A dynamic load switching intelligent response system

Abstract

The application provides a dynamic load switching intelligent response system, comprising an intelligent response starting logic control circuit, an oscillator timing circuit, an output overshoot slope detection circuit, an intelligent maximum period response circuit, an output pull-down slope detection circuit and a PWM control logic circuit. When the full load state is switched into the no load or light load state during the dynamic load switching, the application can effectively reduce the output voltage overshoot amplitude and gently output the voltage. When the no load state is switched into the full load state, the application slows down the output voltage pull-down amplitude and simultaneously quickly charges the power supply system. The application avoids the output voltage overshoot protection or the abnormal phenomenon of the switch power supply system power-down restart during the dynamic load switching.

Description

Technical Field

[0001] This invention relates to the field of primary-side feedback AC / DC switching power supply technology, and more specifically, to a dynamic load switching intelligent response system. Background Technology

[0002] With the increasing demand for switching power supplies, their applications are becoming more widespread. Many scenarios involve repeated load switching. Typically, under full load, to meet power and efficiency requirements, the PWM operating frequency is high, and the primary winding peak current is also high. Under no-load, to meet low standby power consumption requirements, the PWM operating frequency is low, and the primary winding peak current is also low. When switching from full load to no-load, the operating frequency and primary winding peak current will inevitably decrease gradually. However, due to limited system response speed, the operating frequency and primary winding peak current will not immediately drop to the minimum operating frequency or minimum current. Therefore, the output voltage will inevitably overshoot. As the system detects that the output voltage exceeds the set voltage, the feedback loop will adjust the PWM operating frequency to the minimum, while the duty cycle TOFFA remains constant at its maximum. The primary winding peak current will also be adjusted to the minimum and remain constant.

[0003] In traditional solutions, when the load current switches from full load to no load, the output voltage rises rapidly due to the slow response speed, but remains at a fixed TOFFA. At this time, the energy supplied to the system is fixed, so the output voltage overshoot is large, and it is easy to enter the output voltage overvoltage protection state.

[0004] When the load current switches from full load to no load, the switching time is not fixed. For example, if the load at the TC (control circuit power supply transformer) suddenly switches from full load to no load, the output voltage drops rapidly, and the VDD voltage, which provides energy to the entire switching power supply system, also drops sharply because there is no energy output. The next PWM signal after switching from full load to no load must wait for the previous PWM duty cycle to completely end before issuing the next PWM signal to detect the output status. In extreme cases, the output voltage and VDD voltage will drop throughout the TOFFA time. This leads to two potential problems. First, if the output capacitor is small, the output voltage will drop to zero during the entire TOFFA time, meaning there will be no output voltage. Second, if the VDD capacitor is small, the voltage on VDD will drop. If it falls below the set VDD_OF point, the entire switching power supply system will shut down, and no PWM signal will be emitted. It will only restart after several seconds by charging VDD to make the VDD voltage greater than the set VDD_ON point. This is equivalent to the switching power supply system restarting once, failing to maintain a normal state of continuous waveform transmission. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems in the prior art where output voltage overshoot protection is easily triggered during load switching of switching power supplies and abnormal phenomena such as power failure and restart of switching power supply systems occur.

[0006] Therefore, the present invention provides a dynamic load switching intelligent response system.

[0007] This invention provides a dynamic load switching intelligent response system, comprising:

[0008] An oscillator timing circuit is used to output a time signal and a PWM period signal. The time signal includes the output voltage overshoot slope detection threshold time TIMEA, the output voltage pull-down slope detection threshold time TIMEB, and the basic unit time TIMEK. The PWM period signal includes the PWM basic maximum period TOFFA and the extreme PWM maximum period limit TOFFMAX.

[0009] The output overshoot slope detection circuit is connected to the output voltage of the switching power supply, the threshold voltage VA, the threshold voltage VB, and the output voltage overshoot slope detection threshold time TIMEA signal and the basic unit time TIMEK signal output by the oscillator timing circuit. It is used to generate the intelligent unit time TOFFB signal when the rise time of the switching power supply output voltage from the threshold voltage VA to the threshold voltage VB is less than the output voltage overshoot slope detection threshold time TIM EA.

[0010] The intelligent maximum period response circuit is connected to the PWM basic maximum period TOFFA signal output by the oscillator timing circuit and the intelligent unit time TOFFB signal output by the overshoot slope detection circuit. It is used to count the number of PWM waves and save it as N. It also performs logical operations on the number of PWM waves N and the intelligent unit time TOFFB to obtain the intelligent period time TOFFN signal.

[0011] The output pull-down slope detection circuit is connected to the output voltage of the switching power supply, the threshold voltage VC, the threshold voltage VD, and the output voltage pull-down slope detection threshold time TIMEB signal output by the oscillator timing circuit. It is used to immediately generate a PWMON logic signal when the drop time of the switching power supply output voltage from the threshold voltage VC to the threshold voltage VD is less than the output voltage pull-down slope detection threshold time TIMEB, so that the PWM signal is turned on in advance.

[0012] The PWM control logic circuit receives the intelligent cycle time TOFFN signal output by the intelligent maximum cycle response circuit and the PWMON logic signal output by the output pull-down slope detection circuit, and outputs the logic control signal PWM signal.

[0013] According to the above-described technical solution of the present invention, a dynamic load switching intelligent response system may further have the following additional technical features:

[0014] In the above technical solution, the output overshoot slope detection circuit detects the rise slope of the output voltage of the switching power supply from the threshold voltage VA to the threshold voltage VB. When the rise slope of the output voltage reaches the threshold, the intelligent unit time TOFFB signal is output. The intelligent unit time TOFFB is positively correlated with the rise slope of the output voltage from the threshold voltage VA to the threshold voltage VB.

[0015] In the above technical solution, the calculation method for the intelligent unit time TOFFB is as follows:

[0016] TOFFB = K * TIMEK;

[0017] Where K is the slope of the rise of the switching power supply output voltage VOUT from the threshold voltage VA to the threshold voltage VB.

[0018] In the above technical solution, the intelligent maximum cycle response circuit counts the number of PWM waves and saves it as N when the output voltage of the switching power supply exceeds the threshold voltage VB.

[0019] In the above technical solution, the calculation method for the intelligent cycle time TOFFN signal is as follows:

[0020] TOFFN = N * TOFFB + TOFFA.

[0021] In the above technical solution, the threshold voltage VA is less than the threshold voltage VB, and the threshold voltage VC is greater than the threshold voltage VD.

[0022] In the above technical solution, the output terminal of the PWM control logic circuit is connected to the control terminal of the switching transistor, and the logic control signal (PWM signal) output by the PWM control logic circuit is used to control the switching transistor to turn on and off.

[0023] In the above technical solution, the PWM control logic circuit is connected to the limit PWM maximum period limit TOFFMAX signal output by the oscillator timing circuit, and the limit PWM maximum period limit TOFFMAX signal is used as the upper limit of the accumulation of the intelligent period time TOFFN signal.

[0024] The above-mentioned technical solutions also include:

[0025] The intelligent response startup logic control circuit is connected to the output voltage and threshold voltage VA of the switching power supply. When the output voltage of the switching power supply is detected to be greater than the threshold voltage VA, the dynamic load switching intelligent response system is allowed to operate.

[0026] In the above technical solution, the intelligent response activation logic control circuit includes:

[0027] The comparator unit has a first terminal, a second terminal, and an output terminal. The first terminal of the comparator unit is connected to the output voltage of the switching power supply, the second terminal of the comparator unit is connected to the threshold voltage VA, and the output terminal of the comparator unit outputs a logic signal CTR according to the comparison result.

[0028] When the output voltage of the switching power supply is greater than the threshold voltage VA, CTR is at a logic high level, allowing the dynamic load switching intelligent response system to operate.

[0029] In summary, due to the adoption of the above-mentioned technical features, the beneficial effects of the present invention are:

[0030] A dynamic load switching intelligent response circuit is provided. When the switching power supply switches from full load to no-load or light load, it can effectively reduce the output voltage overshoot and smooth the output voltage. When the switching power supply switches from no-load to full load, it reduces the output voltage drop and quickly charges the power system. This avoids output voltage overshoot protection or abnormal restart phenomena of the switching power supply system during dynamic load switching.

[0031] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0033] Figure 1 This is a schematic diagram of the circuit structure of a dynamic load switching intelligent response system according to an embodiment of the present invention;

[0034] Figure 2 This is a typical block diagram of a primary-side feedback detection flyback power converter system application.

[0035] Figure 3 This is a schematic diagram of a dynamic load switching intelligent response system according to an embodiment of the present invention. Detailed Implementation

[0036] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0037] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0038] The following reference Figures 1 to 3 This describes a dynamic load switching intelligent response system provided according to some embodiments of the present invention.

[0039] Some embodiments of this application provide a dynamic load switching intelligent response system.

[0040] like Figures 1 to 3 As shown, the first embodiment of the present invention proposes a dynamic load switching intelligent response system, including: an oscillator timing circuit, an output overshoot slope detection circuit, an intelligent maximum period response circuit, an output pull-down slope detection circuit, and a PWM control logic circuit.

[0041] The oscillator timing circuit is used to output a time signal and a PWM period signal. The time signal includes the output voltage overshoot slope detection threshold time TIMEA, the output voltage pull-down slope detection threshold time TIMEB, and the basic unit time TIMEK. The PWM period signal includes the PWM basic maximum period TOFFA and the extreme PWM maximum period limit TOFFMAX.

[0042] The output overshoot slope detection circuit is connected to the switching power supply output voltage VOUT, threshold voltage VA, threshold voltage VB, and the output voltage overshoot slope detection threshold time TIMEA signal and the basic unit time TIMEK signal from the oscillator timing circuit. It generates a smart unit time TOFFB signal when the rise time of the switching power supply output voltage VOUT from threshold voltage VA to threshold voltage VB is less than the output voltage overshoot slope detection threshold time TIMEA. The smart unit time TOF... FB is equal to the product of the rising slope K of the switching power supply output voltage VOUT and the basic unit time TIMEK, where K is the rising slope of the switching power supply output voltage VOUT from the threshold voltage VA to the threshold voltage VB. Specifically, the output overshoot slope detection circuit detects the rising slope of the switching power supply output voltage VOUT from the threshold voltage VA to the threshold voltage VB. When the rising slope of the output voltage is detected to reach the threshold, that is, when the switching power supply output voltage VOUT is detected to rise too fast, the intelligent unit time TOFFB signal is output. The intelligent unit time TOFFB is positively correlated with the rising slope of the output voltage from the threshold voltage VA to the threshold voltage VB. The faster the rising slope of the switching power supply output voltage VOUT, the longer the intelligent unit time TOFFB is; the slower the rising slope of the switching power supply output voltage VOUT, the shorter the intelligent unit time TOFFB is.

[0043] Therefore, the calculation method for the intelligent unit time TOFFB is as follows:

[0044] TOFFB = K * TIMEK;

[0045] Where K is the slope of the rise of the switching power supply output voltage VOUT from the threshold voltage VA to the threshold voltage VB.

[0046] The intelligent maximum period response circuit connects to the PWM base maximum period TOFFA signal output by the oscillator timing circuit and the intelligent unit time TOFFB signal output by the overshoot slope detection circuit. When the output voltage of the switching power supply exceeds the threshold voltage VB, the intelligent maximum period response circuit counts the number of PWM waves and saves it as N. It then performs logical operations on the number of PWM waves N and the intelligent unit time TOFFB to obtain the intelligent period time TOFFN signal. The calculation method of the intelligent period time TOFFN signal is as follows: first, obtain the N*TOFFB signal through logical operations, and then add the N*TOFFB signal to the base maximum period TOFFA to obtain the intelligent period time TOFFN signal, TOFFN = N*TOFFB + TOFFA.

[0047] The output pull-down slope detection circuit is connected to the output voltage of the switching power supply, the threshold voltage VC, the threshold voltage VD, and the output voltage pull-down slope detection threshold time TIMEB signal output by the oscillator timing circuit. It is used to generate a PWMON logic signal immediately when the drop time of the switching power supply output voltage from the threshold voltage VC to the threshold voltage VD is less than the output voltage pull-down slope detection threshold time TIMEB, without waiting for the end of the previous PWM complete cycle signal to start the PWM signal in advance.

[0048] The PWM control logic circuit receives the intelligent cycle time TOFFN signal output by the intelligent maximum cycle response circuit, the PWMON logic signal output by the output pull-down slope detection circuit, and the limit PWM maximum cycle limit TOFFMAX signal output by the oscillator timing circuit, and outputs a logic control signal PWM signal. The limit PWM maximum cycle limit TOFFMAX signal is used as the upper limit for the accumulation of the intelligent cycle time TOFFN signal. The output terminal of the PWM control logic circuit is connected to the control terminal of the switching transistor, and the logic control signal PWM signal output by the PWM control logic circuit is used to control the switching transistor's on / off state. When the PWM control logic circuit detects the PWMON logic signal output by the output pull-down slope detection circuit, it controls the switching transistor to turn on and output a PWM wave; when the PWM control logic circuit detects the intelligent cycle time TOFFN signal, it controls the switching transistor to turn off. The limit PWM maximum cycle limit TOFFMAX signal serves as the upper limit for the accumulation of the intelligent cycle time TOFFN signal; that is, when the intelligent cycle time TOFFN signal exceeds or is about to exceed the limit PWM maximum cycle limit TOFFMAX signal, a signal to control the switching transistor to turn off is directly output based on the limit PWM maximum cycle limit TOFFMAX signal. Figure 2 The switching transistor shown can be a MOSFET. The gate of the MOSFET is connected to the logic control signal PWM signal, the source is coupled to the system ground, and the drain is coupled to the power supply of the control circuit using a transformer.

[0049] It should be noted that the threshold voltage VA is less than the threshold voltage VB, and the threshold voltage VC is greater than the threshold voltage VD. The threshold voltages VA, VB, VC, and VD can all be flexibly set in the dynamic load switching intelligent response system according to the actual situation.

[0050] The second embodiment of the present invention proposes a dynamic load switching intelligent response system, and based on the first embodiment, as follows: Figures 1 to 3 As shown, it includes: intelligent response start-up logic control circuit, oscillator timing circuit, output overshoot slope detection circuit, intelligent maximum period response circuit, output pull-down slope detection circuit and PWM control logic circuit.

[0051] The intelligent response startup logic control circuit is connected to the output voltage of the switching power supply and a threshold voltage VA. When the output voltage of the switching power supply is detected to be greater than the threshold voltage VA, the dynamic load switching intelligent response system is allowed to operate. Specifically, the intelligent response startup logic control circuit includes a comparator unit with a first terminal, a second terminal, and an output terminal. The first terminal of the comparator unit is connected to the output voltage of the switching power supply, the second terminal of the comparator is connected to the threshold voltage VA, and the output terminal of the comparator unit outputs a logic signal CTR based on the comparison result. The comparator unit can be a comparator or any other form of comparator circuit. When the output voltage of the switching power supply is greater than the threshold voltage VA, CTR is at a logic high level, allowing the dynamic load switching intelligent response system to operate.

[0052] An oscillator timing circuit is used to output a time signal and a PWM period signal. The time signal includes the output voltage overshoot slope detection threshold time TIMEA, the output voltage pull-down slope detection threshold time TIMEB, and the basic unit time TIMEK. The PWM period signal includes the PWM basic maximum period TOFFA and the extreme PWM maximum period limit TOFFMAX.

[0053] The output overshoot slope detection circuit is connected to the switching power supply output voltage VOUT, threshold voltage VA, threshold voltage VB, and the output voltage overshoot slope detection threshold time TIMEA signal and the basic unit time TIMEK signal from the oscillator timing circuit. It generates a smart unit time TOFFB signal when the rise time of the switching power supply output voltage VOUT from threshold voltage VA to threshold voltage VB is less than the output voltage overshoot slope detection threshold time TIMEA. The smart unit time TOF... FB is equal to the product of the rising slope K of the switching power supply output voltage VOUT and the basic unit time TIMEK, where K is the rising slope of the switching power supply output voltage VOUT from the threshold voltage VA to the threshold voltage VB. Specifically, the output overshoot slope detection circuit detects the rising slope of the switching power supply output voltage VOUT from the threshold voltage VA to the threshold voltage VB. When the rising slope of the output voltage is detected to reach the threshold, that is, when the switching power supply output voltage VOUT is detected to rise too fast, the intelligent unit time TOFFB signal is output. The intelligent unit time TOFFB is positively correlated with the rising slope of the output voltage from the threshold voltage VA to the threshold voltage VB. The faster the rising slope of the switching power supply output voltage VOUT, the longer the intelligent unit time TOFFB is; the slower the rising slope of the switching power supply output voltage VOUT, the shorter the intelligent unit time TOFFB is.

[0054] Therefore, the calculation method for the intelligent unit time TOFFB is as follows:

[0055] TOFFB = K * TIMEK;

[0056] Where K is the slope of the rise of the switching power supply output voltage VOUT from the threshold voltage VA to the threshold voltage VB.

[0057] The intelligent maximum cycle response circuit connects to the PWM base maximum cycle TOFFA signal output by the oscillator timing circuit and the intelligent unit time TOFFB signal output by the overshoot slope detection circuit. When the output voltage VOUT of the switching power supply exceeds the threshold voltage VB, the intelligent maximum cycle response circuit counts the number of PWM waves and saves it as N. It then performs logical operations on the number of PWM waves N and the intelligent unit time TOFFB to obtain the intelligent cycle time TOFFN signal. The calculation method of the intelligent cycle time TOFFN signal is as follows: first, obtain the N*TOFFB signal through logical operations, and then add the N*TOFFB signal to the base maximum cycle TOFFA to obtain the intelligent cycle time TOFFN signal, TOFFN = N*TOFFB + TOFFA.

[0058] The output pull-down slope detection circuit is connected to the output voltage VOUT of the switching power supply, the threshold voltage VC, the threshold voltage VD, and the output voltage pull-down slope detection threshold time TIMEB signal output by the oscillator timing circuit. It is used to generate a PWMON logic signal immediately when the drop time of the output voltage VOUT from the threshold voltage VC to the threshold voltage VD is less than the output voltage pull-down slope detection threshold time TIMEB, without waiting for the end of the previous PWM complete cycle signal to start the PWM signal in advance.

[0059] The PWM control logic circuit receives the intelligent cycle time TOFFN signal output by the intelligent maximum cycle response circuit, the PWMON logic signal output by the output pull-down slope detection circuit, and the limit PWM maximum cycle limit TOFFMAX signal output by the oscillator timing circuit, and outputs a logic control signal PWM signal. The limit PWM maximum cycle limit TOFFMAX signal is used as the upper limit for the accumulation of the intelligent cycle time TOFFN signal. The output terminal of the PWM control logic circuit is connected to the control terminal of the switching transistor, and the logic control signal PWM signal output by the PWM control logic circuit is used to control the switching transistor's on / off state. When the PWM control logic circuit detects the PWMON logic signal output by the output pull-down slope detection circuit, it controls the switching transistor to turn on and output a PWM wave; when the PWM control logic circuit detects the intelligent cycle time TOFFN signal, it controls the switching transistor to turn off. The limit PWM maximum cycle limit TOFFMAX signal serves as the upper limit for the accumulation of the intelligent cycle time TOFFN signal; that is, when the intelligent cycle time TOFFN signal exceeds or is about to exceed the limit PWM maximum cycle limit TOFFMAX signal, a signal to control the switching transistor to turn off is directly output based on the limit PWM maximum cycle limit TOFFMAX signal. Figure 2 The switching transistor shown can be a MOSFET. The gate of the MOSFET is connected to the logic control signal PWM signal, the source is coupled to the system ground, and the drain is coupled to the power supply of the control circuit using a transformer.

[0060] It should be noted that the threshold voltage VA is less than the threshold voltage VB, and the threshold voltage VC is greater than the threshold voltage VD. The threshold voltages VA, VB, VC, and VD can all be flexibly set in the dynamic load switching intelligent response system according to the actual situation.

[0061] like Figure 3As shown, under normal circumstances, when switching from full load to no-load voltage, the output voltage continues to rise. When the output voltage VOUT of the switching power supply is detected to be greater than the set threshold voltage VA, the CTR signal output by the intelligent response start logic control circuit goes high, indicating that the system may enter a load switching state, allowing the dynamic load switching intelligent response system to operate. When the switching power supply output voltage VOUT exceeds VA, on the one hand, the overshoot slope detection circuit detects the time it takes for the switching power supply output voltage VOUT to rise from VA to VB. If this time is less than the internally set TIMEA time, it is considered that the switching power supply output voltage VOUT rises too fast, and active intervention is required. On the other hand, the slope K of the time for the switching power supply output voltage VOUT to rise from VA to VB is combined with the internally set TIMEK time to perform logical calculations to obtain a fixed adjustment time TOFFB, TOFFB = K * TIMEK. When the switching power supply output voltage VOUT is greater than VB, it immediately intervenes to actively intervene. Specifically, it immediately increases the maximum duty cycle of the PWM, where TOFFA is the basic maximum duty cycle of the PWM in the traditional structure. Starting from the moment the output voltage VOUT of the switching power supply exceeds VB, for each wave generated, an additional TOFFB is added to the traditional maximum PWM duty cycle TOFFA. Therefore, the duty cycle of the Nth PWM wave is N*TIMEB, which is equal to K*TIMEK*N. Consequently, as the number of PWM waves increases, the maximum PWM duty cycle decreases, and the energy supplied to the switching power supply also decreases. This inevitably leads to a lower output voltage overshoot, and K*TIMEK*N will be less than the internally set maximum duty cycle TOFFMAX.

[0062] When the control switches to full load, the load switching time is random. In extreme conditions, the load switches to full load at the end of the PWM high level, so the next wave must wait for the end of this duty cycle. Therefore, during this entire PWM duty cycle, the output voltage must drop sharply, and the VDD voltage will also drop. Because the previous state was no-load, the output voltage was in an overshoot state, resulting in a long PWM duty cycle. Therefore, in the next full-load state, the output voltages VOUT and VDD will have a long power-down time. During this rapid overshoot, when the output voltage VOUT drops to VC, the output pull-down slope detection circuit also starts working. If the time it takes for the output voltage to drop from VC to VD is less than the internally set TIMEB time, the output pull-down slope detection circuit will generate a PWMON logic signal, forcibly turning on the PWM to power the output voltage VOUT and VDD. This avoids the situation in conventional circuits where a full TOFFA time is required before the PWM is turned on. Because the PWM waveform is generated in a timely manner, the output voltage drop is small, and there will be no abnormal phenomenon where the VDD voltage drops below VDD_OFF and the entire switching power supply restarts.

[0063] In this specification, the illustrative expressions of the terms used do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0064] Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention shall be included within the scope of protection of this invention.

Claims

1. A dynamic load switching intelligent response system, characterized in that, include: An oscillator timing circuit is used to output a time signal and a PWM period signal. The time signal includes the output voltage overshoot slope detection threshold time TIMEA, the output voltage pull-down slope detection threshold time TIMEB, and the basic unit time TIMEK. The PWM period signal includes the PWM basic maximum period TOFFA and the extreme PWM maximum period limit TOFFMAX. The output overshoot slope detection circuit is connected to the output voltage of the switching power supply, the threshold voltage VA, the threshold voltage VB, and the output voltage overshoot slope detection threshold time TIMEA signal and the basic unit time TIMEK signal output by the oscillator timing circuit. It is used to generate the intelligent unit time TOFFB signal when the rise time of the switching power supply output voltage from the threshold voltage VA to the threshold voltage VB is less than the output voltage overshoot slope detection threshold time TIMEA. The intelligent maximum period response circuit connects to the PWM basic maximum period TOFFA signal output from the oscillator timing circuit and the intelligent unit time TOFFB signal output from the overshoot slope detection circuit. It is used to count the number of PWM waves and store it as N. Furthermore, it performs logical operations on the number of PWM waves N and the intelligent unit time TOFFB to obtain the intelligent period time TOFFN signal. The calculation method for the intelligent period time TOFFN signal is as follows: TOFFN = N * TOFFB + TOFFA The output pull-down slope detection circuit is connected to the output voltage of the switching power supply, the threshold voltage VC, the threshold voltage VD, and the output voltage pull-down slope detection threshold time TIMEB signal output by the oscillator timing circuit. It is used to immediately generate a PWMON logic signal when the drop time of the switching power supply output voltage from the threshold voltage VC to the threshold voltage VD is less than the output voltage pull-down slope detection threshold time TIMEB, so that the PWM signal is turned on in advance. The PWM control logic circuit receives the intelligent cycle time TOFFN signal output by the intelligent maximum cycle response circuit and the PWMON logic signal output by the output pull-down slope detection circuit, and outputs the logic control signal PWM signal.

2. The dynamic load switching intelligent response system according to claim 1, characterized in that, The output overshoot slope detection circuit detects the rise slope of the output voltage of the switching power supply from the threshold voltage VA to the threshold voltage VB. When the rise slope of the output voltage reaches the threshold, the intelligent unit time TOFFB signal is output. The intelligent unit time TOFFB is positively correlated with the rise slope of the output voltage from the threshold voltage VA to the threshold voltage VB.

3. The dynamic load switching intelligent response system according to claim 2, characterized in that, The method for calculating the intelligent unit time TOFFB is as follows: TOFFB = K * TIMEK; Where K is the slope of the rise of the switching power supply output voltage VOUT from the threshold voltage VA to the threshold voltage VB.

4. The dynamic load switching intelligent response system according to claim 1, characterized in that, The intelligent maximum cycle response circuit counts the number of PWM waves generated and saves it as N when the output voltage of the switching power supply exceeds the threshold voltage VB.

5. The dynamic load switching intelligent response system according to claim 1, characterized in that, The threshold voltage VA is less than the threshold voltage VB, and the threshold voltage VC is greater than the threshold voltage VD.

6. The dynamic load switching intelligent response system according to claim 1, characterized in that, The output terminal of the PWM control logic circuit is connected to the control terminal of the switching transistor, and the logic control signal (PWM signal) output by the PWM control logic circuit is used to control the switching transistor to turn on and off.

7. The dynamic load switching intelligent response system according to claim 1, characterized in that, The PWM control logic circuit is connected to the maximum period limit TOFFMAX signal of the oscillator timing circuit, and the maximum period limit TOFFMAX signal of the PWM is used as the upper limit of the accumulation of the intelligent period time TOFFN signal.

8. A dynamic load switching intelligent response system according to any one of claims 1 to 7, characterized in that, Also includes: The intelligent response startup logic control circuit is connected to the output voltage and threshold voltage VA of the switching power supply. When the output voltage of the switching power supply is detected to be greater than the threshold voltage VA, the dynamic load switching intelligent response system is allowed to operate.

9. The dynamic load switching intelligent response system according to claim 8, characterized in that, The intelligent response activation logic control circuit includes: The comparator unit has a first terminal, a second terminal, and an output terminal. The first terminal of the comparator unit is connected to the output voltage of the switching power supply, the second terminal of the comparator unit is connected to the threshold voltage VA, and the output terminal of the comparator unit outputs a logic signal CTR according to the comparison result. When the output voltage of the switching power supply is greater than the threshold voltage VA, CTR is at a logic high level, allowing the dynamic load switching intelligent response system to operate.

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