light load, the energy transfer during the switching cycle decreases sharply, and the fast response of the control loop amplifies the oscillations caused by high-frequency switching noise and parasitic parameters, resulting in a significant increase in output voltage ripple; under light load, the equivalent impedance of the resonant cavity of the resonant converter increases, the operating point deviates from the optimal resonant region, and the linear relationship between charge and output voltage weakens. However, the charge control algorithm is designed based on full-load conditions, and its linearization compensation strategy fails under light load, further aggravating the occurrence of ripple. Summary of the Invention

[0004] The main technical problem addressed by this application is to provide a modulation method, circuit, and electronic equipment for LLC converter circuits, which can solve the problem of large output ripple in the control of resonant converters in the prior art under light load or no load conditions.

[0005] To solve the above-mentioned technical problems, one technical solution adopted in this application is: providing a modulation method for an LLC converter circuit, applied to charge modulation of a resonant converter circuit, wherein the modulation method for the LLC converter circuit includes: acquiring the power supply output of the resonant converter circuit; obtaining an output control signal using the error signal between the power supply output and a target reference signal; generating a drive control signal using the output control signal; detecting whether the output control signal is within a dynamic threshold range; wherein the upper and lower limits of the dynamic threshold range are a first comparison threshold and a second comparison threshold, respectively, and the second comparison threshold is negatively correlated with the output control signal; in response to the output control signal being less than the second comparison threshold, blocking the drive control signal until the output control signal is greater than the first comparison threshold; sending the drive control signal to the resonant converter circuit to adjust the switching state of the resonant converter circuit, thereby regulating the power supply output.

[0006] The step of generating a drive control signal using the output control signal includes: detecting whether the output control signal is greater than a first comparison threshold; generating a drive control signal using the output control signal in response to the output control signal being greater than the first comparison threshold; the step of detecting whether the output control signal is within a dynamic threshold range includes: detecting whether the output control signal is less than a second comparison threshold in response to the output control signal not being greater than the first comparison threshold; blocking the drive control signal in response to the output control signal being less than the second comparison threshold until the output control signal is greater than the second comparison threshold includes: blocking the drive control signal in response to the output control signal being less than the second comparison threshold, and re-executing the step of detecting whether the output control signal is greater than the first comparison threshold.

[0007] The step of obtaining the output control signal using the error signal between the power supply output and the target reference signal, and the step of detecting whether the output control signal is within the dynamic threshold range, further includes: processing the output control signal using a first adjustment function to obtain a second comparison threshold; and processing the second comparison threshold using the second adjustment function to obtain a first comparison threshold. The calculation formula for the first adjustment function is as follows: BMTL = BMTLmax - k(Vfb - Vfbmin); The calculation formula for the second adjustment function is: BMTH = BMTL + ΔV; Wherein, BMTL is the second comparison threshold, BMTLmax is the maximum dynamic limit threshold, k is the threshold scaling factor, Vfb is the output control signal, Vfbmin is the minimum output limit threshold, BMTH is the first comparison threshold, and ΔV is the dynamic step threshold.

[0008] The step of obtaining the output control signal using the error signal between the power supply output and the target reference signal includes: subtracting the target reference signal from the power supply output to obtain the error signal; and using proportional and integral adjustment coefficients to proportionally and integrally adjust the error signal to obtain the output control signal.

[0009] The step of blocking the drive control signal in response to the output control signal being less than the second comparison threshold until the output control signal is greater than the second comparison threshold further includes: adjusting the proportional adjustment coefficient to the minimum proportional coefficient and adjusting the integral adjustment coefficient to the minimum integral coefficient during the time interval from when the output control signal is less than the second comparison threshold to when it is greater than the second comparison threshold.

[0010] The step of responding to the output control signal from being less than the second comparison threshold to being greater than the second comparison threshold within a time interval includes: responding to the output control signal being less than the second comparison threshold, using a preset arithmetic function to gradually adjust the proportional adjustment coefficient from a preset proportional coefficient to equal the minimum proportional coefficient in each signal cycle of the current drive control signal.

[0011] The step of adjusting the integral adjustment coefficient to the minimum integral coefficient includes: in response to the output control signal being less than the second comparison threshold, using a preset arithmetic function to gradually adjust the integral adjustment coefficient from the preset integral coefficient to equal the minimum integral coefficient in each signal cycle of the current drive control signal.

[0012] The modulation method of the LLC converter circuit further includes: in response to the output control signal being greater than the second comparison threshold, using a preset arithmetic function to gradually adjust the proportional adjustment coefficient from the minimum proportional coefficient to equal the preset proportional coefficient in each signal cycle of the current drive control signal; and using a preset arithmetic function to gradually adjust the integral adjustment coefficient from the minimum integral coefficient to equal the preset integral coefficient in each signal cycle of the current drive control signal.

[0013] To solve the above-mentioned technical problems, another technical solution adopted in this application is: to provide a modulation circuit, wherein the modulation circuit is used to couple with the resonant converter circuit; wherein the modulation circuit is used to control the resonant converter circuit using the modulation method of the LLC converter circuit as described in any of the above claims.

[0014] To solve the above-mentioned technical problems, another technical solution adopted in this application is: to provide an electronic device, wherein the electronic device includes a housing and a modulation circuit connected to the housing; wherein the modulation circuit is the modulation circuit as described above.

[0015] The beneficial effects of this application are as follows: Unlike the prior art, the modulation method of the LLC converter circuit provided in this application obtains the power supply output of the resonant converter circuit, uses the error signal between the power supply output and the target reference signal to obtain the output control signal, and blocks the drive control signal when the detected output control signal is less than a second comparison threshold that is negatively correlated with it. When the output control signal is greater than a first comparison threshold, the drive control signal is generated using the output control signal and sent to the resonant converter circuit to adjust the switching state of the resonant converter circuit to regulate the power supply output. This allows the second comparison threshold to be larger when the output control signal is small, i.e., under light load or no load. The lighter the load, the more sensitive it is to entering the hiccup mode. In the hiccup mode, the system bandwidth is reduced and the response speed is slower, which is beneficial to suppressing the output ripple. That is, while retaining high dynamic performance, it suppresses light load ripple through adaptive control strategy or nonlinear correction mechanism, and also reduces the resource occupation of digital controller and reduces storage and computing resources through parameterless algorithm. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a flowchart illustrating the first embodiment of the modulation method for the LLC converter circuit of this application; Figure 2 This is a schematic diagram of the first embodiment of the modulation circuit of this application; Figure 3 yes Figure 1 A flowchart of an embodiment of S13; Figure 4 This is a flowchart illustrating the second embodiment of the modulation method for the LLC converter circuit of this application; Figure 5 This is a flowchart illustrating the third embodiment of the modulation method for the LLC converter circuit of this application; Figure 6 This is a schematic diagram of the second embodiment of the modulation circuit of this application; Figure 7 yes Figure 5 A schematic diagram of the signal processing logic framework for the modulation method in the LLC converter circuit; Figure 8 yes Figure 5 A waveform diagram of the relevant signals of the modulation method in the LLC converter circuit according to an embodiment; Figure 9 yes Figure 5 A waveform diagram illustrating the functional relationship between the second comparison threshold and the output control signal in the modulation method of the LLC converter circuit in one embodiment; Figure 10 yes Figure 5 A waveform diagram of another embodiment of the modulation method for the LLC converter circuit and related signals; Figure 11 This is a schematic diagram of one embodiment of the electronic device of this application. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] The terms "first," "second," and "third" in this application are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indications also change accordingly. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0019] In this document, the term "implementation" means that a specific feature, structure, or characteristic described in connection with an implementation may be included in at least one implementation of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same implementation, nor is it a separate or alternative implementation mutually exclusive with other implementations. It will be explicitly and implicitly understood by those skilled in the art that the implementations described herein can be combined with other implementations.

[0020] The present application will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] Please refer to the following: Figure 1 and Figure 2 ,in, Figure 1 This is a flowchart illustrating the first embodiment of the modulation method for the LLC converter circuit of this application. Figure 2 This is a schematic diagram of the first embodiment of the modulation circuit of this application. Specifically, it may include the following steps: S11: Obtain the power supply output of the resonant converter circuit.

[0022] It is understood that the modulation method of the LLC converter circuit in this embodiment is specifically applied to, for example... Figure 2 The charge modulation of the first resonant converter circuit 20 shown is illustrated by a first modulation circuit 30 for coupling with the first resonant converter circuit 20; wherein the first modulation circuit 30 is used to control the first resonant converter circuit 20 using the modulation method of the LLC converter circuit of any of the present invention.

[0023] In some embodiments, the first resonant converter 20 may be a half-bridge LLC (inductance capacitor, an additional inductor connected in series with two other inductors and capacitors) converter, a full-bridge LLC converter, or other forms of LLC circuit topology, which are not limited in this embodiment.

[0024] In some embodiments, the first modulation circuit 30 may specifically include any reasonable circuit unit with signal processing function, such as a control chip, a DSP (Digital Signal Processing) chip, an MCU (Micro Controller Unit) circuit, a CPU (Central Processing Unit), a microcontroller, a field-programmable gate array, a programmable logic device, a discrete gate or transistor logic device, or discrete hardware. This application does not limit this.

[0025] It is worth noting that the term "coupled" in this article refers to any direct or indirect connection. Therefore, if the article describes a first circuit coupled to a second circuit, it means that the first circuit can be directly connected to the second circuit via electrical connection or signal connection methods such as wireless transmission or optical transmission, or indirectly connected to the second circuit via other circuits or connection methods via electrical connection or signal connection.

[0026] Specifically, the first modulation circuit 30 samples the power supply output from the first resonant conversion circuit 20; wherein the power supply output may specifically include output voltage and / or output current.

[0027] In some embodiments, the first modulation circuit 30 can be obtained through a voltage transformer, current transformer, voltage divider, sampling resistor or other types of circuit units, and converted into a digital signal by an ADC (Analog to Digital Converter) for use by the first modulation circuit 30. This application does not limit this.

[0028] S12: The output control signal is obtained by using the error signal between the power supply output and the target reference signal.

[0029] The first modulation circuit 30 sets a target reference signal according to the current power supply requirements, or receives a target reference signal obtained by the host computer through experimental calibration or simulation optimization for the specific operating conditions and power supply requirements of the load circuit. The target reference signal is then subtracted from the power supply output to obtain an error signal, and the error signal is proportional-integral adjustment to obtain an output control signal. Specifically, when the power supply output is an output voltage, the target reference signal is a target reference voltage; when the power supply output is an output current, the target reference signal is a target reference current.

[0030] It's worth noting that a host computer typically refers to a computer system with powerful computing and data processing capabilities. It is responsible for monitoring the entire control system, issuing commands, acquiring data, processing and analyzing data, and facilitating user interaction. As the "brain" of the system, the host computer can handle complex algorithms, store long-term data, and provide a graphical user interface for operation.

[0031] A lower-level controller is a device or controller directly connected to hardware such as sensors and actuators in a control system. It is responsible for executing specific control commands issued by the upper-level controller, such as outputting switch signals, adjusting analog signals, and acquiring data. Lower-level controllers typically perform simple logical judgments and real-time control tasks.

[0032] In this embodiment, the host computer can be specifically understood as the system controller at the front end of the first modulation circuit 30, and the slave computer is the first modulation circuit 30.

[0033] S13: Generate drive control signal using output control signal.

[0034] The output control signal is processed by a preset control algorithm, a preset adjustment function, a voltage loop, or a current loop to obtain the drive control signal.

[0035] In some embodiments, the drive control signal may be one or more of any reasonable control signal such as PWM (Pulse Width Modulation) signal or PFM (Pulse Frequency Modulation) signal, and this application does not limit it.

[0036] S14: Detect whether the output control signal is within the dynamic threshold range.

[0037] Understandably, in order to reduce the standby power loss of the first resonant converter circuit 20 and solve the problem of unstable output voltage, the first resonant converter circuit 20 usually needs to adopt an intermittent working mode, namely the hiccup mode, under light load or no load, in order to balance efficiency and stability through periodic oscillation stop and restart (similar to "hiccup" behavior).

[0038] It's worth noting that the trigger condition for this hiccup mode is as follows: when the load rate falls below a set threshold (e.g., 10% of the rated load), hiccup mode is activated, manifesting as periodic interruptions in the operating frequency. Light load optimization: intermittent oscillation reduces switching losses and improves light load efficiency. Capacitive area protection: under overload conditions, excessively low frequencies may trigger capacitive switching; hiccup mode prevents device damage.

[0039] Additionally, load factor refers to the ratio between the actual load carried by electrical equipment or a system and its rated capacity, usually expressed as a percentage. Its definition and optimization scope differ across different application scenarios. Load factor = Actual load / Rated load * 100%, used to measure equipment utilization. Too low a load factor results in wasted capacity, while too high a load factor exacerbates wear and tear and shortens lifespan.

[0040] In this embodiment, in order to retain high dynamic performance, light load ripple is suppressed by adaptive control strategy or nonlinear correction mechanism to meet the stability requirements of the full load range. Specifically, the hiccup mode under light load or no load is optimized to use a dynamic threshold range that changes dynamically in response to changes in the output control signal to determine whether to enter the hiccup mode.

[0041] The dynamic threshold range can be obtained by monitoring the dynamic performance, power supply stability requirements and output ripple of the first resonant converter circuit 20 under different load rates, and by fitting and setting it through corresponding simulation prediction or experimental optimization.

[0042] Specifically, the upper and lower limits of the dynamic threshold range are the first comparison threshold and the second comparison threshold, respectively. The second comparison threshold is negatively correlated with the output control signal. That is, when the output control signal is large, the second comparison threshold is small, and when the output control signal is small, the second comparison threshold is large. The first modulation circuit 30 is used to detect whether the output control signal is within the dynamic threshold range in order to determine whether to enter the hiccup mode, i.e., the corresponding burst mode.

[0043] If the output control signal is greater than the first comparison threshold, or changes from not less than the first comparison threshold to less than the second comparison threshold, then S15 is executed; if the output control signal changes from less than the second comparison threshold to greater than the first comparison threshold, then S16 is executed.

[0044] S15: Send the drive control signal to the resonant converter circuit to adjust the switching state of the resonant converter circuit, thereby regulating the power supply output.

[0045] Understandably, when the output control signal is determined to be greater than the first comparison threshold, that is, the first resonant converter circuit 20 has a large load rate and there is no need to enter the hiccup mode, the first resonant converter circuit 20 is normally driven and controlled by feedback adjustment; and when the output control signal changes from not less than the first comparison threshold to less than the second comparison threshold, the current drive control strategy remains unchanged.

[0046] Specifically, a drive control signal is sent to the first resonant converter circuit 20 to trigger the first resonant converter circuit 20 to change the switching state of its internal switching elements, thereby regulating the power supply output, i.e., the output voltage and / or output current.

[0047] S16: Block the drive control signal.

[0048] When the output control signal is determined to be less than the second comparison threshold, the system enters a hiccup mode, which means that the drive control signal is blocked and no drive control signal is sent to the first resonant conversion circuit 20; or, when the output control signal is determined to be less than the second comparison threshold, the system does not use the output control signal to generate a drive control signal until the output control signal is detected to be greater than the first comparison threshold, at which point the current output control signal is reused to generate a drive control signal.

[0049] It is worth noting that wave blocking refers to forcibly shutting down the drive control signal under specific conditions, causing it to enter a safe state (usually a low level or high impedance state), which is mainly used for equipment protection or precise control.

[0050] The above scheme blocks the drive control signal when the output control signal is less than a second comparison threshold that is negatively correlated with it, until the output control signal is greater than a first comparison threshold. Then, the drive control signal is generated using the output control signal. This allows the second comparison threshold to be larger when the output control signal is small, i.e., under light load or no load. The lighter the load, the more sensitive the system is to hiccup mode. In hiccup mode, the system bandwidth decreases and the response speed slows down, which is beneficial for suppressing output ripple. When the output control signal is large, i.e., the system becomes less sensitive as the load increases, the anti-interference ability of hiccup mode is enhanced. It is extremely difficult to trigger hiccup mode under heavy load and micro-heavy load conditions. This retains the advantages of dynamic response under heavy load while eliminating the need for manual parameter adjustment during the blocking phase. The scheme also achieves full-load adaptive control through dynamic hysteresis threshold and natural stopping mechanism. In other words, while retaining high dynamic performance, the scheme suppresses light load ripple through adaptive control strategy or nonlinear correction mechanism. This effectively meets the stringent stability requirements of high-end power supply systems across the entire load range and also reduces the resource consumption of digital controllers by reducing storage and computing resources through parameterless algorithms.

[0051] Furthermore, in one embodiment, after S12 and before S13, the method further includes: processing the output control signal using a first adjustment function to obtain a second comparison threshold; The calculation formula for the first adjustment function is as follows: BMTL = BMTLmax - k(Vfb - Vfbmin).

[0052] The second comparison threshold is obtained by processing the second comparison threshold using the second adjustment function; The calculation formula for the second adjustment function is as follows: BMTH = BMTL + ΔV; Wherein, BMTL is the second comparison threshold, BMTLmax is the maximum dynamic limit threshold, k is the threshold scaling factor, Vfb is the output control signal, Vfbmin is the minimum output limit threshold, BMTH is the first comparison threshold, and ΔV is the dynamic step threshold.

[0053] Understandably, the upper and lower limits of this dynamic threshold range are the first comparison threshold BMTH and the second comparison threshold BMTL, respectively, and the burst mode enters / exits the dynamic threshold range in real time based on the output control signal of the digital proportional-integral controller.

[0054] Specifically, when the output control signal Vfb is less than the second comparison threshold BMTL, the waveform transmission stops, and when the output control signal Vfb is greater than the first comparison threshold BMTH, the waveform transmission resumes. The second comparison threshold BMTL and the first comparison threshold BMTH are dynamically changed according to the load rate and the output control signal. The second comparison threshold BMTL is negatively correlated with the output control signal Vfb. That is, when the output control signal Vfb is large, the second comparison threshold BMTL is large, and when the output control signal Vfb is small, the second comparison threshold BMTL is small.

[0055] Wherein, the output control signal Vfb is a real-time calculated value, the maximum dynamic limit threshold BMTLmax is the maximum set value for entering the burst mode, and the minimum output limit threshold Vfbmin is the minimum value that limits the output control signal Vfb.

[0056] In some embodiments, the threshold scaling factor K can specifically range from 0.01 to 0.2, and the dynamic step threshold ΔV can specifically range from 0.01V to 0.2V. This application does not limit these values.

[0057] For ease of understanding, taking an output control signal Vfb with a range of 2.5V under full load and 0.1V under no load, a threshold proportional coefficient K=0.1, a maximum dynamic limiting threshold BMTLmax=0.3V, and a dynamic step threshold ΔV=0.1V as an example, we can see that: When the output control signal Vfb = 0.3V, BMTL=0.3-0.1*(0.3-0.1)=0.298, BMTH=BMTL+0.1V=0.398V; When the output control signal Vfb = 1V BMTL=0.3-0.1*(1-0.1)=0.21, BMTH=BMTL+0.1V=0.31V; When the output control signal Vfb = 2.5V, BMTL=0.3-0.1*(2.5-0.1)=0.06, BMTH=BMTL+0.1V=0.106V.

[0058] Therefore, it can be seen that the lighter the load, that is, the smaller the output control signal Vfb, the closer the output control signal Vfb is to the second comparison threshold BMTL, and the more sensitive it is to entering the hiccup mode. As the load becomes heavier, it becomes less sensitive (less prone to false triggering). At the same time, the time for the burst mode to stop generating waves is determined by the time it takes for the output control signal Vfb voltage to rise from the second comparison threshold BMTL to the first comparison threshold BMTH. Thus, while maintaining high dynamic performance, it is possible to suppress light load ripple through adaptive control strategies or nonlinear correction mechanisms to meet the stringent stability requirements of high-end power supply systems across the entire load range.

[0059] Please continue reading. Figure 3 , Figure 3 yes Figure 1 A flowchart illustrating an embodiment of S13 is shown. In one embodiment, the modulation method of the LLC converter circuit of this application, in addition to the above-described S11-S16, further includes some more specific steps. Specifically, S13 may further include the following steps: S131: Subtract the target reference signal from the power supply output to obtain the error signal.

[0060] Specifically, the first modulation circuit 30 sets a target reference signal according to the current power supply requirements, or receives a target reference signal obtained by the host computer through experimental calibration or simulation optimization for the specific operating conditions and power supply requirements of the load circuit, so as to subtract the target reference signal from the power supply output to obtain an error signal.

[0061] S132: The error signal is proportionally and integrally adjusted using proportional and integral adjustment coefficients to obtain the output control signal.

[0062] A digital PI (proportional integral) controller is used to obtain the proportional and integral adjustment coefficients by fitting the power supply demand, control effect, and corresponding simulation prediction or experimental optimization. The error signal is then proportionally and integrally adjusted using these coefficients to obtain the output control signal.

[0063] Please see Figure 4 , Figure 4 This is a flowchart illustrating the second embodiment of the modulation method for the LLC converter circuit of this application. The modulation method for the LLC converter circuit in this embodiment... Figure 1 A detailed implementation flowchart of the modulation method for the LLC converter circuit is shown, specifically including the following steps: S41: Obtain the power supply output of the resonant converter circuit.

[0064] S42: The output control signal is obtained by using the error signal between the power supply output and the target reference signal.

[0065] Among them, S41 and S42 and Figure 1 S11 and S12 are the same. Please refer to the textual descriptions of S11 and S12 for details, which will not be repeated here.

[0066] S43: Detect whether the output control signal is greater than the first comparison threshold.

[0067] Understandably, by monitoring the dynamic performance, power supply stability requirements, and output ripple of the first resonant converter circuit 20 under different load rates, and by fitting and setting the dynamic threshold range through corresponding simulation prediction or experimental optimization, the dynamic threshold range can be used to determine whether to enter the hiccup mode.

[0068] The upper and lower limits of the dynamic threshold range are the first comparison threshold and the second comparison threshold, respectively, and the second comparison threshold is negatively correlated with the output control signal.

[0069] Specifically, the first modulation circuit 30 monitors the output control signal in real time to determine whether the output control signal is greater than the first comparison threshold.

[0070] If the output control signal is greater than the first comparison threshold, then S45 is executed; if the output control signal is not greater than the first comparison threshold, then S44 is executed.

[0071] S44: Detect whether the output control signal is less than the second comparison threshold.

[0072] If it is determined that the currently acquired output control signal is not greater than the first comparison threshold, the output control signal is further detected to see if it is less than the second comparison threshold.

[0073] If the output control signal is less than the second comparison threshold, then S47 is executed; if the output control signal is not less than the second comparison threshold, then S43 is executed.

[0074] S45: Generate drive control signals using output control signals.

[0075] Understandably, when the output control signal is determined to be greater than the first comparison threshold, that is, when the load rate of the first resonant converter circuit 20 is large, there is no need to enter the hiccup mode. At this time, the preset control algorithm or preset adjustment function is normally used to process the output control signal to obtain the drive control signal.

[0076] It is worth noting that when the output control signal is detected to be no greater than the first comparison threshold but greater than the second comparison threshold, the current transmission state of the drive control signal remains unchanged; and there are two amplitude change directions, namely, when the output control signal changes from no greater than the first comparison threshold to greater than the second comparison threshold, the transmission of the drive control signal is maintained; while when the output control signal changes from greater than the second comparison threshold to no greater than the first comparison threshold, the transmission of the drive control signal is maintained.

[0077] S46: Sends the drive control signal to the resonant converter circuit to adjust the switching state of the resonant converter circuit, thereby regulating the power supply output.

[0078] S47: Block the drive control signal.

[0079] Among them, S46 and S47 and Figure 1 S15 and S16 are the same. Please refer to S15 and S16 and their related textual descriptions for details. They will not be repeated here.

[0080] Please see Figure 5 , Figure 5 This is a flowchart illustrating the third embodiment of the modulation method for the LLC converter circuit of this application. The modulation method for the LLC converter circuit in this embodiment... Figure 1 A detailed implementation flowchart of the modulation method for the LLC converter circuit is shown, specifically including the following steps: S51: Obtain the power supply output of the resonant converter circuit.

[0081] Among them, S51 and Figure 1 The same applies to S11. Please refer to S11 and its related textual descriptions for details, which will not be repeated here.

[0082] S52: Subtract the target reference signal from the power supply output to obtain the error signal.

[0083] It is understood that the modulation method of the LLC converter circuit in this embodiment can specifically be as follows: Figure 6 The second modulation circuit 70 (not shown) implements charge modulation on the second resonant conversion circuit 60.

[0084] Please continue reading. Figure 6 and Figure 7 ,in, Figure 6 This is a schematic diagram of the second embodiment of the modulation circuit of this application. Figure 7 yes Figure 5 A schematic diagram of the signal processing logic framework for the modulation method of the LLC converter circuit.

[0085] In some embodiments, the second resonant converter circuit 60 includes a power switch circuit 61, a resonant circuit 63, a switching freewheeling circuit 62, an isolation transformer 64, a rectifier circuit 65, and a regulated output circuit 66; the power switch circuit 61 includes a first switching transistor Q1 and a second switching transistor Q2; the resonant circuit 63 includes a first resonant inductor Lr1, a second resonant inductor Lr2, and a resonant capacitor Cr; the switching freewheeling circuit 62 includes a first freewheeling capacitor C1, a second freewheeling capacitor C2, a first diode D1, and a second diode D2; the isolation transformer 64 includes a primary winding RZ0, a first secondary winding RZ1, and a second secondary winding RZ2; the rectifier circuit 65 includes a third diode D3 and a fourth diode D4; and the regulated output circuit 66 further includes a regulated resistor Ro and a regulated capacitor Co.

[0086] In this circuit, the first terminal of the first switch Q1 is coupled to the second terminal of the first diode D1 and the first terminal of the first resonant capacitor Cr1, and is used to couple to the first terminal of the power supply circuit 101. The second terminal of the second switch Q2 is coupled to the first terminal of the second diode D2 and the second terminal of the second resonant capacitor Cr2, and is used to couple to the second terminal of the power supply circuit 101. The second terminal of the first freewheeling capacitor C1 is coupled to the first terminal of the first diode D1, the second terminal of the first switch Q1, the first terminal of the second switch Q2, the first terminal of the second freewheeling capacitor C2, the second terminal of the second diode D2, and the first terminal of the first resonant inductor Lr1. The second terminal of the second switch Q2 is coupled to the second terminal of the second freewheeling capacitor C2, the first terminal of the second diode D2, and the first terminal of the resonant capacitor Cr, and is grounded, and is used to couple to the second terminal of the power supply circuit 101. The second terminal of the first resonant inductor Lr1 is coupled to the first terminal of the second resonant inductor Lr2 and the first terminal of the primary winding RZ0. The second terminal of the resonant capacitor Cr is coupled to the second terminal of the second resonant inductor Lr2 and the second terminal of the primary winding RZ0.

[0087] The primary winding RZ0 is coupled to the first sub-secondary winding RZ1 and the second sub-secondary winding RZ2. The first end of the third diode D3 is coupled to the first end of the first sub-secondary winding RZ1. The second end of the third diode D3 is coupled to the second end of the fourth diode D4, the first end of the voltage regulator Co, and the first end of the voltage regulator Ro. The first end of the fourth diode D4 is coupled to the second end of the second sub-secondary winding RZ2. The second end of the voltage regulator Co is coupled to the second end of the voltage regulator Ro, the second end of the first sub-secondary winding RZ1, and the first end of the second sub-secondary winding RZ2.

[0088] In some embodiments, the second modulation circuit 70 further includes a digital proportional-integral controller 71, a burst-mode hysteresis circuit 72, a ramp generator 73, a sampling and detection circuit 74, and a signal generator 75. The digital proportional-integral controller 71 is coupled to a voltage regulator resistor Ro and the burst-mode hysteresis circuit 72. The burst-mode hysteresis circuit 72 is coupled to the ramp generator 73. The ramp generator 73 is coupled to the signal generator 75. The sampling and detection circuit 74 is coupled to the signal generator 75, the first resonant inductor Lr1, and / or the resonant capacitor Cr. The signal generator 75 is coupled to the third terminal of the first switch Q1 and the third terminal of the second switch Q2.

[0089] In some embodiments, the first switch Q1 and the second switch Q2 may be a MOSFET (Metal-Oxide Semiconductor Field Effect Transistor), a transistor, a thin-film transistor, a field-effect transistor, or any other reasonable switch, and this application does not limit them.

[0090] It is worth noting that, to distinguish the two ends of each switching transistor except for the control terminal, one terminal is referred to as the first terminal and the other as the second terminal. When each switching transistor is a bipolar junction transistor (BJT), the control terminal, i.e., the third terminal, can specifically be the base, the first terminal as the collector, and the second terminal as the emitter; or, the third terminal can specifically be the base, the first terminal as the emitter, and the second terminal as the collector.

[0091] When the switching transistors mentioned above are MOSFETs, thin-film transistors, or field-effect transistors, the third terminal can be the gate, the first terminal is the drain, and the second terminal is the source; or, the third terminal can also be the gate, the first terminal is the source, and the second terminal is the drain.

[0092] In particular, when each switching transistor is a MOSFET, a thin film transistor, or a field-effect transistor, it can also be a composite transistor or a single transistor, which is not limited in this application.

[0093] It is worth noting that in other embodiments, the second resonant converter circuit 60 may be a half-bridge LLC converter, a full-bridge LLC converter, or any other reasonable LLC circuit topology. For example, the power switch circuit 61 may be a full-bridge switch circuit or an asymmetrical half-bridge switch circuit, and the rectifier circuit 65 may be a full-bridge rectifier circuit or a half-bridge rectifier circuit composed of various switching transistors, or any reasonable circuit form for realizing AC to DC conversion. This application does not limit this.

[0094] Specifically, taking the power supply output as the output voltage Vo as an example, the digital proportional-integral controller 71 sets the target reference signal Vref according to the current power supply demand, or receives the target reference signal Vref obtained by the host computer through experimental calibration or simulation optimization for the specific operating conditions and power supply demand of the load circuit, so as to subtract the target reference signal Vref from the currently acquired output voltage Vo to obtain the error signal.

[0095] Of course, in other embodiments, the power supply output can also be an output current, which will not be elaborated here.

[0096] S53: The error signal is proportionally and integrally adjusted using proportional and integral adjustment coefficients to obtain the output control signal.

[0097] The digital proportional-integral controller 71 obtains the proportional adjustment coefficient and integral adjustment coefficient by fitting the power supply demand, feedback control results and corresponding simulation predictions or experimental optimizations. The output control signal Vfb is obtained by proportional-integral adjustment of the error signal through the proportional adjustment coefficient and integral adjustment coefficient.

[0098] S54: Detect whether the output control signal is within the dynamic threshold range.

[0099] Please continue reading. Figure 8 and Figure 9 ,in, Figure 8 yes Figure 5 A waveform diagram of the relevant signals in an embodiment of the modulation method of the LLC converter circuit. Figure 9 yes Figure 5 A waveform diagram illustrating the functional relationship between the second comparison threshold and the output control signal in the modulation method of the LLC converter circuit in one embodiment.

[0100] The burst-mode hysteresis circuit 72 monitors the dynamic performance, power supply stability requirements, and output ripple of the second resonant converter circuit 60 under different load rates, and obtains the dynamic threshold range by fitting the settings through corresponding simulation prediction or experimental optimization.

[0101] In some embodiments, such as Figure 8As shown, the upper and lower limits of the dynamic threshold range are the first comparison threshold BMTH and the second comparison threshold BMTL, respectively. Based on the output control signal Vfb of the digital proportional-integral controller 71, the burst mode entry / exit thresholds, the first comparison threshold BMTH and the second comparison threshold BMTL, are calculated in real time. Specifically, when the output control signal Vfb is less than the second comparison threshold BMTL, wave transmission stops; when the output control signal Vfb is greater than the first comparison threshold BMTH, wave transmission resumes. The second comparison threshold BMTL and the first comparison threshold BMTH dynamically change with the load rate and the output control signal Vfb. Furthermore, the second comparison threshold BMTL is negatively correlated with the output control signal Vfb; that is, when the output control signal Vfb is large, the second comparison threshold BMTL is large, and when the output control signal Vfb is small, the second comparison threshold BMTL is small.

[0102] In some embodiments, such as Figure 9 As shown, the second comparison threshold BMTL and the output control signal Vfb can have a linear functional relationship with a negative slope, or they can have any reasonable negative correlation functional relationship, such as a first-order or second-order nonlinear functional relationship. This application does not limit this relationship.

[0103] The burst mode hysteresis circuit 72 is used to detect whether the output control signal Vfb is within the dynamic threshold range in order to determine whether to enter the hiccup mode, i.e., the corresponding burst mode.

[0104] Specifically, if the output control signal Vfb changes from less than the second comparison threshold BMTL to greater than the first comparison threshold BMTH, then S55 is executed; if the output control signal Vfb changes from not greater than the first comparison threshold BMTH to greater than the first comparison threshold BMTH, then S58 is executed; if the output control signal Vfb is greater than the first comparison threshold BMTH, or changes from not less than the first comparison threshold BMTH to less than the second comparison threshold BMTL, then S510 is executed.

[0105] S55: Blocks the drive control signal.

[0106] When the burst-mode hysteresis circuit 72 determines that the output control signal Vfb is less than the second comparison threshold BMTL, it enters the hiccup mode, that is, it blocks the drive control signal until it detects that the output control signal Vfb is greater than the first comparison threshold BMTH and then terminates. In other words, the burst-mode hysteresis circuit 72 does not output a signal to the downstream harmonic generator during the period from when the output control signal Vfb is less than the second comparison threshold BMTL to when it is greater than the first comparison threshold BMTH.

[0107] S56: Adjust the proportional adjustment coefficient to the minimum proportional coefficient.

[0108] The burst mode hysteresis circuit 72 is also used to gradually adjust the proportional adjustment coefficient to the minimum proportional coefficient at any time during the stage from when the output control signal Vfb is less than the second comparison threshold BMTL to when it is greater than the first comparison threshold BMTH, and preferably at the time when the output control signal Vfb is less than the second comparison threshold BMTL, using any reasonable function such as a linear function, an arithmetic function, or a first or second nonlinear function relationship.

[0109] It is worth noting that the minimum proportional coefficient, as well as the minimum integral coefficient, preset proportional coefficient, and preset integral coefficient mentioned later, can be understood as set values ​​obtained by fitting through simulation prediction or experimental optimization based on the actual application scenario. The preset proportional coefficient and preset integral coefficient are initial set values, which will not be elaborated here.

[0110] S57: Adjust the integral adjustment coefficient to the minimum integral coefficient.

[0111] Similarly, the burst mode hysteresis circuit 72 is also used to gradually adjust the integral adjustment coefficient to the minimum integral coefficient using any reasonable function such as a linear function, an arithmetic function, or a first or second nonlinear function relationship.

[0112] S59: Using a preset arithmetic function, the proportional adjustment coefficient is gradually adjusted from the minimum proportional coefficient to equal the preset proportional coefficient in each signal cycle of the current drive control signal.

[0113] When the burst mode hysteresis circuit 72 determines that the output control signal Vfb changes from not greater than the first comparison threshold BMTH to greater than the first comparison threshold BMTH, it is also used to use a preset arithmetic function to increase the proportional adjustment coefficient by a certain value in each signal cycle of the current drive control signal, that is, in each cycle, until the proportional adjustment coefficient is gradually adjusted from the minimum proportional coefficient to equal the preset proportional coefficient, that is, the adjustment is terminated after restoring to the initial set value.

[0114] S59: Using a preset arithmetic function, the integral adjustment coefficient is gradually adjusted from the minimum integral coefficient to equal the preset integral coefficient in each signal cycle of the current drive control signal.

[0115] Similarly, a preset arithmetic function is used to increase the integral adjustment coefficient by a certain value in each signal cycle of the current drive control signal, until the integral adjustment coefficient is gradually adjusted from the minimum integral coefficient to equal the preset integral coefficient, that is, the adjustment is terminated when the initial setting value is restored.

[0116] S510: Generates drive control signals using output control signals.

[0117] Please continue reading. Figure 10 , Figure 10 yes Figure 5 A waveform diagram of another embodiment of the modulation method for the LLC converter circuit and related signals.

[0118] Specifically, when the burst mode hysteresis circuit 72 determines that the output control signal Vfb is greater than the first comparison threshold BMTH, or from not less than the first comparison threshold BMTH to less than the second comparison threshold BMTL, it sends the currently acquired output control signal Vfb to the ramp generator 73 inside the second modulation circuit 70, so that the ramp generator 73 can perform corresponding ramp compensation to generate the comparison signal Vcomp.

[0119] The sampling and detection circuit 74 is used to sample the capacitor voltage in the resonant capacitor Cr, so as to obtain the resonant current integral signal Vcr using the capacitor voltage; or, to sample the inductor current flowing through the first resonant inductor Lr1, so as to obtain the resonant current integral signal Vcr by integrating and adjusting the inductor current.

[0120] The signal generator 75 is used to compare the comparison signal Vcomp with the resonant current integral signal Vcr to generate a drive control signal. The drive control signal specifically includes a first drive signal Gate_H and a second drive signal Gate_L with complementary phases.

[0121] It is worth noting that when the output control signal Vfb changes from not greater than the first comparison threshold BMTH to greater than the first comparison threshold BMTH, the proportional and integral adjustment coefficients corresponding to the proportional-integral adjustment of the error signal change in real time. As a result, the output control signal Vfb will also change in different states in response to the proportional adjustment coefficient being adjusted from the minimum proportional coefficient to equal to the preset proportional coefficient, and the integral adjustment coefficient being adjusted from the minimum integral coefficient to equal to the preset integral coefficient. This allows for a smoother gradual adjustment of the current output voltage Vo to approach the target reference signal Vref, thereby suppressing output ripple as much as possible.

[0122] S511: Sends the drive control signal to the resonant converter circuit to adjust the switching state of the resonant converter circuit, thereby regulating the power supply output.

[0123] Understandably, the signal generator 75 is also used to send the first drive signal Gate_H and the second drive signal Gate_L to the first switch Q1 and the second switch Q2 respectively, so as to trigger the first switch Q1 and the second switch Q2 to turn on or off respectively, so as to regulate the output voltage Vo.

[0124] Furthermore, in one embodiment, the above-mentioned S56 may specifically include: in response to the output control signal Vfb being less than the second comparison threshold BMTL, using a preset arithmetic function to gradually adjust the proportional adjustment coefficient ki from the preset proportional coefficient to equal the minimum proportional coefficient β1 in each signal cycle of the current drive control signal.

[0125] Understandably, after entering the burst mode, the proportional adjustment coefficient ki will decrease cycle by cycle, that is, it will decrease by a certain value α1 each cycle. The specific amount of decrease each cycle can be adjusted as needed, for example, 0.1 or 0.2, until the proportional adjustment coefficient ki is reduced to the minimum proportional coefficient β1, for example, 0.5 or 0.6.

[0126] In some embodiments, the decrease value α1 per cycle can be 0.01-0.5, the minimum proportional coefficient β1 can be 0.01-1, and the integrator is frozen after the proportional adjustment coefficient Ki drops to the minimum proportional coefficient β1 until the output control signal Vfb is greater than the first comparison threshold BMTH. The proportional adjustment coefficient Ki is then increased cycle by cycle according to the same adjustment rule until the PI parameter in the normal mode is restored, i.e., the preset proportional coefficient. This application does not limit this.

[0127] Furthermore, in one embodiment, the above-mentioned S57 may specifically include: in response to the output control signal Vfb being less than the second comparison threshold BMTL, using a preset arithmetic function to gradually adjust the integral adjustment coefficient kp from the preset integral coefficient to equal the minimum integral coefficient β2 in each signal cycle of the current drive control signal.

[0128] Similarly, after entering the burst mode, the integral adjustment coefficient kp will decrease cycle by cycle, decaying by a certain value α2 each cycle. The specific amount of decrease each cycle can be adjusted as needed, for example, 0.1 or 0.2, until the integral adjustment coefficient kp is reduced to the minimum integral coefficient β2, for example, 0.5 or 0.6.

[0129] In some embodiments, the decrease value α2 per cycle can be 0.01-0.5, and the minimum integral coefficient β2 can be 0.01-1. When the integral adjustment coefficient kp drops to the minimum integral coefficient β2, the integrator is frozen until the output control signal Vfb is greater than the first comparison threshold BMTH. Then, the integral adjustment coefficient kp is increased cycle by cycle according to the same adjustment rule until it is restored to the preset proportional coefficient. This application does not limit this.

[0130] This application also provides an electronic device, please refer to... Figure 11 , Figure 11 This is a schematic diagram of one embodiment of the electronic device of this application. In this embodiment, the electronic device 80 includes a housing 81 and a third modulation circuit 82 connected to the housing 81.

[0131] It should be noted that the third modulation circuit 82 described in this embodiment is either the first modulation circuit 30 or the second modulation circuit 70 described in any of the above embodiments. Please refer to [link / reference] for details. Figures 1-10 The relevant textual content will not be elaborated upon here.

[0132] The beneficial effects of this application are as follows: Unlike existing technologies, the modulation method for the LLC converter circuit provided in this application obtains the power supply output of the resonant converter circuit, uses the error signal between the power supply output and the target reference signal to obtain an output control signal, and blocks the drive control signal when the detected output control signal is less than a second comparison threshold negatively correlated with it. This process continues until the output control signal exceeds a first comparison threshold, at which point a drive control signal is generated using the output control signal and sent to the resonant converter circuit. This drive control signal adjusts the switching state of the resonant converter circuit to regulate the power supply output. Therefore, when the output control signal is small (i.e., under light load or no load), the second comparison threshold is larger, and the lighter the load, the more sensitive the entry into the hiccup mode. The reduced system bandwidth and slower response speed help suppress output ripple. When the output control signal is large, i.e., the load becomes heavier and the response becomes slower, the anti-interference capability of the hiccup mode is enhanced. It is extremely difficult to trigger the hiccup mode under heavy load and micro-heavy load conditions. While retaining the advantages of dynamic response under heavy load, it can also eliminate the need for manual parameter adjustment during the ripple blocking phase. It can also achieve full load adaptive control through dynamic hysteresis threshold and natural ripple stopping mechanism. That is, while retaining high dynamic performance, it can suppress light load ripple through adaptive control strategy or nonlinear correction mechanism. It can effectively meet the stringent requirements of high-end power supply systems for stability across the entire load range, and also reduce the resource occupation of digital controller by reducing storage and computing resources through parameterless algorithm.

[0133] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A modulation method for an LLC converter circuit, applied to charge modulation of a resonant converter circuit, characterized in that, The modulation method of the LLC converter circuit includes: Obtain the power supply output of the resonant converter circuit; The output control signal is obtained by using the error signal between the power supply output and the target reference signal; The output control signal is used to generate a drive control signal; Detect whether the output control signal is within a dynamic threshold range; wherein, the upper limit and lower limit of the dynamic threshold range are a first comparison threshold and a second comparison threshold, respectively, and the second comparison threshold is negatively correlated with the output control signal; In response to the output control signal being less than the second comparison threshold, the drive control signal is blocked until the output control signal is greater than the first comparison threshold; The drive control signal is sent to the resonant converter circuit to adjust the switching state of the resonant converter circuit, thereby regulating the power supply output.

2. The modulation method for the LLC converter circuit according to claim 1, characterized in that, The step of generating a drive control signal using the output control signal includes: Detect whether the output control signal is greater than the first comparison threshold; In response to the output control signal being greater than the first comparison threshold, a drive control signal is generated using the output control signal; The step of detecting whether the output control signal is within the dynamic threshold range includes: In response to the output control signal not being greater than the first comparison threshold, it is detected whether the output control signal is less than the second comparison threshold; The step of blocking the drive control signal in response to the output control signal being less than the second comparison threshold until the output control signal is greater than the first comparison threshold includes: In response to the output control signal being less than the second comparison threshold, the drive control signal is blocked, and the step of detecting whether the output control signal is greater than the first comparison threshold is performed again.

3. The modulation method for the LLC converter circuit according to claim 1, characterized in that, After the step of obtaining the output control signal using the error signal between the power supply output and the target reference signal, and before the step of detecting whether the output control signal is within the dynamic threshold range, the method further includes: The output control signal is processed using a first adjustment function to obtain the second comparison threshold. The first comparison threshold is obtained by processing the second comparison threshold using the second adjustment function; The calculation formula for the first adjustment function is as follows: BMTL = BMTLmax - k(Vfb - Vfbmin); The calculation formula for the second adjustment function is as follows: BMTH = BMTL + ΔV; Wherein, BMTL is the second comparison threshold, BMTLmax is the maximum dynamic limit threshold, k is the threshold ratio coefficient, Vfb is the output control signal, Vfbmin is the minimum output limit threshold, BMTH is the first comparison threshold, and ΔV is the dynamic step threshold.

4. The modulation method for the LLC converter circuit according to claim 1, characterized in that, The step of obtaining the output control signal using the error signal between the power supply output and the target reference signal includes: The error signal is obtained by subtracting the target reference signal from the power supply output. The output control signal is obtained by proportional-integral adjustment of the error signal using proportional and integral adjustment coefficients.

5. The modulation method for the LLC converter circuit according to claim 4, characterized in that, The step of blocking the drive control signal in response to the output control signal being less than the second comparison threshold, until the output control signal is greater than the first comparison threshold, further includes: In response to the output control signal during a time interval from less than the second comparison threshold to greater than the first comparison threshold, the proportional adjustment coefficient is adjusted to the minimum proportional coefficient; Adjust the integral adjustment coefficient to the minimum integral coefficient.

6. The modulation method for the LLC converter circuit according to claim 5, characterized in that, The step of responding to the output control signal within a time interval from less than the second comparison threshold to greater than the first comparison threshold includes: In response to the output control signal being less than the second comparison threshold, a preset arithmetic function is used to gradually adjust the proportional adjustment coefficient from the preset proportional coefficient to equal the minimum proportional coefficient in each signal cycle of the current drive control signal.

7. The modulation method for the LLC converter circuit according to claim 6, characterized in that, The step of adjusting the integral adjustment coefficient to the minimum integral coefficient includes: In response to the output control signal being less than the second comparison threshold, the integral adjustment coefficient is gradually adjusted from the preset integral coefficient to the minimum integral coefficient in each signal cycle of the current drive control signal using the preset arithmetic function.

8. The modulation method for the LLC converter circuit according to claim 7, characterized in that, The modulation method of the LLC converter circuit further includes: In response to the output control signal being greater than the second comparison threshold, the preset arithmetic function is used to gradually adjust the proportional adjustment coefficient from the minimum proportional coefficient to equal the preset proportional coefficient in each signal cycle of the current drive control signal; The preset arithmetic progression function is used to gradually adjust the integral adjustment coefficient from the minimum integral coefficient to equal the preset integral coefficient in each signal cycle of the current drive control signal.

9. A modulation circuit, characterized in that, The modulation circuit is used to couple with the resonant converter circuit; The modulation circuit uses the modulation method of the LLC converter circuit as described in any one of claims 1-8 to control the resonant converter circuit.

10. An electronic device, characterized in that, The electronic device includes a housing and a modulation circuit connected to the housing; The modulation circuit is the modulation circuit as described in claim 9.

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