Time control circuit and control method

Abstract

The present invention discloses a time control circuit and a control method, wherein the time control circuit is configured to respectively obtain a switching cycle value and a forward timing value representing the previous switching cycle; the forward timing time of the current switching cycle is adjusted according to the cycle timing value and the forward timing value, wherein the forward timing time is advanced at the start of the next switching cycle to trigger a predetermined action, thereby realizing high-precision time control.

Description

Technical Field

[0001] The present invention relates to a power electronic technology, and more specifically, to a time control circuit and a control method. Background Art

[0002] The switching circuit needs to monitor and control the time of a specific event. The time control of a specific event can be roughly divided into two situations: 1. Counting backwards when a specific event occurs, and triggering the corresponding action after the timing is completed; 2. Counting forwards when a specific event occurs, and triggering the corresponding work after the timing is completed.

[0003] In the existing scheme, in the switching circuit, a specific event is timed forward, and it is considered that the interval of the event in adjacent switching cycles is consistent with the cycle value. Then, the time of occurrence of the event in the previous switching cycle is used to predict the time of occurrence of the event in the next switching cycle, such as Figure 1 As shown: first sample the switching cycle value and convert it into a voltage value; then use a timer with the same parameters to start timing when a specific event in the previous cycle occurs. When the timing reaches the voltage corresponding to the cycle value minus the voltage value Vref corresponding to the control time amount, an action occurs, thereby realizing the forward timing trigger action of the specific event.

[0004] However, voltage errors will occur in the process of converting the switching cycle value into a voltage value; the voltage value corresponding to the control time will have errors due to the deviation of the slope of the timing circuit in different batches; and the comparator of the circuit will have errors in different batches due to the existence of offset voltage. In addition, since the amplitude of the upper limit of the voltage value inside the chip is determined by the chip process, when the cycle value of the switching circuit is large, the voltage value corresponding to the smaller time will be very small. If there is a large voltage value error in the control circuit, it is impossible to achieve accurate control of the smaller time. Summary of the invention

[0005] In view of this, the present invention provides a time control circuit and a control method to solve the existing problems.

[0006] According to a first aspect of the present invention, a time control circuit is provided, characterized in that the time control circuit is configured to: respectively obtain a cycle timing value and a forward timing value representing a switching cycle value and a forward timing time of a previous switching cycle; and adjust the forward timing time of a current switching cycle according to the cycle timing value and the forward timing value, wherein the forward timing time is advanced at the start of the next switching cycle to trigger a predetermined action.

[0007] Preferably, the time control circuit includes: an error compensation circuit for generating an error compensation signal based on an error between a forward timing value representing the forward timing time of the previous switching cycle and a forward timing reference; and a threshold adjustment circuit configured to adjust the starting moment of the forward timing time of the current switching cycle based on the difference between the cycle timing value and the error compensation signal.

[0008] Preferably, the threshold adjustment circuit is configured to correct the cycle timing value according to the error compensation signal to obtain a forward timing threshold, and trigger the predetermined action when the time elapsed by the current switching cycle reaches the forward timing threshold.

[0009] Preferably, the time control circuit includes: a first timing circuit, which is used to time the switching cycle value of the previous switching cycle to convert the time detection quantity into a voltage detection quantity, and output a first voltage threshold representing the cycle timing value of the previous switching cycle; and a second timing circuit, which is used to time the switching cycle value of the current switching cycle to obtain a real-time timing value representing the time elapsed in the current switching cycle.

[0010] Preferably, the threshold adjustment circuit includes: a threshold generating circuit, which is used to subtract the first voltage threshold and the error compensation signal to output a second voltage threshold representing the forward timing threshold, and a first comparator, which inputs the real-time timing value at its positive input terminal and the second voltage threshold at its reverse input terminal, and outputs a signal that triggers the predetermined action.

[0011] Preferably, the first timing circuit includes: a first switch, which is closed once at the beginning of the previous switching cycle and immediately turned off, a first current source, which is connected in parallel with the first switch, a first capacitor, which is connected in parallel with the first current source and generates a first timing signal at both ends thereof, a second switch, which is connected in series with the first capacitor and is closed once at the beginning of the current switching cycle, a second capacitor, which is connected in parallel with the first capacitor, the second switch is connected between the first end of the first capacitor and the first end of the second capacitor, and the second capacitor generates the first voltage threshold at both ends thereof.

[0012] Preferably, the error compensation circuit includes: a second current source, controlled by the forward timing reference; a third current source, connected in series with the second current source and controlled by the forward timing time of the previous switching cycle; and a third capacitor, connected in parallel with the third current source, outputting the error compensation signal.

[0013] Preferably, the threshold generating circuit includes: a fourth current source, a first end of which receives the first voltage threshold; a fifth current source, connected in series with the fourth current source, a first end of the fifth current source receives the error compensation signal; and a first resistor, connected in parallel with the fifth current source, outputting the second voltage threshold.

[0014] Preferably, the second timing circuit includes: a third switch, which is closed once at the beginning of the current switching cycle, a sixth current source, which is connected in parallel with the third switch, and a fourth capacitor, which is connected in parallel with the sixth current source and generates a real-time timing voltage representing the real-time timing value at both ends thereof.

[0015] Preferably, it also includes a forward timing generation circuit, which includes: a second comparator, whose positive input terminal inputs a drain-source voltage, whose reverse input terminal inputs a reference voltage, and outputs a second comparison signal; a first trigger circuit, whose D terminal inputs a high level, the clock terminal is connected to a drive shutdown signal, the reset terminal receives the second comparison signal, and outputs a forward timing signal representing the forward timing time of the previous switching cycle.

[0016] Preferably, the first current source and the sixth current source have the same parameters, and the first capacitor and the fourth capacitor also have the same parameters.

[0017] Preferably, the second current source, the third current source, the fourth current source and the fifth current source have the same parameters.

[0018] According to a second aspect of the present invention, there is provided a time control method, characterized in that it includes: respectively obtaining a cycle timing value and a forward timing value representing the switching cycle value and the forward timing time of the previous switching cycle; adjusting the forward timing time of the current switching cycle according to the cycle timing value and the forward timing value, wherein the forward timing is advanced at the start time of the next switching cycle to trigger a predetermined action.

[0019] Preferably, an error compensation signal is generated according to the error between a forward timing value representing the forward timing time of the previous switching cycle and a forward timing reference, and the start time of the forward timing time is adjusted according to the difference between the cycle timing value and the error compensation signal.

[0020] Preferably, it also includes: timing the switching cycle value of the current switching cycle to obtain a real-time timing value, correcting the cycle timing value according to the error compensation signal to obtain a forward timing threshold, and when the real-time timing value of the current switching cycle reaches the forward timing threshold, triggering the predetermined action.

[0021] Preferably, the method further comprises: timing the switching cycle value of the previous switching cycle to convert the time detection quantity into a voltage detection quantity, and outputting a first voltage threshold representing the cycle timing value of the previous switching cycle.

[0022] Preferably, it also includes: subtracting the first voltage threshold and the error compensation signal to output a second voltage threshold representing the forward timing threshold; when the real-time timing voltage representing the real-time timing value reaches the second voltage threshold, triggering the predetermined action.

[0023] The time control circuit and method provided by the present invention can realize high-precision time control by respectively obtaining the switching cycle value representing the previous switching cycle and the cycle timing value representing the forward timing time and the forward timing value; and adjusting the forward timing time of the current switching cycle according to the cycle timing value and the forward timing value, wherein the predetermined action is triggered in advance of the forward timing at the start of the next switching cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0025] Figure 1 A schematic diagram of triggering actions when a specific event in adjacent cycles of the prior art occurs and counts forward;

[0026] Figure 2 is a structural diagram of a time control circuit of the present invention;

[0027] Figure 3 is a specific circuit diagram of the time control circuit of the present invention;

[0028] Figure 4 A specific circuit diagram of a forward timing generating circuit of the present invention;

[0029] Figure 5 A specific circuit diagram of the timing reference generation circuit of the present invention;

[0030] Figure 6 The working waveform of the time control circuit of the present invention is adopted;

[0031] Figure 7 It is a flow chart of the time control method of the present invention. DETAILED DESCRIPTION

[0032] The present invention is described below based on embodiments, but the present invention is not limited to these embodiments. In the detailed description of the present invention below, some specific details are described in detail. It is possible for a person skilled in the art to fully understand the present invention without the description of these details. In order to avoid confusing the essence of the present invention, known methods, processes, flows, components and circuits are not described in detail.

[0033] In addition, persons of ordinary skill in the art will appreciate that the drawings provided herein are for illustration purposes and are not necessarily drawn to scale.

[0034] At the same time, it should be understood that in the following description, "circuit" refers to a conductive loop composed of at least one element or subcircuit through electrical connection or electromagnetic connection. When an element or circuit is said to be "connected to" another element or an element / circuit is said to be "connected between" two nodes, it can be directly coupled or connected to another element or there can be an intermediate element, and the connection between the elements can be physical, logical, or a combination thereof. On the contrary, when an element is said to be "directly coupled to" or "directly connected to" another element, it means that there is no intermediate element between the two.

[0035] Unless the context clearly requires otherwise, throughout the specification and claims, the words "include", "comprising" and similar words should be interpreted in an inclusive sense rather than an exclusive or exhaustive sense; that is, in the sense of "including but not limited to".

[0036] In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0037] The present invention provides a time control circuit, which is configured to respectively obtain a switching cycle value and a cycle timing value and a forward timing value representing the forward timing time of the previous switching cycle; adjust the forward timing time of the current switching cycle according to the cycle timing value and the forward timing value, wherein the forward timing time is advanced at the start of the next switching cycle to trigger a predetermined action. In the present application, taking the synchronous rectifier circuit as an example, the forward timing time is the dead time, and the start time of each switching cycle is the turn-on time of the primary tube. In other embodiments, the forward timing time may also be other times. For example, in some zero-voltage turn-on schemes, the synchronous rectifier tube may also be turned on once in advance at the forward timing time before the start of the next switching cycle to reduce the voltage across the main power tube. No limitation is made here.

[0038] Figure 2 FIG. 1 is a structural diagram of the time control circuit of the present invention. Figure 2 As shown, the time control circuit includes an error compensation circuit 22 and a threshold adjustment circuit 23. The error compensation circuit 22 is used to generate an error compensation signal Vcom according to the error between the forward timing value representing the forward timing time of the previous switching cycle and the forward timing reference. The threshold adjustment circuit 23 is configured to adjust the starting time of the forward timing time of the current switching cycle according to the difference between the cycle timing value of the previous switching cycle and the error compensation signal Vcom.

[0039] Furthermore, the threshold adjustment circuit 23 is configured to correct the cycle timing value of the previous switching cycle acquired according to the error compensation signal Vcom to obtain a forward timing threshold of the current cycle, and trigger the predetermined action when the time elapsed in the current switching cycle reaches the forward timing threshold.

[0040] The time control circuit also includes a first timing circuit 21 and a second timing circuit 24. The first timing circuit 21 is used to time the switching cycle value of the previous switching cycle to convert the time detection amount into a voltage detection amount, output a first voltage threshold V1 representing the cycle timing value of the previous switching cycle, and maintain it until the next switching cycle. The second timing circuit 24 is used to time the switching cycle value of the current cycle to obtain a real-time timing value representing the time elapsed in the current switching cycle. The threshold adjustment circuit 23 includes a threshold generation circuit 25 and a first comparator 26. The threshold generation circuit 25 is used to output a second voltage threshold V2 representing the forward timing threshold of the current switching cycle according to the difference between the first voltage threshold V1 and the error compensation signal Vcom. The first comparator 26 inputs the real-time timing value at its positive input terminal and the second voltage threshold V2 at its reverse input terminal, and outputs a signal that triggers the predetermined action.

[0041] The time control circuit may further include a forward timing generation circuit and a timing reference generation circuit, wherein the forward timing generation circuit is used to generate a forward timing time signal representing the forward timing time of the previous switching cycle; and the timing reference generation circuit is used to generate a forward timing reference signal representing the forward timing reference. The error compensation circuit 22 receives the forward timing time signal and the forward timing reference signal to generate the error compensation signal Vcom.

[0042] In the last switching cycle, a timing circuit is used to obtain the switching cycle value and actual dead time of the last switching cycle, and the actual dead time of the last switching cycle is compared with the reference dead time to obtain an error compensation value. Then, correction is made based on the switching cycle value of the last switching cycle according to the error compensation value to obtain the voltage value corresponding to the start time of the dead time of the current switching cycle. When the voltage value corresponding to the time elapsed in the current switching cycle reaches the voltage value corresponding to the start time of the dead time of the current switching cycle, the dead time of the current switching cycle starts.

[0043] It should be noted that adjusting the dead time of the current switching cycle to the reference dead time usually requires adjustment of several switching cycles, and cannot be achieved by adjusting the switching cycle once.

[0044] Figure 3 FIG. 1 is a specific circuit diagram of the time control circuit of the present invention. Figure 3 As shown, the first timing circuit 21 includes a first switch S1, a first current source I1, a first capacitor C1, a second capacitor C2 and a second switch S2. The first switch S1 is connected in parallel with the first current source I1, and its first end is connected to the first end of the first current source I1, and its second end is grounded. The first capacitor C1 is connected in parallel with the first current source I1, and a first timing signal is generated at both ends thereof. The second switch S2, whose first end is connected to the first end of the first capacitor C1, is connected in series with the first capacitor C1. The second capacitor C2, whose first end is connected to the second end of the second switch S2, and its second end is grounded. At the beginning of the last switching cycle, the first switch S1 is controlled to close once and then immediately disconnected, so that the first timing circuit starts timing from zero, and generates a first timing signal at both ends of the first capacitor C1; at the beginning of the current switching cycle, the second switch is closed once, and a first voltage threshold V1 representing the cycle timing value of the last switching cycle is generated at both ends of the second capacitor C2. Subsequently, the first switch S1 is controlled to close once again and then immediately disconnected, and the timing of the current switching cycle begins. It should be noted that the delayed closing time of the first switch S1 can be compensated by the negative feedback inside the circuit, that is, can be ignored.

[0045] The error compensation circuit 22 includes a second current source I2, a third current source I3 and a third capacitor C3. The second current source I2 is controlled by a forward timing reference signal representing a forward timing reference; the third current source I3 is connected in series with the second current source I2 and is controlled by a forward timing time signal representing the forward timing time of the previous switching cycle; and the third capacitor C3 is connected in parallel with the third current source I3 to output the error compensation signal Vcom. The forward timing reference signal controls the second current source I2 to generate a second current, and the forward timing time signal of the previous switching cycle controls the third current source I3 to generate a third current, so that when the forward timing time is greater than the forward timing reference, the error compensation signal Vcom decreases, and vice versa. It should be understood that the present invention only provides one implementation of the error compensation circuit, and other circuits that can generate an error compensation signal based on the error between the forward timing value representing the forward timing time of the previous switching cycle and the forward timing reference can be applied here, and the present invention is not limited.

[0046] The threshold generation circuit 25 includes a fourth current source I4, a fifth current source I5 and a first resistor R1. The fourth current source I4, at its first end, receives the first voltage threshold V1; the fifth current source I5 is connected in series with the fourth current source I4, and the first end of the fifth current source I5 receives the error compensation signal Vcom; and the first resistor R1 is connected in parallel with the fifth current source I5 to output a second voltage threshold V2 representing the forward timing threshold. It should be understood that the present invention only provides one implementation of the threshold generation circuit, and other methods that can generate the second voltage threshold V2 representing the forward timing threshold based on the difference between the first voltage threshold and the error compensation signal can be applied here, and the present invention is not limited thereto.

[0047] When the forward timing time is greater than the forward timing reference, the error compensation signal Vcom decreases, thereby increasing the difference between the first voltage threshold V1 and the error compensation signal Vcom, that is, the second voltage threshold V2 increases, thereby delaying the trigger action; conversely, when the forward timing time is less than the forward timing reference, the error compensation signal Vcom increases, thereby decreasing the difference between the first voltage threshold V1 and the error compensation signal Vcom, that is, the second voltage threshold V2 decreases, thereby advancing the trigger action.

[0048] The second timing circuit 24 includes a third switch S3, a sixth current source I6 and a fourth capacitor C4. The third switch S3 is closed once at the beginning of the current switching cycle and then immediately opened, and the second timing circuit 24 starts timing from zero; the sixth current source I6 is connected in parallel with the third switch, and the fourth capacitor C4 is connected in parallel with the sixth current source, and the second timing signal V3 representing the real-time timing value of the current switching cycle is generated at both ends thereof.

[0049] When the second timing signal V3 reaches the second voltage threshold V2, the predetermined action is triggered. In this embodiment, when the second timing signal V3 reaches the second voltage threshold V2, it means that a driving shutdown signal is generated and the dead time starts.

[0050] Figure 4 Detailed circuit diagram of the forward timing generation circuit of the present invention. Figure 4 As shown, the forward timing generation circuit includes a second comparator U2 and a first trigger circuit U3. The positive input terminal of the second comparator U2 inputs the drain-source voltage Vds, and the negative input terminal thereof inputs the reference voltage Vref1, and outputs a second comparison signal. The D terminal of the first trigger circuit U3 inputs a high level, the clock terminal CLK is connected to the driving shutdown signal of the synchronous rectification circuit, the reset terminal RESET receives the second comparison signal, and outputs a forward timing time signal. The reference voltage Vref1 is a voltage significantly greater than 0, and at the same time less than the maximum value of the drain-source voltage Vds.

[0051] When the driving shutdown signal of the synchronous rectification circuit appears, the first trigger circuit U3 outputs a high level; when the drain-source voltage Vds is greater than the reference voltage Vref1, the output second comparison signal is a high level, that is, the reset terminal RESET of the first trigger circuit U3 receives a high level, and the first trigger circuit U3 outputs a low level. Specifically, when the PWM driving shutdown signal of the synchronous rectification circuit appears, the forward timing time signal rises from a low level to a high level until the drain-source voltage Vds is greater than the reference voltage Vref1, and the forward timing signal drops from a high level to a low level.

[0052] Figure 5 FIG. 1 is a specific circuit diagram of the timing reference generation circuit of the present invention. Figure 5 As shown, the timing reference generating circuit includes a third timing circuit 51, a third comparator U4 and a second trigger U5. Among them, the third timing circuit 51 includes a fourth switch S4, a seventh current source I7 and a fifth capacitor C5. The fourth switch S4 is connected in parallel with the seventh current source I7 and is controlled by the driving shutdown signal of the synchronous rectification circuit; the seventh current source I7 is connected in parallel with the fifth capacitor C5 to generate a third voltage across the fifth capacitor C5. The third voltage is input to the positive input terminal of the third comparator U4, and the voltage reference Vref2 is input to the negative input terminal thereof, and a third comparison signal is output. A high level is input to the D terminal of the second trigger U5, the clock terminal CLK is connected to the driving shutdown signal of the synchronous rectification circuit, the reset terminal RESET receives the third comparison signal, and outputs a forward timing reference signal.

[0053] When the driving shutdown signal appears, the second trigger U5 outputs a high level, and the fourth switch S4 is closed once and then immediately opened, and the third timing circuit 51 starts timing. When the timing reaches the design value T=C5*Vref2 / I7, the output third comparison signal is high, that is, the reset terminal RESET of the second trigger U5 receives a high level, and the second trigger U5 outputs a low level. Specifically, when the PWM driving shutdown signal of the synchronous rectification circuit appears, the forward timing reference signal rises from a low level to a high level until the set design value T ends, and the forward timing reference signal drops from a high level to a low level.

[0054] It should be noted that, here, the first current source I1, the sixth current source I6 and the seventh current source I7 have the same parameters, and the first capacitor C1, the fourth capacitor C4 and the fifth capacitor C5 also have the same parameters. The purpose of doing so is that the same voltage value can be used in different timing circuits to represent the same time, so as to facilitate time comparison.

[0055] The second current source I2 , the third current source I3 , the fourth current source I4 and the fifth current source I5 have the same parameters.

[0056] Figure 6 is the working waveform of the time control circuit of the present invention. Figure 6 As shown:

[0057] The time when the forward timing time signal and the forward timing reference signal of the previous switching cycle start is time t1, that is, the actual dead time start time of the previous switching cycle;

[0058] At time t2, the forward timing reference signal ends, and the current source I2 stops generating current. Thereafter, the forward timing time signal controls the current source I3 to discharge the third capacitor C3, thereby reducing the error compensation signal Vcom.

[0059] At time t3, the forward timing time of the previous switching cycle ends, that is, the previous switching cycle ends, the error compensation signal Vcom reaches the minimum, and the first timing circuit generates a first voltage threshold V1 representing the cycle timing value of the previous switching cycle; the threshold generating circuit subtracts the first voltage threshold V1 from the error compensation signal Vcom, and outputs a second voltage threshold V2 representing the forward timing threshold. It can be seen from the figure that the second voltage threshold V2 has increased compared with the previous cycle.

[0060] At time t4, the second timing signal representing the real-time timing value of the current switching cycle reaches the second voltage threshold V2, triggering the predetermined action, that is, the dead time of the current switching cycle begins. As can be seen from the figure, the time of triggering the predetermined action is delayed compared to the previous switching cycle, which means that the dead time in the current switching cycle is shortened.

[0061] At t5, the current switching cycle ends, the forward timing time ends, and the forward timing reference signal has not yet ended. Therefore, the forward timing reference signal controls the current source I2 to charge the third capacitor C3, so that the error compensation signal Vcom increases until t6, when the forward timing reference signal ends timing, and the error compensation signal Vcom reaches the maximum and maintains, so as to advance the time when the predetermined action is triggered in the next switching cycle. After the above cycles are repeated, the actual forward timing time is finally equal to the forward timing reference time.

[0062] Figure 7 This is a flow chart of the time control method of the present invention. It includes:

[0063] Step S1: respectively obtaining a switching cycle value representing the last switching cycle and a cycle timing value and a forward timing value representing the forward timing time.

[0064] Step S2: adjusting the forward timing time of the current switching cycle according to the cycle timing value and the forward timing value, wherein the forward timing is advanced at the start time of the next switching cycle to trigger a predetermined action;

[0065] Specifically, an error compensation signal is generated according to the error between a forward timing value representing the forward timing time of the previous switching cycle and a forward timing reference; and a start time of the forward timing time is adjusted according to the difference between the cycle timing value and the error compensation signal.

[0066] Further: timing the switching cycle value of the current switching cycle to obtain a real-time timing value,

[0067] The period timing value is corrected according to the error compensation signal to obtain a forward timing threshold, and the predetermined action is triggered when the real-time timing value of the current switching cycle reaches the forward timing threshold.

[0068] Furthermore, the switching cycle value of the previous switching cycle is timed to convert the time detection quantity into a voltage detection quantity, and a first voltage threshold representing the cycle timing value of the previous switching cycle is output; the first voltage threshold and the error compensation signal are subtracted to output a second voltage threshold representing the forward timing threshold; when the real-time timing voltage representing the real-time timing value reaches the second voltage threshold, the predetermined action is triggered.

[0069] Step S3: Record the forward timing time of the current switching cycle and the switching cycle value of the current switching cycle.

[0070] It can be seen that the time control circuit and method of the present invention respectively time the switching cycle value and the forward timing time of the previous switching cycle to obtain the cycle timing value and the forward timing value; and adjust the forward timing time of the current switching cycle according to the cycle timing value and the forward timing value, wherein the predetermined action is triggered in advance of the forward timing at the start of the next switching cycle. High-precision time control can be achieved.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A time control circuit, characterized in that: The time control circuit comprises: A first timing circuit is configured to time the switching cycle value of the previous switching cycle to obtain the cycle timing value of the previous switching cycle; A second timing circuit is configured to time the switching cycle value of the current switching cycle to obtain a real-time timing value representing the time elapsed in the current switching cycle; an error compensation circuit configured to generate an error compensation signal according to an error between a forward timing value representing a forward timing time of a previous switching cycle and a forward timing reference; as well as A threshold adjustment circuit, which adjusts the forward timing time of the current switching cycle according to the cycle timing value of the previous switching cycle and the error compensation signal, and triggers a predetermined action when the real-time timing value reaches the forward timing time of the current switching cycle; So that the predetermined action is triggered in advance of the forward timing time of the current switching cycle at the start time of the next switching cycle.

2. The time control circuit according to claim 1, characterized in that : The threshold adjustment circuit is configured to adjust the starting moment of the forward timing time of the current switching cycle according to the difference between the cycle timing value and the error compensation signal.

3. The time control circuit according to claim 1, characterized in that: The threshold adjustment circuit is configured to modify the cycle timing value according to the error compensation signal to obtain a forward timing threshold, and trigger the predetermined action when the time elapsed in the current switching cycle reaches the forward timing threshold.

4. The time control circuit according to claim 1, characterized in that: The first timing circuit is used to time the switching cycle value of the previous switching cycle to convert the time detection quantity into a voltage detection quantity, and output a first voltage threshold representing the cycle timing value of the previous switching cycle.

5. The time control circuit according to claim 4, characterized in that: The threshold adjustment circuit comprises: a threshold generating circuit, configured to perform a subtraction between the first voltage threshold and the error compensation signal, and output a second voltage threshold representing the forward timing threshold, and The first comparator has the real-time timing value inputted into its positive input terminal and the second voltage threshold inputted into its negative input terminal, and outputs a signal for triggering the predetermined action.

6. The time control circuit according to claim 4, characterized in that: The first timing circuit comprises: The first switch is closed once at the beginning of the last switching cycle and immediately turned off. a first current source connected in parallel with the first switch, A first capacitor is connected in parallel with the first current source to generate a first timing signal at both ends thereof, a second switch connected in series with the first capacitor and closed once at the beginning of a current switching cycle, and The second capacitor is connected in parallel with the first capacitor, the second switch is connected between the first end of the first capacitor and the first end of the second capacitor, and the second capacitor generates the first voltage threshold at both ends thereof.

7. The time control circuit according to claim 5, characterized in that: The threshold generating circuit comprises: a fourth current source, a first end of which receives the first voltage threshold; a fifth current source, connected in series with the fourth current source, wherein a first terminal of the fifth current source receives the error compensation signal; and The first resistor is connected in parallel with the fifth current source and outputs the second voltage threshold.

8. The time control circuit according to claim 7, characterized in that: The error compensation circuit comprises: a second current source controlled by the forward timing reference; a third current source connected in series with the second current source and controlled by the forward timing time of the previous switching cycle; and The third capacitor is connected in parallel with the third current source and outputs the error compensation signal.

9. The time control circuit according to claim 6, characterized in that: The second timing circuit comprises: The third switch is closed once at the beginning of the current switching cycle. a sixth current source connected in parallel with the third switch, and A fourth capacitor is connected in parallel with the sixth current source and generates a real-time timing voltage representing the real-time timing value at both ends of the fourth capacitor.

10. The time control circuit according to claim 1, characterized in that: Also included is a forward timing generation circuit, the forward timing generation circuit comprising: A second comparator, a positive input terminal of which inputs a drain-source voltage, a negative input terminal of which inputs a reference voltage, and outputs a second comparison signal; and The first trigger circuit has a D terminal input of a high level, a clock terminal connected to a driving shutdown signal, a reset terminal receiving the second comparison signal, and outputting a forward timing signal representing the forward timing time of the previous switching cycle.

11. The time control circuit according to claim 9, characterized in that: The first current source and the sixth current source have the same parameters, and the first capacitor and the fourth capacitor also have the same parameters.

12. The time control circuit according to claim 8, characterized in that: The second current source, the third current source, the fourth current source and the fifth current source have the same parameters.

13. A time control method, characterized in that: include: Timing the switching cycle value of the previous switching cycle to obtain the switching cycle timing value of the previous switching cycle; as well as timing the switching cycle value of the current switching cycle to obtain a real-time timing value representing the time elapsed in the current switching cycle; generating an error compensation signal according to an error between a forward timing value representing a forward timing time of a previous switching cycle and a forward timing reference; Adjusting the forward timing time of the current switching cycle according to the switching cycle timing value of the previous switching cycle and the error compensation signal, and triggering a predetermined action when the real-time timing value reaches the forward timing time of the current switching cycle; So that the predetermined action is triggered in advance of the forward timing time of the current switching cycle at the start time of the next switching cycle.

14. The time control method according to claim 13, characterized in that: The starting time of the forward timing time of the current switching cycle is adjusted according to the difference between the cycle timing value and the error compensation signal.

15. The time control method according to claim 13, characterized in that: Also includes: The switching cycle value of the current switching cycle is timed to obtain the real-time timing value, The period timing value is corrected according to the error compensation signal to obtain a forward timing threshold, and the predetermined action is triggered when the real-time timing value of the current switching cycle reaches the forward timing threshold.

16. The time control method according to claim 15, characterized in that: Also includes: The switching cycle value of the last switching cycle is timed to convert the time detection quantity into a voltage detection quantity, and a first voltage threshold representing the cycle timing value of the last switching cycle is output.

17. The time control method according to claim 16, characterized in that: Also includes: Subtract the first voltage threshold from the error compensation signal to output a second voltage threshold representing the forward timing threshold; as well as When the real-time timing voltage representing the real-time timing value reaches the second voltage threshold, the predetermined action is triggered.

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