Light load control method and apparatus for switching power supply

Abstract

This application discloses a light-load control method and apparatus for a switching power supply, relating to the field of switching power supply technology. In this method, when the switching power supply is under light-load operation, it is controlled to enter a burst mode. Within each cycle of the burst mode, the total duration of a single cycle is fixed, and the duration of the waveform generation phase is adaptively adjusted to dynamically search for the steady-state waveform generation duration when the switching power supply is in a steady state. The duration of the steady-state waveform generation phase is reduced from the steady-state waveform generation duration to the target waveform generation duration, thereby reducing the number of pulse waves sent in a single waveform generation phase, lowering the average energy provided in a single waveform generation phase, reducing the amplitude of the output voltage or output current, suppressing the amplitude fluctuation of the output ripple, and improving the overall reliability and lifespan of the switching power supply. Furthermore, since the absolute difference between the optimized waveform generation ratio and the unoptimized waveform generation ratio is less than a preset accuracy threshold, the average energy supply before and after optimization is essentially the same, ensuring the control accuracy of voltage or current regulation.

Description

Technical Field

[0001] This application relates to the field of switching power supply technology, and in particular to a light-load control method and apparatus for switching power supplies. Background Technology

[0002] Switch-mode power supplies (SMPS), also known as switching power supplies, are electronic power devices that convert electrical energy based on high-frequency pulse modulation technology. Their core function is to convert input electrical energy into DC or AC output that meets the load requirements, and they are widely used in various power electronic devices.

[0003] To improve conversion efficiency under light load conditions, switching power supplies typically operate in burst mode. Burst mode alternates between a pulse generation phase and a sleep phase. During the pulse generation phase, a cluster of pulse waves is continuously sent, while during the sleep phase, pulse generation is continuously stopped, thus achieving intermittent power supply and reducing switching losses and energy consumption.

[0004] In existing burst mode control schemes, the duration of the waveform generation phase (referred to as waveform duration) is usually a preset fixed value and lacks adaptive adjustment capability. When the switching power supply is under light load conditions, the fixed-duration waveform generation mechanism can easily lead to excessive average energy provided in a single waveform generation phase, resulting in a mismatch between the average energy supply and the load energy consumption. This causes severe fluctuations in the average energy supply per cycle, forming output ripple with high amplitude fluctuations. High-amplitude output ripple not only reduces the voltage or current regulation accuracy under light load conditions but also causes periodic voltage or current surge stress on power devices and the load, accelerating device aging and damage, and reducing the overall reliability and lifespan of the switching power supply. Summary of the Invention

[0005] This application provides a light-load control method and apparatus for a switching power supply, which aims to ensure that the average energy supply matches the load energy consumption while maintaining the ripple ratio in steady state under light-load burst mode, reducing the duration of the ripple generation stage in steady state, suppressing the amplitude fluctuation of the output ripple under light-load conditions, improving the overall reliability and service life of the switching power supply, and ensuring the control accuracy of voltage regulation or current regulation.

[0006] In a first aspect, this application provides a light-load control method for a switching power supply, the method being applied to a switching power supply, the method comprising: When the switching power supply is under light load, the control switch power supply enters burst mode. Burst mode is a mode in which the switching power supply alternately executes the wave generation phase and the sleep phase. The wave generation phase is a period of continuously sending at least one pulse wave, and the sleep phase is a period of continuously stopping sending at least one pulse wave. The pulse wave is used to drive the power switching transistor in the switching power supply to turn on and off. The sum of the duration of the wave generation phase and the duration of the sleep phase is the single cycle of burst mode. Within each cycle of the burst mode, the single cycle period is fixed as the first total duration, and the duration of the wave generation phase is adaptively adjusted until the steady-state wave generation duration is determined. The steady-state wave generation duration is the duration of the wave generation phase when the switching power supply is in a steady state. Based on the steady-state transmission duration and the first total duration, the proportion of the first transmission is calculated, which is the ratio of the steady-state transmission duration to the first total duration. Based on the first wave emission ratio and the preset wave emission ratio, the steady-state wave emission duration is optimized to determine the corresponding target wave emission duration and target sleep duration, so that the target wave emission duration is less than the steady-state wave emission duration, and the absolute difference between the second wave emission ratio and the first wave emission ratio is less than the preset accuracy threshold. The second wave emission ratio is the ratio of the target wave emission duration to the second total duration, and the second total duration is the sum of the target wave emission duration and the target sleep duration. The control switching power supply executes the waveform generation phase using a target waveform generation duration and the sleep phase using a target sleep duration.

[0007] Using the above method, within each cycle of the burst mode, the steady-state waveform duration of the switching power supply when it is in a steady state is dynamically searched by fixing the total duration of a single cycle and adaptively adjusting the duration of the waveform generation phase. Since the steady-state waveform duration is determined by adaptive adjustment based on the duration of the waveform generation phase, rather than by pre-fixing the duration of the waveform generation phase, the average energy provided within the steady-state waveform generation duration can be matched with the load energy consumption.

[0008] Furthermore, by reducing the duration of the steady-state wave generation phase from the steady-state wave generation duration to the target wave generation duration, the number of pulse waves sent in a single wave generation phase is reduced, thereby lowering the average energy provided in a single wave generation phase, reducing the amplitude of the output voltage or output current, suppressing the amplitude fluctuation of the output ripple, and improving the overall reliability and service life of the switching power supply.

[0009] Finally, since the absolute difference between the optimized second wave ratio and the unoptimized first wave ratio is less than the preset accuracy threshold, while ensuring the reduction of the wave phase duration and the decrease in average energy supply, the wave ratio before and after optimization remains basically unchanged, so that the average energy supply before and after optimization is basically consistent, avoiding the drop in output voltage or output current due to excessive reduction of the wave phase duration, and ensuring the control accuracy of voltage regulation or current regulation.

[0010] In one possible example of the first aspect, the duration of the wave generation phase is adaptively adjusted until a steady-state wave generation duration is determined, including: Starting with a preset initial duration for the wave emission phase, the wave emission phase is executed cyclically. After the wave generation phase ends in each loop, obtain the instruction duty cycle of the pulse wave corresponding to this loop; If the instruction duty cycle is greater than or equal to the first preset judgment threshold, the duration of the wave transmission phase in the current cycle is adjusted according to the first preset step size, and the adjusted duration is used in the next cycle until the instruction duty cycle is less than the first preset judgment threshold. The duration of the wave transmission phase when the instruction duty cycle is less than the first preset threshold is determined as the steady-state wave transmission duration.

[0011] In this example, by adjusting the duration of the wave generation phase in the next cycle according to the first preset step size and repeating the process until the instruction duty cycle is less than the first preset judgment threshold, the average energy supply is matched with the load energy consumption, ensuring the control accuracy of voltage regulation or current regulation.

[0012] In one possible example of the first aspect, the duty cycle of the instruction for obtaining the pulse wave corresponding to the current loop includes: The sampled switching power supply outputs current or voltage within the current cycle to obtain the sampled value. Based on the loop calculation of the error between the current sampled value and the loop reference value, the command duty cycle of the pulse wave corresponding to the current cycle is determined. The loop reference value is the reference current value or reference voltage value of the loop control circuit in the input switching power supply.

[0013] In this example, by sampling the output current or output voltage within the current cycle and determining the command duty cycle through loop calculation, a closed-loop feedback generation mechanism for the command duty cycle in burst mode is established. This enables the command duty cycle to reflect the actual output state under light load conditions in real time, providing an accurate quantitative basis for determining the steady-state wave transmission duration based on the comparison between the command duty cycle and the first preset judgment threshold.

[0014] In one possible example of the first aspect, the initial duration is preset to be the period of a pulse wave, and the first preset step size is the period of a pulse wave; Adjust the duration of the wave generation phase within the current loop according to the first preset step size, including: The duration of the wave generation phase within this cycle is increased by one pulse wave period.

[0015] In this example, by setting both the preset initial transmission duration and the first preset step size to the period of a single pulse wave, the basic unit for adjusting the duration of the transmission phase is the period of a single pulse wave. Furthermore, using the period of a single pulse wave as the step size ensures synchronization with the switching frequency of the power switch, so that each adjustment increment corresponds exactly to one switching cycle of the power switch, improving the accuracy of the adaptive adjustment of the transmission phase duration and correspondingly reducing the complexity of the adaptive adjustment.

[0016] In one possible example of the first aspect, the steady-state transmission duration is optimized based on the first transmission ratio and a preset transmission ratio to determine the corresponding target transmission duration and target sleep duration, including: If the proportion of the first wave transmission is less than the preset wave transmission proportion, then the minimum wave transmission duration corresponding to the steady-state wave transmission duration is selected as the target wave transmission duration, and the target sleep duration corresponding to the minimum wave transmission duration is determined. If the proportion of the first wave transmission is greater than or equal to the preset wave transmission proportion, then the minimum sleep duration corresponding to the steady-state wave transmission duration is selected as the target sleep duration, and the target wave transmission duration corresponding to the minimum sleep duration is determined.

[0017] In this example, the minimum wave transmission duration corresponding to the steady-state wave transmission duration refers to the preset minimum value that can be achieved when optimizing the steady-state wave transmission duration by using the period of a single pulse wave as the basic unit, while maintaining the wave transmission ratio before and after optimization as basically unchanged.

[0018] The minimum sleep duration corresponding to the steady-state transmission duration refers to the steady-state sleep duration that can be determined based on a fixed first total duration and steady-state transmission duration. That is, the steady-state sleep duration is the difference between the first total duration and the steady-state transmission duration. Under the constraint of maintaining the transmission ratio before and after optimization to remain basically unchanged, the minimum value that can be achieved by reducing the steady-state sleep duration using the period of a single pulse wave as the basic unit.

[0019] When the proportion of the first wave emission is less than the preset wave emission proportion, it indicates that the proportion of the wave emission phase in steady state is small, meaning that the dormancy phase in steady state is dominant. In this case, directly selecting the minimum wave emission duration corresponding to the steady-state wave emission duration as the target wave emission duration can reduce the duration of the wave emission phase to the physically achievable minimum, reducing the average energy transmitted in a single wave emission phase and suppressing the amplitude fluctuation of the output ripple. Simultaneously, under the constraint of maintaining a basically unchanged wave emission proportion before and after optimization, and knowing that the target wave emission duration is the minimum wave emission duration, the target dormancy duration can be determined, ensuring that the proportion of average energy supply before and after optimization is basically consistent, and guaranteeing precise control of voltage or current regulation.

[0020] When the proportion of the first wave emission is greater than or equal to the preset wave emission proportion, it indicates that the wave emission phase in steady state accounts for a large proportion, meaning that the wave emission phase in steady state is dominant. In this case, the minimum sleep duration corresponding to the steady-state wave emission duration is directly selected as the target sleep duration. Under the constraint of maintaining a basically unchanged wave emission proportion before and after optimization, when the steady-state sleep duration is reduced to the minimum, the steady-state wave emission duration can also be reduced accordingly, thereby reducing the average energy transmitted in a single wave emission phase and suppressing the amplitude fluctuation of the output ripple.

[0021] In one possible example of the first aspect, the minimum transmission duration corresponding to the steady-state transmission duration is the period of a pulse wave; The minimum sleep duration corresponding to the steady-state wave generation duration is the period of one pulse wave.

[0022] In this example, by setting the minimum transmission duration corresponding to the steady-state transmission duration to the period of a pulse wave, the physical minimum duration of the transmission phase in steady state can be guaranteed. By setting the minimum sleep duration corresponding to the steady-state transmission duration to the period of a pulse wave, the intermittent operation characteristics of the burst mode can be maintained.

[0023] In one possible example of the first aspect, the minimum transmission duration corresponding to the steady-state transmission duration is the period of a pulse wave; determining the target sleep duration corresponding to the minimum transmission duration includes: The target sleep duration is determined as the difference between the first rounded value multiplied by the period of the pulse wave and the minimum transmission duration. The first rounded value is the value obtained by dividing the first total duration by the steady-state transmission duration and then rounding it down.

[0024] In one possible example of the first aspect, the minimum sleep duration corresponding to the steady-state transmission duration is the period of a pulse wave; determining the target transmission duration corresponding to the minimum sleep duration includes: The target transmission duration is determined as the product of the second rounded value and the period of the pulse wave. The second rounded value is the result of dividing the steady-state transmission duration by the steady-state sleep duration and then rounding it down. The steady-state sleep duration is the difference between the first total duration and the steady-state transmission duration.

[0025] In one possible example of the first aspect, the above method also includes: After the current loop finishes executing the wave transmission phase with the target wave transmission duration, obtain the instruction duty cycle of the pulse wave corresponding to the current loop; If the instruction duty cycle is less than the first preset judgment threshold and greater than or equal to the second preset judgment threshold, then the target transmission duration and the target sleep duration remain unchanged. If the instruction duty cycle is greater than or equal to the first preset judgment threshold, or the instruction duty cycle is less than the second preset judgment threshold, then the correction target is determined in the target transmission duration and the target sleep duration according to the second transmission ratio and the preset transmission ratio, and the correction direction of the correction target is determined according to the instruction duty cycle, the first preset judgment threshold and the second preset judgment threshold. Among them, the first preset judgment threshold is greater than the second preset judgment threshold.

[0026] In this example, it can be seen that, based on the previously determined target transmission duration and target sleep duration, this application introduces a closed-loop correction mechanism based on command duty cycle. By obtaining the command duty cycle after the transmission phase ends and comparing it with a first preset judgment threshold and a second preset judgment threshold, it is determined whether the target transmission duration and target sleep duration match the actual load requirements, so as to determine whether to perform closed-loop correction on the target transmission duration or target sleep duration.

[0027] When the instruction duty cycle is greater than or equal to the first preset judgment threshold, it indicates that the target's wave transmission duration is too short and the energy supply is insufficient. It is necessary to increase the target's wave transmission duration or the proportion of the second wave transmission, or reduce the target's sleep duration and increase the energy supply.

[0028] When the command duty cycle is less than the second preset judgment threshold, it indicates that the target's wave transmission duration is too long and the energy supply is excessive. It is necessary to reduce the target's wave transmission duration or the proportion of the second wave transmission, or increase the target's sleep duration in order to reduce the energy supply.

[0029] When the instruction duty cycle is less than the first preset judgment threshold and greater than or equal to the second preset judgment threshold, the switching power supply is still in steady state and does not need to be corrected, keeping the target transmission duration and target sleep duration unchanged.

[0030] Finally, based on the second emission ratio and the preset emission ratio, it is determined whether the correction target is the target emission duration or the target sleep duration, as well as the correction direction. The target emission duration or the target sleep duration is then corrected according to the second preset step size, thereby achieving closed-loop correction of the target emission duration or the target sleep duration. This avoids output jumps and system oscillations caused by excessively large single correction amplitudes, ensuring the stability of the closed-loop correction process. It also ensures that the average system power supply matches the load power consumption, achieving final steady-state convergence and providing closed-loop protection for suppressing output ripple and improving steady-state accuracy.

[0031] In one possible example of the first aspect, the instruction duty cycle for obtaining the pulse wave corresponding to the current loop includes: The sampled switching power supply outputs current or voltage within the current cycle to obtain the current sampled value; based on the loop operation of the error between the current sampled value and the loop reference value, the command duty cycle of the pulse wave corresponding to the current cycle is determined.

[0032] In this example, by sampling the output current or output voltage in the current cycle and determining the command duty cycle through loop calculation, a closed-loop feedback generation mechanism for the command duty cycle in burst mode is established, so that the command duty cycle can reflect the actual output state under light load conditions in real time, so that the command duty cycle can be compared with the first preset judgment threshold and the second preset judgment threshold in the future.

[0033] In one possible example of the first aspect, the correction target is determined from the target transmission duration and the target sleep duration based on the second transmission ratio and the preset transmission ratio, and the correction direction of the correction target is determined based on the command duty cycle, the first preset judgment threshold, and the second preset judgment threshold, including: If the second wave emission ratio is greater than or equal to the preset wave emission ratio and the instruction duty cycle is greater than or equal to the first preset judgment threshold, then the target wave emission duration is determined to be the target wave emission duration, and the target wave emission duration is increased according to the second preset step size. If the proportion of the second wave transmission is less than the preset wave transmission proportion and the instruction duty cycle is greater than or equal to the first preset judgment threshold, then the target sleep duration is determined to be the target sleep duration, and the target sleep duration is reduced according to the second preset step size. If the second wave emission ratio is greater than or equal to the preset wave emission ratio and the instruction duty cycle is less than the second preset judgment threshold, then the target wave emission duration is determined to be the target wave emission duration, and the target wave emission duration is reduced according to the second preset step size. If the proportion of the second wave transmission is less than the preset wave transmission proportion and the instruction duty cycle is less than the second preset judgment threshold, then the target sleep duration is determined to be the target sleep duration, and the target sleep duration is increased according to the second preset step size.

[0034] In this example, when the proportion of the second wave transmission is greater than or equal to the preset wave transmission proportion, and the command duty cycle is greater than or equal to the first preset judgment threshold, it indicates that the proportion of the optimized wave transmission phase in steady state is large (i.e., the wave transmission phase is dominant), and the energy provided by the wave transmission phase is insufficient. At this time, since the wave transmission phase is dominant, it is only necessary to increase the target wave transmission duration to correct the target wave transmission duration, thereby increasing the number of pulse waves sent by the corrected wave transmission phase and improving the average energy provided within the loop.

[0035] When the proportion of the second wave transmission is less than the preset wave transmission proportion, and the command duty cycle is greater than or equal to the first preset judgment threshold, it indicates that the proportion of the optimized sleep phase in steady state is large (i.e., the sleep phase is dominant), and the energy provided by the wave transmission phase is insufficient. At this time, since the sleep phase is dominant, it is only necessary to reduce the target sleep duration to correct the target sleep duration, thereby reducing the number of pulse waves stopped in the corrected sleep phase and increasing the average energy provided within the loop.

[0036] When the proportion of the second wave transmission is greater than or equal to the preset wave transmission proportion, and the command duty cycle is less than the second preset judgment threshold, it indicates that the proportion of the optimized wave transmission phase in steady state is large (i.e., the wave transmission phase is dominant), and the energy provided by the wave transmission phase is excessive. At this time, since the wave transmission phase is dominant, it is only necessary to reduce the target wave transmission duration to correct the target wave transmission duration, thereby reducing the number of pulse waves sent by the corrected wave transmission phase and reducing the average energy provided within the loop.

[0037] When the proportion of the second wave transmission is less than the preset wave transmission proportion and the command duty cycle is less than the second preset judgment threshold, it indicates that the proportion of the optimized sleep phase in steady state is large (i.e., the sleep phase is dominant) and the energy provided by the wave transmission phase is excessive. At this time, since the sleep phase is dominant, it is only necessary to increase the target sleep duration to correct the target sleep duration, thereby reducing the number of pulse waves stopped in the corrected sleep phase and increasing the average energy provided within the loop.

[0038] Secondly, this application provides a light-load control device for a switching power supply, the device comprising: The control unit is used to control the switching power supply to enter the burst mode when the switching power supply is under light load conditions. The burst mode is a mode in which the switching power supply alternately executes the wave generation phase and the sleep phase. The wave generation phase is a period of continuously sending at least one pulse wave, and the sleep phase is a period of continuously stopping sending at least one pulse wave. The pulse wave is used to drive the power switching transistor in the switching power supply to turn on and off. The sum of the duration of the wave generation phase and the duration of the sleep phase is the single cycle of the burst mode. The adjustment unit is used to fix the single cycle period as the first total duration in each cycle of the burst mode, and adaptively adjust the duration of the wave generation phase until the steady-state wave generation duration is determined. The steady-state wave generation duration is the duration of the wave generation phase when the switching power supply is in a steady state. The calculation unit is used to calculate the first wave emission ratio based on the steady-state wave emission duration and the first total duration. The first wave emission ratio is the ratio of the steady-state wave emission duration to the first total duration. The optimization unit is used to optimize the steady-state transmission duration based on the first transmission ratio and the preset transmission ratio to determine the corresponding target transmission duration and target sleep duration, so that the target transmission duration is less than the steady-state transmission duration and the absolute difference between the second transmission ratio and the first transmission ratio is less than the preset accuracy threshold. The second transmission ratio is the ratio of the target transmission duration to the second total duration, and the second total duration is the sum of the target transmission duration and the target sleep duration. The control unit is also used to control the switching power supply to perform the wave generation phase with a target wave generation duration and to perform the sleep phase with a target sleep duration.

[0039] In one possible example of the second aspect, regarding the adaptive adjustment of the duration of the wave generation phase until the steady-state wave generation duration is determined, the adjustment unit is used for: Starting with a preset initial duration for the wave emission phase, the wave emission phase is executed cyclically. After the wave generation phase ends in each loop, obtain the instruction duty cycle of the pulse wave corresponding to this loop; If the instruction duty cycle is greater than or equal to the first preset judgment threshold, the duration of the wave transmission phase in the current cycle is adjusted according to the first preset step size, and the adjusted duration is used in the next cycle until the instruction duty cycle is less than the first preset judgment threshold. The duration of the wave transmission phase when the instruction duty cycle is less than the first preset threshold is determined as the steady-state wave transmission duration.

[0040] In one possible example of the second aspect, the adjustment unit is used to: obtain the duty cycle of the instruction corresponding to the pulse wave in the current loop. The sampled switching power supply outputs current or voltage within the current cycle to obtain the sampled value. Based on the loop calculation of the error between the current sampled value and the loop reference value, the command duty cycle of the pulse wave corresponding to the current cycle is determined. The loop reference value is the reference current value or reference voltage value of the loop control circuit in the input switching power supply.

[0041] In one possible example of the second aspect, the initial duration is preset to be the period of a pulse wave, and the first preset step size is the period of a pulse wave; In adjusting the duration of the wave generation phase within the current cycle according to the first preset step size, the adjustment unit is used for: The duration of the wave generation phase within this cycle is increased by one pulse wave period.

[0042] In a possible example of the second aspect, in determining the corresponding target transmission duration and target sleep duration by optimizing the steady-state transmission duration based on the first transmission ratio and the preset transmission ratio, the optimization unit is used for: If the proportion of the first wave transmission is less than the preset wave transmission proportion, then the minimum wave transmission duration corresponding to the steady-state wave transmission duration is selected as the target wave transmission duration, and the target sleep duration corresponding to the minimum wave transmission duration is determined. If the proportion of the first wave transmission is greater than or equal to the preset wave transmission proportion, then the minimum sleep duration corresponding to the steady-state wave transmission duration is selected as the target sleep duration, and the target wave transmission duration corresponding to the minimum sleep duration is determined.

[0043] In one possible example of the second aspect, the minimum transmission duration corresponding to the steady-state transmission duration is the period of a pulse wave; The minimum sleep duration corresponding to the steady-state wave generation duration is the period of one pulse wave.

[0044] In one possible example of the second aspect, the minimum transmission duration corresponding to the steady-state transmission duration is the period of a pulse wave; in determining the target sleep duration corresponding to the minimum transmission duration, the optimization unit is used to: The target sleep duration is determined as the difference between the first rounded value multiplied by the period of the pulse wave and the minimum transmission duration. The first rounded value is the value obtained by dividing the first total duration by the steady-state transmission duration and then rounding it down.

[0045] In one possible example of the second aspect, the minimum sleep duration corresponding to the steady-state transmission duration is the period of a pulse wave; in determining the target transmission duration corresponding to the minimum sleep duration, the optimization unit is used to: The target transmission duration is determined as the product of the second rounded value and the period of the pulse wave. The second rounded value is the result of dividing the steady-state transmission duration by the steady-state sleep duration and then rounding it down. The steady-state sleep duration is the difference between the first total duration and the steady-state transmission duration.

[0046] In one possible example of the second aspect, the above-described apparatus further includes a correction unit, which is used for: After the current loop finishes executing the wave transmission phase with the target wave transmission duration, obtain the instruction duty cycle of the pulse wave corresponding to the current loop; If the instruction duty cycle is less than the first preset judgment threshold and greater than or equal to the second preset judgment threshold, then the target transmission duration and the target sleep duration remain unchanged. If the instruction duty cycle is greater than or equal to the first preset judgment threshold, or the instruction duty cycle is less than the second preset judgment threshold, then the correction target is determined in the target transmission duration and the target sleep duration according to the second transmission ratio and the preset transmission ratio, and the correction direction of the correction target is determined according to the instruction duty cycle, the first preset judgment threshold and the second preset judgment threshold. Among them, the first preset judgment threshold is greater than the second preset judgment threshold.

[0047] In one possible example of the second aspect, the correction unit is used to: obtain the instruction duty cycle of the pulse wave corresponding to the current loop. The sampled switching power supply outputs current or voltage within the current cycle to obtain the current sampled value; based on the loop operation of the error between the current sampled value and the loop reference value, the command duty cycle of the pulse wave corresponding to the current cycle is determined.

[0048] In one possible example of the second aspect, regarding determining the correction target from the target transmission duration and target sleep duration based on the second transmission ratio and the preset transmission ratio, and determining the correction direction of the correction target based on the command duty cycle, the first preset judgment threshold, and the second preset judgment threshold, the correction unit is used for: If the second wave emission ratio is greater than or equal to the preset wave emission ratio and the instruction duty cycle is greater than or equal to the first preset judgment threshold, then the target wave emission duration is determined to be the target wave emission duration, and the target wave emission duration is increased according to the second preset step size. If the proportion of the second wave transmission is less than the preset wave transmission proportion and the instruction duty cycle is greater than or equal to the first preset judgment threshold, then the target sleep duration is determined to be the target sleep duration, and the target sleep duration is reduced according to the second preset step size. If the second wave emission ratio is greater than or equal to the preset wave emission ratio and the instruction duty cycle is less than the second preset judgment threshold, then the target wave emission duration is determined to be the target wave emission duration, and the target wave emission duration is reduced according to the second preset step size. If the proportion of the second wave transmission is less than the preset wave transmission proportion and the instruction duty cycle is less than the second preset judgment threshold, then the target sleep duration is determined to be the target sleep duration, and the target sleep duration is increased according to the second preset step size.

[0049] Thirdly, this application provides a light-load control device for a switching power supply, the device including a processor, a memory, and a computer program or signaling stored in the memory, wherein the processor executes the computer program or signaling to implement the method described in the first aspect above.

[0050] Fourthly, this application provides a computer-readable storage medium storing a computer program or instructions that, when executed, implement the steps of the method described in the first aspect.

[0051] Fifthly, this application provides a computer program product, including a computer program or instructions, which, when executed, implement the steps of the method described in the first aspect. For example, the computer program product may be a software installation package.

[0052] It is worth noting that the beneficial effects of the technical solutions in the second to fifth aspects can be found in the technical effects of the technical solution in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0053] Figure 1 This is a block diagram of a switching power supply according to an embodiment of this application; Figure 2 This is a schematic diagram of the output current ripple under a burst mode according to an embodiment of this application; Figure 3 This is a schematic flowchart of a light-load control method for a switching power supply according to an embodiment of this application. Figure 4 This is a schematic flowchart illustrating the process of determining the steady-state wave transmission duration according to an embodiment of this application; Figure 5This is a schematic diagram of a process for determining the target transmission duration and the target dormancy duration according to an embodiment of this application; Figure 6 This is a flowchart illustrating a closed-loop correction method for duration according to an embodiment of this application; Figure 7 This is a flowchart illustrating another light-load control method for a switching power supply according to an embodiment of this application. Figure 8 This is a functional unit block diagram of a light-load control device for a switching power supply according to an embodiment of this application. Figure 9 This is a schematic diagram of the structure of a light-load control device for a switching power supply according to an embodiment of this application. Detailed Implementation

[0054] The terms "first," "second," etc., used in the embodiments of this application are used to distinguish different objects, not to describe a specific order. "At least one of the following" or similar expressions in the embodiments of this application refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent the following seven cases: a, b, c; a and b; a and c; b and c; a, b, and c. Each of a, b, and c can be an element or a set containing one or more elements.

[0055] Furthermore, in the embodiments of this application, "equal to" can be used in conjunction with "greater than" or "less than". When "equal to" is used with "greater than", that is, greater than or equal to, "equal to" is not used in conjunction with "less than"; when "equal to" is used with "less than", that is, less than or equal to, "equal to" is not used in conjunction with "greater than".

[0056] The switching power supply in the embodiments of this application will be described in detail below.

[0057] A switching power supply is a power electronic device that uses high-frequency pulse modulation technology to convert electrical energy into DC or AC output that meets the load requirements.

[0058] A switching power supply consists of a power circuit and a loop control circuit. The power circuit is the main power path for the switching power supply to realize the transmission and conversion of electrical energy, and it plays a core role in energy storage, conversion, transmission, and filtering output.

[0059] The loop control circuit is the core regulation unit of the switching power supply. It is responsible for real-time monitoring of the system operating status, comparing command deviations, calculating and generating pulse waves to drive the power switching transistors, and realizing closed-loop voltage regulation, current regulation and working mode switching under all operating conditions.

[0060] In this way, the loop control circuit can output pulse waves to drive the power switching transistors, precisely control the on / off timing and duty cycle of the power switching transistors, and enable the switching power supply to maintain a stable and reliable working state under different operating conditions such as heavy load, medium load, and light load.

[0061] A pulse wave is a square wave signal generated by a loop control circuit to drive the switching of power transistors. It is also the signal used by a switching power supply to achieve controllable energy supply, voltage regulation, and mode switching.

[0062] Optionally, the pulse wave can be a pulse width modulation (PWM) signal or a pulse frequency modulation (PFM) signal.

[0063] Optionally, the pulse wave includes a high level and a low level. The high level is used to drive the power switch to turn on, and the low level is used to drive the power switch to turn off. Therefore, the duration of the high level corresponds to the on-time of the power switch, and the duration of the low level corresponds to the off-time of the power switch.

[0064] During the high-level period, the power switch is turned on, the primary winding of the inductor or transformer begins to store energy, the current rises, and electrical energy is supplied from the input side to the output side. During the low-level period, the power switch is turned off, the inductor or transformer releases energy, and the output current is maintained through the rectifier.

[0065] Optionally, the period of the pulse wave is the sum of a high-level duration and a low-level duration, and the duty cycle of the pulse wave is the ratio of the high-level duration to its period. Thus, by adjusting the duty cycle of the pulse wave, the input electrical energy can be precisely changed, achieving precise control of the output voltage or output current of the switching power supply.

[0066] In one possible example, the power circuit includes devices such as power switches, transformers, inductors, capacitors, and rectifiers. Among them, power switches, such as metal-oxide-semiconductor field-effect transistors (MOSFETs) and insulated-gate bipolar transistors (IGBTs), can be used to chop the input DC voltage into a high-frequency pulse voltage by turning it on and off under drive.

[0067] Transformers can be used in isolation topologies (such as half-bridge and full-bridge) to achieve electrical isolation between input and output, and to raise or lower voltage through the turns ratio. Inductors can be used to smooth current and store magnetic field energy. Capacitors can be used to filter out high-frequency ripple in the output voltage, resulting in a smooth DC output. Rectifier diodes, including diodes or synchronous rectifier diodes, are used to provide a freewheeling path for inductor current during the turn-off period of the power switches, or to rectify current in the secondary winding of the transformer.

[0068] In one possible example, the loop control circuit employs either a single-loop control architecture or a dual-loop control architecture. In a single-loop control architecture, the loop control circuit is either a voltage loop control circuit (referred to as the voltage loop) or a current loop control circuit (referred to as the current loop). In a dual-loop control architecture, the loop control circuit includes a voltage loop and a current loop, with the voltage loop being the outer loop control circuit and the current loop being the inner loop control circuit.

[0069] The voltage loop can sample the output voltage of the switching power supply in real time, compare the sampled actual voltage value with the system's preset voltage reference value, and perform loop calculations on the error to generate relevant control commands.

[0070] In this way, the voltage loop can keep the output voltage highly stable when the load changes or the input voltage fluctuates, ensuring the long-term steady-state accuracy of the output voltage and realizing the system voltage regulation function.

[0071] The current loop can sample the output current of the power circuit (such as inductor current, load current, switching transistor current, etc.) in real time, compare the actual current sample value with the current reference value, and perform loop calculations on the error to generate the command duty cycle of the pulse wave.

[0072] In this way, the current loop can not only achieve overcurrent protection, current limiting, and dynamic load response adjustment, but also determine the load condition based on the duty cycle threshold and complete the switching control between continuous wave generation mode and burst mode.

[0073] In one possible example, the loop control circuit includes a sampling feedback circuit, a reference circuit, an error amplifier circuit, and a modulation circuit.

[0074] The sampling feedback circuit is used to sample the output voltage or output current of the switching power supply to obtain the sampled value, and input the sampled value into the error amplifier circuit.

[0075] The reference circuit is used to provide a loop reference value and input the loop reference value into the error amplifier circuit. The loop reference value is the current reference value or voltage reference value input into the loop control circuit.

[0076] The error amplifier circuit is used to perform error calculation and amplification between the sampled value and the loop reference value to obtain the control signal, and then input the control signal into the modulation circuit.

[0077] The modulation circuit is used to convert the control signal into a pulse wave that drives the power switch transistor and adjusts the duty cycle of the pulse wave, ultimately changing the on-time of the power switch transistor. The modulation circuit includes a PWM modulator or a PFM modulator.

[0078] In one possible example, the topology of a switching power supply determines the energy delivery method and operating characteristics of the power circuit. Topologies are broadly classified into two categories: non-isolated and isolated. Non-isolated topologies include buck, boost, and buck-boost converters, while isolated topologies include half-bridge, full-bridge, and LLC resonant converters.

[0079] Based on the above, Figure 1 This is a block diagram of a switching power supply according to an embodiment of this application. Figure 1 In the switching power supply 10, there are a power circuit 110 and a loop control circuit 120. The power circuit 110 includes a power switching transistor 1101, an inductor 1102, a capacitor 1103 and a rectifier transistor 1104. The loop control circuit 120 includes a sampling feedback circuit 1201, a reference circuit 1202, an error amplifier circuit 1203 and a modulation circuit 1204.

[0080] It is worth noting that, Figure 1 The switching power supply 10 in the middle includes, in addition to Figure 1 In addition to the relevant circuits, other circuits may be included, and no specific limitations are imposed on this. Furthermore, the switching power supply in the embodiments of this application is not limited to... Figure 1 As shown, this will not be elaborated further.

[0081] The load conditions, continuous wave generation mode, and burst mode in the embodiments of this application are described in detail below.

[0082] In switching power supplies, the load condition refers to the magnitude of the load connected to the output terminal of the power supply, usually expressed as a percentage of the output value (such as output power, output current, etc.) relative to the rated value (such as rated power or rated current) of the power supply. Different load conditions directly affect the operating mode, control strategy, loss distribution, and efficiency characteristics of the switching power supply.

[0083] Load conditions can be categorized into no-load, light-load, medium-load, heavy-load, full-load, and overload conditions. No-load condition refers to the state where there is no load at the output of the switching power supply. Light-load condition refers to a small load where the output value is far below the rated value, such as 20% to 30% below the rated value. Under light-load conditions, the output current and pulse duty cycle of the switching power supply are small. Medium-load condition refers to a moderate load where the output value is approximately 30% to 75% of the rated value. Heavy-load condition refers to a heavy load that is close to or reaches the rated value (e.g., 75% to 100%). Full-load condition refers to the state where the output value reaches the rated value. Overload condition refers to the state where the output value exceeds the rated value.

[0084] Under different load conditions, switching power supplies can adopt different operating modes. For example, under medium or heavy load conditions, switching power supplies adopt continuous waveform mode; under light load conditions, switching power supplies adopt burst mode or continuous waveform mode.

[0085] Continuous pulse transmission mode is a working mode in which the switching power supply continuously transmits pulse waves at a set fixed frequency without interruption. In this mode, the switching power supply has no sleep phase; the power switching transistors turn on and off normally in each switching cycle, and the output is stabilized by adjusting the duty cycle of the pulse wave.

[0086] Burst mode is a working mode in which the switching power supply alternately performs the wave generation phase and the sleep phase, that is, the working mode of intermittently sending pulse waves.

[0087] The waveform generation phase is a period in which at least one pulse wave (i.e., a cluster of pulse waves) is continuously transmitted. In this way, the power switch is controlled to turn on and off through the waveform generation phase, continuously providing energy to the output side and causing the output voltage or output current to rise rapidly.

[0088] The sleep phase is a period during which at least one pulse wave is continuously stopped. In this way, the power switch is kept off by controlling the sleep phase, so that the output side relies on the discharge of the output capacitor to maintain the load power supply, and the output voltage or output current gradually decreases.

[0089] The duration of the transmission phase (referred to as transmission duration) is denoted as... , which is the duration or length of a single pulse transmission phase in burst mode. Optionally, the duration of the pulse transmission phase is the product of the number of pulse waves transmitted in the pulse transmission phase and the period of a single pulse wave.

[0090] Thus, the longer the duration of the wave generation phase, the more pulse waves are sent during the wave generation phase, the more energy is provided in a single pulse, the more the output capacitor is charged, the greater the rise in output voltage or output current, and the greater the amplitude fluctuation of output ripple.

[0091] The duration of the dormancy phase (referred to as dormancy duration) is denoted as... , which is the duration or length of a single sleep phase in burst mode. Optionally, the duration of the sleep phase is the product of the number of pulse waves that are stopped during the sleep phase and the period of a single pulse wave.

[0092] Thus, the longer the sleep phase lasts, the more pulse waves are stopped during the sleep phase, the more the output capacitor discharges, the greater the drop in output voltage or output current, and the greater the amplitude fluctuation of output ripple.

[0093] The total duration of a single cycle in the burst mode is denoted as . , which is the duration or length of the emission phase and the dormancy phase within one complete cycle. Optionally, the total duration of a single cycle is the sum of the duration of the emission phase and the duration of the dormancy phase, i.e. .

[0094] The proportion of waves emitted is denoted as This characterizes the percentage of time the switching power supply is in the energy transfer phase within a single cycle, reflecting the average energy delivery capacity of the switching power supply to the load per unit time. Optionally, the waveform generation percentage is the ratio of the waveform generation phase duration to the total duration of a single cycle, denoted as [missing value]. .

[0095] The following is a detailed description of a light-load control method for a switching power supply in an embodiment of this application.

[0096] In existing burst mode control schemes, the duration of the waveform generation phase is usually a preset fixed value and lacks adaptive adjustment capability. When the switching power supply is under light load conditions, the fixed-duration waveform generation mechanism can easily lead to excessive energy provided in a single waveform generation phase, resulting in drastic energy fluctuations within a single cycle and forming output ripple with high amplitude fluctuations, such as high amplitude fluctuations in the output voltage ripple of the voltage loop or high amplitude fluctuations in the output current ripple of the current loop.

[0097] High amplitude fluctuations in output ripple not only degrade power supply quality and reduce the accuracy of voltage or current regulation under light load conditions, making it difficult to meet the load's requirements for power supply stability, but also apply periodic voltage or current impact stress to power devices such as inductors, capacitors, and power switching transistors, as well as the load. Under long-term operation, this will exacerbate device heating and aging damage, reducing the overall reliability and service life of the switching power supply.

[0098] For example, Figure 2 This is a schematic diagram of the output current ripple under a burst mode according to an embodiment of this application. Figure 2In this system, the switching power supply includes a current loop. After the switching power supply is under light load and enters burst mode, the current loop compares the sampled actual current value with the current reference value to calculate the error, and performs loop operations on the error to generate the command duty cycle for the pulse wave. When the command duty cycle is greater than the minimum duty cycle, the switching power supply executes the wave generation phase and sends a cluster of pulse waves within the duration of the wave generation phase on the time axis.

[0099] exist Figure 2 During the power generation phase, the energy supplied to the output side is excessive, far exceeding the actual energy consumption of the load. This excess energy is stored in the filter capacitor. Upon entering the subsequent sleep phase, the power circuit stops supplying energy, relying solely on the filter capacitor to release its stored energy to power the load, causing the capacitor voltage to slowly decrease. This periodic cycle of concentrated charging and slow discharging causes significant periodic fluctuations in the output current, ultimately resulting in a high-amplitude output current ripple.

[0100] Based on this, the present application provides a light-load control method for a switching power supply, which aims to ensure that the average energy supply matches the load energy consumption while maintaining the ripple ratio corresponding to the steady state under light-load burst mode, reducing the duration of the ripple generation stage in the steady state, suppressing the amplitude fluctuation of the output ripple under light-load conditions, improving the overall reliability and service life of the switching power supply, and ensuring the control accuracy of voltage regulation or current regulation.

[0101] Figure 3 This is a flowchart illustrating a light-load control method for a switching power supply according to an embodiment of this application. Figure 3 In this context, the method is applied to switching power supplies, and the method includes: S310. When the switching power supply is under light load, control the switching power supply to enter burst mode.

[0102] S320. In each cycle of the burst mode, the total duration of a single cycle is fixed as the first total duration, and the duration of the waveform generation phase is adaptively adjusted until the steady-state waveform generation duration is determined. The steady-state waveform generation duration is the duration of the waveform generation phase when the switching power supply is in a steady state.

[0103] S330. Calculate the first wave emission ratio based on the steady-state wave emission duration and the first total duration. The first wave emission ratio is the ratio of the steady-state wave emission duration to the first total duration.

[0104] S340. Based on the first wave emission ratio and the preset wave emission ratio, optimize the steady-state wave emission duration to determine the corresponding target wave emission duration and target sleep duration, so that the target wave emission duration is less than the steady-state wave emission duration, and the absolute difference between the second wave emission ratio and the first wave emission ratio is less than the preset accuracy threshold. The second wave emission ratio is the ratio of the target wave emission duration to the second total duration, and the second total duration is the sum of the target wave emission duration and the target sleep duration.

[0105] S350. Controls the switching power supply to perform the waveform generation phase with a target waveform generation duration and to perform the sleep phase with a target sleep duration.

[0106] Using the above method, within each cycle of the burst mode, the steady-state waveform duration of the switching power supply when it is in a steady state is dynamically searched by fixing the total duration of a single cycle and adaptively adjusting the duration of the waveform generation phase. Since the steady-state waveform duration is determined by adaptive adjustment based on the duration of the waveform generation phase, rather than by pre-fixing the duration of the waveform generation phase, the average energy provided within the steady-state waveform generation duration can be matched with the load energy consumption.

[0107] Furthermore, by reducing the duration of the steady-state wave generation phase from the steady-state wave generation duration to the target wave generation duration, the number of pulse waves sent in a single wave generation phase is reduced, thereby lowering the average energy provided in a single wave generation phase, reducing the amplitude of the output voltage or output current, suppressing the amplitude fluctuation of the output ripple, and improving the overall reliability and service life of the switching power supply.

[0108] Finally, since the absolute difference between the optimized second wave ratio and the unoptimized first wave ratio is less than the preset accuracy threshold, while ensuring the reduction of the wave phase duration and the decrease in average energy supply, the wave ratio before and after optimization remains basically unchanged, so that the average energy supply before and after optimization is basically consistent, avoiding the drop in output voltage or output current due to excessive reduction of the wave phase duration, and ensuring the control accuracy of voltage regulation or current regulation.

[0109] The following provides further examples illustrating the content of S320 above.

[0110] Within each cycle of burst mode, the switching power supply alternates between the waveform generation phase and the sleep phase. When the total duration of a single cycle is fixed as the first total duration, the sum of the duration of the waveform generation phase and the duration of the sleep phase within each cycle is the first total duration.

[0111] In this way, by fixing the total duration of each single cycle to a first total duration, a fixed and unified duration benchmark is established for adjusting the duration of the wave transmission phase. Under this benchmark, the wave transmission ratio can change with the duration of the wave transmission phase, making the changes in the wave transmission ratio during the adaptive adjustment process clearly comparable and measurable.

[0112] In one possible example, the first total duration is a directly preset duration.

[0113] In one possible example, the first total duration is the product of the preset total number of pulse waves and the period of the pulse waves. For example, the first total duration satisfies the following: ; in, Indicates the first total duration. Indicates the preset total number of pulse waves. This indicates the period of the pulse wave.

[0114] As can be seen, the first total duration can be determined based on the preset total number of pulse waves and the period of the pulse waves. In this way, the total duration of a single cycle can be fixed by directly setting the total number of pulse waves in each cycle.

[0115] When a switching power supply is in steady state, it can be understood that in burst mode, with one complete cycle as the period, the duration of the pulse generation phase and the duration of the sleep phase are repeated successively, and the output voltage or output current and the pulse generation ratio do not change with the number of cycles. This makes the average energy supply of the switching power supply in each cycle match the load energy consumption, without the need to correct the duty cycle of the pulse wave to compensate for the output deviation.

[0116] In one possible example, the duration of the wave generation phase is adaptively adjusted until a steady-state wave generation duration is determined, including: Starting with a preset initial wave transmission duration, the wave transmission phase is executed cyclically. After the wave transmission phase ends in each cycle, the instruction duty cycle of the pulse wave corresponding to this cycle is obtained. If the instruction duty cycle is greater than or equal to a first preset judgment threshold, the duration of the wave transmission phase in this cycle is adjusted according to a first preset step size, and the adjusted duration is used in the next cycle until the instruction duty cycle is less than the first preset judgment threshold. The duration of the wave transmission phase when the instruction duty cycle is less than the first preset judgment threshold is determined as the steady-state wave transmission duration.

[0117] It is worth noting that since the total duration of a single cycle is fixed as the first total duration, while adaptively adjusting the duration of the transmission phase, it is also necessary to adaptively adjust the duration of the sleep phase to ensure that the sum of the adjusted transmission phase duration and the adjusted sleep phase duration is the first total duration.

[0118] For example, taking the duration as the product of the number of pulse waves and the period of the pulse waves, assume that the preset initial transmission duration within the initial cycle satisfies the following: ; in, This indicates the preset initial transmission duration. This indicates the number of initial pulse waves transmitted during the transmission phase, and .

[0119] Correspondingly, the sleep duration within the initial loop satisfies the following: ; in, This indicates the sleep duration within the initial loop.

[0120] After the wave generation phase ends in each loop, obtain the command duty cycle (denoted as ) of the pulse wave corresponding to this loop. ), and on And the first preset judgment threshold (denoted as) Compare them. If Then, according to the first preset step size (denoted as...) Adjust the duration of the wave generation phase in the current cycle and use the adjusted duration in the next cycle.

[0121] Assume the duration of the wave generation phase within the current loop satisfies the following: ; in, This indicates the duration of the wave generation phase within the current loop. This indicates the number of pulse waves transmitted during the current wave transmission phase in the loop, and .

[0122] Meanwhile, assume that the duty cycle of the instruction acquired after the wave generation phase in the current loop ends satisfies At this point, the stable transmission duration is determined to be... .

[0123] In this example, the duration of the transmission phase is gradually adjusted according to the first preset step size, starting from the preset initial transmission duration, and the comparison result of the command duty cycle and the first preset judgment threshold is used as the judgment basis for adaptive adjustment.

[0124] When the instruction duty cycle is greater than or equal to the first preset threshold, such as This indicates that the average energy provided during the wave generation phase in this cycle is insufficient, the average energy supply is mismatched with the load energy consumption, and the error between the current sampled value and the loop command value is large.

[0125] When the instruction duty cycle is less than the first preset threshold, such as This indicates that the average energy provided by the wave generation phase in this cycle is just sufficient, and the average energy supply matches the load energy consumption. There is no need to significantly adjust the command duty cycle to compensate for the deviation. At this time, the duration of the corresponding wave generation phase is the steady-state wave generation duration, and the switching power supply enters the steady-state operation state in the burst mode.

[0126] As can be seen, by adjusting the duration of the wave generation phase in the next cycle according to the first preset step size and repeating the process until the instruction duty cycle is less than the first preset judgment threshold, the average energy supply and load energy consumption are matched, ensuring the control accuracy of voltage or current stabilization.

[0127] Optionally, the instruction duty cycle of the pulse wave corresponding to the current loop is obtained, including: The sampled switching power supply outputs current or voltage within the current cycle to obtain the current sampled value; based on the loop operation of the error between the current sampled value and the loop reference value, the command duty cycle of the pulse wave corresponding to the current cycle is determined, and the loop reference value is the reference current value or reference voltage value of the input loop control circuit.

[0128] The loop operation includes proportional-integral (PI) operation or proportional-integral-derivative (PID) operation.

[0129] As can be seen, by sampling the output current or output voltage in this cycle and determining the command duty cycle through loop calculation, a closed-loop feedback generation mechanism for the command duty cycle in burst mode is established, so that the command duty cycle can reflect the actual output state under light load conditions in real time, providing an accurate quantitative basis for determining the steady-state wave transmission duration based on the comparison between the command duty cycle and the first preset judgment threshold.

[0130] Optionally, the initial transmission duration is preset to be the period of one or more pulse waves. For example, taking the preset initial transmission duration as the period of one pulse wave as an example, in middle, .

[0131] Optionally, the first preset duration is the period of one or more pulse waves. For example, taking the first preset duration as the period of one pulse wave as an example, .

[0132] Optionally, the initial transmission duration is preset to the period of one pulse wave, and the first preset step size is the period of one pulse wave; the duration of the transmission phase within the current cycle is adjusted according to the first preset step size, including: The duration of the wave generation phase within this cycle is increased by one pulse wave period.

[0133] For example, suppose the duration of the wave generation phase in the initial cycle is... And the duty cycle of the command acquired after the wave generation phase in the initial loop meets the following requirements. At this point, the duration of the wave generation phase in the initial cycle is increased by one pulse wave period, i.e. = .

[0134] As can be seen, by setting both the preset initial transmission duration and the first preset step size to the period of a single pulse wave, the basic unit for adjusting the duration of the transmission phase is achieved using the period of a single pulse wave. Furthermore, using the period of a single pulse wave as the step size ensures synchronization with the switching frequency of the power switch, so that each adjustment increment corresponds exactly to one switching cycle of the power switch, improving the accuracy of the adaptive adjustment of the transmission phase duration and correspondingly reducing the complexity of the adaptive adjustment.

[0135] Based on the above example, the following example illustrates the complete process of S320, with the duration being the product of the number of pulse waves and the period of the pulse waves.

[0136] Figure 4 This is a schematic flowchart illustrating one embodiment of determining the steady-state wave transmission duration according to this application. Figure 4 In this context, the method is applied to switching power supplies, and the method includes: S410. In each cycle of the burst mode, the total duration of a single cycle is fixed as the first total duration, and the wave generation phase is executed cyclically starting from the duration of the wave generation phase, which is one pulse wave period.

[0137] S420. After the wave generation phase ends in each cycle, sample the output current or output voltage of the switching power supply in this cycle to obtain the sampled value.

[0138] S430. Based on the loop operation of the error between the current sampled value and the loop reference value, determine the instruction duty cycle of the pulse wave corresponding to the current cycle.

[0139] S440. If the instruction duty cycle is greater than or equal to the first preset judgment threshold, the duration of the wave generation phase in the current cycle is increased by one pulse wave period, and the adjusted duration is used in the next cycle until the instruction duty cycle is less than the first preset judgment threshold.

[0140] S450. The duration of the wave transmission phase when the instruction duty cycle is less than the first preset judgment threshold is determined as the steady-state wave transmission duration.

[0141] It can be seen that in each cycle of the burst mode, by fixing the total duration of a single cycle and using the period of a single pulse wave as the step size, the duration of the wave generation phase is adaptively adjusted until the instruction duty cycle is less than the first preset judgment threshold, thereby realizing the steady-state wave generation duration when the dynamic search system is in steady state.

[0142] The following provides further examples illustrating the content of S340 above.

[0143] The target wave transmission duration is less than the steady-state wave transmission duration. This can be understood as the optimized wave transmission duration (i.e., the target wave transmission duration) is less than the original wave transmission duration when the switching power supply is in steady state.

[0144] In this way, by reducing the duration of the steady-state wave generation phase from the steady-state wave generation duration to the target wave generation duration, the number of pulse waves sent in a single wave generation phase is reduced, the average energy provided in a single wave generation phase is reduced, the amplitude of the output voltage or output current is reduced, the amplitude fluctuation of the output ripple is suppressed, and the overall reliability and service life of the switching power supply are improved.

[0145] The absolute difference between the second wave emission ratio and the first wave emission ratio is less than the preset accuracy threshold. This can be understood as the deviation between the optimized wave emission ratio (i.e., the second wave emission ratio) and the unoptimized wave emission ratio (i.e., the first wave emission ratio) when the switching power supply is in a steady state being constrained within a controllable small range.

[0146] For example, the proportion of the first wave is recorded as The proportion of the second wave is recorded as follows: The preset precision threshold is denoted as For example, .

[0147] In this way, since the absolute difference between the emission ratio before and after optimization is less than the preset accuracy threshold, while ensuring that the duration of the emission phase is reduced and the average energy supply is lowered, the emission ratio before and after optimization remains basically unchanged, so that the average energy supply before and after optimization is basically consistent, avoiding the drop in output voltage or output current due to excessive reduction in the duration of the emission phase, and ensuring the control accuracy of voltage regulation or current regulation.

[0148] In one possible example, based on the proportion of the first wave transmission and the preset wave transmission proportion, the steady-state wave transmission duration is optimized to determine the corresponding target wave transmission duration and target sleep duration, including: If the proportion of the first wave transmission is less than the preset wave transmission proportion, then the minimum wave transmission duration corresponding to the steady-state wave transmission duration is selected as the target wave transmission duration, and the target sleep duration corresponding to the minimum wave transmission duration is determined. If the proportion of the first wave transmission is greater than or equal to the preset wave transmission proportion, then the minimum sleep duration corresponding to the steady-state wave transmission duration is selected as the target sleep duration, and the target wave transmission duration corresponding to the minimum sleep duration is determined.

[0149] For example, taking the duration as the product of the number of pulse waves and the period of the pulse waves, assume that the steady-state transmission duration satisfies the following: ; in, Indicates the steady-state wave generation duration. This represents the number of pulse waves transmitted during the initial wave generation phase before optimization in steady state, and .

[0150] At this point, the proportion of the first wave meets the following requirements: .

[0151] At this time, if Then choose The corresponding minimum transmission duration is the target transmission duration; if Then choose The corresponding minimum sleep duration is the target sleep duration. This indicates the preset wave ratio.

[0152] In this example, the minimum wave transmission duration corresponding to the steady-state wave transmission duration refers to the preset minimum value that can be achieved when optimizing the steady-state wave transmission duration by using the period of a single pulse wave as the basic unit, while maintaining the wave transmission ratio before and after optimization as basically unchanged.

[0153] The minimum sleep duration corresponding to the steady-state transmission duration refers to the steady-state sleep duration that can be determined based on a fixed first total duration and steady-state transmission duration. That is, the steady-state sleep duration is the difference between the first total duration and the steady-state transmission duration. Under the constraint of maintaining the transmission ratio before and after optimization to remain basically unchanged, the minimum value that can be achieved by reducing the steady-state sleep duration using the period of a single pulse wave as the basic unit.

[0154] When the proportion of the first wave is less than the preset wave proportion, such as This indicates that the proportion of the wave generation phase in steady state is small, meaning that the dormancy phase is dominant in steady state. Therefore, directly selecting the minimum wave generation duration corresponding to the steady-state wave generation duration as the target wave generation duration can reduce the duration of the wave generation phase to the physically achievable minimum, reducing the average energy transmitted in a single wave generation phase and suppressing the amplitude fluctuation of the output ripple. Simultaneously, under the constraint of maintaining a basically unchanged wave generation proportion before and after optimization, and knowing that the target wave generation duration is the minimum wave generation duration, the target dormancy duration can be determined, ensuring that the proportion of average energy supply before and after optimization is basically consistent, and guaranteeing precise control of voltage or current regulation.

[0155] When the proportion of the first wave is greater than or equal to the preset wave proportion, such as This indicates that the wave generation phase accounts for a large proportion in steady state, meaning that the wave generation phase dominates in steady state. Therefore, the minimum sleep duration corresponding to the steady-state wave generation duration is directly selected as the target sleep duration. Under the constraint of maintaining a basically unchanged wave generation proportion before and after optimization, when the steady-state sleep duration is reduced to its minimum, the corresponding steady-state wave generation duration can also be reduced, thereby reducing the average energy transmitted in a single wave generation phase and suppressing the amplitude fluctuation of the output ripple.

[0156] Optionally, the preset wave transmission ratio is one-half, such as... When the proportion of the first wave is less than half, it indicates that the duration of the wave-emitting phase in steady state is shorter than the duration of the dormant phase, and the dormant phase is dominant. When the proportion of the first wave is greater than or equal to half, it indicates that the duration of the wave-emitting phase is longer than the duration of the dormant phase, and the wave-emitting phase is dominant.

[0157] It can be seen that by setting the emission ratio to half, the duration ratio of the emission phase and the dormancy phase can be distinguished, so that the optimization strategy can adaptively select the minimum emission duration or the minimum dormancy duration as the optimization direction.

[0158] Optionally, the minimum transmission duration corresponding to the steady-state transmission duration is the period of one pulse wave. In this case, the target transmission duration is the period of one pulse wave, and the number of pulse waves transmitted in the optimized transmission stage is 1.

[0159] In switching power supplies, pulse waves are signals that control the switching of power transistors. A single pulse wave consists of a complete on / off cycle, or one switching cycle. If at least one pulse wave is transmitted during the pulse generation phase, the power transistor completes at least one on / off cycle, transferring energy once. If the duration of the pulse generation phase is zero, the pulse generation phase does not exist, and the system essentially stops working, unable to maintain output. Therefore, using the period of a single pulse wave as the basic unit of measurement, the period of a single pulse wave is the physically minimum achievable duration of the pulse generation phase.

[0160] In this way, by setting the minimum wave transmission duration corresponding to the steady-state wave transmission duration to the period of a pulse wave, the duration of the wave transmission phase in steady state can be guaranteed to be the minimum that can be physically achieved.

[0161] Optionally, the minimum sleep duration corresponding to the steady-state transmission duration is the period of one pulse wave. In this case, the number of pulse waves that are stopped during the corresponding optimized sleep phase is 1.

[0162] As can be seen, in a switching power supply, the sleep phase is the period during which pulse wave transmission stops and the power switching transistor remains off. If the sleep phase duration is zero, the pulse wave transmission phase is directly connected to the next pulse wave transmission phase, which is equivalent to exiting the burst mode and entering the continuous pulse wave transmission mode. Therefore, the minimum sleep phase duration should be one pulse wave period to maintain the intermittent operation characteristics of the burst mode.

[0163] In this way, by setting the minimum sleep duration corresponding to the steady-state wave transmission duration to the period of a pulse wave, the intermittent working characteristics of the burst mode can be maintained.

[0164] Optionally, the minimum transmission duration corresponding to the steady-state transmission duration is the period of one pulse wave; determining the target sleep duration corresponding to the minimum transmission duration includes: The target sleep duration is determined as the difference between the first rounded value multiplied by the period of the pulse wave and the minimum transmission duration. The first rounded value is the value obtained by dividing the first total duration by the steady-state transmission duration and then rounding it down.

[0165] For example, the target transmission duration satisfies the following: ; ; The target sleep duration satisfies the following: ; ; The proportion of the second wave meets the following requirements: ; ; in, Indicates the duration of the target's wave transmission. Indicates the target's sleep duration. This represents the rounding function. Indicates the first integer value. This represents the number of pulse waves transmitted during the optimized wave generation phase in steady state. This represents the number of pulse waves that are stopped during the optimized sleep phase in steady state. This indicates the second total duration.

[0166] It is understandable that the number of pulse waves transmitted during the steady-state wave generation phase decreases from the number before optimization. Adjusted to the optimized version ,and .

[0167] Optionally, the minimum sleep duration corresponding to the steady-state transmission duration is the period of one pulse wave; determining the target transmission duration corresponding to the minimum sleep duration includes: The target transmission duration is determined as the product of the second rounded value and the period of the pulse wave. The second rounded value is the result of dividing the steady-state transmission duration by the steady-state sleep duration and then rounding it down. The steady-state sleep duration is the difference between the first total duration and the steady-state transmission duration.

[0168] For example, the target sleep duration satisfies the following: ; ; The target transmission duration satisfies the following: ; ; in, This represents the second integer value.

[0169] Based on the above example, the following example illustrates the complete process of S340, where the duration is the product of the number of pulse waves and the period of the pulse waves.

[0170] Figure 5 This is a schematic flowchart illustrating a method for determining the target transmission duration and the target dormancy duration according to an embodiment of this application. Figure 5 In this context, the method is applied to switching power supplies, and the method includes: S510. If the proportion of the first wave transmission is less than one-half, the target wave transmission duration is determined to be the period of one pulse wave, and the target sleep duration is determined to be the difference between the first rounded value multiplied by the period of the pulse wave and the period of one pulse wave. The first rounded value is the value obtained by dividing the first total duration by the steady-state wave transmission duration and then rounding it down.

[0171] For example, if Then the following exists: ; ; ; .

[0172] S520. If the proportion of the first wave transmission is greater than or equal to one-half, the target sleep duration is determined to be the period of one pulse wave, and the target wave transmission duration is determined to be the product of the second rounded value and the period of the pulse wave. The second rounded value is the value obtained by dividing the steady-state wave transmission duration by the steady-state sleep duration and then rounding it down. The steady-state sleep duration is the difference between the first total duration and the steady-state wave transmission duration.

[0173] For example, if Then the following exists: ; ; ; .

[0174] The following is about the above. Figure 3 The method also includes illustrative examples.

[0175] Based on the previously determined target transmission duration and target dormancy duration, the above... Figure 3The method also requires, after the current loop finishes executing the wave transmission phase using the target wave transmission duration, obtaining the instruction duty cycle of the pulse wave corresponding to the current loop, comparing this instruction duty cycle with a first preset judgment threshold and a second preset judgment threshold, and determining whether to perform closed-loop correction on the target wave transmission duration or the target sleep duration based on the comparison result. The first preset judgment threshold is greater than the second preset judgment threshold.

[0176] This closed-loop correction scheme, located after step S350, performs closed-loop correction on the determined target emission duration or target sleep duration to achieve closed-loop control of the switching power supply.

[0177] In specific implementation, the above Figure 3 The method further includes: After the current loop finishes executing the wave transmission phase with the target wave transmission duration, obtain the instruction duty cycle of the pulse wave corresponding to the current loop; If the instruction duty cycle is less than the first preset judgment threshold and greater than or equal to the second preset judgment threshold, then the target transmission duration and the target sleep duration remain unchanged. If the instruction duty cycle is greater than or equal to the first preset judgment threshold, or the instruction duty cycle is less than the second preset judgment threshold, then the correction target is determined in the target transmission duration and the target sleep duration according to the second transmission ratio and the preset transmission ratio, and the correction direction of the correction target is determined according to the instruction duty cycle, the first preset judgment threshold and the second preset judgment threshold. Among them, the first preset judgment threshold is greater than the second preset judgment threshold.

[0178] It is worth noting that after correcting the target transmission duration or the target sleep duration, the corrected duration is used in the next loop until the instruction duty cycle is less than the first preset judgment threshold and greater than or equal to the second preset judgment threshold.

[0179] For example, let the first preset judgment threshold be denoted as The second preset judgment threshold is denoted as For example, in the current cycle, the target transmission duration is used. After the waveform generation phase ends, obtain the instruction duty cycle of the pulse wave corresponding to the current loop. .like Then keep and Unchanged; if ,or Then for or Make adjustments and use the adjusted duration in the next loop until... .

[0180] As can be seen, based on the previously determined target transmission duration and target sleep duration, this application introduces a closed-loop correction mechanism based on command duty cycle. By obtaining the command duty cycle after the transmission phase ends and comparing it with a first preset judgment threshold and a second preset judgment threshold, it is determined whether the target transmission duration and target sleep duration match the actual load requirements, so as to determine whether to perform closed-loop correction on the target transmission duration or target sleep duration.

[0181] When the instruction duty cycle is greater than or equal to the first preset threshold, such as This indicates that the target's wave transmission duration is too short and the energy supply is insufficient. It is necessary to increase the target's wave transmission duration or the proportion of the second wave transmission, or reduce the target's dormancy time, and improve the energy supply.

[0182] When the instruction duty cycle is less than the second preset threshold, such as This indicates that the target's emission duration is too long and the energy supply is excessive. It is necessary to reduce the target's emission duration or the proportion of the second emission, or increase the target's dormancy time, in order to reduce the energy supply.

[0183] When the instruction duty cycle is less than the first preset threshold and greater than or equal to the second preset threshold, such as The switching power supply remains in a steady state and does not require time correction, keeping the target transmission time and target sleep time unchanged.

[0184] Finally, based on the second emission ratio and the preset emission ratio, it is determined whether the correction target is the target emission duration or the target sleep duration, as well as the correction direction. The target emission duration or the target sleep duration is then corrected according to the second preset step size, thereby achieving closed-loop correction of the target emission duration or the target sleep duration. This avoids output jumps and system oscillations caused by excessively large single correction amplitudes, ensuring the stability of the closed-loop correction process. It also ensures that the average system power supply matches the load power consumption, achieving final steady-state convergence and providing closed-loop protection for suppressing output ripple and improving steady-state accuracy.

[0185] In one possible example, the duty cycle of the instruction corresponding to the pulse wave in the current loop is obtained, including: The sampled switching power supply outputs current or voltage within the current cycle to obtain the current sampled value; based on the loop operation of the error between the current sampled value and the loop reference value, the command duty cycle of the pulse wave corresponding to the current cycle is determined.

[0186] Among them, loop operations include PI operations or PID operations.

[0187] As can be seen, by sampling the output current or output voltage in the current cycle and determining the command duty cycle through loop calculation, a closed-loop feedback generation mechanism for the command duty cycle in burst mode is established, so that the command duty cycle can reflect the actual output state under light load conditions in real time, so that the command duty cycle can be compared with the first preset judgment threshold and the second preset judgment threshold in the future.

[0188] In one possible example, based on the second transmission ratio and the preset transmission ratio, the correction target is determined from the target transmission duration and the target sleep duration. Furthermore, based on the command duty cycle, the first preset judgment threshold, and the second preset judgment threshold, the correction direction of the correction target is determined, including: If the second wave emission ratio is greater than or equal to the preset wave emission ratio and the instruction duty cycle is greater than or equal to the first preset judgment threshold, then the target wave emission duration is determined to be the target wave emission duration, and the target wave emission duration is increased according to the second preset step size. If the proportion of the second wave transmission is less than the preset wave transmission proportion and the instruction duty cycle is greater than or equal to the first preset judgment threshold, then the target sleep duration is determined to be the target sleep duration, and the target sleep duration is reduced according to the second preset step size. If the second wave emission ratio is greater than or equal to the preset wave emission ratio and the instruction duty cycle is less than the second preset judgment threshold, then the target wave emission duration is determined to be the target wave emission duration, and the target wave emission duration is reduced according to the second preset step size. If the proportion of the second wave transmission is less than the preset wave transmission proportion and the instruction duty cycle is less than the second preset judgment threshold, then the target sleep duration is determined to be the target sleep duration, and the target sleep duration is increased according to the second preset step size.

[0189] For example, if and Then increase according to the second preset step size. ;like and Then decrease according to the second preset step size. ;like and Then decrease according to the second preset step size. ;like and Then increase according to the second preset step size. .

[0190] In this example, when the proportion of the second wave transmission is greater than or equal to the preset wave transmission proportion, and the command duty cycle is greater than or equal to the first preset judgment threshold, such as and This indicates that the optimized wave generation phase accounts for a large proportion in steady state (i.e., the wave generation phase is dominant), and the energy provided by the wave generation phase is insufficient. At this time, since the wave generation phase is dominant, it is only necessary to increase the target wave generation duration to correct the target wave generation duration, thereby increasing the number of pulse waves sent by the corrected wave generation phase and improving the average energy provided within the cycle.

[0191] When the proportion of the second wave transmission is less than the preset wave transmission proportion, and the command duty cycle is greater than or equal to the first preset judgment threshold, such as and This indicates that the optimized sleep phase accounts for a large proportion in steady state (i.e., the sleep phase is dominant), and the energy provided by the emission phase is insufficient. At this time, since the sleep phase is dominant, it is only necessary to reduce the target sleep duration to correct the target sleep duration, thereby reducing the number of pulse waves that are stopped in the corrected sleep phase and increasing the average energy provided within the cycle.

[0192] When the proportion of the second wave transmission is greater than or equal to the preset wave transmission proportion, and the command duty cycle is less than the second preset judgment threshold, such as and This indicates that the optimized wave generation phase accounts for a large proportion in steady state (i.e., the wave generation phase is dominant) and the energy provided by the wave generation phase is excessive. At this time, since the wave generation phase is dominant, it is only necessary to reduce the target wave generation duration to correct the target wave generation duration, thereby reducing the number of pulse waves sent by the corrected wave generation phase and reducing the average energy provided within the cycle.

[0193] When the proportion of the second wave transmission is less than the preset wave transmission proportion, and the command duty cycle is less than the second preset judgment threshold, such as and This indicates that the optimized sleep phase accounts for a large proportion in steady state (i.e., the sleep phase is dominant), and the energy provided by the emission phase is excessive. At this time, since the sleep phase is dominant, it is only necessary to increase the target sleep duration to correct the target sleep duration, thereby reducing the number of pulse waves that are stopped in the corrected sleep phase and increasing the average energy provided within the cycle.

[0194] Optionally, the second preset duration is the period of one or more pulse waves. For example, the second preset duration (denoted as...) Taking the period of a pulse wave as an example, .

[0195] Based on the examples above, the following example illustrates the complete closed-loop correction process, using the duration being the product of the number of pulse waves and the period of the pulse waves.

[0196] Figure 6 This is a flowchart illustrating a closed-loop correction method for duration according to an embodiment of this application. Figure 6 In this context, the method is applied to switching power supplies, and the method includes: S610. After the wave generation phase ends in the current cycle with the target wave generation duration, sample the output current or output voltage of the switching power supply in the current cycle to obtain the current sampled value.

[0197] S620. Based on the loop operation of the error between the current sampled value and the loop reference value, determine the instruction duty cycle of the pulse wave corresponding to the current cycle.

[0198] S630. If the instruction duty cycle is less than the first preset judgment threshold and greater than or equal to the second preset judgment threshold, then keep the target transmission duration and the target sleep duration unchanged.

[0199] For example, if Then keep and constant.

[0200] S640. If the proportion of the second wave is greater than or equal to one-half and the instruction duty cycle is greater than or equal to the first preset judgment threshold, then the target wave duration is increased by one pulse wave period, while the target sleep duration remains unchanged.

[0201] For example, if and The corrected target transmission duration is At this point, it's equivalent to increasing the number of pulse waves transmitted during the transmission phase by 1, i.e. .

[0202] S650. If the proportion of the second wave transmission is less than the preset wave transmission proportion and the instruction duty cycle is greater than or equal to the first preset judgment threshold, then the target sleep duration is reduced by one pulse wave period, while the target wave transmission duration remains unchanged.

[0203] For example, if and The corrected target sleep duration is At this point, the number of pulse waves that were stopped during the dormant phase is reduced by 1, i.e. .

[0204] S660. If the second wave emission ratio is greater than or equal to the preset wave emission ratio and the instruction duty cycle is less than the second preset judgment threshold, then the target wave emission duration is reduced by one pulse wave period, and the target sleep duration remains unchanged.

[0205] For example, if and The corrected target transmission duration is At this point, it's equivalent to reducing the number of pulse waves transmitted during the transmission phase by 1, i.e. .

[0206] S670. If the proportion of the second wave transmission is less than the preset wave transmission proportion and the instruction duty cycle is less than the second preset judgment threshold, then the target sleep duration is increased by one pulse wave period, and the target wave transmission duration remains unchanged.

[0207] For example, if and The corrected target sleep duration is At this point, it's equivalent to increasing the number of pulse waves that were stopped during the dormant phase by 1, i.e. .

[0208] S680. After correcting the target transmission duration or the target sleep duration, the corrected duration is used in the next loop until the instruction duty cycle is less than the first preset judgment threshold and greater than or equal to the second preset judgment threshold.

[0209] Based on the examples above, the following example illustrates the complete process of the light-load control method for the switching power supply, with the duration being the product of the number of pulse waves and the period of the pulse waves.

[0210] Figure 7 This is a flowchart illustrating another light-load control method for a switching power supply according to an embodiment of this application. Figure 7 In this context, the method is applied to switching power supplies, and the method includes: S701. When the switching power supply is under light load, control the switching power supply to enter burst mode.

[0211] S702. Calculation .

[0212] in, The calculation process can be referred to in S320 and S330 above, and will not be repeated here.

[0213] S703. Determine if the condition is met. .

[0214] If yes, then execute S704 to S710; otherwise, execute S711 to S717.

[0215] S704. Confirm .

[0216] S705. Calculation .

[0217] S706. Determine if the condition is met. .

[0218] If yes, then execute S707; otherwise, execute S708.

[0219] S707. Confirm Then return to execute S705.

[0220] S708. Determine if the condition is met. .

[0221] If yes, then execute S709; otherwise, execute S710.

[0222] S709. Confirm Then return to execute S705.

[0223] S710. Maintain and constant.

[0224] S711. Confirm .

[0225] S712. Calculation .

[0226] S713. Determine if the condition is satisfied. .

[0227] If yes, then execute S714; otherwise, execute S715.

[0228] S714. Confirm Then return to execute S712.

[0229] S715. Determine if the condition is met. .

[0230] If yes, then execute S716; otherwise, execute S717.

[0231] S716. Confirm Then return to execute S712.

[0232] S717. Maintain and constant.

[0233] The following is an example of a light-load control device for a switching power supply according to this embodiment.

[0234] The above describes the light-load control method of the switching power supply in the embodiments of this application from the perspective of the method. The functional units of the light-load control device of the switching power supply in the embodiments of this application are illustrated below.

[0235] To implement the steps described above, embodiments of this application divide each step into functional units to obtain a light-load control device for a switching power supply. The light-load control device for a switching power supply includes units that execute each function. These units are implemented in a combination of hardware and / or software. The division of these units is illustrative and represents only a logical functional division; in actual implementation, there may be other division methods.

[0236] When using integrated units, Figure 8 This is a functional unit block diagram of a light-load control device for a switching power supply according to an embodiment of this application. The light-load control device 800 includes a control unit 801, an adjustment unit 802, a calculation unit 803, and an optimization unit 804.

[0237] Optionally, the control unit 801 is a unit for controlling the operating mode of the switching power supply, and there are no specific limitations on it.

[0238] Optionally, the adjustment unit 802 is a unit that adaptively adjusts the duration of the transmission phase, without any specific limitations.

[0239] Optionally, the calculation unit 803 is a unit used to calculate the proportion of emitted waves, and there are no specific limitations on it.

[0240] Optionally, optimization unit 804 is a unit used to optimize duration, and there are no specific restrictions on it.

[0241] Optionally, the light-load control device 800 of the switching power supply further includes a storage unit for storing computer program code or instructions executed by the light-load control device 800 of the switching power supply. Optionally, the storage unit includes a memory.

[0242] Optionally, the light-load control device 800 of the switching power supply is a chip or chip module.

[0243] Optionally, the control unit 801 is integrated into the communication unit. The communication unit may be a communication interface, transceiver, transceiver circuit, etc. The communication unit may include a transmitting unit and / or a receiving unit.

[0244] Optionally, the control unit 801, adjustment unit 802, calculation unit 803, and optimization unit 804 are integrated into the processing unit.

[0245] The processing unit can be a processor or a controller, such as a central processing unit (CPU), a general-purpose processor, an electronic control unit (ECU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of these embodiments. The processing unit can also be a combination that implements computational functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0246] In specific implementation, the control unit 801, adjustment unit 802, calculation unit 803 and optimization unit 804 are used to execute any of the steps in the above method embodiments, and when performing actions such as sending, other units can be selectively called to complete the corresponding operation.

[0247] Control unit 801 is used to control the switching power supply to enter burst mode when the switching power supply is under light load condition. The burst mode is a mode in which the switching power supply alternately executes the wave generation phase and the sleep phase. The wave generation phase is a period of continuously sending at least one pulse wave, and the sleep phase is a period of continuously stopping sending at least one pulse wave. The pulse wave is used to drive the power switching transistor in the switching power supply to turn on and off. The sum of the duration of the wave generation phase and the duration of the sleep phase is the single cycle of the burst mode. The adjustment unit 802 is used to fix the single cycle period as the first total duration in each cycle of the burst mode, and adaptively adjust the duration of the wave generation phase until the steady-state wave generation duration is determined. The steady-state wave generation duration is the duration of the wave generation phase when the switching power supply is in a steady state. The calculation unit 803 is used to calculate the first wave transmission ratio based on the steady-state wave transmission duration and the first total duration. The first wave transmission ratio is the ratio of the steady-state wave transmission duration to the first total duration. The optimization unit 804 is used to optimize the steady-state transmission duration based on the first transmission ratio and the preset transmission ratio to determine the corresponding target transmission duration and target sleep duration, so that the target transmission duration is less than the steady-state transmission duration and the absolute difference between the second transmission ratio and the first transmission ratio is less than the preset accuracy threshold. The second transmission ratio is the ratio of the target transmission duration to the second total duration, and the second total duration is the sum of the target transmission duration and the target sleep duration. The control unit 801 is also used to control the switching power supply to perform the wave generation phase with a target wave generation duration and to perform the sleep phase with a target sleep duration.

[0248] As can be seen, within each cycle of the burst mode, the steady-state waveform duration of the switching power supply is dynamically searched by fixing the total duration of a single cycle and adaptively adjusting the duration of the waveform generation phase. Since the steady-state waveform duration is determined based on the adaptive adjustment of the waveform generation phase duration, rather than by pre-fixing the waveform generation phase duration, the average energy provided within the steady-state waveform generation duration can match the load energy consumption.

[0249] Furthermore, by reducing the duration of the steady-state wave generation phase from the steady-state wave generation duration to the target wave generation duration, the number of pulse waves sent in a single wave generation phase is reduced, thereby lowering the average energy provided in a single wave generation phase, reducing the amplitude of the output voltage or output current, suppressing the amplitude fluctuation of the output ripple, and improving the overall reliability and service life of the switching power supply.

[0250] Finally, since the absolute difference between the optimized second wave ratio and the unoptimized first wave ratio is less than the preset accuracy threshold, while ensuring the reduction of the wave phase duration and the decrease in average energy supply, the wave ratio before and after optimization remains basically unchanged, so that the average energy supply before and after optimization is basically consistent, avoiding the drop in output voltage or output current due to excessive reduction of the wave phase duration, and ensuring the control accuracy of voltage regulation or current regulation.

[0251] The following is an example description of another light-load control device for a switching power supply according to an embodiment of this application.

[0252] Please see Figure 9 , Figure 9 This is a schematic diagram of a light-load control device for a switching power supply according to an embodiment of this application. The light-load control device 900 includes a processor 910, a memory 920, and a communication bus for connecting the processor 910 and the memory 920.

[0253] Optionally, the memory 920 may include, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or compact disc read-only memory (CD-ROM). The memory 920 is used to store the program code executed by the light-load control device 900 of the switching power supply and the data transmitted therefrom.

[0254] Optionally, the light-load control device 900 of the switching power supply also includes a communication interface for receiving and sending data.

[0255] Optionally, the processor 910 may be a chip, CPU, ECU, general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, transistor logic device, hardware component or any combination thereof.

[0256] In specific implementation, the processor 910 in the light-load control device 900 of the switching power supply executes the computer program or instructions 921 stored in the memory 920 to perform the following operations: When the switching power supply is under light load, the control switch power supply enters burst mode. Burst mode is a mode in which the switching power supply alternately executes the wave generation phase and the sleep phase. The wave generation phase is a period of continuously sending at least one pulse wave, and the sleep phase is a period of continuously stopping sending at least one pulse wave. The pulse wave is used to drive the power switching transistor in the switching power supply to turn on and off. The sum of the duration of the wave generation phase and the duration of the sleep phase is the single cycle of burst mode. Within each cycle of the burst mode, the single cycle period is fixed as the first total duration, and the duration of the wave generation phase is adaptively adjusted until the steady-state wave generation duration is determined. The steady-state wave generation duration is the duration of the wave generation phase when the switching power supply is in a steady state. Based on the steady-state transmission duration and the first total duration, the proportion of the first transmission is calculated, which is the ratio of the steady-state transmission duration to the first total duration. Based on the first wave emission ratio and the preset wave emission ratio, the steady-state wave emission duration is optimized to determine the corresponding target wave emission duration and target sleep duration, so that the target wave emission duration is less than the steady-state wave emission duration, and the absolute difference between the second wave emission ratio and the first wave emission ratio is less than the preset accuracy threshold. The second wave emission ratio is the ratio of the target wave emission duration to the second total duration, and the second total duration is the sum of the target wave emission duration and the target sleep duration. The control switching power supply executes the waveform generation phase using a target waveform generation duration and the sleep phase using a target sleep duration.

[0257] Using the above method, within each cycle of the burst mode, the steady-state waveform duration of the switching power supply when it is in a steady state is dynamically searched by fixing the total duration of a single cycle and adaptively adjusting the duration of the waveform generation phase. Since the steady-state waveform duration is determined by adaptive adjustment based on the duration of the waveform generation phase, rather than by pre-fixing the duration of the waveform generation phase, the average energy provided within the steady-state waveform generation duration can be matched with the load energy consumption.

[0258] Furthermore, by reducing the duration of the steady-state wave generation phase from the steady-state wave generation duration to the target wave generation duration, the number of pulse waves sent in a single wave generation phase is reduced, thereby lowering the average energy provided in a single wave generation phase, reducing the amplitude of the output voltage or output current, suppressing the amplitude fluctuation of the output ripple, and improving the overall reliability and service life of the switching power supply.

[0259] Finally, since the absolute difference between the optimized second wave ratio and the unoptimized first wave ratio is less than the preset accuracy threshold, while ensuring the reduction of the wave phase duration and the decrease in average energy supply, the wave ratio before and after optimization remains basically unchanged, so that the average energy supply before and after optimization is basically consistent, avoiding the drop in output voltage or output current due to excessive reduction of the wave phase duration, and ensuring the control accuracy of voltage regulation or current regulation.

[0260] It should be noted that the specific implementation of each operation can adopt the corresponding description of the method embodiment shown above. The light load control device 900 of the switching power supply can be used to execute the relevant content in the above method embodiment, which will not be described again.

[0261] Other related content of the embodiments of this application will be illustrated below.

[0262] In one possible example, embodiments of this application provide a computer-readable storage medium storing a computer program or instructions that, when executed, implement the steps described in the above method embodiments.

[0263] In one possible example, embodiments of this application provide a computer program product, including a computer program or instructions that, when executed, implement the steps described in the above method embodiments.

[0264] It is worth noting that, for the sake of simplicity, the above embodiments are all described as a series of actions. Those skilled in the art should understand that this application is not limited to the described order of actions, as some steps in the embodiments of this application can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions, steps, modules, or units involved are not necessarily essential to the embodiments of this application. In the above embodiments, the descriptions of each embodiment in this application have different focuses; parts not described in detail in a certain embodiment can be referred to the relevant descriptions of other embodiments.

[0265] The steps of the methods or algorithms described in the embodiments of this application can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in RAM, flash memory, ROM, EPROM, electrically erasable programmable read-only memory (EEPROM), registers, hard disk, portable hard disk, read-only optical disk (CD-ROM), or any other form of storage medium well known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Furthermore, the ASIC can reside in a terminal device or management device. Alternatively, the processor and storage medium can exist as discrete components in the terminal device or management device.

[0266] Those skilled in the art will recognize that, in one or more of the examples above, the functions described in the embodiments of this application can be implemented, in whole or in part, by software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. This computer program product includes one or more computer instructions. When these computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs (DVDs)), or semiconductor media (e.g., solid-state disks (SSDs)).

[0267] The modules or units included in the various devices and products described in the above embodiments can be software modules or units, hardware modules or units, or a combination of both. For example, for devices and products applied to or integrated into a chip, all modules or units can be implemented using hardware methods such as circuits, or at least some modules or units can be implemented using software programs that run on a processor integrated within the chip, while the remaining (if any) modules or units can be implemented using hardware methods such as circuits. For devices and products applied to or integrated into a chip module, all modules or units can be implemented using hardware methods such as circuits. Different modules or units can be located in the same component (e.g., chip, circuit module, etc.) or different components of the chip module, or at least some modules or units can be implemented using hardware methods such as circuits. The implementation is achieved through a software program that runs on a processor integrated within the chip module. The remaining modules or units (if any) can be implemented using hardware methods such as circuits. For various devices or products applied to or integrated into terminal equipment, each of its modules or units can be implemented using hardware methods such as circuits. Different modules or units can be located in the same component (e.g., chip, circuit module, etc.) or different components within the terminal equipment. Alternatively, at least some modules or units can be implemented using a software program that runs on a processor integrated within the terminal equipment. The remaining modules or units (if any) can be implemented using hardware methods such as circuits.

[0268] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the embodiments of this application. It should be understood that the above descriptions are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solutions of the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims

1. A light-load control method for a switching power supply, characterized in that, The method includes: When the switching power supply is under light load, the switching power supply is controlled to enter a burst mode. The burst mode is a mode in which the switching power supply alternately executes a pulse wave generation phase and a sleep phase. The pulse wave generation phase is a period of continuously sending at least one pulse wave, and the sleep phase is a period of continuously stopping sending at least one pulse wave. The pulse wave is used to drive the power switching transistor in the switching power supply to turn on and off. The sum of the duration of the pulse wave generation phase and the duration of the sleep phase is the single cycle period of the burst mode. Within each cycle of the burst mode, the single cycle period is fixed as the first total duration, and the duration of the wave generation phase is adaptively adjusted until the steady-state wave generation duration is determined. The steady-state wave generation duration is the duration of the wave generation phase when the switching power supply is in a steady state. Based on the steady-state transmission duration and the first total duration, the first transmission ratio is calculated, whereby the first transmission ratio is the ratio of the steady-state transmission duration to the first total duration. Based on the first emission ratio and the preset emission ratio, the steady-state emission duration is optimized to determine the corresponding target emission duration and target sleep duration, so that the target emission duration is less than the steady-state emission duration, and the absolute difference between the second emission ratio and the first emission ratio is less than a preset accuracy threshold. The second emission ratio is the ratio of the target emission duration to the second total duration, and the second total duration is the sum of the target emission duration and the target sleep duration. The switching power supply is controlled to perform the wave transmission phase with the target wave transmission duration and to perform the sleep phase with the target sleep duration.

2. The method according to claim 1, characterized in that, The adaptive adjustment of the duration of the wave transmission phase until a steady-state wave transmission duration is determined includes: Starting from a preset initial duration, the wave generation phase is executed cyclically. After the wave generation phase ends in each loop, the instruction duty cycle of the pulse wave corresponding to this loop is obtained; If the instruction duty cycle is greater than or equal to the first preset judgment threshold, the duration of the wave transmission phase in the current cycle is adjusted according to the first preset step size, and the adjusted duration is used in the next cycle until the instruction duty cycle is less than the first preset judgment threshold. The duration of the wave transmission phase when the duty cycle of the instruction is less than the first preset threshold is determined as the steady-state wave transmission duration.

3. The method according to claim 2, characterized in that, The step of obtaining the duty cycle of the pulse wave corresponding to the current loop includes: The output current or output voltage of the switching power supply in the current cycle is sampled to obtain the sampled value. Based on the loop operation of the error between the current sampled value and the loop reference value, the command duty cycle of the pulse wave corresponding to the current cycle is determined. The loop reference value is the reference current value or reference voltage value input to the loop control circuit in the switching power supply.

4. The method according to claim 2, characterized in that, The preset initial duration is one period of the pulse wave, and the first preset step size is one period of the pulse wave; The step of adjusting the duration of the wave generation phase within the current cycle according to the first preset step size includes: The duration of the wave generation phase within the current cycle is increased by one period of the pulse wave.

5. The method according to claim 1, characterized in that, The step of optimizing the steady-state transmission duration based on the first transmission ratio and the preset transmission ratio to determine the corresponding target transmission duration and target sleep duration includes: If the first wave transmission ratio is less than the preset wave transmission ratio, then the minimum wave transmission duration corresponding to the steady-state wave transmission duration is selected as the target wave transmission duration, and the target sleep duration corresponding to the minimum wave transmission duration is determined. If the first wave transmission ratio is greater than or equal to the preset wave transmission ratio, then the minimum sleep duration corresponding to the steady-state wave transmission duration is selected as the target sleep duration, and the target wave transmission duration corresponding to the minimum sleep duration is determined.

6. The method according to claim 5, characterized in that, The minimum transmission duration corresponding to the steady-state transmission duration is the period of one pulse wave; The minimum sleep duration corresponding to the steady-state wave emission duration is one period of the pulse wave.

7. The method according to any one of claims 1-6, characterized in that, The method further includes: After the current loop finishes executing the wave transmission phase using the target wave transmission duration, the instruction duty cycle of the pulse wave corresponding to the current loop is obtained; If the duty cycle of the instruction is less than the first preset judgment threshold and greater than or equal to the second preset judgment threshold, then the target transmission duration and the target sleep duration remain unchanged. If the instruction duty cycle is greater than or equal to the first preset judgment threshold, or the instruction duty cycle is less than the second preset judgment threshold, then the correction object is determined in the target transmission duration and the target sleep duration according to the second transmission ratio and the preset transmission ratio, and the correction direction of the correction object is determined according to the instruction duty cycle, the first preset judgment threshold and the second preset judgment threshold. Wherein, the first preset judgment threshold is greater than the second preset judgment threshold.

8. The method according to claim 7, characterized in that, The step of determining the correction target from the target transmission duration and the target sleep duration based on the second transmission ratio and the preset transmission ratio, and determining the correction direction of the correction target based on the command duty cycle, the first preset judgment threshold, and the second preset judgment threshold, includes: If the second wave transmission ratio is greater than or equal to the preset wave transmission ratio and the instruction duty cycle is greater than or equal to the first preset judgment threshold, then the target wave transmission duration is determined to be the target wave transmission duration, and the target wave transmission duration is increased according to the second preset step size; If the second transmission ratio is less than the preset transmission ratio and the instruction duty cycle is greater than or equal to the first preset judgment threshold, then the target sleep duration is determined to be the target sleep duration, and the target sleep duration is reduced according to the second preset step size; If the second wave emission ratio is greater than or equal to the preset wave emission ratio and the instruction duty cycle is less than the second preset judgment threshold, then the target wave emission duration is determined to be the target wave emission duration, and the target wave emission duration is reduced according to the second preset step size; If the second wave transmission ratio is less than the preset wave transmission ratio and the instruction duty cycle is less than the second preset judgment threshold, then the target sleep duration is determined to be the target sleep duration, and the target sleep duration is increased according to the second preset step size.

9. A light-load control device for a switching power supply, characterized in that, The device includes: The control unit is used to control the switching power supply to enter a burst mode when the switching power supply is under light load conditions. The burst mode is a mode in which the switching power supply alternately executes a pulse wave generation phase and a sleep phase. The pulse wave generation phase is a period of continuously sending at least one pulse wave, and the sleep phase is a period of continuously stopping sending at least one pulse wave. The pulse wave is used to drive the power switching transistor in the switching power supply to switch on and off. The sum of the duration of the pulse wave generation phase and the duration of the sleep phase is the single cycle period of the burst mode. An adjustment unit is configured to fix the single cycle period as a first total duration within each cycle of the burst mode, and adaptively adjust the duration of the wave generation phase until a steady-state wave generation duration is determined, wherein the steady-state wave generation duration is the duration of the wave generation phase when the switching power supply is in a steady state. The calculation unit is used to calculate the first wave transmission ratio based on the steady-state wave transmission duration and the first total duration, wherein the first wave transmission ratio is the ratio of the steady-state wave transmission duration to the first total duration; An optimization unit is configured to optimize the steady-state transmission duration based on the first transmission ratio and a preset transmission ratio to determine the corresponding target transmission duration and target sleep duration, such that the target transmission duration is less than the steady-state transmission duration and the absolute difference between the second transmission ratio and the first transmission ratio is less than a preset accuracy threshold, wherein the second transmission ratio is the ratio of the target transmission duration to the second total duration and the second total duration is the sum of the target transmission duration and the target sleep duration; The control unit is also configured to control the switching power supply to perform the wave generation phase with the target wave generation duration and to perform the sleep phase with the target sleep duration.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program or instructions that, when executed, implement the method as described in any one of claims 1-8.

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