Self-tracking zero-crossing detection method, circuit and device with three-mode search mode
Through the self-tracking zero-crossing detection method of the three-mode search method, the unity gain is dynamically adjusted and the search mode is switched, which solves the trade-off between TOFF accuracy and adjustment time, and achieves the effect of quickly finding the optimal value of TOFF.
Patent Information
- Application Number
- CN202510030183.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-08
- Publication Date
- 2025-04-18
AI Technical Summary
In the prior art, the large range of load current changes leads to a trade-off relationship between the accuracy of the conduction time of the freewheeling tube and the adjustment time, and it is difficult to accurately adjust the TOFF in a short time.
The self-tracking zero-crossing detection method is adopted with the three-mode search method. By collecting the signal to be tracked and comparing it with the target time window, the unity gain is dynamically adjusted, and the search mode is switched to quickly achieve the TOFF optimal value. Specifically, the use of variable gain mode and successive approximation mode is included.
It realizes that when the load current changes greatly, the optimal value of TOFF is quickly found, the trade-off relationship between the accuracy of TOFF and the adjustment time is optimized, and the risk of reverse inductor current is reduced.
Smart Images
Figure CN119846299A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the field of electronic technology, and in particular, relates to a self-tracking zero-crossing detection method, circuit and device with a three-mode search method. Background Art
[0002] With the rapid development of wearable devices and IoT devices, the demand for reducing system power consumption in circuit design is growing; since such devices are often powered by low-voltage batteries, a boost switching power converter is required to convert the battery voltage into the voltage required for normal operation of the device. Such devices often operate in standby or sleep mode with a small operating current, so the power converter is required to achieve high-efficiency operation in discontinuous current mode (DCM). In order to prevent reverse inductor current in DCM, the circuit must integrate a zero crossing detection (ZCD) function module so that the freewheeling tube is turned off in time when the inductor current drops to zero during the freewheeling tube conduction phase (TOFF). Since the reverse inductor current not only reduces the efficiency of the boost switching power converter, but also has the risk of damaging the circuit and power supply, the importance of the zero crossing detection circuit (ZCD circuit) is self-evident.
[0003] However, the zero-crossing detection circuit involved in the prior art has a large load current range, which will lead to a large variation range of the freewheeling tube conduction time TOFF, and it is necessary to refine the TOFF unit increment to improve the TOFF accuracy under different loads. However, although increasing the number of control code bits can improve TOFF accuracy, it takes a longer adjustment time to iterate to the optimal TOFF value, that is, there is a trade-off between TOFF accuracy and adjustment time.
[0004] Therefore, a self-tracking zero-crossing detection method is particularly needed to optimize the trade-off relationship between the accuracy of the freewheeling tube conduction time and the adjustment time when the load current changes in a large range. Summary of the invention
[0005] The purpose of the present application is to provide a self-tracking zero-crossing detection method, circuit and device with a three-mode search method, so as to at least solve one technical problem in the prior art.
[0006] The technical solution of this application is:
[0007] A self-tracking zero-crossing detection method with a three-mode search method, comprising:
[0008] Collect the signal to be tracked and compare it with the target time window to determine whether the current freewheeling tube conduction time allows the freewheeling tube to be accurately turned off when the inductor current is zero, and output an update request for the freewheeling tube conduction time in the next cycle;
[0009] Obtaining an update request for the conduction time of the freewheeling tube in the next cycle, and converting the update request into a switching request for the search mode, which is ultimately expressed as a single change in the number of bits of different control codes;
[0010] The number of bits of the control code that changes at a single time is monitored, and the unit gain is dynamically adjusted according to the change of the number of bits of the control code that changes at a single time within a continuous period, so as to achieve the optimal freewheeling tube conduction time at the fastest speed.
[0011] The obtaining of the update request for the conduction time of the freewheeling tube in the next cycle and converting the update request into a switching request for the search mode, which is finally expressed as different single-time change digits of the control code; monitoring the single-time change digits of the control code and dynamically adjusting the unit gain according to the change of the single-time change digits of the control code to achieve the optimal conduction time of the freewheeling tube at the fastest speed, including:
[0012] Receive an update request for the conduction time of the freewheeling tube in the next cycle, and convert the update request into a switching request for the search mode, which is ultimately expressed as a single change in the number of bits of a different control code, that is, a unit gain Δk;
[0013] When it is detected that the freewheeling tube conduction time update request has been increasing or decreasing for at least 7 cycles, a mode switching request is sent to switch to the variable gain mode. At this time, the unit gain Δk is increased to a preset multiple to search for the optimal value of the freewheeling tube conduction time.
[0014] When it is detected that the freewheeling tube conduction time update request has been increasing or decreasing for at least 7 cycles, a mode switching request is sent to switch to a variable gain mode, and the unit gain Δk at this time is increased to a preset multiple, and also includes:
[0015] If the variable gain mode fails to find the optimal value of the freewheeling tube conduction time within the set period, then:
[0016] A mode switching request will be sent again to switch to the successive approximation mode to ensure that the unit gain Δk is set cycle by cycle using the successive approximation method to achieve the optimal TOFF value at the fastest speed.
[0017] The collected signal to be tracked is compared with the target time window to determine whether the current freewheeling tube conduction time allows the freewheeling tube to be accurately turned off when the inductor current is zero, and output an update request for the freewheeling tube conduction time of the next cycle, including:
[0018] Compare the falling edge of the signal to be tracked with the target time window to capture and determine whether the current freewheeling diode conduction time allows the freewheeling diode to be accurately turned off when the inductor current is zero;
[0019] And, output a 2-bit signal [S1, S0] as a request to update the conduction time of the freewheeling tube in the next cycle.
[0020] The next cycle freewheeling tube conduction time update request includes three states:
[0021] The conduction time of the freewheeling tube in the next cycle remains unchanged at the current value.
[0022] The freewheeling tube conduction time of the next cycle needs to be increased based on the current value, and
[0023] The TOFF of the next cycle needs to be reduced based on the current value.
[0024] A self-tracking zero-crossing detection circuit with a three-mode search method, based on the above self-tracking zero-crossing detection method, comprises:
[0025] The state detection subcircuit is connected to the signal terminal to be tracked, and is used to collect the signal to be tracked and compare it with the target time window to determine whether the current freewheeling tube conduction time allows the freewheeling tube to be accurately turned off when the inductor current is zero, and output an update request for the freewheeling tube conduction time in the next cycle;
[0026] The mode selection subcircuit is connected to the output end of the state detection subcircuit, and is used to obtain an update request for the conduction time of the freewheeling tube in the next cycle, and convert the update request into a switching request of the search mode, which is finally expressed as different single-time change bits of the control code; monitor the single-time change bits of the control code, and dynamically adjust the unit gain according to the change of the single-time change bits of the control code in continuous cycles, so as to achieve the optimal conduction time of the freewheeling tube at the fastest speed;
[0027] The control subcircuit is connected to the output end of the mode selection subcircuit, and is used to generate a set freewheeling tube conduction time and update the control code according to the control signal.
[0028] The mode selection subcircuit comprises:
[0029] A mode determiner, connected to the output end of the state detection subcircuit, for receiving an update request for the next state;
[0030] The three-mode controller is electrically connected to the mode determiner and is used to convert the update request into a switching request of the search mode, which is finally expressed as a single change bit number of different control codes, that is, a unit gain Δk.
[0031] A boost switch power supply conversion device includes: the self-tracking zero-crossing detection circuit with a three-mode search method as described above.
[0032] A boost switching power supply conversion control electronic device, comprising:
[0033] Storage medium for storing computer programs;
[0034] The processing unit exchanges data with the storage medium and is used to execute the computer program through the processing unit to perform the steps of the self-tracking zero-crossing detection method as described above when performing the boost switching power supply conversion control.
[0035] A computer readable storage medium:
[0036] The computer readable storage medium stores a computer program;
[0037] When the computer program is running, the steps of the self-tracking zero-crossing detection method described above are executed.
[0038] The beneficial effects of this application include at least:
[0039] The method described in the present application, after collecting the signal to be tracked, compares it with the target time window to determine whether the current freewheeling tube conduction time allows the freewheeling tube to be accurately turned off when the inductor current is zero, and outputs an update request for the freewheeling tube conduction time of the next cycle; then obtains the update request for the freewheeling tube conduction time of the next cycle, and converts the update request into a switching request for the search mode, which is ultimately manifested as different control code single-time change bits; finally, monitors the control code single-time change bits, and dynamically adjusts the unit gain according to the change of the control code single-time change bits in continuous cycles, so as to achieve the optimal freewheeling tube conduction time at the fastest speed. The method described in the present invention increases the search logic of variable gain and successive approximation, and in T OFF It can achieve faster optimal value search when the optimal value changes greatly; it also has a linear search mode to ensure that T OFF The accuracy of the present invention enables the optimization of T when the load current varies over a large range. OFF The trade-off between accuracy and adjustment time. BRIEF DESCRIPTION OF THE DRAWINGS
[0040] Figure 1 This is the traditional ZCD circuit diagram;
[0041] Figure 2 This is the digital self-tracing ZCD circuit diagram using a D flip-flop to capture the SW node;
[0042] Figure 3 yes Figure 2 Different T in the circuit diagram OFF Corresponding key waveforms;
[0043] Figure 4 It is a flow chart of the self-tracking zero-crossing detection method with a three-mode search method according to the present invention;
[0044] Figure 5 It is a circuit diagram of a self-tracking zero-crossing detection circuit with a three-mode search method described in the present application;
[0045] Figure 6 yes Figure 5 The working flow diagram of the mode selection subcircuit in the circuit shown;
[0046] Figure 7 is T in different search modes OFF Adjust the speed contrast waveform. DETAILED DESCRIPTION
[0047] The present application is further described below in conjunction with the accompanying drawings.
[0048] In order to explain the present application in more detail, it is necessary to explain the prior art in detail.
[0049] like Figure 1 The traditional ZCD circuit shown in part (a) compares the voltages of the SW node and the VOUT node to determine whether the current inductor current is zero. Part (b) shows the key waveform of the circuit; when the inductor current is greater than zero, the node voltage SW>V OUT , at this time the comparator output ZCD = 0; when the inductor current is less than or equal to zero, the node voltage SW <V OUT , at this time, the comparator outputs ZCD=1, indicating that the current has entered DCM, and the controller will turn off the PMOS tube used for freewheeling. The offset voltage of the comparator is crucial to the accuracy of the ZCD circuit and determines its flip timing. When the offset voltage is greater than zero, the freewheeling tube is turned off too early, and the inductor current flows through the body diode, causing the SW node to have a voltage greater than V OUT When the offset voltage is less than zero, the freewheeling diode is turned off too late, and the inductor current flows in the reverse direction, causing the SW node to be lower than V IN Although designers have conducted various studies and designs on the compensation and elimination of the offset voltage and flip delay of the comparator, it cannot be ignored that the power consumption, area and design complexity of the circuit will increase simultaneously.
[0050] like Figure 2 The circuit uses OFF Timer to control the on-time of the freewheeling tube T OFF , the remaining modules evaluate the current T OFF Whether the freewheeling diode is accurately turned off when the inductor current is zero, that is, to achieve the optimal T OFF , and realize T OFF Iteration of . Figure 3 As shown in the figure, the circuit uses the timing of the SW falling edge as the judgment point. OFF Appropriateness standard: When the freewheeling tube is turned off, a target time window ZCD_WD is generated. If the falling edge of SW appears within this time, it indicates that the current TOFF The optimal value has been reached; if T OFF If T is too small, the freewheeling tube will be turned off too early, and the falling edge of SW will be delayed and later than ZCD_WD. OFF If the freewheeling diode is too large, that is, it is turned off too late, the SW falling edge will be advanced and earlier than ZCD_WD. Based on these characteristics, the current T OFF Is it optimal? Figure 2 As shown in (b), after obtaining the test results, T OFF The request to increase, decrease or hold will be loaded into the M-bit counter, and the counter will turn OFF the updated or held data. <m:0>Send to OFF Timer to generate T of next cycle OFF . Through the self-tracking design, we continuously search for the optimal T OFF The ST-ZCD avoids the error caused by the comparator offset voltage and delay in the traditional ZCD circuit. OFF time, and reduces power consumption accordingly. Figure 2 (a) Block diagram of a digital self-tracking ZCD circuit using a D flip-flop to capture the SW node; Figure 2 (b) The self-tracing process of the digital self-tracing ZCD circuit using a D flip-flop to capture the SW node; Figure 3 (a) is the optimal T OFF The corresponding waveform of Figure 3 (b) is T OFF The corresponding waveform when the time is too small; Figure 3 (c)T OFF The corresponding waveform when it is too large.
[0051] As the standby current of the device decreases, ST-ZCD is required to output a smaller T OFF , so the accuracy requirements are getting higher and higher, that is, the unit increment T OFF,unit Assume that the maximum current in DCM mode corresponds to the maximum conduction time of the freewheeling diode is T OFF,max , the control code is known to be OFF <m-1:0>If the number of digits is M, then the following relationship holds:
[0052]
[0053] It can be seen that if we need to refine T OFF If the unit increment is , the number of control code bits must be increased. However, load jump will cause the new optimal value to be far from the current value, and switching to the new optimal value can only be done cycle by cycle, so searching for the optimal T OFF The time to adjust the value, that is, the adjustment time, is greatly increased. In other words, T OFF There is a trade-off between accuracy and adjustment time.
[0054] Disadvantages of the existing technology: A large load current range will cause the freewheeling tube conduction time T OFF The range of variation is large and needs to be refined. OFF Unit increments to increase T at different loads OFF However, although increasing the number of control codes can improve T OFF Accuracy, but it takes longer to adjust and iterate to T OFF The optimal value, i.e. T OFF There is a trade-off between accuracy and adjustment time. Specific embodiment 1:
[0056] In view of ST-ZCD, in order to improve the conduction time T of the freewheeling tube OFF In order to solve the problem that the adjustment time cannot be taken into account when adjusting the accuracy, the present invention proposes a self-tracking zero-crossing detection method with a three-mode search method, such as Figure 4 , including: collecting the signal to be tracked and comparing it with the target time window to determine whether the current freewheeling tube conduction time allows the freewheeling tube to be accurately turned off when the inductor current is zero, and outputting an update request for the freewheeling tube conduction time of the next cycle; obtaining an update request for the freewheeling tube conduction time of the next cycle, and converting the update request into a switching request for the search mode, which is ultimately expressed as different single-time change bits of the control code; monitoring the single-time change bits of the control code, and dynamically adjusting the unit gain according to the change in the single-time change bits of the control code, so as to achieve the optimal freewheeling tube conduction time at the fastest speed.
[0057] The obtaining of an update request for the conduction time of the freewheeling tube in the next cycle, and converting the update request into a switching request for the search mode, which is ultimately expressed as different single-change bits of the control code; monitoring the single-change bits of the control code, and dynamically adjusting the unit gain according to the change of the single-change bits of the control code, so as to achieve the optimal conduction time of the freewheeling tube at the fastest speed, includes: receiving an update request for the conduction time of the freewheeling tube in the next cycle, and converting the update request into a switching request for the search mode, which is ultimately expressed as different single-change bits of the control code, i.e., unit gain Δk; when it is detected that the update request for the conduction time of the freewheeling tube has been increasing or decreasing for at least 7 cycles, a mode switching request is sent to switch to a variable gain mode, and the unit gain Δk at this time is increased to a preset multiple to search for the optimal value of the conduction time of the freewheeling tube.
[0058] When it is detected that the freewheeling tube conduction time update request has been increasing or decreasing for at least 7 cycles, a mode switching request is sent to switch to the variable gain mode. At this time, the unit gain Δk is increased to a preset multiple. It also includes: if the variable gain mode fails to search for the optimal value of the freewheeling tube conduction time within the set cycle, then: a mode switching request is sent again to switch to the successive approximation mode to ensure that the control code is set cycle by cycle by the successive approximation method to reach the optimal value of TOFF at the fastest speed.
[0059] The method collects the signal to be tracked and compares it with the target time window to determine whether the current freewheeling tube conduction time allows the freewheeling tube to be accurately turned off when the inductor current is zero, and outputs an update request for the freewheeling tube conduction time of the next cycle, including: comparing the falling edge of the signal to be tracked with the target time window, capturing and determining whether the current freewheeling tube conduction time allows the freewheeling tube to be accurately turned off when the inductor current is zero; and outputting a 2-bit signal [S1, S0] as an update request for the freewheeling tube conduction time of the next cycle.
[0060] The request to update the freewheeling tube on-time of the next cycle includes three states: the freewheeling tube on-time of the next cycle remains unchanged at the current value, the freewheeling tube on-time of the next cycle needs to be increased based on the current value, and TOFF of the next cycle needs to be reduced based on the current value. Specific embodiment 2:
[0062] At the same time, this embodiment provides a tri-mode searching digital self-tracking zero crossing detection circuit (TST-ZCD). Figure 5 As shown in (a), the circuit consists of a state detection subcircuit, a mode selection subcircuit and a T OFF The state detection subcircuit is responsible for capturing the current state of the SW node and determining the T OFF In the next cycle, the state is maintained, increased or decreased, and the update request is transmitted through [S1, S0]; its truth table is as follows Figure 5 (b) The mode selection subcircuit is responsible for determining which search mode the ZCD should work in. It consists of a mode determiner and a three-mode controller, and ultimately outputs the control signal Δk and [S1, S0]. OFF The control subcircuit is responsible for receiving the control signal and then updating the T OFF Control code OFF <m-1:0>The output signal truth table of the mode decision device is as follows: Figure 5 (c) as shown. Figure 5 (a) is a block diagram of a self-tracking zero-crossing detection circuit with a three-mode search method.
[0063] The waveform performance of the state detection subcircuit in the present invention under different working conditions is Figure 3 The same as shown in the figure, both compare the SW falling edge with the target time window ZCD_WD to capture and judge the current T OFF Whether to make the freewheeling tube turn off accurately when the inductor current is zero. This subcircuit will output a 2-bit signal [S1, S0] as the T of the next cycle. OFF Update request, its truth table is as follows Figure 5 (b) shows three states: the "Stay" state, which is the T of the next cycle. OFF Keep the current value unchanged; increase the state "Increase", that is, T of the next cycle OFF It needs to be increased based on the current value; the decrease state is "Decrease", that is, T of the next cycle OFF Need to be reduced based on the current value.
[0064] The mode selection subcircuit in the present invention receives the update request of the next state through the mode determiner, and this update request will be converted into a switching request of the search mode by the three-mode controller, and finally manifested as a single change bit number of different control codes, that is, unit gain Δk. Figure 6 As shown, the mode decision device uses a counter to record the update request within 7 consecutive cycles. When TST-ZCD works in the linear search mode "Linear" in the steady state, the update request will not be increasing (Increase) or decreasing (Decrease) for 7 consecutive cycles, so the mode switching request is always [M1, M0] = (0, 0), and the unit gain Δk at this time is only 1.
[0065] When a large load jump occurs, T OFF The optimal value will deviate significantly from the current T OFF value, resulting in T OFF Update requests are always increasing or decreasing, and since the unity gain Δk is only 1, ZCD will take multiple cycles to reach the new most appropriate T OFF Optimal value, which is the defect of traditional ST-ZCD, but this problem will be avoided in the proposed TST-ZCD.
[0066] like Figure 6 As shown in ①, when T is detected OFF If the update request is increasing or decreasing within 7 cycles, which is manifested by the continuous count of S1 or S0 being greater than 7, a mode switching request [M1, M0] = (0, 1) is sent to the three-mode controller; at this time, the variable gain mode "Variable Gain" is set, and the unit gain Δk is increased to VG times. The specific multiple of VG can be set according to the needs. However, if Figure 6 As shown in ②, if the variable gain mode fails to find T within 7 cycles, OFF The optimal value is shown as the continuous count of S1 or S0 is greater than 7, then the mode switching request [M1, M0] = (1, 0) will be sent to the three-mode controller again; at this time, it will be set to the successive approximation mode "SAR", and the unit gain Δk will be set cycle by cycle according to the idea of successive approximation to reach T at the fastest speed. OFF Optimal value.
[0067] In general, the same T appears multiple times in a row OFF When updating the request, it indicates that TST-ZCD failed to search for the best T in time. OFF value, then TST-ZCD will increase the number of bits of the control code in the order of linear search, variable gain search, and successive approximation search, that is, increase the unit gain Δk to accelerate the search for the optimal value. When the optimal value is found, T OFF The update request will change to the hold state "Stay". When this request is maintained for 4 cycles, it indicates that the TST-ZCD search has been preliminarily completed. Figure 6 As shown in ①②③, the number of bits of the control code that change at a single time will be reduced in the order of successive approximation search, variable gain search, and linear search, that is, the unit gain Δk will be reduced to further achieve high-precision T OFF value.
[0068] In the present invention, T OFF The control subcircuit is responsible for receiving the control signal and generating T OFF Specifically, the sub-circuit can update the control code OFF according to the control signal Δk and [S1, S0]. <m-1:0>, and generates the set T in the OFF Timer OFF This section is related to Figure 5 (a) is similar, but the number of bits of the control code that changes at a single time can be changed according to the previous sub-circuit.
[0069] Through the state detection sub-circuit, mode selection sub-circuit and T OFF The control subcircuit determines the conduction time T of the freewheeling tube. OFF When the current value is not the optimal value, it can realize fast and accurate optimal value search. OFF The optimal value has changed greatly, and the search speed can be increased and the adjustment time can be reduced by switching the three modes. OFF Quickly search and adjust to the exact T while increasing accuracy OFF Optimal value, optimized T OFF The trade-off between accuracy and adjustment time.
[0070] like Figure 7 Shown are T in different search modes OFF Adjust the speed comparison waveform and find that in T OFF After the optimal target value is switched, the linear search mode used by the traditional ST-ZCD can achieve the optimal value, but its adjustment time is too long, which may cause a large amount of efficiency loss in the actual circuit, and even have a great negative impact on the circuit and power supply; however, in the variable gain search mode, its adjustment time will be greatly reduced. The specific shortening effect depends on Figure 6 The mode selection subcircuit shown sets the unity gain Δk amplification factor VG; and for the successive approximation search (SAR) mode, the adjustment time is shortened even more significantly. It can be foreseen that even if the control code OFF <m-1:0>The number of bits increases, and the present invention can still quickly complete the search for the optimal value under the step-by-step switching of the three modes to reach T as soon as possible. OFF Optimal value.
[0071] Table 1 Performance comparison between the TST-ZCD of the present invention and the traditional ST-ZCD
[0072]
[0073] As shown in Table 1, the performance comparison between the proposed TST-ZCD and the traditional ST-ZCD is listed. It can be found that when the unit increment is small, that is, T OFF In the case of high precision, due to the use of three-mode control, TST-ZCD can achieve the self-tracking effect of traditional ST-ZCD through a shorter self-tracking time, thereby greatly reducing the reverse current in the search process and thus improving the overall efficiency of the converter.
[0074] In summary, in this embodiment, the freewheeling tube conduction time T OFF Large range of variation, T OFF When the accuracy requirement is high and the number of control codes increases, a shorter adjustment time can achieve T OFF Optimal value. Specific embodiment 3:
[0076] This application also provides an embodiment:
[0077] An electronic device comprises: a storage medium and a processing unit; wherein the storage medium is used to store a computer program, and the processing unit exchanges data with the storage medium, and is used to execute the computer program through the processing unit when performing a boost switching power supply conversion control, and perform the steps of the self-tracking zero-crossing detection method as described in specific embodiment 1. Specific embodiment 4:
[0079] A computer-readable storage medium having a computer program stored therein; when the computer program is run, the steps of the self-tracking zero-crossing detection method described in Specific Embodiment 1 are executed.
[0080] In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in combination with an instruction execution system, apparatus, or device. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in combination with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium may be transmitted using any suitable medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.
[0081] The above disclosures are only several specific implementation scenarios of the present application, but the present application is not limited thereto, and any changes that can be thought of by a person skilled in the art should fall within the protection scope of the present application. The above application numbers are only for description and do not represent the advantages and disadvantages of the implementation scenarios.
Claims
1. A self-tracking zero-crossing detection method with a three-mode search method, characterized in that: include: Collect the signal to be tracked and compare it with the target time window to determine whether the current freewheeling tube conduction time allows the freewheeling tube to be accurately turned off when the inductor current is zero, and output an update request for the freewheeling tube conduction time in the next cycle; Obtaining an update request for the conduction time of the freewheeling tube in the next cycle, and converting the update request into a switching request for the search mode, which is ultimately expressed as a single change in the number of bits of different control codes; The number of bits of the control code that changes at a single time is monitored, and the unit gain is dynamically adjusted according to the change of the number of bits of the control code that changes at a single time within a continuous period, so as to achieve the optimal freewheeling tube conduction time at the fastest speed.
2. The self-tracking zero-crossing detection method with a three-mode search method according to claim 1, characterized in that: The obtaining of the update request for the conduction time of the freewheeling tube in the next cycle and converting the update request into a switching request for the search mode, which is finally expressed as different single-time change digits of the control code; monitoring the single-time change digits of the control code and dynamically adjusting the unit gain according to the change of the single-time change digits of the control code to achieve the optimal conduction time of the freewheeling tube at the fastest speed, including: Receive an update request for the conduction time of the freewheeling tube in the next cycle, and convert the update request into a switching request for the search mode, which is ultimately expressed as a single change in the number of bits of a different control code, that is, a unit gain Δk; When it is detected that the freewheeling tube conduction time update request has been increasing or decreasing for at least 7 cycles, a mode switching request is sent to switch to the variable gain mode. At this time, the unit gain Δk is increased to a preset multiple to search for the optimal value of the freewheeling tube conduction time.
3. The self-tracking zero-crossing detection method with a three-mode search method according to claim 2, characterized in that: When it is detected that the freewheeling tube conduction time update request has been increasing or decreasing for at least 7 cycles, a mode switching request is sent to switch to a variable gain mode, and the unit gain Δk at this time is increased to a preset multiple, and also includes: If the variable gain mode fails to find the optimal value of the freewheeling tube conduction time within the set period, then: The mode switching request will be sent again to switch to the successive approximation mode, and the control code will be set cycle by cycle through the successive approximation method to achieve the optimal value of the freewheeling tube conduction time at the fastest speed.
4. The self-tracking zero-crossing detection method with a three-mode search method according to claim 1, characterized in that: The collected signal to be tracked is compared with the target time window to determine whether the current freewheeling tube conduction time allows the freewheeling tube to be accurately turned off when the inductor current is zero, and output an update request for the freewheeling tube conduction time of the next cycle, including: Compare the falling edge of the signal to be tracked with the target time window to capture and determine whether the current freewheeling diode conduction time allows the freewheeling diode to be accurately turned off when the inductor current is zero; And, output a 2-bit signal [S1, S0] as a request to update the conduction time of the freewheeling tube in the next cycle.
5. The self-tracking zero-crossing detection method with a three-mode search method according to claim 4, characterized in that: The next cycle freewheeling tube conduction time update request includes three states: The conduction time of the freewheeling tube in the next cycle remains unchanged at the current value. The freewheeling tube conduction time of the next cycle needs to be increased based on the current value, and The conduction time of the freewheeling tube in the next cycle needs to be reduced based on the current value.
6. A self-tracking zero-crossing detection circuit with a three-mode search method, based on the self-tracking zero-crossing detection method according to any one of claims 1 to 5, characterized in that: include: The state detection subcircuit is connected to the signal terminal to be tracked, and is used to collect the signal to be tracked and compare it with the target time window to determine whether the current freewheeling tube conduction time allows the freewheeling tube to be accurately turned off when the inductor current is zero, and output an update request for the freewheeling tube conduction time in the next cycle; A mode selection subcircuit is connected to the output end of the state detection subcircuit, and is used to obtain an update request for the conduction time of the freewheeling tube in the next cycle, and convert the update request into a switching request of the search mode, which is finally expressed as different single-time change bits of the control code; monitor the single-time change bits of the control code, and dynamically adjust the unit gain according to the change of the single-time change bits of the control code, so as to achieve the optimal conduction time of the freewheeling tube at the fastest speed; The control subcircuit is connected to the output end of the mode selection subcircuit, and is used to generate a set freewheeling tube conduction time and update the control code according to the control signal.
7. The self-tracking zero-crossing detection circuit with a three-mode search method according to claim 6, characterized in that: The mode selection subcircuit comprises: A mode determiner, connected to the output end of the state detection subcircuit, for receiving an update request for the next state; The three-mode controller is electrically connected to the mode determiner and is used to convert the update request into a switching request of the search mode, which is finally expressed as a single change bit number of different control codes, that is, a unit gain Δk.
8. A boost switching power supply conversion device, characterized in that: include: A self-tracking zero-crossing detection circuit with a three-mode search method as claimed in claim 6 or 7.
9. A boost switching power supply conversion control electronic device, comprising: Storage medium for storing computer programs; A processing unit exchanges data with the storage medium, and is used to execute the computer program through the processing unit when performing boost switching power supply conversion control to perform the steps of the self-tracking zero-crossing detection method as described in any one of claims 1 to 5.
10. A computer-readable storage medium, characterized in that: The computer readable storage medium stores a computer program; When the computer program is running, the steps of the self-tracking zero-crossing detection method according to any one of claims 1 to 5 are executed.