Valley function module control circuit, control method, switching power supply and controller

Abstract

The application provides a valley function module control circuit, a control method, a switching power supply and a controller, and solves the problem of low reliability of a quasi-resonant switching power supply with a valley lock function. The valley function module control circuit comprises a generation module and an updating module. The generation module is configured to determine a real-time working state signal based on a feedback voltage; when the real-time working state signal is a first working state signal, it is determined that the working state signal is switched between an nth valley lock state signal and a frequency reduction state signal, and the working state signal at the current time is maintained until a preset condition is met; the working state signal at the current time is updated based on the feedback voltage, and the updated working state signal is output; the first working state signal comprises the nth valley lock state signal and the frequency reduction state signal; and the updating module is configured to update the selected working state signal of the current switching period based on the updated working state signal, so as to control the opening position of the power tube in the next switching period.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of switching power supply, in particular to a valley function module control circuit, a control method, a switching power supply and a controller. BACKGROUND

[0002] In recent years, the application of quasi-resonant switching power supply with valley lock function is more and more widely. The switching power supply usually adaptively selects the valley to be turned on based on multiple electrical signals in the switching power supply, and locks the selected valley, so as to realize the valley lock function. When the switching power supply performs valley lock, there are often problems such as ripple in output voltage and frequent switching between adjacent working states, which affect the reliability of the switching power supply. SUMMARY

[0003] Therefore, the embodiments of the present application provide a valley function module control circuit, a control method and a control device, a switching power supply and a controller thereof, and a storage medium, to solve the problem of low reliability of the quasi-resonant switching power supply with valley lock function in the prior art.

[0004] The first aspect of the present application provides a valley function module control circuit used in a switching power supply controller. The valley function module control circuit comprises a generation module and an update module. The input end of the generation module receives a feedback voltage of the output voltage of the switching power supply, and the first input end of the update module is connected to the output end of the generation module. The generation module outputs a working state signal in a current switching period, and the update module outputs a selected working state signal of the current switching period, which is selected from the working state signal in the last switching period. The working state signal comprises any one of a jth valley lock state signal and a frequency reduction state signal, j = 1, 2, 3, …, n, n is a positive integer greater than 1. Wherein, the generation module is used to determine a real-time working state signal based on the feedback voltage; when the real-time working state signal is a first working state signal, the working state signal is determined to switch between the nth valley lock state signal and the frequency reduction state signal, and when the working state signal at the current time meets a preset condition, the working state signal at the current time is updated based on the feedback voltage, and the updated working state signal is outputted. The first working state signal comprises the nth valley lock state signal and the frequency reduction state signal. The update module is used to update the selected working state signal of the current switching period based on the updated working state signal, so as to control the opening position of the power tube in the next switching period.

[0005] The second aspect of the application provides a valley function module control method, which is used in a switching power supply controller and includes the following steps: determining a real-time working state signal of a power tube in the switching power supply based on a feedback voltage of an output voltage of the switching power supply; when the real-time working state signal is a first working state signal, determining that the working state signal of the power tube in the switching power supply in a current switching period switches between an nth valley bottom locking state signal and a frequency reduction state signal, the working state signal includes any one of the jth valley bottom locking state signal and the frequency reduction state signal, j = 1, 2, 3, …, n, the first working state signal includes the nth valley bottom locking state signal and the frequency reduction state signal, and n is a positive integer greater than 1; maintaining the working state signal at the current time until a preset condition is met, and then updating the working state signal at the current time based on the feedback voltage of the output voltage of the switching power supply; and updating a selected working state signal of the current switching period based on the updated working state signal, so as to be used for controlling an opening position of the power tube in a next switching period, wherein the selected working state signal is selected from the working state signal in the last switching period.

[0006] The third aspect of the application provides a valley function module control device, which is used in a switching power supply controller and includes the following steps: a determining module is configured to determine a real-time working state signal of a power tube in the switching power supply based on a feedback voltage of an output voltage of the switching power supply; when the real-time working state signal is a first working state signal, determining that the working state signal of the power tube in the switching power supply in a current switching period switches between an nth valley bottom locking state signal and a frequency reduction state signal, the working state signal includes any one of the jth valley bottom locking state signal and the frequency reduction state signal, j = 1, 2, 3, …, n, n is a positive integer greater than 1, the first working state signal includes the nth valley bottom locking state signal and the frequency reduction state signal, and n is a positive integer greater than 1; a first updating module is configured to maintain the working state signal at the current time until a preset condition is met, and then update the working state signal at the current time based on the feedback voltage of the output voltage of the switching power supply; and a second updating module is configured to update a selected working state signal of the current switching period based on the updated working state signal, so as to be used for controlling an opening position of the power tube in a next switching period, wherein the selected working state signal is selected from the working state signal in the last switching period.

[0007] The fourth aspect of the application provides a switching power supply controller, which includes a valley function module control circuit provided in an embodiment of the application and a control signal generation circuit configured to update a gate voltage signal of a power tube based on a selected working state signal of a next switching period, so that the power tube is turned on at a position corresponding to the selected working state signal of the next switching period.

[0008] A fifth aspect of this application provides a switching power supply, including: a switching power supply controller provided in the embodiments of this application; and a power conversion circuit including a power transistor, the gate of which is connected to the switching power supply controller.

[0009] The sixth aspect of this application provides a computer storage medium storing a computer program thereon, characterized in that the computer program, when executed by a processor, implements the steps of the valley bottom function module control method provided in the embodiments of this application.

[0010] According to the valley-level function module control circuit, control method, control device, switching power supply and its controller, and storage medium provided in the embodiments of this application, when the operating state signal is determined to switch between the nth valley-level locked state signal and the frequency reduction state signal, the operating state signal at the current moment is not updated in real time. Instead, the operating state signal at the current moment is maintained until a predetermined condition is met, and then the current operating state signal is updated according to the feedback voltage. This avoids the problem of frequent switching of the power transistor between the nth valley-level locked state and the frequency reduction state, thereby improving the reliability of the switching power supply used in the operating state determination circuit. Compared with increasing the hysteresis voltage, the operating range of the feedback voltage and the number of valley-level locks can be guaranteed to be unlimited. Attached Figure Description

[0011] Figure 1 This is a circuit diagram of a quasi-resonant flyback switching power supply in related technologies.

[0012] Figure 2 for Figure 1 A partial structural schematic diagram of the quasi-resonant controller 20 in the switching power supply shown.

[0013] Figure 3 for Figure 2 The diagram shows the relationship between the valley locking frequency curve and the feedback voltage when the quasi-resonant controller performs valley locking based on the frequency of the gate signal.

[0014] Figure 4 This is a schematic diagram of the valley bottom function module control circuit provided in the first embodiment of this application.

[0015] Figure 5 This is a schematic diagram of the valley bottom function module control circuit provided in the second embodiment of this application.

[0016] Figure 6 This is a schematic diagram of the valley bottom function module control circuit provided in the third embodiment of this application.

[0017] Figure 7 for Figure 6 The diagram shows the output waveform of the generation module.

[0018] Figure 8 The output waveform diagram of the updating module.

[0019] Figure 9 The control method flow chart of the valley function module is provided for the first embodiment of the application.

[0020] Figure 10 The structure block diagram of the valley function module control device is provided for an embodiment of the application.

[0021] Figure 11 The structure block diagram of the switching power supply controller is provided for an embodiment of the application.

[0022] Figure 12 The structure block diagram of the switching power supply is provided for an embodiment of the application. DETAILED DESCRIPTION

[0023] Figure 1 The circuit structure diagram of the quasi-resonant flyback switching power supply in the related art is shown in FIG. 1. As shown in FIG. 1, when the power tube M1 is turned on, the input voltage AC charges the primary side inductance Np of the transformer, and the freewheeling diode D1 in series with the secondary side inductance Ns is turned off, and no power is supplied to the load. When the power tube M1 is turned off, the primary side inductance Np starts to demagnetize, the freewheeling diode D1 is turned on, and the secondary side inductance Ns supplies power to the load. When the primary side inductance Np demagnetization ends, the primary side inductance Np and the parasitic capacitor C enter the free resonance state. Figure 1

[0024] The partial structure schematic diagram of the quasi-resonant controller 20 in the switching power supply shown in FIG. 2 is shown in FIG. 3. As shown in FIG. 3 and FIG. 4, the output voltage Vout is fed back to the quasi-resonant controller 20 through the error amplification and isolation module 11. The feedback voltage FB detected by the quasi-resonant controller 20 is input to the pulse width modulation (PWM) comparator together with the detected drain sampling voltage CS after passing through the feedback sampling circuit 23, so as to control the output frequency and duty cycle of the gate signal GATE, thereby keeping the output voltage Vout constant. Figure 2 Figure 1 Figure 1 Figure 2 The partial structure schematic diagram of the quasi-resonant controller 20 in the switching power supply shown in FIG. 2 is shown in FIG. 3. As shown in FIG. 3 and FIG. 4, the output voltage Vout is fed back to the quasi-resonant controller 20 through the error amplification and isolation module 11. The feedback voltage FB detected by the quasi-resonant controller 20 is input to the pulse width modulation (PWM) comparator together with the detected drain sampling voltage CS after passing through the feedback sampling circuit 23, so as to control the output frequency and duty cycle of the gate signal GATE, thereby keeping the output voltage Vout constant.

[0025] The valley detection module 21 receives the output sampling voltage DMG, generates the resonance valley bottom pulse signal of the drain resonance voltage waveform of the power tube Q1, and outputs it to the valley lock module 22. The valley lock module 22 can select the conduction valley bottom based on the resonance valley bottom pulse signal, the internal signal FB_in generated by the feedback sampling circuit 23 after FB, and the gate signal GATE, and lock the selected valley bottom.

[0026] Figure 3 The partial structure schematic diagram of the quasi-resonant controller 20 in the switching power supply shown in FIG. 2 is shown in FIG. 3. As shown in FIG. 3 and FIG. 4, the output voltage Vout is fed back to the quasi-resonant controller 20 through the error amplification and isolation module 11. The feedback voltage FB detected by the quasi-resonant controller 20 is input to the pulse width modulation (PWM) comparator together with the detected drain sampling voltage CS after passing through the feedback sampling circuit 23, so as to control the output frequency and duty cycle of the gate signal GATE, thereby keeping the output voltage Vout constant. Figure 2 ​​​The relationship between the valley lock frequency curve and the feedback voltage when the quasi-resonant controller 20 performs valley lock based on the frequency of the gate signal GATE is shown. The relationship between the valley lock frequency curve and the feedback voltage when the quasi-resonant controller 20 performs valley lock based on the frequency of the gate signal GATE is shown in conjunction with Figure 2 and Figure 3 As shown, the operating states of the power tube include a frequency reduction state and valley lock states, which include a first valley lock state, a second valley lock state, a third valley lock state, and an nth valley lock state. When the output load decreases from a heavy load to a light load, the feedback voltage FB gradually decreases, and the gate on-time and the demagnetization time gradually decrease. Since valley lock is performed, the operating frequency of the switching power supply gradually increases. When the operating frequency increases to exceed the first valley reference frequency curve Finc, the quasi-resonant controller 20 can achieve the purpose of reducing the operating frequency by moving the valley position of the drain resonant voltage during the on-time of the power tube backward (for example, switching from on-time at the nth valley to on-time at the (n+1)th valley, i.e., switching from the nth valley lock state to the (n+1)th valley lock state). After moving the on-time valley position backward, the operating frequency of the switching power supply is between the first valley reference frequency curve Finc and the second valley reference frequency curve Fdec, until the output load again decreases to cause the operating frequency to again exceed the first valley reference frequency curve Finc, and the on-time valley position can again be moved backward. When the output load increases from a light load to a heavy load, the feedback voltage FB gradually increases, and the gate on-time and the demagnetization time gradually increase. Since valley lock is performed, the operating frequency of the switching power supply gradually decreases. When the operating frequency decreases to the second valley reference frequency curve Fdec, the quasi-resonant controller 20 can achieve the purpose of increasing the operating frequency by moving the valley position of the drain resonant voltage during the on-time of the power tube forward (for example, switching from on-time at the (n+1)th valley to on-time at the nth valley, i.e., switching from the (n+1)th valley lock state to the nth valley lock state). After the on-time valley position is determined, the on-time valley position is latched.

[0027] Referring to Figure 3 It can be seen that the above switching power supply has the following two problems:

[0028] First, when the switching power supply switches from the nth valley lock state to the frequency reduction state, the operating frequency decreases, and the feedback voltage increases. When the feedback voltage exceeds the threshold interval controlled by the frequency reduction state and reenters the nth valley lock state, the switching power supply reenters the nth valley lock state, and thus the problem of frequent switching between the nth valley lock state and the frequency reduction state occurs. Although the problem of frequent switching can be avoided by increasing the hysteresis, this will make the operating range of the feedback voltage smaller, the number of locked valleys smaller, and the efficiency in the full load range affected.

[0029] Secondly, during the power tube Q1 is off, when the load gradually increases, the feedback voltage FB increases, and the corresponding number of the locked valley bottom decreases. If the number of the locked valley bottom corresponding to the feedback voltage FB (i.e. the expected locked valley bottom) is less than the number of the currently detected valley bottom, that is, the expected locked valley bottom appears at the previous time, and the current time cannot lock it. In this case, the switching power supply cannot be turned on at the expected valley bottom, but works at a lower working frequency, resulting in a drop in output voltage and a larger output ripple.

[0030] The above two problems have a bad influence on the reliability of the switching power supply. In view of this, the embodiments of the present application provide a valley bottom function module control circuit, a control method and a control device, a switching power supply and a controller thereof, and a storage medium. The valley bottom function module control circuit comprises a generation module and an update module. The input end of the generation module receives the feedback voltage of the output voltage of the switching power supply, and the first input end of the update module is connected to the output end of the generation module. The generation module outputs the working state signal in the current switching period, and the update module outputs the selected working state signal in the current switching period, which is selected from the working state signal in the previous switching period. The working state signal comprises any one of the jth valley bottom locking state signal and the frequency reduction state signal, j = 1, 2, 3,..., n, n is a positive integer greater than 1. The generation module is used to determine the real-time working state signal based on the feedback voltage; when the real-time working state signal is the first working state signal, the working state signal is switched between the nth valley bottom locking state signal and the frequency reduction state signal, and the working state signal at the current time is maintained until the preset condition is met. The working state signal at the current time is updated based on the feedback voltage, and the updated working state signal is outputted. The first working state signal comprises the nth valley bottom locking state signal and the frequency reduction state signal. The update module is used to update the working state signal in the current switching period based on the updated working state signal, and output the working state signal in the next switching period, which is used to control the opening position of the power tube.

[0031] It can be seen that, according to the valley bottom function module control circuit provided by the embodiments of the present application, when it is determined that the working state signal is switched between the nth valley bottom locking state signal and the frequency reduction state signal, the working state signal at the current time is not updated in real time, but is maintained until the predetermined condition is met. The working state signal at the current time is updated according to the feedback voltage, thereby avoiding the problem of frequent switching of the power tube between the nth valley bottom locking state and the frequency reduction state, and further improving the reliability of the switching power supply applied by the working state determination circuit. Compared with the method of increasing the hysteresis, the working range of the feedback voltage is not limited, and the number of valley bottom locking is not limited.

[0032] With reference to the drawings and embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0033] Figure 4 The structure diagram of the valley function module control circuit is provided for the first embodiment of the present application. As shown in the figure, Figure 4 The generating module 41 and the updating module 42 are included in the valley function module control circuit 40. The input end of the generating module receives the feedback voltage of the output voltage of the switching power supply, and the first input end of the updating module is connected to the output end of the generating module. The output end of the generating module outputs the working state signal in the current switching period, and the output end of the updating module 42 outputs the selected working state signal in the current switching period, which is selected from the working state signal in the last switching period. The working state signal includes any one of the j-th valley lock state signal and the frequency reduction state signal, j = 1, 2, 3, …, n, n is a positive integer greater than 1. The specific value of n is defined by the designer during circuit design.

[0034] The generating module 41 is configured to determine the real-time working state signal based on the feedback voltage. When the real-time working state signal is the first working state signal, the working state signal is switched between the n-th valley lock state signal and the frequency reduction state signal. When the working state signal at the current time satisfies the preset condition, the working state signal at the current time is updated based on the feedback voltage, and the updated working state signal is output. The first working state signal includes the n-th valley lock state signal and the frequency reduction state signal.

[0035] The feedback voltage FB can represent the size of the load, and the size of the load determines the switching frequency of the power tube. The switching frequency of the power tube corresponds to different working states, so the working state signal corresponding to the load can be generated based on the feedback voltage FB. The entire numerical interval of the feedback voltage FB is divided into different interval ranges, and one interval range corresponds to one working state signal of the power tube. The generating module 11 can compare the detected feedback voltage FB with the boundary values of each interval range of the feedback voltage to determine the current working state signal corresponding to the feedback voltage FB.

[0036] In order of the feedback voltage FB from small to large, the working states of the power tube include a frequency reduction state, an nth valley bottom locking state, an n-1th valley bottom locking state, and an 1th valley bottom locking state. Correspondingly, the working state signals include a frequency reduction state signal and a jth valley bottom locking state signal, the frequency reduction state signal is used to indicate that the power tube is in the frequency reduction state, and the jth valley bottom locking state signal is used to indicate that the power tube is in the jth valley bottom conduction state, j = 1, 2, …, n. In an example, each working state can be represented by an encoding sequence. For example, the encoding sequence corresponding to the frequency reduction state signal is 000000, the encoding sequence corresponding to the 1th valley bottom locking state signal is 000001, the encoding sequence corresponding to the 2th valley bottom locking state signal is 000010, the encoding sequence corresponding to the 3th valley bottom locking state signal is 000100, and so on. Then the generation module 11 can output any one of the above encoding sequences.

[0037] The updating module 42 is used to update the selected working state signal of the current switching period based on the updated working state signal, and output the selected working state signal of the next switching period, for controlling the opening position of the power tube in the next switching period.

[0038] According to the valley bottom function module control circuit provided in the embodiment, when it is determined that the working state signal switches between the n th valley bottom locking state signal and the frequency reduction state signal, the working state signal at the current time is not updated in real time, but is maintained until a predetermined condition is met, and then the current working state signal is updated according to the feedback voltage, thereby avoiding the problem that the power tube frequently switches between the n th valley bottom locking state and the frequency reduction state, and further improving the reliability of the switching power supply applied by the working state determination circuit. Compared with the way of increasing the hysteresis, the working range of the feedback voltage is not limited, and the number of valley bottom locking is not limited.

[0039] In an embodiment, the generation module 41 is further used to, during the period of maintaining the working state signal at the current time until the preset condition is met, update the working state signal at the current time in real time based on the feedback voltage when the real-time working state signal determined by the feedback voltage is a second working state signal, the second working state signal includes an i th valley bottom locking state signal, i = 1, 2, 3, …, n-1. That is, during the period of maintaining the working state signal at the current time until the preset condition is met, as soon as the real-time working state signal corresponding to the feedback voltage appears the second working state signal, the real-time working state signal corresponding to the feedback voltage is outputted, so as to ensure the response speed.

[0040] Figure 5 A structural schematic diagram of the valley bottom function module control circuit provided in the second embodiment is shown in FIG. 2. As shown in FIG. 2, the valley bottom function module control circuit includes a working state determination circuit 21, a generation module 41, an updating module 42, and a selection module 43. Figure 5As shown, in the embodiment, the generating module 51 comprises a bidirectional encoding unit 511, a first logic unit 512, a second logic unit 513 and an output unit 514. The input end of the bidirectional encoding unit 511 receives the feedback voltage FB, and the output end is connected to the input end of the first logic unit 512 and the input end of the second logic unit 513. The output end of the first logic unit 512 outputs the flag signal of the first i valley bottoms. The output end of the second logic unit 513 is connected to the input end of the output unit 514. The second logic unit 513 outputs the identification signal of the working state signal. The output unit 514 outputs the flag signal of the n th valley bottom and the flag signal of the frequency reduction state. The flag signal of the first i valley bottoms, the flag signal of the n th valley bottom and the flag signal of the frequency reduction state jointly constitute the working state signal.

[0041] Specifically, the bidirectional encoding unit 511 is configured to receive the feedback voltage FB and encode the feedback voltage FB. For example, the bidirectional encoding unit 511 performs addition or subtraction operation according to the change of the feedback voltage FB to generate a corresponding encoding sequence Q[m:0].

[0042] The first logic unit 512 is configured to generate the flag signal of the first i valley bottoms according to the encoding sequence Q[m:0], i = 1, 2,..., n-1. The working state signal comprises a plurality of flag bits, which represent the flag bit of the first valley bottom, the flag bit of the second valley bottom, the flag bit of the third valley bottom,..., the flag bit of the n th valley bottom and the flag bit of the frequency reduction state in sequence from left to right. The value of each flag bit can be 1 or 0. Taking n = 6 as an example, when the encoding sequence Q[m:0] corresponds to the 5 th valley bottom locking state, the first logic unit 512 outputs 00001. When the encoding sequence Q[m:0] corresponds to the 6 th valley bottom locking state, the first logic unit 512 outputs 00000.

[0043] The second logic unit 513 is configured to determine that the working state signal switches between the n th valley bottom locking state signal and the frequency reduction mode state signal based on the identification signal, and update the identification signal at the current time based on the encoding sequence Q[m:0] when the identification signal at the current time is maintained to satisfy a preset condition. For example, the identification signal output by the second logic unit 513 at the current time is 1, indicating the frequency reduction state signal. The identification signal output by the second logic unit 513 at the previous time is 0, indicating the n th valley bottom locking state signal. Thus, it can be determined that the working state signal switches between the n th valley bottom locking state signal and the frequency reduction mode state signal. In this case, the identification signal at the aforementioned current time is updated using the identification signal corresponding to the encoding sequence Q[m:0] at the time when the frequency reduction state signal is maintained to satisfy the preset condition. In an example, the preset condition is to maintain for a preset time.

[0044] The output unit 514 is configured to generate the flag signal of the n th valley bottom and the flag signal of the frequency reduction state based on the updated identification signal. For example, when the updated identification signal is 1, indicating the frequency reduction state signal, the output unit 514 outputs 01. For another example, when the updated identification signal is 0, indicating the n th valley bottom lock state signal, the output unit 514 outputs 10. For yet another example, when the updated identification signal is 3, indicating the i th valley bottom lock state signal, the output unit 514 outputs 00.

[0045] The sequence output by the first logic unit 512 and the sequence output by the output unit 514 are combined to generate the working state signal of the power tube.

[0046] According to the valley bottom function module control circuit provided in the embodiment, the working state signal corresponding to the feedback voltage FB is split into two groups of sequences, one group of sequences indicating the flag signals of the first i valley bottoms, and the other group of sequences indicating the flag signals of the n th valley bottom and the frequency reduction state. In this way, it is convenient to perform a predetermined operation for the scene of switching between the n th valley bottom lock state signal and the frequency reduction state signal.

[0047] Figure 6 FIG. 6 is a structural schematic diagram of a valley bottom function module control circuit provided in a third embodiment of the present application. As shown in the figure, in the embodiment, the second logic unit includes a detection circuit 6121, a sampling circuit 6122, an output control circuit 6123, a trigger circuit 6124, and a timing circuit 6125. Figure 6

[0048] The detection circuit 6121 determines the identification signal of the working state based on the encoding sequence Q[m:0], and the identification signal is used to indicate that the working state signal is one of the j th valley bottom lock state signal and the frequency reduction state signal, j = 1, 2, 3,..., n.

[0049] Specifically, the detection circuit 6121 includes a first working state detection circuit and a frequency reduction state detection circuit. The input end of the first working state detection circuit is connected to the output end of the bidirectional encoding unit 611, and is configured to determine whether the encoding sequence Q[m:0] corresponds to the n th valley bottom lock state signal or the frequency reduction state signal. If it is the n th valley bottom lock state signal or the frequency reduction state signal, a high level is output; if it is neither the n th valley bottom lock state signal nor the frequency reduction state signal, a low level is output. The frequency reduction state detection circuit is configured to determine whether the encoding sequence Q[m:0] corresponds to the valley bottom lock state signal or the frequency reduction state signal. The valley bottom lock state signal mentioned here includes the j th valley bottom lock state signal, j = 1, 2, 3,..., n. If the working state signal is the valley bottom lock state signal, a low level is output; if the working state is the frequency reduction state signal, a high level is output.

[0050] ​The sampling circuit 6122 is used to sample the identification signal output by the output control circuit 6123 according to a predetermined period to obtain the identification signal at the current moment and the identification signal at the previous moment. For example, when the rising edge of the clock sampling signal arrives, it receives the output signal of the output control circuit 6123 and outputs the sampling state signal samp_state, maintaining the sampling state until the next sampling begins.

[0051] The trigger circuit 6124 triggers the timing circuit 6125 to start timing when the current identification signal differs from the previous identification signal. When the timing circuit 6125 has counted for a preset time, and the identification signal corresponding to the encoded sequence continuously indicates the first working state signal during the timing process, the trigger output control circuit 6123 outputs the identification signal corresponding to the encoded sequence to update the current identification signal. The first working state signal includes the nth valley lock state signal and the frequency reduction state signal. When the identification signal corresponding to the encoded sequence indicates the second working state signal during the timing process, the trigger output control circuit 6123 outputs the identification signal corresponding to the encoded sequence in real time to update the current identification signal. The second working state signal includes the i-th valley lock state signal.

[0052] Specifically, the trigger circuit 6124 includes a comparator circuit and a flip-flop. The comparator circuit compares the sampled state signal `samp_state` with the current state signal `cur_state` output by the output control circuit 6123. When the two states are different, the output is high; when the two states are the same, the output is low. The flip-flop generates a latch signal `lock` or an update signal `update`. When the sampled state signal `samp_state` and the current state signal `cur_state` are different, and the encoded sequence Q[m:0] corresponds to the nth valley lock state signal or the down-frequency state signal, the latch signal `lock` is valid. When the encoded sequence Q[m:0] corresponds to the ith valley lock state, or when the timing circuit 6125 reaches a preset time, the flip-flop is cleared, and the update signal `update` is valid.

[0053] The timing circuit 6125 is used to receive the latch signal 'lock' output from the trigger. When the latch signal 'lock' is valid, the timing circuit 6125 starts timing, and when the preset time is reached, it outputs a high level.

[0054] The output control circuit 6123 determines the flag signal of the nth valley and the flag signal of the frequency reduction state based on the output signal of the flip-flop and the output of the frequency reduction state detection circuit. The output signal of the flip-flop includes a latch signal (lock) and an update signal (update). When the latch signal (lock) is valid, the output control circuit 6123 latches the output of the frequency reduction state detection circuit and does not update the flag signal of the nth valley and the flag signal of the frequency reduction state. When the update signal (update) is valid, the output control circuit 6123 outputs the output signal of the frequency reduction state detection circuit in real time to update the flag signal of the nth valley and the flag signal of the frequency reduction state.

[0055] When the output control circuit 6123 outputs a high level and the first operating state detection circuit outputs a high level, the flag signal for the frequency reduction state is high, and the flag signal for the j-th valley is low, where j = 1, 2, 3, ..., n. When the output control circuit 6123 outputs a low level and the first operating state detection circuit outputs a high level, the flag signal for the n-th valley is high, and the flag signals for the ith valley and the frequency reduction state are both low.

[0056] According to the valley bottom function module control circuit provided in this embodiment, in scenarios where the working state signal switches between the nth valley bottom locked state signal and the frequency reduction state signal, the working state signal corresponding to the feedback voltage needs to be output when preset conditions are met, thereby avoiding the problem of frequent switching between the nth valley bottom locked state signal and the frequency reduction state signal. In scenarios where the working state signal does not switch between the nth valley bottom locked state signal and the frequency reduction state signal, the working state signal corresponding to the feedback voltage is output in real time to ensure dynamic response speed.

[0057] In one embodiment, such as Figure 6 As shown, the second input terminal of the update module 62 receives the gate voltage signal of the power transistor in the switching power supply. Specifically, the update module 62 is used to update the selected operating state signal of the current switching cycle based on the updated operating state signal at the falling edge of the gate voltage signal.

[0058] Specifically, the update module 62 includes n+1 flip-flops, respectively denoted as DFF_m, m=0, 1, 2, 3, …, n. The input end of the first flip-flop DFF_1 receives the flag signal of the 1st valley bottom, the input end of the second flip-flop DFF_2 receives the flag signal of the 2nd valley bottom, the input end of the third flip-flop DFF_3 receives the flag signal of the 3rd valley bottom, …, the input end of the n-th flip-flop DFF_n receives the flag signal of the n-th valley bottom, and the input end of the n+1 flip-flop DFF_0 receives the flag signal of the frequency reduction state. The clock signal end of the n+1 flip-flops receives the gate voltage signal GATE, and when the falling edge of the gate voltage signal GATE is detected, the selected working state signal of the current switching period is updated by using the working state signal output by the generation module.

[0059] According to the valley bottom function module control circuit provided in the embodiment, at the rising edge of the gate voltage signal GATE, the selected working state signal of the current switching period is updated by using the updated working state signal, so that the working state signal output by the generation module is not immediately used to control the power tube, but is used to control the power tube in the next switching period, thereby avoiding the problem that when the expected locking valley bottom number is less than the currently detected valley bottom number, the output voltage is lowered due to the fact that the power tube can only be controlled at a minimum switching frequency during the load increasing process, and further improving the reliability of the switching power supply applied by the working state determination circuit.

[0060] Figure 6 The working flow of the valley bottom function module control circuit includes the following steps.

[0061] Step 1, the bidirectional encoding unit 511 receives the feedback voltage FB, and generates the encoding sequence Q[m:0] according to the feedback voltage FB.

[0062] Step 2, the first logic unit 512 outputs the flag signals of the first i valley bottoms according to the encoding sequence Q[m:0], i=1, 2, 3, …, n-1.

[0063] Step 3, the first working state detection circuit judges whether the encoding sequence Q[m:0] corresponds to the n-th valley bottom locking state signal or the frequency reduction state signal. If yes, step 4 is executed; otherwise, the output unit 514 outputs the flag signals of the n-th valley bottom and the frequency reduction state corresponding to the encoding sequence Q[m:0] in real time, i.e., 00. Then, step 8 is executed.

[0064] Step 4, it is judged whether the timing circuit 6125 is full of the preset time. If yes, step 7 is executed; if no, step 5 is executed.

[0065] Step 5, judge whether the sampling state signal samp_state and the current state signal cur_state are same. If same, the flip-flop maintains the state of the previous sampling time; if different, execute step S6.

[0066] Step 6, the latch signal lock outputted by the flip-flop is valid, the timing circuit 6125 starts timing, the output control circuit 6123 locks the working state signal of the current sampling time, and executes step S8.

[0067] Step 7, the update signal outputted by the flip-flop is valid, and the output control circuit 6123 outputs the flag signal of the nth valley and the flag signal of the frequency reduction state in real time.

[0068] Step 8, at the falling edge of the gate voltage signal GATE, the working state signal of the current switching period is updated by using the updated working state signal.

[0069] Figure 7 For Figure 6 the output waveform diagram of the generation module. In combination with Figure 6 and Figure 7 , when the feedback voltage FB corresponds to the frequency reduction state, the generation module outputs the frequency reduction state signal, and the timing circuit 6125 starts timing. When the load is heavy, the feedback voltage FB rises, and the working state corresponding to the feedback voltage FB is switched from the frequency reduction state State1 to the nth valley locking state State2. When the timing circuit 6125 timing reaches the preset time, the output unit 514 will output the valid flag signal of the nth valley, and the timing circuit 6125 restarts timing. Subsequently, when the load is light, the feedback voltage FB decreases, and the working state corresponding to the feedback voltage FB is switched from the nth valley locking state State2 back to the frequency reduction state State1, and when the timing circuit 6125 timing reaches the preset time, the output unit 514 will output the valid flag signal of the frequency reduction state, and the timing circuit 6125 restarts timing. Subsequently, the load suddenly becomes heavy, the feedback voltage FB rises, the working state corresponding to the feedback voltage FB is switched from the frequency reduction state State1 to the ith valley locking state State3, at this time the timing circuit 6125 is immediately cleared, and the output unit 514 outputs the invalid flag signal of the frequency reduction state and the invalid flag signal of the nth valley in real time.

[0070] Figure 8 For the output waveform diagram of the update module. In combination with Figure 6 and Figure 8As shown, when the load is heavy, the output voltage decreases, the feedback voltage FB rises, and the working state is switched from the nth valley bottom locking state to the ith valley bottom locking state. When the update module 62 detects the falling edge of the gate voltage signal GATE, i.e. the rising edge of the auxiliary voltage signal DGM, the output generation module outputs the working state signal.

[0071] The embodiment of the present application also provides a valley bottom function module control method, which can be executed by the valley bottom function module control circuit provided by any of the above embodiments, or can be realized by software coding.

[0072] Figure 9 A flowchart of the valley bottom function module control method provided by the first embodiment of the present application is shown in FIG. 9. Figure 9 As shown, the valley bottom function module control method 900 includes:

[0073] In step S910, the real-time working state signal of the power tube is determined based on the feedback voltage.

[0074] In step S920, when the real-time working state signal is the first working state signal, it is determined that the working state signal of the power tube in the switching power supply in the current switching period is switched between the nth valley bottom locking state signal and the frequency reduction state signal, and the working state signal includes any one of the jth valley bottom locking state signal and the frequency reduction state signal, j = 1, 2, 3, …, n. The first working state signal includes the nth valley bottom locking state signal and the frequency reduction state signal.

[0075] For example, the working state signal is sampled at a predetermined period, and it is determined whether the working state signal is switched between the nth valley bottom locking state signal and the frequency reduction state signal based on the working state signal at the current time and the working state signal at the previous time. For example, the working state signal at the current time is the nth valley bottom locking state signal, and the working state signal at the previous time is the frequency reduction state signal, and it is determined that the working state signal is switched between the nth valley bottom locking state signal and the frequency reduction state signal. For another example, the working state signal at the current time is the frequency reduction state signal, and the working state signal at the previous time is the nth valley bottom locking state signal, and it is determined that the working state signal is switched between the nth valley bottom locking state signal and the frequency reduction state signal.

[0076] In step S930, when the working state signal at the current time is maintained until the preset condition is met, the working state signal at the current time is updated based on the feedback voltage of the output voltage of the switching power supply.

[0077] Specifically, the working state signal at the current time is maintained for a preset time, and within the preset time, when the feedback voltage continues to correspond to the first working state signal, the working state signal at the current time is updated based on the feedback voltage, and the first working state signal includes the nth valley bottom locking state signal and the frequency reduction state signal. That is, in the scenario where the working state signal switches between the nth valley bottom locking state signal and the frequency reduction state signal, the working state signal at the current time is not updated in real time, but is maintained until a predetermined condition is met, and then the current working state signal is updated according to the feedback voltage, thereby avoiding the problem of frequent switching of the power tube between the nth valley bottom locking state and the frequency reduction state, and thereby improving the reliability of the switching power supply to which the working state determination circuit is applied. Compared with the method of increasing the hysteresis, the working range of the feedback voltage can be ensured to be unlimited, and the number of valley bottom locks is not limited.

[0078] In step S940, the selected working state signal of the current switching period is updated based on the updated working state signal, so as to be used to control the opening position of the power tube in the next switching period, and the selected working state signal is selected from the working state signal in the previous switching period.

[0079] For example, at the rising edge of the gate voltage signal of the power tube, the selected working state signal of the current switching period is updated based on the updated working state signal, so as to be used to control the opening position of the power tube in the next switching period. In this case, the working state signal output by the generation module will not be used to control the power tube immediately, but will be used to control the power tube in the next switching period, thereby avoiding the problem of output voltage drop caused by the fact that, during the load increase process, when the expected locking valley bottom number is less than the currently detected valley bottom number, the power tube can only be controlled at a minimum switching frequency, and further improving the reliability of the switching power supply to which the working state determination circuit is applied.

[0080] In one embodiment, before step S930, it further includes:

[0081] In step S950, during the period in which the working state signal at the current time is maintained until the preset condition is met, when the real-time working state signal determined by the feedback voltage is the second working state signal, the working state signal at the current time is updated in real time based on the feedback voltage, and the second working state signal includes the ith valley bottom locking state signal. That is, in the scenario where the working state signal switches between the nth valley bottom locking state signal and the frequency reduction state signal, when it is detected that the working state signal corresponding to the feedback voltage is the second working state signal, it indicates that the load is heavy, and the system is out of the state of switching between the nth valley bottom locking state signal and the frequency reduction state signal, and at this time, the working state signal corresponding to the feedback voltage is output in real time to ensure the dynamic response speed.

[0082] It should be understood that step S950 and step S920 are two parallel schemes.

[0083] The embodiment of the present application also provides a valley function module control device. Figure 10 A structural block diagram of the valley function module control device provided by the embodiment of the present application is shown in the figure. Figure 10 As shown in the figure, the valley function module control 1000 comprises a determination module 1010, a first updating module 1020 and a second updating module 1030. The determination module 1010 is configured to determine a real-time working state signal based on a feedback voltage, and when the real-time working state signal is a first working state signal, determine that the working state signal of a power tube in the switching power supply switches between an nth valley bottom locking state signal and a frequency reduction state signal in a current switching period, the working state signal comprises any one of the jth valley bottom locking state signal and the frequency reduction state signal, j = 1, 2, 3, …, n, and the first working state signal comprises the nth valley bottom locking state signal and the frequency reduction state signal. The first updating module 1020 is configured to maintain the working state signal at the current time, and when the working state signal at the current time meets a preset condition, update the working state signal at the current time based on a feedback voltage of an output voltage of the switching power supply. The second updating module 1030 is configured to update a selected working state signal of the current switching period based on the updated working state signal, so as to be used for controlling the opening position of the power tube in the next switching period, and the selected working state signal is selected from the working state signal in the previous switching period.

[0084] In one embodiment, the determination module 1010 is specifically configured to sample the working state signal according to a predetermined period; and determine that the working state signal switches between the nth valley bottom locking state signal and the frequency reduction state signal based on the sampling signal at the current time and the sampling signal at the previous time.

[0085] In one embodiment, the first updating module 1020 is specifically configured to maintain the working state signal at the current time for a preset time, and when the feedback voltage corresponds to the first working state signal within the preset time, update the working state signal at the current time based on the feedback voltage, the first working state signal comprises the nth valley bottom locking state signal and the frequency reduction state signal. When the preset time is not counted, and the feedback voltage corresponds to a second working state signal, update the working state signal at the current time based on the feedback voltage in real time, and the second working state signal comprises the ith valley bottom locking state signal, i = 1, 2, 3, …, n-1.

[0086] In one embodiment, the second updating module 1030 is specifically configured to update the selected working state signal of the current switching period based on the updated working state signal at the rising edge of the gate voltage signal of the power tube, so as to be used for controlling the opening position of the power tube in the next switching period.

[0087] In one embodiment, the first updating module 1020 is further configured to update the working state signal at the current time instant in real time based on the feedback voltage when the real-time working state signal determined by the feedback voltage is a second working state signal during a period in which the working state signal at the current time instant is maintained to satisfy the preset condition, and the second working state signal comprises an ith valley bottom locking state signal.

[0088] The embodiment of the present application further provides a switching power supply controller. Figure 11 A structural block diagram of the switching power supply controller provided by an embodiment of the present application is shown in FIG. 11. Figure 11 As shown in FIG. 11, the switching power supply controller 1100 comprises the valley bottom function module control circuit 1110 and the control signal generation circuit 1120 provided by any of the above embodiments, and the control signal generation circuit 1120 is configured to update the gate voltage signal based on the selected working state signal of the next switching period, so that the power tube is turned on at the position corresponding to the selected working state signal of the next switching period.

[0089] The embodiment of the present application further provides a switching power supply. Figure 12 A structural block diagram of the switching power supply provided by an embodiment of the present application is shown in FIG. 12. Figure 12 As shown in FIG. 12, the switching power supply 1200 comprises Figure 11 the switching power supply controller 1100 and the power conversion circuit 1210 shown in FIG. 11, and the power conversion circuit 1210 comprises a power tube, and the gate of the power tube is connected to the switching power supply controller 1100. The power conversion circuit 1210 is configured to convert the electric power at the input end into a predetermined electric power.

[0090] The present application further provides a computer readable storage medium, which stores a computer program. The computer program is executed by a processor to implement the steps of the working state determination method provided by any of the above embodiments. The computer readable storage medium can adopt any combination of one or more readable media. The readable storage medium can be in any one of the following forms: electric, magnetic, optical, electromagnetic, infrared, semiconductor, or a combination thereof. For example, the readable storage medium includes a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, etc.

[0091] The above description has been given for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although a plurality of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A valley bottom functional module control circuit, used in a switching power supply controller, characterized in that, It includes a generation module and an update module; the input terminal of the generation module receives the feedback voltage of the output voltage of the switching power supply, and the first input terminal of the update module is connected to the output terminal of the generation module; the generation module outputs the operating status signal in the current switching cycle, and the update module outputs the selected operating status signal in the current switching cycle. The selected operating status signal is selected from the operating status signal in the previous switching cycle. The operating status signal includes either the j-th valley lock-in status signal or the frequency reduction status signal, where j = 1, 2, 3, ..., n, and n is a positive integer greater than 1. The generation module is used to determine a real-time operating status signal based on the feedback voltage; when the real-time operating status signal is a first operating status signal, it determines that the operating status signal switches between the nth valley lock-in status signal and the frequency reduction status signal, maintains the operating status signal at the current moment until a preset condition is met, updates the operating status signal at the current moment based on the feedback voltage, and outputs the updated operating status signal. The first operating status signal includes the nth valley lock-in status signal and the frequency reduction status signal, and the preset condition is to maintain for a preset time. The update module is used to update the selected operating state signal based on the updated operating state signal, so as to control the turn-on position of the power transistor in the next switching cycle.

2. The valley bottom functional module control circuit according to claim 1, characterized in that, The generation module is further configured to, while maintaining the current working status signal until the preset conditions are met, update the current working status signal in real time based on the feedback voltage when the real-time working status signal determined by the feedback voltage is the second working status signal. The second working status signal includes the i-th valley bottom locking status signal, i=1, 2, 3, ..., n-1.

3. The valley bottom functional module control circuit according to claim 1 or 2, characterized in that, The generation module includes a bidirectional encoding unit, a first logic unit, a second logic unit, and an output unit; the second logic unit outputs an identification signal of the working status signal; The bidirectional encoding unit is used to encode the feedback voltage to generate an encoding sequence; the first logic unit is used to generate the flag bit signals of the first i valleys according to the encoding sequence, i=1,2,3,...,n-1; the second logic unit is used to determine the switching of the working state signal between the locked state signal of the nth valley and the frequency reduction state signal based on the identification signal, maintain the identification signal at the current moment until a preset condition is met, and update the identification signal at the current moment based on the encoding sequence; the output unit is used to generate the flag bit signal of the nth valley and the flag bit signal of the frequency reduction state based on the updated identification signal; the flag bit signals of the first i valleys, the flag bit signal of the nth valley, and the flag bit signal of the frequency reduction state constitute the updated working state signal.

4. The valley bottom functional module control circuit according to claim 3, characterized in that, The second logic unit includes a detection circuit, a sampling circuit, a trigger circuit, a timing circuit, and an output control circuit; The detection circuit is used to determine the identification signal based on the encoded sequence; the sampling circuit samples the identification signal output by the output control circuit according to a predetermined period to obtain the identification signal at the current moment and the identification signal at the previous moment; the triggering circuit is used to trigger the timing circuit to start timing when the identification signal at the current moment and the identification signal at the previous moment are different; when the timing circuit counts for a preset time and the identification signal corresponding to the encoded sequence continuously indicates the first working state signal during the timing process, the output control circuit is triggered to output the identification signal corresponding to the encoded sequence to update the identification signal at the current moment; the output circuit is used to output the flag bit signal of the nth valley and the flag bit signal of the frequency reduction state based on the updated identification signal.

5. The valley bottom functional module control circuit according to claim 4, characterized in that, The trigger circuit is also used to trigger the output control circuit to output the identifier signal corresponding to the encoding sequence in real time when the identifier signal corresponding to the encoding sequence indicates the second working state signal during the timing process, so as to update the identifier signal at the current time. The second working state signal includes the i-th valley bottom locking state signal.

6. The valley bottom functional module control circuit according to claim 1 or 2, characterized in that, The second input terminal of the update module receives the gate voltage signal of the power transistor in the switching power supply; the update module is used to update the selected operating state signal based on the updated operating state signal at the falling edge of the gate voltage signal.

7. The valley bottom functional module control circuit according to claim 6, characterized in that, The update module includes multiple triggers, and the signal terminals of the multiple triggers respectively receive the flag bit signals of the first i valleys, the flag bit signal of the nth valley, and the flag bit signal of the down-frequency state.

8. A valley bottom functional module control method, used in a switching power supply controller, characterized in that, include: The real-time operating status signal of the power transistor in the switching power supply is determined by the feedback voltage based on the output voltage of the switching power supply. When the real-time operating status signal is the first operating status signal, it is determined that the operating status signal of the power transistor in the current switching cycle switches between the nth valley-locked state signal and the frequency reduction state signal. The operating status signal includes either the jth valley-locked state signal or the frequency reduction state signal, j=1, 2, 3, ..., n. The first operating status signal includes the nth valley-locked state signal and the frequency reduction state signal, where n is a positive integer greater than 1. The current operating status signal is maintained until a preset condition is met. Then, the current operating status signal is updated based on the feedback voltage of the output voltage of the switching power supply. The preset condition is to maintain the signal for a preset time. The selected operating state signal of the current switching cycle is updated based on the updated operating state signal to control the turn-on position of the power transistor in the next switching cycle. The selected operating state signal is selected from the operating state signal in the previous switching cycle.

9. The valley bottom functional module control method according to claim 8, characterized in that, The step of determining whether the operating state signal of the power transistor in the switching power supply switches between the nth valley-locked state signal and the frequency reduction state signal during the current switching cycle includes: The working status signal is sampled according to a predetermined period; The operating state signal is determined to switch between the valley-locked state signal and the frequency reduction state signal based on the sampling signal at the current moment and the sampling signal at the previous moment.

10. The valley bottom functional module control method according to claim 9, characterized in that, Maintaining the current operating state signal until a preset condition is met, and updating the current operating state signal based on the feedback voltage of the output voltage of the switching power supply, includes: The operating status signal at the current moment is maintained for a preset time, and when the feedback voltage continuously corresponds to the first operating status signal within the preset time, the operating status signal at the current moment is updated based on the feedback voltage. The first operating status signal includes the nth valley lock-in status signal and the frequency reduction status signal.

11. The valley bottom functional module control method according to any one of claims 8-10, characterized in that, Before updating the selected operating state signal of the current switching cycle based on the updated operating state signal, the method further includes: During the period of maintaining the current working status signal until the preset conditions are met, when the real-time working status signal determined by the feedback voltage is the second working status signal, the working status signal at the current moment is updated in real time based on the feedback voltage. The second working status signal includes the i-th valley locking status signal, i=1, 2, 3, ..., n-1.

12. The valley bottom functional module control method according to any one of claims 8-10, characterized in that, The step of updating the selected operating state signal of the current switching cycle based on the updated operating state signal for controlling the turn-on position of the power transistor in the next switching cycle includes: At the rising edge of the gate voltage signal of the power transistor, the selected operating state signal is updated based on the updated operating state signal to control the turn-on position of the power transistor in the next switching cycle.

13. A valley bottom functional module control device, used in a switching power supply controller, characterized in that, include: The determination module is used to determine the real-time operating status signal of the power transistor in the switching power supply based on the feedback voltage of the output voltage of the switching power supply; When the real-time operating status signal is the first operating status signal, it is determined that the operating status signal of the power transistor in the switching power supply switches between the nth valley-locked state signal and the frequency reduction state signal in the current switching cycle. The operating status signal includes either the jth valley-locked state signal or the frequency reduction state signal, j=1, 2, 3, ..., n, where n is a positive integer greater than 1. The first operating status signal includes the nth valley-locked state signal and the frequency reduction state signal. The first update module is used to maintain the current working state signal until a preset condition is met, and then update the current working state signal based on the feedback voltage of the output voltage of the switching power supply. The preset condition is to maintain the signal for a preset time. The second update module is used to update the selected operating state signal of the current switching cycle based on the updated operating state signal, so as to control the turn-on position of the power transistor in the next switching cycle. The selected operating state signal is selected from the operating state signal in the previous switching cycle.

14. A switching power supply controller, characterized in that, include: Valley bottom functional module control circuit as described in any one of claims 1-7; and A control signal generation circuit is used to update the gate voltage signal of the power transistor based on the selected operating state signal of the next switching cycle, so that the power transistor is turned on at the position corresponding to the selected operating state signal of the next switching cycle.

15. A switching power supply, characterized in that, include: The switching power supply controller according to claim 14; and A power conversion circuit includes the power transistor, the gate of which is connected to the switching power supply controller.

16. A computer storage medium, characterized in that, It stores a computer program, characterized in that, when the computer program is executed by a processor, it implements the steps of the valley bottom functional module control method as described in any one of claims 8 to 12.

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