Switching power ripple adjustment system and ripple suppression method

Abstract

This application discloses a switching power supply ripple adjustment system and ripple suppression method, relating to the field of ripple suppression technology. The switching power supply ripple adjustment system includes: a ripple processing module, a synchronous rectification module, a rectifier output capacitor, and at least one synchronous rectification branch; each synchronous rectification branch includes: a synchronous rectifier transistor and a secondary coil connected in series; the ripple processing module is connected to the rectifier output capacitor, the ripple processing module is connected to the synchronous rectification module, the rectifier output capacitor is connected to the synchronous rectifier transistor, and the synchronous rectification module is connected to the synchronous rectifier transistor in any synchronous rectification branch; the ripple processing module is used to acquire the branch sampling signal on the rectifier output capacitor, and to obtain the synchronous rectification frequency of the synchronous rectification module, and to suppress the ripple on the synchronous rectification branch according to the branch sampling signal and the change in the synchronous rectification frequency.

Description

Technical Field

[0001] This invention relates to the field of ripple suppression technology, and in particular to a switching power supply ripple adjustment system and ripple suppression method. Background Technology

[0002] With the development of server technology, servers are equipped with a large number of precision electronic components. Even small voltage fluctuations can affect server performance. Therefore, servers have an urgent need for low output ripple in their Common Redundant Power Supply (CRPS). Lower output ripple means a more stable and smoother power supply voltage, reducing high-frequency noise interference. Low output ripple ensures the stable operation of core components such as the CPU and memory, reducing the risk of data errors and loss due to voltage instability. A stable power supply can extend the lifespan of server hardware, reduce downtime caused by power problems, improve the reliability and availability of the server system, and ensure that the server provides users with efficient and uninterrupted data processing and storage services.

[0003] Currently, the main methods for suppressing ripple are adding capacitors and adjusting the circuit. While adding capacitors can buffer some ripple, large-capacity capacitors have a slow response to low-frequency ripple and are difficult to adjust quickly; while high-frequency ripple changes extremely rapidly, and ordinary capacitors cannot effectively filter it. As for the adjustment circuit, due to its limited adjustment range and complex parameter settings, it lacks sensitivity and cannot respond promptly and accurately to ripple with varying frequencies. This results in unsatisfactory handling of both low-frequency and high-frequency ripple, leading to poor power supply output stability, affecting the normal operation of precision components within the server, and ultimately reducing the overall reliability and performance of the server system. Summary of the Invention

[0004] This application provides a switching power supply ripple adjustment system and ripple suppression method, which at least solves the problem that it is difficult to effectively improve server power supply ripple by adding capacitors and adjustment loops.

[0005] In a first aspect, this application provides a switching power supply ripple adjustment system, including: a ripple processing module, a synchronous rectification module, a rectifier output capacitor, and at least one synchronous rectification branch;

[0006] At least one synchronous rectification branch includes: a synchronous rectification transistor and a secondary coil connected in series;

[0007] The ripple processing module is connected to the rectifier output capacitor, the ripple processing module is connected to the synchronous rectification module, the rectifier output capacitor is connected to the synchronous rectification transistor, and the synchronous rectification module is connected to the synchronous rectification transistor in any synchronous rectification branch.

[0008] The ripple processing module is used to acquire the branch sampling signal on the rectifier output capacitor and obtain the synchronous rectification frequency of the synchronous rectification module. Based on the branch sampling signal and the change of the synchronous rectification frequency, it suppresses the ripple on the synchronous rectification branch.

[0009] Secondly, this application also provides a ripple suppression method, characterized in that the controller applied to the switching power supply ripple adjustment system described in the first aspect includes:

[0010] In response to acquiring the ripple adjustment signal, the switching power supply ripple adjustment system is activated, and the sampling signal of the output branch of the switching power supply is acquired.

[0011] Based on the sampling signal of the output branch, the adjustment signals of the adjustable devices are determined, including: the adjustment signal of the adjustable resistor, the adjustment signal of the adjustable capacitor, and the adjustment signal of the adjustable inductor.

[0012] Adjust the adjustable resistor in the switching power supply ripple adjustment system according to the adjustable resistor adjustment signal, adjust the adjustable capacitor in the switching power supply ripple adjustment system according to the adjustable capacitor adjustment signal, and adjust the adjustable inductor in the switching power supply ripple adjustment system according to the adjustable inductor adjustment signal to reduce the output ripple of the switching power supply.

[0013] The beneficial effects of the technical solution provided in this application are: by implementing the switching power supply ripple adjustment system and ripple suppression method provided in this application, the output ripple can be quickly suppressed and the power quality improved by actively intervening in the adjustment, based on the synchronous rectification frequency of the switching power supply and the sampling signal of the synchronous rectification branch. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of a switching power supply ripple adjustment system provided in an embodiment of this application;

[0016] Figure 2 This is a schematic diagram of the ripple processing module provided in an embodiment of this application;

[0017] Figure 3 This is a schematic diagram of the comparison module provided in an embodiment of this application;

[0018] Figure 4 This is a schematic diagram of the adjustable device module provided in an embodiment of this application;

[0019] Figure 5 This is a schematic diagram of a ripple suppression method provided in an embodiment of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The numbers in the accompanying drawings are only used to distinguish individual functional parts or modules and do not indicate logical relationships between parts or modules. The terms “comprising,” “including,” or “including,” and similar terms mean that the element or object preceding the term encompasses the element or object listed following the term and its equivalents, without excluding other elements or objects. The terms “connected,” “linked,” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. “Above,” “below,” “left,” “right,” etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] The various embodiments according to this disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that in the drawings, the same reference numerals are assigned to components having substantially the same or similar structure and function, and repeated descriptions of them will be omitted.

[0023] In addressing the problem that existing technologies struggle to effectively improve server power supply ripple by adding capacitors and adjusting loops, this application provides the following implementation method.

[0024] In some embodiments, such as Figure 1 As shown, a switching power supply ripple adjustment system includes: a ripple processing module 1, a synchronous rectification module 2, a rectifier output capacitor 3, and at least one synchronous rectification branch 4.

[0025] At least one synchronous rectification branch 4 includes: a synchronous rectification transistor 41 connected in series with a secondary coil 42;

[0026] Ripple processing module 1 is connected to rectifier output capacitor 3, ripple processing module 1 is connected to synchronous rectification module 2, rectifier output capacitor 3 is connected to synchronous rectification transistor 41, and synchronous rectification module 2 is connected to synchronous rectification transistor 41 in any synchronous rectification branch 4.

[0027] Ripple processing module 1 is used to collect the branch sampling signal on the rectifier output capacitor and obtain the synchronous rectification frequency of synchronous rectification module 2, and suppress the ripple on synchronous rectification branch 4 according to the branch sampling signal and the change of synchronous rectification frequency.

[0028] like Figure 2 As shown, the ripple processing module 1 includes: a controller 110, a comparison module 120, an adjustable device module 130, a switch T, and a sampling resistor R. s ;

[0029] The controller 110 has: a first controller port 110a, a second controller port 110b, a third controller port 110c, a fourth controller port 110d, and a fifth controller port 110e;

[0030] Comparison module 120 has: a first comparison module port 120a, a second comparison module port 120b and a third comparison module port 120c;

[0031] The adjustable device module 130 has: a first adjustable port 130a, a second adjustable port 130b, a third adjustable port 130c, a fourth adjustable port 130d, and a fifth adjustable port 130e;

[0032] The switch T has: a first switch port T1, a second switch port T2, and a third switch port T3;

[0033] Sampling resistor R s The two ends are respectively connected to the first comparison module port 120a and the third comparison module port 120c; the first comparison module port 120a is also connected to the second switch port T2, the third switch port T3 is connected to the second comparison module port 120b, the second comparison module port 120b is also connected to the first adjustable port 130a, the second adjustable port 130b is connected to the third comparison module port 120c, the first switch port T1 is connected to the first controller port 110a, the third controller port 110c is connected to the third adjustable port 130c, the fourth controller port 110d is connected to the fourth adjustable port 130d, and the fifth controller port 110e is connected to the fifth adjustable port 130e;

[0034] The second controller port 110b is used to acquire the received ripple adjustment signal.

[0035] The controller 110 sends an adjustable resistor adjustment signal to the adjustable device module 130 through the third controller port 110c to adjust the value of the adjustable resistor, an adjustable capacitor adjustment signal to the adjustable device module 130 through the fourth controller port 110d to adjust the value of the adjustable capacitor, and an adjustable inductor adjustment signal to the adjustable device module 130 through the fifth controller port 110e to adjust the value of the adjustable inductor.

[0036] like Figure 3 As shown, the comparison module 120 includes: a comparator 121 and a feedback resistor R. f ;

[0037] Comparator 121 has: non-inverting input terminal 121a, inverting input terminal 121b, comparator output terminal 121c, comparator power supply terminal 121d, and comparator ground terminal 121e;

[0038] The non-inverting input terminal 121a serves as the first comparator module port 120a, and the inverting input terminal 121b is connected in series with the feedback resistor R. f The comparator output terminal 121c is connected to the comparator power supply terminal 121d, which serves as the third comparator module port 120c. The comparator ground terminal 121e is grounded.

[0039] like Figure 4 As shown, the adjustable device module 130 includes: an adjustable resistor R v Adjustable capacitor C v and adjustable inductor L v ;

[0040] Adjustable resistor R v One end is connected to the adjustable capacitor C v One end is connected as the first adjustable port 130a, and the adjustable resistor R v The other end is connected to the adjustable inductor L v One end is connected to the adjustable inductor L v The other end is connected to the adjustable capacitor C v The other end is connected and serves as the second adjustable port 130b;

[0041] The resistance adjustment port of the adjustable resistor is designated as the third adjustable port 130c, the capacitance adjustment port of the adjustable capacitor is designated as the fourth adjustable port 130d, and the inductance adjustment port of the adjustable inductor is designated as the fifth adjustable port 130e.

[0042] The adjustable device module can adjust the values ​​of the internal adjustable resistor, adjustable capacitor, and adjustable inductor according to the adjustable resistor adjustment signal, adjustable capacitor adjustment signal, and adjustable inductor adjustment signal sent by the controller, thereby suppressing the ripple of the synchronous rectification branch.

[0043] In other embodiments, such as Figure 5 As shown, a ripple suppression method is applied to the controller of the switching power supply ripple adjustment system described above, comprising:

[0044] S100: In response to acquiring the ripple adjustment signal, the switching power supply ripple adjustment system is activated, and the sampling signal of the output branch of the switching power supply is acquired.

[0045] S200: Based on the sampling signal of the output branch, determine the adjustment signal of the adjustable device, which includes: the adjustment signal of the adjustable resistor, the adjustment signal of the adjustable capacitor, and the adjustment signal of the adjustable inductor;

[0046] S300: Adjusts the adjustable resistor in the switching power supply ripple adjustment system according to the adjustable resistor adjustment signal, adjusts the adjustable capacitor in the switching power supply ripple adjustment system according to the adjustable capacitor adjustment signal, and adjusts the adjustable inductor in the switching power supply ripple adjustment system according to the adjustable inductor adjustment signal, so as to reduce the output ripple of the switching power supply.

[0047] Specifically, S200: Based on the output branch sampling signal, determine the adjustment signal for the adjustable device, including:

[0048] S210: Determine the synchronous rectification frequency of the switching power supply based on the sampling signal of the output branch to stabilize the output branch voltage of the switching power supply. The synchronous rectification frequency is determined by the output voltage of the output branch.

[0049] S220: Determine the adjustment signal of the adjustable device based on the sampling signal of the output branch and the change of the synchronous rectification frequency.

[0050] In some embodiments, the increase in ripple is caused by an increase in the synchronous rectification frequency. Accordingly, S221a: In response to the increase in the synchronous rectification frequency, then according to... L adj = L 0· ( 1 + k 1· Δ f / f nom ), determine the target value of the adjustable inductor, where, L adj This indicates the adjusted target value of the adjustable inductor. L 0 indicates the initial inductance value before adjustment. k 1 represents the inductance compensation coefficient, Δ f =f sw - f nom , representing the change in frequency. f sw Indicates the current synchronous rectification frequency. f nom Indicates the rated resonant frequency;

[0051] S222a: According to C adj = C 0· ( 1 - k 2· Δ V r / V o ), determine the target value of the adjustable capacitor, where, C adj This indicates the adjusted target value of the adjustable capacitor. C 0 indicates the initial value of the capacitor before adjustment. k 2 represents the capacitance attenuation coefficient, Δ V r This indicates the peak-to-peak value of the ripple voltage. V o This indicates the output voltage of the synchronous rectification branch;

[0052] S223a: According to R adj = R 0· ( 1 + k 3· Δ f / f nom ), determine the target value of the adjustable resistor, where, R adj This indicates the target value of the adjustable resistor after adjustment. R 0 indicates the initial resistance value before adjustment. k 3 indicates the damping coefficient;

[0053] S224a: Generates an adjustable inductor adjustment signal based on the target value of the adjustable inductor, an adjustable capacitor adjustment signal based on the target value of the adjustable capacitor, and an adjustable resistor adjustment signal based on the target value of the adjustable resistor.

[0054] In other embodiments, the increased ripple is due to a decrease in the synchronous rectification frequency. Accordingly, S221b: In response to the decrease in the synchronous rectification frequency, then according to... L adj = L 0· ( 1 - k 4· Δ V r / V o), determine the target value of the adjustable inductor, where, L adj This indicates the adjusted target value of the adjustable inductor. L 0 indicates the initial inductance value before adjustment. k 4 represents the inductance attenuation coefficient, Δ V r This indicates the peak-to-peak value of the ripple voltage. V o This indicates the output voltage of the synchronous rectification branch;

[0055] S222b: According to C adj = C 0· ( 1 + k 5· Δ I / I nom ), determine the target value of the adjustable capacitor, where, C adj This indicates the adjusted target value of the adjustable capacitor. C 0 indicates the initial value of the capacitor before adjustment. k 5 represents the capacitance enhancement factor, Δ I = I load - I nom This represents the change in load current. I load Indicates the current load current. I nom Indicates the rated load current;

[0056] S223b: R adj = R 0· ( 1 - k 6· Δ f / f nom ), determine the target value of the adjustable resistor, where, R adj This indicates the target value of the adjustable resistor after adjustment. R 0 indicates the initial resistance value before adjustment. k 6 represents the resistance attenuation coefficient, Δ f = f sw - f nom , representing the change in frequency. f sw Indicates the current synchronous rectification frequency. f nom Indicates the rated resonant frequency;

[0057] S224b: Generates an adjustable inductor adjustment signal based on the target value of the adjustable inductor, an adjustable capacitor adjustment signal based on the target value of the adjustable capacitor, and an adjustable resistor adjustment signal based on the target value of the adjustable resistor.

[0058] In other embodiments, S221c: In response to the output branch sampling signal indicating that the switching power supply ripple has increased, then according to L adj = L 0+ Δ L Determine the target value of the adjustable inductor, based on C adj = C 0+ Δ C Determine the target value of the adjustable capacitor based on... R adj = R 0+ Δ R = R 0· ( f do / f nom ) -1 / 2 Determine the target value of the adjustable resistor, where, L adj express, L 0 represents, C adj express, C 0 represents, R adj express, R 0 represents Δ L It means that Δ C It means that Δ R It means that Δ L Δ C Δ R According to Δ V r = k L · Δ L + k C · Δ C + k R · Δ R With fre = 1 / 2π( L adj · C adj ) -1 / 2 Solving the system of equations simultaneously, we get Δ V r This indicates the peak-to-peak value of the ripple voltage. k L Indicates the inductance sensitivity coefficient. kC Indicates the capacitance sensitivity coefficient. k R Indicates the resistance sensitivity coefficient. f re Indicates the resonant frequency. f do Indicates the dominant frequency of ripple energy. f nom Indicates the rated resonant frequency;

[0059] S222c: Generates an adjustable inductor adjustment signal based on the target value of the adjustable inductor, an adjustable capacitor adjustment signal based on the target value of the adjustable capacitor, and an adjustable resistor adjustment signal based on the target value of the adjustable resistor.

[0060] An adjustable resistor is a resistor whose resistance value can be changed. Adjustable resistors can be implemented in various ways, including digital potentiometers, MOSFETs simulating variable resistors, and voltage-controlled resistors.

[0061] Taking a digital potentiometer as an example, the controller 110 communicates via SPI or I / O. 2 The C bus sends commands to the third adjustable port 130c to directly adjust the internal resistance value of the digital potentiometer. This is achieved using I... 2 Taking C bus transmission commands as an example, I 2 The C bus corresponds to the SCL and SDA pins of the digital potentiometer. The digital potentiometer connects to the I / O pins. 2 The C bus receives control signals and adjusts the resistance value according to the control signals.

[0062] Taking a MOSFET as an example, this MOSFET is an enhancement-mode N-channel MOSFET. By transmitting a pulse width modulation signal to its gate, the gate voltage is controlled, thereby changing the on-resistance between the drain and source of the MOSFET.

[0063] A typical voltage-controlled resistor is a junction field-effect transistor (JFET). Taking a JFET as an example, its gate receives a control signal from a controller to change the resistance between its drain and source. The control signal for a JFET can be a pulse width modulation (PWM) signal.

[0064] An adjustable inductor is an inductor whose inductance value can be changed. Adjustable inductors can be implemented in various ways, including magnetically controlled inductors, switched inductor arrays, and magnetically saturated reactors.

[0065] Taking a magnetically controlled inductor as an example, a solenoid or stepper motor is used to move the magnetic core, and the inductance value can be changed by controlling the position of the solenoid or stepper motor.

[0066] Taking a switching inductor array as an example, multiple fixed-value inductors and relays are used. Different inductor combinations are selected by controlling the switching state of the relays to adjust the inductance value.

[0067] Taking a magnetically saturated reactor as an example, the controller converts the control signal or pulse width modulation signal generated by the digital-to-analog converter into a DC current signal, and inputs the DC current into the winding of the reactor to adjust the saturation of the magnetic core, thereby changing the inductance value of the winding.

[0068] An adjustable capacitor is a capacitor whose capacitance value can be changed. Adjustable capacitors can be implemented using methods such as varactor diodes and switching capacitor arrays.

[0069] Taking a varactor diode as an example, an adjustable voltage is generated using a digital-to-analog converter, and the varactor diode is reverse biased. The capacitance value is adjusted by changing the reverse bias voltage.

[0070] Taking a capacitor array as an example, multiple fixed-value capacitors and relays are used. Different capacitor combinations are selected to adjust the capacitor value by controlling the switching state of the relays.

[0071] Preferably, in response to acquiring the ripple adjustment signal, the method further includes:

[0072] S010: A ripple adjustment signal is generated in response to the power-on of an appliance powered by the switching power supply;

[0073] S020: A ripple adjustment signal is generated in response to the initiation of the shutdown process for the electrical appliance;

[0074] S030: A ripple adjustment signal is generated in response to changes in the load of electrical appliances.

[0075] The beneficial effects of the technical solution provided in this application are as follows: By implementing the switching power supply ripple adjustment system and ripple suppression method provided in this application, output ripple can be quickly suppressed and power quality improved through active intervention adjustment based on the synchronous rectification frequency and sampling signal of the synchronous rectification branch of the switching power supply. By providing various examples of variable resistors, variable capacitors, and variable inductors, along with corresponding control and adjustment methods, more choices and design flexibility are provided for the design and implementation of the switching power supply ripple adjustment system to adapt to design requirements in different scenarios.

[0076] Example 1

[0077] A switching power supply ripple regulation system, such as Figure 1 As shown, it includes: a ripple processing module 1, a synchronous rectification module 2, a rectifier output capacitor 3, and at least one synchronous rectification branch 4.

[0078] At least one synchronous rectification branch 4 includes: a synchronous rectification transistor 41 connected in series with a secondary coil 42;

[0079] Ripple processing module 1 is connected to rectifier output capacitor 3, ripple processing module 1 is connected to synchronous rectification module 2, rectifier output capacitor 3 is connected to synchronous rectification transistor 41, and synchronous rectification module 2 is connected to synchronous rectification transistor 41 in any synchronous rectification branch 4.

[0080] Ripple processing module 1 is used to collect the branch sampling signal on the rectifier output capacitor and obtain the synchronous rectification frequency of synchronous rectification module 2, and suppress the ripple on synchronous rectification branch 4 according to the branch sampling signal and the change of synchronous rectification frequency.

[0081] Ripple processing module 1, such as Figure 2 As shown, it includes: a controller 110, a comparison module 120, an adjustable device module 130, a switch T, and a sampling resistor R. s ;

[0082] The controller 110 has: a first controller port 110a, a second controller port 110b, a third controller port 110c, a fourth controller port 110d, and a fifth controller port 110e;

[0083] Comparison module 120 has: a first comparison module port 120a, a second comparison module port 120b and a third comparison module port 120c;

[0084] The adjustable device module 130 has: a first adjustable port 130a, a second adjustable port 130b, a third adjustable port 130c, a fourth adjustable port 130d, and a fifth adjustable port 130e;

[0085] The switch T has: a first switch port T1, a second switch port T2, and a third switch port T3;

[0086] Sampling resistor R s The two ends are respectively connected to the first comparison module port 120a and the third comparison module port 120c; the first comparison module port 120a is also connected to the second switch port T2, the third switch port T3 is connected to the second comparison module port 120b, the second comparison module port 120b is also connected to the first adjustable port 130a, the second adjustable port 130b is connected to the third comparison module port 120c, the first switch port T1 is connected to the first controller port 110a, the third controller port 110c is connected to the third adjustable port 130c, the fourth controller port 110d is connected to the fourth adjustable port 130d, and the fifth controller port 110e is connected to the fifth adjustable port 130e;

[0087] The second controller port 110b is used to acquire the received ripple adjustment signal.

[0088] The controller 110 sends an adjustable resistor adjustment signal to the adjustable device module 130 through the third controller port 110c to adjust the value of the adjustable resistor, an adjustable capacitor adjustment signal to the adjustable device module 130 through the fourth controller port 110d to adjust the value of the adjustable capacitor, and an adjustable inductor adjustment signal to the adjustable device module 130 through the fifth controller port 110e to adjust the value of the adjustable inductor.

[0089] Comparison module 120, such as Figure 3 As shown, it includes: comparator 121 and feedback resistor R. f ;

[0090] Comparator 121 has: non-inverting input terminal 121a, inverting input terminal 121b, comparator output terminal 121c, comparator power supply terminal 121d, and comparator ground terminal 121e;

[0091] The non-inverting input terminal 121a serves as the first comparator module port 120a, and the inverting input terminal 121b is connected in series with the feedback resistor R. f The comparator output terminal 121c is connected to the comparator power supply terminal 121d, which serves as the third comparator module port 120c. The comparator ground terminal 121e is grounded.

[0092] Adjustable device module 130, such as Figure 4 As shown, it includes: an adjustable resistor R v Adjustable capacitor C v and adjustable inductor L v ;

[0093] Adjustable resistor R v One end is connected to the adjustable capacitor C v One end is connected as the first adjustable port 130a, and the adjustable resistor R v The other end is connected to the adjustable inductor L v One end is connected to the adjustable inductor L v The other end is connected to the adjustable capacitor C v The other end is connected and serves as the second adjustable port 130b;

[0094] The resistance adjustment port of the adjustable resistor is designated as the third adjustable port 130c, the capacitance adjustment port of the adjustable capacitor is designated as the fourth adjustable port 130d, and the inductance adjustment port of the adjustable inductor is designated as the fifth adjustable port 130e.

[0095] The adjustable device module can adjust the values ​​of the internal adjustable resistor, adjustable capacitor, and adjustable inductor according to the adjustable resistor adjustment signal, adjustable capacitor adjustment signal, and adjustable inductor adjustment signal sent by the controller, thereby suppressing the ripple of the synchronous rectification branch.

[0096] Example 2

[0097] This embodiment describes a ripple suppression method applied to the controller of the switching power supply ripple adjustment system described in Embodiment 1, including:

[0098] S100: In response to acquiring the ripple adjustment signal, the switching power supply ripple adjustment system is activated, and the sampling signal of the output branch of the switching power supply is acquired.

[0099] S200: Based on the sampling signal of the output branch, determine the adjustment signal of the adjustable device, which includes: the adjustment signal of the adjustable resistor, the adjustment signal of the adjustable capacitor, and the adjustment signal of the adjustable inductor;

[0100] S300: Adjusts the adjustable resistor in the switching power supply ripple adjustment system according to the adjustable resistor adjustment signal, adjusts the adjustable capacitor in the switching power supply ripple adjustment system according to the adjustable capacitor adjustment signal, and adjusts the adjustable inductor in the switching power supply ripple adjustment system according to the adjustable inductor adjustment signal, so as to reduce the output ripple of the switching power supply.

[0101] The ripple suppression method described in this embodiment corresponds to the situation where the ripple increases due to the increase in synchronous rectification frequency.

[0102] Accordingly, S200: Based on the sampling signal of the output branch, determine the adjustment signal of the adjustable device, specifically including:

[0103] S210: Determine the synchronous rectification frequency of the switching power supply based on the sampling signal of the output branch to stabilize the output branch voltage of the switching power supply. The synchronous rectification frequency is determined by the output voltage of the output branch.

[0104] S220: Determine the adjustment signal of the adjustable device based on the sampling signal of the output branch and the change of the synchronous rectification frequency.

[0105] In some embodiments, the increase in ripple is caused by an increase in the synchronous rectification frequency. Accordingly, S221a: In response to the increase in the synchronous rectification frequency, then according to... L adj = L 0· ( 1 + k 1· Δ f / f nom ), determine the target value of the adjustable inductor, where, L adjThis indicates the adjusted target value of the adjustable inductor. L 0 indicates the initial inductance value before adjustment. k 1 represents the inductance compensation coefficient, Δ f = f sw - f nom , representing the change in frequency. f sw Indicates the current synchronous rectification frequency. f nom Indicates the rated resonant frequency;

[0106] S222a: According to C adj = C 0· ( 1 - k 2· Δ V r / V o ), determine the target value of the adjustable capacitor, where, C adj This indicates the adjusted target value of the adjustable capacitor. C 0 indicates the initial value of the capacitor before adjustment. k 2 represents the capacitance attenuation coefficient, Δ V r This indicates the peak-to-peak value of the ripple voltage. V o This indicates the output voltage of the synchronous rectification branch;

[0107] S223a: According to R adj = R 0· ( 1 + k 3· Δ f / f nom ), determine the target value of the adjustable resistor, where, R adj This indicates the target value of the adjustable resistor after adjustment. R 0 indicates the initial resistance value before adjustment. k 3 indicates the damping coefficient;

[0108] S224a: Generates an adjustable inductor adjustment signal based on the target value of the adjustable inductor, an adjustable capacitor adjustment signal based on the target value of the adjustable capacitor, and an adjustable resistor adjustment signal based on the target value of the adjustable resistor.

[0109] The adjustable inductor is a magnetically saturated reactor. The controller converts the control signal or pulse width modulation signal generated by the digital-to-analog converter into a DC current signal and inputs the DC current into the winding of the reactor to adjust the saturation of the magnetic core, thereby changing the inductance value of the winding.

[0110] The adjustable capacitor is a varactor diode. The adjustable capacitor is generated by the digital-to-analog converter in the controller. The controller outputs a control signal to reverse bias the varactor diode. Changing the reverse bias voltage of the varactor diode adjusts the capacitance of the varactor diode.

[0111] The adjustable resistor is a digital potentiometer. The controller 110 communicates via SPI or I / O. 2 The C bus sends commands to the third adjustable port 130c to directly adjust the internal resistance value of the digital potentiometer. This is achieved using I... 2 Taking C bus transmission commands as an example, I 2 The C bus corresponds to the SCL and SDA pins of the digital potentiometer. The digital potentiometer connects to the I / O pins. 2 The C bus receives control signals and adjusts the resistance value according to the control signals.

[0112] Example 3

[0113] This embodiment describes a ripple suppression method applied to the controller of the switching power supply ripple adjustment system described in Embodiment 1, including:

[0114] S100: In response to acquiring the ripple adjustment signal, the switching power supply ripple adjustment system is activated, and the sampling signal of the output branch of the switching power supply is acquired.

[0115] S200: Based on the sampling signal of the output branch, determine the adjustment signal of the adjustable device, which includes: the adjustment signal of the adjustable resistor, the adjustment signal of the adjustable capacitor, and the adjustment signal of the adjustable inductor;

[0116] S300: Adjusts the adjustable resistor in the switching power supply ripple adjustment system according to the adjustable resistor adjustment signal, adjusts the adjustable capacitor in the switching power supply ripple adjustment system according to the adjustable capacitor adjustment signal, and adjusts the adjustable inductor in the switching power supply ripple adjustment system according to the adjustable inductor adjustment signal, so as to reduce the output ripple of the switching power supply.

[0117] The ripple suppression method described in this embodiment corresponds to the situation where the ripple increases due to the decrease in synchronous rectification frequency.

[0118] Accordingly, S200: Based on the sampling signal of the output branch, determine the adjustment signal of the adjustable device, specifically including:

[0119] S221b: In response to a decrease in the synchronous rectification frequency, then according to L adj = L 0· ( 1 - k 4· Δ V r / V o), determine the target value of the adjustable inductor, where, L adj This indicates the adjusted target value of the adjustable inductor. L 0 indicates the initial inductance value before adjustment. k 4 represents the inductance attenuation coefficient, Δ V r This indicates the peak-to-peak value of the ripple voltage. V o This indicates the output voltage of the synchronous rectification branch;

[0120] S222b: According to C adj = C 0· ( 1 + k 5· Δ I / I nom ), determine the target value of the adjustable capacitor, where, C adj This indicates the adjusted target value of the adjustable capacitor. C 0 indicates the initial value of the capacitor before adjustment. k 5 represents the capacitance enhancement factor, Δ I = I load - I nom This represents the change in load current. I load Indicates the current load current. I nom Indicates the rated load current;

[0121] S223b: R adj = R 0· ( 1 - k 6· Δ f / f nom ), determine the target value of the adjustable resistor, where, R adj This indicates the target value of the adjustable resistor after adjustment. R 0 indicates the initial resistance value before adjustment. k 6 represents the resistance attenuation coefficient, Δ f = f sw - f nom , representing the change in frequency. f sw Indicates the current synchronous rectification frequency. f nom Indicates the rated resonant frequency;

[0122] S224b: Generates an adjustable inductor adjustment signal based on the target value of the adjustable inductor, an adjustable capacitor adjustment signal based on the target value of the adjustable capacitor, and an adjustable resistor adjustment signal based on the target value of the adjustable resistor.

[0123] The adjustable inductor-switching inductor array uses multiple fixed-value inductors and relays. By controlling the switching state of the relays, different inductor combinations are selected to adjust the inductance value. The control signals generated by the controller are used to control the on / off state of the corresponding relay contacts, adjusting the inductor array to achieve the target inductance value.

[0124] The adjustable capacitor is a capacitor array that uses multiple fixed-value capacitors and relays. Different capacitor combinations are selected by controlling the switching state of the relays to adjust the capacitor value to achieve the target capacitor value.

[0125] The adjustable resistor is a junction field-effect transistor (JFET). Its gate receives a control signal from the controller to change the resistance between its drain and source. The control signal for the JFET is a pulse-width modulation (PWM) signal.

[0126] Example 4

[0127] This embodiment describes a ripple suppression method applied to the controller of the switching power supply ripple adjustment system described in Embodiment 1, including:

[0128] S100: In response to acquiring the ripple adjustment signal, the switching power supply ripple adjustment system is activated, and the sampling signal of the output branch of the switching power supply is acquired.

[0129] S200: Based on the sampling signal of the output branch, determine the adjustment signal of the adjustable device, which includes: the adjustment signal of the adjustable resistor, the adjustment signal of the adjustable capacitor, and the adjustment signal of the adjustable inductor;

[0130] S300: Adjusts the adjustable resistor in the switching power supply ripple adjustment system according to the adjustable resistor adjustment signal, adjusts the adjustable capacitor in the switching power supply ripple adjustment system according to the adjustable capacitor adjustment signal, and adjusts the adjustable inductor in the switching power supply ripple adjustment system according to the adjustable inductor adjustment signal, so as to reduce the output ripple of the switching power supply.

[0131] The ripple suppression method described in this embodiment corresponds to the situation where the output branch sampling signal indicates that the ripple of the switching power supply is increasing.

[0132] Accordingly, S200: Based on the sampling signal of the output branch, determine the adjustment signal of the adjustable device, specifically including:

[0133] S221c: In response to the output branch sampling signal indicating an increase in the switching power supply ripple, then according to... L adj =L 0+ Δ L Determine the target value of the adjustable inductor, based on C adj = C 0+ Δ C Determine the target value of the adjustable capacitor based on... R adj = R 0+ Δ R = R 0· ( f do / f nom ) -1 / 2 Determine the target value of the adjustable resistor, where, L adj express, L 0 represents, C adj express, C 0 represents, R adj express, R 0 represents Δ L It means that Δ C It means that Δ R It means that Δ L Δ C Δ R According to Δ V r = k L · Δ L + k C · Δ C + k R · Δ R With fre = 1 / 2π ( L adj · C adj ) -1 / 2 Solving the system of equations simultaneously, we get Δ V r This indicates the peak-to-peak value of the ripple voltage. k L Indicates the inductance sensitivity coefficient. k C Indicates the capacitance sensitivity coefficient. k R Indicates the resistance sensitivity coefficient. f re Indicates the resonant frequency. f do Indicates the dominant frequency of ripple energy. f nom Indicates the rated resonant frequency;

[0134] S222c: Generates an adjustable inductor adjustment signal based on the target value of the adjustable inductor, an adjustable capacitor adjustment signal based on the target value of the adjustable capacitor, and an adjustable resistor adjustment signal based on the target value of the adjustable resistor.

[0135] The adjustable inductor is a magnetically saturated reactor. The controller converts the control signal or pulse width modulation signal generated by the digital-to-analog converter into a DC current signal and inputs the DC current into the winding of the reactor to adjust the saturation of the magnetic core, thereby changing the inductance value of the winding.

[0136] The adjustable capacitor is a varactor diode. The adjustable capacitor is generated by the digital-to-analog converter in the controller. The controller outputs a control signal to reverse bias the varactor diode. Changing the reverse bias voltage of the varactor diode adjusts the capacitance of the varactor diode.

[0137] The adjustable resistor is a digital potentiometer. The controller 110 communicates via SPI or I / O. 2 The C bus sends commands to the third adjustable port 130c to directly adjust the internal resistance value of the digital potentiometer. This is achieved using I... 2 Taking C bus transmission commands as an example, I 2 The C bus corresponds to the SCL and SDA pins of the digital potentiometer. The digital potentiometer connects to the I / O pins. 2 The C-bus receives control signals and adjusts the resistor value accordingly. This is shown, but these steps are not necessarily performed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order in which these steps are performed; they can be performed in other orders. Furthermore, Figure 4 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0138] The beneficial effects of the technical solution provided in this application are: by implementing the switching power supply ripple adjustment system and ripple suppression method provided in this application, the output ripple can be quickly suppressed and the power quality improved by actively intervening in the adjustment, based on the synchronous rectification frequency of the switching power supply and the sampling signal of the synchronous rectification branch.

[0139] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0140] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to the descriptions in the method embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0141] The technical solutions provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

[0142] The foregoing has provided a detailed description of a switching power supply ripple adjustment system and ripple suppression method provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. These embodiments are merely preferred embodiments of this application, used to help understand the method and core ideas of this application, and are not intended to limit this application. It should be noted that for those skilled in the art, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application without departing from its principles are also within the protection scope of the claims of this application.

Claims

1. A switching power supply ripple adjustment system, characterized in that, include: Ripple processing module, synchronous rectification module, rectifier output capacitor, and at least one synchronous rectification branch; Each of the at least one synchronous rectification branch includes: a synchronous rectification transistor and a secondary coil connected in series; The ripple processing module is connected to the rectifier output capacitor, the ripple processing module is connected to the synchronous rectification module, the rectifier output capacitor is connected to the synchronous rectification transistor, and the synchronous rectification module is connected to the synchronous rectification transistor in any synchronous rectification branch. The ripple processing module is used to collect the branch sampling signal on the rectifier output capacitor and obtain the synchronous rectification frequency of the synchronous rectification module, and suppress the ripple on the synchronous rectification branch according to the branch sampling signal and the change of the synchronous rectification frequency. The ripple processing module includes: a controller, a comparison module, an adjustable device module, a switch, and a sampling resistor; The two ends of the sampling resistor are respectively connected to the first comparison module port and the third comparison module port of the comparison module; the first comparison module port of the comparison module is also connected to the second switch port of the switch, the third switch port of the switch is connected to the second comparison module port of the comparison module, the second comparison module port of the comparison module is also connected to the first adjustable port of the adjustable device module, the second adjustable port of the adjustable device module is connected to the third comparison module port of the comparison module, the first switch port of the switch is connected to the first controller port of the controller, the third controller port of the controller is connected to the third adjustable port of the adjustable device module, the fourth controller port of the controller is connected to the fourth adjustable port of the adjustable device module, and the fifth controller port of the controller is connected to the fifth adjustable port of the adjustable device module. The second controller port of the controller is used to acquire the received ripple adjustment signal, and in response to acquiring the ripple adjustment signal, the switching power supply ripple adjustment system is started. The controller sends an adjustable resistor adjustment signal to the adjustable device module through the third controller port to adjust the value of the adjustable resistor, an adjustable capacitor adjustment signal to the adjustable device module through the fourth controller port to adjust the value of the adjustable capacitor, and an adjustable inductor adjustment signal to the adjustable device module through the fifth controller port to adjust the value of the adjustable inductor; in response to acquiring the ripple adjustment signal, the switching power supply ripple adjustment system is started, and the output branch sampling signal of the switching power supply is acquired; In response to the increase in the synchronous rectification frequency, then according to L adj = L 0·(1+ k 1·Δ f / f nom ), determine the target value of the adjustable inductor, where, L adj This indicates the adjusted target value of the adjustable inductor. L 0 indicates the initial inductance value before adjustment. k 1 represents the inductance compensation coefficient, Δ f = f sw - f nom , representing the change in frequency. f sw Indicates the current synchronous rectification frequency. f nom Indicates the rated resonant frequency; according to C adj = C 0·(1- k 2·Δ V r / V o ), determine the target value of the adjustable capacitor, where, C adj This indicates the adjusted target value of the adjustable capacitor. C 0 indicates the initial value of the capacitor before adjustment. k 2 represents the capacitance attenuation coefficient, Δ V r This indicates the peak-to-peak value of the ripple voltage. V o This indicates the output voltage of the synchronous rectification branch; according to R adj = R 0·(1+ k 3·Δ f / f nom ), determine the target value of the adjustable resistor, where, R adj This indicates the target value of the adjustable resistor after adjustment. R 0 indicates the initial resistance value before adjustment. k 3 indicates the damping coefficient; An adjustable inductor adjustment signal is generated based on the target value of the adjustable inductor; an adjustable capacitor adjustment signal is generated based on the target value of the adjustable capacitor; and an adjustable resistor adjustment signal is generated based on the target value of the adjustable resistor. In response to the decrease in the synchronous rectification frequency, then according to L adj = L 0·(1- k 4·Δ V r / V o ), determine the target value of the adjustable inductor, where, L adj This indicates the adjusted target value of the adjustable inductor. L 0 indicates the initial inductance value before adjustment. k 4 represents the inductance attenuation coefficient, Δ V r This indicates the peak-to-peak value of the ripple voltage. V o This indicates the output voltage of the synchronous rectification branch; according to C adj = C 0·(1+ k 5·Δ I / I nom ), determine the target value of the adjustable capacitor, where, C adj This indicates the adjusted target value of the adjustable capacitor. C 0 indicates the initial value of the capacitor before adjustment. k 5 represents the capacitance enhancement factor, Δ I = I load - I nom This represents the change in load current. I load Indicates the current load current. I nom Indicates the rated load current; R adj = R 0·(1- k 6·Δ f / f nom ), determine the target value of the adjustable resistor, where, R adj This indicates the target value of the adjustable resistor after adjustment. R 0 indicates the initial resistance value before adjustment. k 6 represents the resistance attenuation coefficient, Δ f = f sw - f nom , representing the change in frequency. f sw Indicates the current synchronous rectification frequency. f nom Indicates the rated resonant frequency; An adjustable inductor adjustment signal is generated based on the target value of the adjustable inductor, an adjustable capacitor adjustment signal is generated based on the target value of the adjustable capacitor, and an adjustable resistor adjustment signal is generated based on the target value of the adjustable resistor.

2. The switching power supply ripple adjustment system according to claim 1, characterized in that, The comparison module includes: a comparator and a feedback resistor; The comparator has: a non-inverting input terminal, an inverting input terminal, a comparator output terminal, a comparator power supply terminal, and a comparator ground terminal; The non-inverting input terminal serves as the port of the first comparator module, the inverting input terminal is connected in series with the feedback resistor and then connected to the comparator output terminal, the comparator power supply terminal serves as the port of the third comparator module, and the comparator ground terminal is grounded.

3. The switching power supply ripple adjustment system according to claim 1, characterized in that, The adjustable device module includes: an adjustable resistor, an adjustable capacitor, and an adjustable inductor; One end of the adjustable resistor is connected to one end of the adjustable capacitor to serve as the first adjustable port, and the other end of the adjustable resistor is connected to one end of the adjustable inductor. The other end of the adjustable inductor is connected to the other end of the adjustable capacitor to serve as the second adjustable port. The resistance adjustment port of the adjustable resistor serves as the third adjustable port, the capacitance adjustment port of the adjustable capacitor serves as the fourth adjustable port, and the inductance adjustment port of the adjustable inductor serves as the fifth adjustable port.

4. A ripple suppression method, characterized in that, The controller applied to the switching power supply ripple adjustment system according to any one of claims 1-3 includes: In response to acquiring the ripple adjustment signal, the switching power supply ripple adjustment system is activated, and the sampling signal of the output branch of the switching power supply is acquired. Based on the output branch sampling signal, the adjustable device adjustment signal is determined, wherein the adjustable device adjustment signal includes: an adjustable resistor adjustment signal, an adjustable capacitor adjustment signal, and an adjustable inductor adjustment signal; The adjustable resistor in the switching power supply ripple adjustment system is adjusted according to the adjustable resistor adjustment signal, the adjustable capacitor in the switching power supply ripple adjustment system is adjusted according to the adjustable capacitor adjustment signal, and the adjustable inductor in the switching power supply ripple adjustment system is adjusted according to the adjustable inductor adjustment signal, so as to reduce the output ripple of the switching power supply.

5. The ripple suppression method according to claim 4, characterized in that, The step of determining the adjustable device adjustment signal based on the output branch sampling signal includes: Based on the sampling signal of the output branch, the synchronous rectification frequency of the switching power supply is determined to stabilize the output branch voltage of the switching power supply, wherein the synchronous rectification frequency is determined by the output voltage of the output branch. The adjustment signal of the adjustable device is determined based on the sampling signal of the output branch and the change of the synchronous rectification frequency.

6. The ripple suppression method according to claim 5, characterized in that, The step of determining the adjustable device adjustment signal based on the output branch sampling signal and the change in the synchronous rectification frequency includes: In response to the increase in the synchronous rectification frequency, then according to L adj = L 0·(1+ k 1·Δ f / f nom ), determine the target value of the adjustable inductor, where, L adj This indicates the adjusted target value of the adjustable inductor. L 0 indicates the initial inductance value before adjustment. k 1 represents the inductance compensation coefficient, Δ f = f sw - f nom , representing the change in frequency. f sw Indicates the current synchronous rectification frequency. f nom Indicates the rated resonant frequency; according to C adj = C 0·(1- k 2·Δ V r / V o ), determine the target value of the adjustable capacitor, where, C adj This indicates the adjusted target value of the adjustable capacitor. C 0 indicates the initial value of the capacitor before adjustment. k 2 represents the capacitance attenuation coefficient, Δ V r This indicates the peak-to-peak value of the ripple voltage. V o This indicates the output voltage of the synchronous rectification branch; according to R adj = R 0·(1+ k 3·Δ f / f nom ), determine the target value of the adjustable resistor, where, R adj This indicates the target value of the adjustable resistor after adjustment. R 0 indicates the initial resistance value before adjustment. k 3 indicates the damping coefficient; An adjustable inductor adjustment signal is generated based on the target value of the adjustable inductor, an adjustable capacitor adjustment signal is generated based on the target value of the adjustable capacitor, and an adjustable resistor adjustment signal is generated based on the target value of the adjustable resistor.

7. The ripple suppression method according to claim 5, characterized in that, The step of determining the adjustable device adjustment signal based on the output branch sampling signal and the change in the synchronous rectification frequency further includes: In response to the decrease in the synchronous rectification frequency, then according to L adj = L 0·(1- k 4·Δ V r / V o ), determine the target value of the adjustable inductor, where, L adj This indicates the adjusted target value of the adjustable inductor. L 0 indicates the initial inductance value before adjustment. k 4 represents the inductance attenuation coefficient, Δ V r This indicates the peak-to-peak value of the ripple voltage. V o This indicates the output voltage of the synchronous rectification branch; according to C adj = C 0·(1+ k 5·Δ I / I nom ), determine the target value of the adjustable capacitor, where, C adj This indicates the adjusted target value of the adjustable capacitor. C 0 indicates the initial value of the capacitor before adjustment. k 5 represents the capacitance enhancement factor, Δ I = I load - I nom This represents the change in load current. I load Indicates the current load current. I nom Indicates the rated load current; R adj = R 0·(1- k 6·Δ f / f nom ), determine the target value of the adjustable resistor, where, R adj This indicates the target value of the adjustable resistor after adjustment. R 0 indicates the initial resistance value before adjustment. k 6 represents the resistance attenuation coefficient, Δ f = f sw - f nom , representing the change in frequency. f sw Indicates the current synchronous rectification frequency. f nom Indicates the rated resonant frequency; An adjustable inductor adjustment signal is generated based on the target value of the adjustable inductor, an adjustable capacitor adjustment signal is generated based on the target value of the adjustable capacitor, and an adjustable resistor adjustment signal is generated based on the target value of the adjustable resistor.

8. The ripple suppression method according to claim 4, characterized in that, The response prior to acquiring the ripple adjustment signal further includes: The ripple adjustment signal is generated in response to the power-on of the electrical appliance powered by the switching power supply. In response to initiating a shutdown process for the electrical appliance, the ripple adjustment signal is generated; The ripple adjustment signal is generated in response to a change in the load of the electrical appliance.

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