CN114825896A - Mute valley bottom locking control circuit of high-frequency valley bottom jumping mode flyback switching power supply - Google Patents
Mute valley bottom locking control circuit of high-frequency valley bottom jumping mode flyback switching power supply Download PDFInfo
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- CN114825896A CN114825896A CN202210180971.3A CN202210180971A CN114825896A CN 114825896 A CN114825896 A CN 114825896A CN 202210180971 A CN202210180971 A CN 202210180971A CN 114825896 A CN114825896 A CN 114825896A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/36—Means for starting or stopping converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
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Abstract
The invention discloses a mute valley bottom locking control circuit of a high-frequency valley bottom jumping mode flyback switching power supply, which belongs to the field of integrated circuits and comprises a valley bottom filter circuit, a valley bottom detection and quantization circuit, an FB interval comparison circuit, a valley bottom selection circuit, an FB interval threshold selection circuit, a valley bottom selection state latch and operation circuit, a PWM (pulse-width modulation) starting logic circuit, a peak current setting circuit, a PWM (pulse-width modulation) turn-off logic circuit, a PWM generation circuit and a driving circuit. The invention can effectively eliminate the frequency hopping phenomenon caused by valley bottom switching in the traditional quasi-resonant power supply, thereby avoiding the occurrence of audible noise of human ears. Meanwhile, the valley bottom is selected through the FB voltage, so that the problem that the working frequency range is narrow due to time limitation is solved, and the application range of the circuit can be effectively enlarged.
Description
Technical Field
The invention relates to the field of integrated circuits, in particular to a mute valley bottom locking control circuit of a high-frequency valley bottom jumping mode flyback switching power supply.
Background
With the gradual consensus of energy conservation and environmental protection, the corresponding energy efficiency standards established by each country have more and more strict requirements on the efficiency and energy consumption of peripheral power supply products. The valley jump mode can reduce the system switching loss to a great extent and improve the system transmission efficiency by controlling the conduction of the main switching tube at different valleys, and the current mainstream valley jump mode mainly has two problems, namely that the valley jumps back and forth due to discontinuous energy during valley bottom switching, so that audio noise is brought to the system; the second problem is that the conventional valley-locking scheme may greatly limit the operating frequency of the system, which may also limit the conversion efficiency of the system to some extent, and may also generate audio noise when the operating frequency of the system is low.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a mute valley bottom locking control circuit of a flyback switching power supply in a high-frequency valley bottom jumping mode, which can effectively eliminate the frequency hopping phenomenon caused by valley bottom switching in the traditional quasi-resonant power supply, thereby avoiding audible noise of human ears. Meanwhile, the valley bottom is selected through the FB voltage, so that the problem that the working frequency range is narrow due to time limitation is solved, and the application range of the circuit can be effectively enlarged.
The purpose of the invention is realized by the following scheme:
a silence valley bottom locking control circuit of a high-frequency valley bottom jumping mode flyback switching power supply comprises: the peak current detection circuit comprises a valley bottom filter circuit, a valley bottom detection and quantization circuit, an FB interval comparison circuit, a valley bottom selection circuit, an FB interval threshold selection circuit, a valley bottom selection state latch and operation circuit, a PWM (pulse width modulation) starting logic circuit, a peak current setting circuit, a PWM (pulse width modulation) turn-off logic circuit, a PWM generating circuit and a driving circuit;
the valley bottom filtering circuit is connected with the valley bottom detection and quantization circuit, the valley bottom detection and quantization circuit is connected with the valley bottom selected state latch and operation circuit, the valley bottom selected state latch and operation circuit is connected with the PWM opening logic circuit, the PWM opening logic circuit is connected with the PWM generating circuit, and the PWM generating circuit is connected with the driving circuit;
the FB interval comparison circuit is connected with the valley bottom selection circuit, the valley bottom selection circuit is connected with the valley bottom selection state latch and operation circuit, and the valley bottom selection state latch and operation circuit is connected with the PWM starting logic circuit;
the FB interval threshold value selection circuit is connected with the valley bottom selection circuit and the FB interval comparison circuit, the FB interval comparison circuit is connected with the peak current setting circuit, and the peak current setting circuit is connected with the PWM turn-off logic circuit.
Furthermore, the PWM off-state circuit comprises a ZCD pin, an FB pin and a CS pin, wherein the ZCD pin is connected with the valley bottom filter circuit, the FB pin is connected with the FB interval comparison circuit, and the CS pin is connected with the PWM off-state logic circuit.
Further, the ZCD pin is used for detecting drain voltage VD of the driving power tube; the FB pin is used for detecting the size of the output load of the power supply and is in direct proportion to the size of the output load; the CS pin is used to detect the magnitude of the peak current Ipk.
Further, the valley bottom filter circuit is used for filtering the ZCD pin voltage and filtering high-frequency components higher than the valley bottom resonant frequency so as to ensure that the valley bottom detection circuit can accurately detect the valley bottom.
Further, the valley bottom detection and quantization circuit is used for simultaneously quantizing the detected valley bottoms and sending the detected valley bottom quantity to the valley bottom selected state latch and operation circuit.
Furthermore, the FB interval comparison circuit compares the voltage detected by the FB pin with a set interval threshold value, and sends the comparison result to the valley bottom selection circuit.
Furthermore, the valley bottom selection circuit selects the valley bottom at which the quasi-resonant switch is turned on according to the result given by the FB interval comparison circuit, and sends the current state to the valley bottom selected state latch and operation circuit after the valley bottom is selected.
Further, the FB interval threshold selecting circuit selects a threshold for FB voltage comparison according to the valley selected by the valley selecting circuit, where the threshold includes a maximum threshold and a minimum threshold; this threshold interval determines the range of variation of the FB voltage when the system is operating at the current valley.
Further, the valley bottom selected state latch and operation circuit is used for latching the valley bottom state selected in the previous valley bottom selected circuit, then comparing the latched valley bottom number with the valley bottom number detected by the valley bottom detection circuit, and when the two are equal, sending a signal to the PWM on logic circuit.
Further, the PWM on logic circuit is configured to generate a PWM wave on signal.
The invention has the beneficial effects that:
the invention can effectively eliminate the frequency hopping phenomenon caused by valley bottom switching in the traditional quasi-resonant power supply, thereby avoiding the occurrence of audible noise of human ears. Meanwhile, the valley bottom is selected through the FB voltage, so that the problem that the working frequency range is narrow due to time limitation is solved, and the application range of the circuit can be effectively enlarged.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic diagram of a frequency hopping phenomenon generated in valley-bottom locking of a conventional quasi-resonant power supply;
FIG. 2 is a schematic diagram of valley bottom locking in an embodiment of the present invention;
FIG. 3 is a functional block diagram of a valley bottom locking implementation in an embodiment of the present invention;
the ZCD pin is used for detecting drain voltage VD of the driving power tube, the FB pin is used for detecting the size of the output load of the power supply and is in direct proportion to the size of the output load, the CS pin is used for detecting the size of peak current Ipk, and P is o Representing the output load power.
Detailed Description
All features disclosed in all embodiments in this specification, or all methods or process steps implicitly disclosed, may be combined and/or expanded, or substituted, in any way, except for mutually exclusive features and/or steps.
In the traditional quasi-resonant circuit, by detecting the FB voltage, the FB voltage controls the magnitude of the peak current and sets the limit time T limit The method has the greatest disadvantage that the valley bottom is switchedWhen the switching is performed, the output power is discontinuous, which may cause a frequency hopping phenomenon to occur easily during valley bottom switching. As shown in fig. 1, the reason why the frequency hopping phenomenon occurs at the time of valley switching in the conventional quasi-resonant circuit is shown. When the output power is in P o1 In the process, the valley bottom locking circuit controls the driving circuit to be started at the first valley bottom, but the minimum output power after the first valley bottom is started is still larger than P o1 The valley bottom locking circuit can control the driving circuit to be opened at the second valley bottom, but the maximum output power after the second valley bottom is opened is less than P o1 In this way, the system will enter the first valley again, and the valley switching is repeated until the output power is greater than the minimum output power of the first valley or the second maximum output power is less than the first valley. Audible noise is generated in the human ear during frequency hopping. Limiting the time T when the system is operating at a higher frequency limit Will be correspondingly reduced and the time T will be limited limit The smaller the requirements on the device, the higher the difficulty of implementing the control circuit, and therefore the time limit T is set limit The system operating frequency may be limited. Because of different systems, FB and resonant period have different sizes, which makes the circuit poorly adaptable to different systems.
In the embodiment, the valley bottom is directly selected by detecting the FB voltage, the threshold value of the FB voltage interval comparison circuit is adjusted by the FB interval threshold value selection circuit after the valley bottom is selected, when the FB voltage exceeds the interval threshold value range, the system can perform valley bottom switching, and meanwhile, the frequency hopping phenomenon during valley bottom switching can be well avoided by reasonably setting the threshold value of the FB interval comparison circuit. Now, referring to fig. 2 and fig. 3, the bottom-locking principle and the specific circuit implementation process in the present embodiment will be specifically explained, assuming that the system is currently located at the third bottom, when the output load is gradually increased, the voltage V is gradually increased FB Increase when the voltage V is increased FB Greater than V 3-2 (V 3-2 Represents the voltage level V just entering the second valley bottom from the third valley bottom FB And simultaneously, the maximum threshold value of the FB interval comparison circuit when the FB interval comparison circuit is positioned at the third valley bottom) is shown), the system enters the second valley bottom, and when the system enters the second valley bottom, the FB interval threshold value selection circuit adjusts the FB voltage interval comparison circuit to compareAnd the threshold value of the circuit, wherein the threshold value interval defines the maximum range of the FB voltage which can be changed when the system is at the second valley bottom. There are two situations when the FB voltage is greater than V if the output power continues to increase 2-1 At that time, the system enters the first valley. When the output power decreases, the FB voltage decreases to V 2-3 The system will switch to the third valley again. It can be clearly seen from the above valley bottom switching process that the maximum value of the power at the third valley bottom is less than or equal to the minimum value of the power at the second valley bottom, and after the third valley bottom enters the second valley bottom, even if the output power is reduced, the system still stays at the second valley bottom, and because the threshold range of the FB interval is set to be large, the system jumps to the third valley bottom again only when the output power is greatly changed. Therefore, the frequency hopping phenomenon can be avoided when the valley bottom is switched, and the audible noise of human ears is avoided. Meanwhile, it can be clearly seen that the limiting time T is not set in the embodiment limit The valley bottom is determined only by the magnitude of the FB voltage, so that the limitation of the system operating frequency in this embodiment is small, the system operating frequency can be further increased, and the occurrence of audible noise can be further avoided. The advantage of determining the valley bottom by the FB voltage is that this embodiment can be applied when the system valley bottom resonance period changes for different systems. Therefore, the embodiment is better adaptive to different systems. The threshold voltage of the FB interval can be generated by the voltage division of the resistors in the embodiment, so that the threshold voltage of the FB interval can be conveniently adjusted in different systems, the adaptability of the embodiment to different systems can be further improved by reasonably setting the threshold value of the interval, and the output power range can be expanded.
With the above working principle, the specific implementation process of the valley bottom locking in the embodiment is specifically explained according to the valley bottom locking block diagram as follows:
the valley bottom filter circuit filters the ZCD pin voltage, and filters high-frequency components higher than the valley bottom resonant frequency to eliminate the influence of the high-frequency components on valley bottom detection.
The valley bottom detection and quantification circuit is used for detecting the valley bottom and quantifying the detected valley bottom at the same time, and particularly, the valley bottom detection and quantification circuit firstly detects the valley bottom of the filtered voltage, quantifies the detected valley bottom at the same time, and transmits the valley bottom quantity to the valley bottom state latch and operation circuit.
The FB interval comparison circuit compares the voltage detected by the FB pin with a set interval threshold value and transmits the comparison result to the valley bottom selection circuit so as to assist the valley bottom selection circuit in valley bottom selection.
The valley bottom selection circuit selects which valley bottom the quasi-resonant switch is switched on according to the result given by the FB interval comparison circuit, valley bottom switching is completed in time, and after valley bottom selection is completed, the result is transmitted to the FB interval threshold selection circuit and the valley bottom state latch and operation circuit. When the valley bottom state latch and operation circuit locks the valley bottom, the system works at the current valley bottom, and only when the FB voltage is larger than the interval voltage threshold exceeding the current valley bottom, the system can perform valley bottom switching again.
The FB interval threshold value selecting circuit selects threshold values of FB voltage comparison according to the valley bottom selected by the valley bottom selecting circuit, and the threshold values comprise a maximum threshold value and a minimum threshold value. Assume that the valley select circuit is currently located at the nth (N is a positive integer) valley bottom and switches to the N-1 th valley bottom when the FB voltage is greater than the maximum threshold, and switches to the N +1 th valley bottom when the FB voltage is less than the minimum threshold. By reasonably setting the threshold value of the FB interval, the maximum output power of the Nth valley bottom is smaller than the minimum output power of the (N-1) th valley bottom, so that the frequency hopping phenomenon can be avoided when the valley bottoms are switched, and the audible noise of human ears is further avoided.
The valley bottom state latch and operation circuit mainly completes two functions, firstly latches the valley bottom state selected in the previous valley bottom selection circuit, and when the valley bottom state is locked, the system works in the current state, thus completing the valley bottom locking. The second function is to compare the latched valley number with the valley number detected by the valley detection circuit, and when the two are equal, send a signal to the PWM on logic circuit. The drive circuit is turned on only when the number of valley bottoms of the valley bottom lock circuit is equal to the number of valley bottoms detected by the valley bottom detection circuit.
The peak current setting circuit determines the value of the peak current according to the voltage of the FB pin, when the FB voltage is lower than V min The peak current setting circuit can make the value of the peak current be a constant value I min (ii) a When the FB voltage is higher than V max The peak current setting circuit keeps the peak current at a constant value I max (ii) a When the FB voltage is between the maximum value and the minimum value, the peak current setting circuit enables the peak current to be K times V FB (K < 1). The peak current is mainly set to control the turn-off of the driving circuit, and when the CS pin detects that the peak current is equal to the set peak current, the system turns off the driving circuit.
In summary, the mute valley bottom locking control circuit of the flyback switching power supply in the high-frequency valley bottom mode provided in this embodiment can effectively eliminate the frequency hopping phenomenon caused by valley bottom switching in the conventional quasi-resonant power supply, thereby avoiding audible noise of human ears. Meanwhile, the operating frequency of the system can be improved by selecting the valley through the FB voltage, the audible noise of human ears can be reduced by improving the operating frequency of the system, and meanwhile, the valley is selected through the FB voltage, so that the control scheme can be used in other switching power supply chips, the compatibility is good, and meanwhile, the output power can be increased through the control scheme.
Example 1: a silence valley bottom locking control circuit of a high-frequency valley bottom jumping mode flyback switching power supply is characterized by comprising: the peak current detection circuit comprises a valley bottom filter circuit, a valley bottom detection and quantization circuit, an FB interval comparison circuit, a valley bottom selection circuit, an FB interval threshold selection circuit, a valley bottom selection state latch and operation circuit, a PWM (pulse width modulation) starting logic circuit, a peak current setting circuit, a PWM (pulse width modulation) turn-off logic circuit, a PWM generating circuit and a driving circuit; the valley bottom filtering circuit is connected with the valley bottom detection and quantization circuit, the valley bottom detection and quantization circuit is connected with the valley bottom selected state latch and operation circuit, the valley bottom selected state latch and operation circuit is connected with the PWM opening logic circuit, the PWM opening logic circuit is connected with the PWM generating circuit, and the PWM generating circuit is connected with the driving circuit; the FB interval comparison circuit is connected with the valley bottom selection circuit, the valley bottom selection circuit is connected with the valley bottom selection state latch and operation circuit, and the valley bottom selection state latch and operation circuit is connected with the PWM starting logic circuit; the FB interval threshold value selection circuit is connected with the valley bottom selection circuit and the FB interval comparison circuit, the FB interval comparison circuit is connected with the peak current setting circuit, and the peak current setting circuit is connected with the PWM turn-off logic circuit.
Example 2: on the basis of the embodiment 1, the PWM switching-off circuit comprises a ZCD pin, an FB pin and a CS pin, wherein the ZCD pin is connected with a valley filter circuit, the FB pin is connected with an FB interval comparison circuit, and the CS pin is connected with a PWM switching-off logic circuit.
Example 3: on the basis of embodiment 2, the ZCD pin is used to detect a drain voltage VD of the driving power transistor; the FB pin is used for detecting the size of the output load of the power supply and is in direct proportion to the size of the output load; the CS pin is used to detect the magnitude of the peak current Ipk.
Example 4: on the basis of embodiment 2, the valley bottom filter circuit is used for filtering the ZCD pin voltage, and filtering out a high-frequency component higher than the valley bottom resonant frequency, so as to ensure that the valley bottom detection circuit can accurately detect the valley bottom.
Example 5: in addition to the embodiment 1, the bottom detection and quantization circuit is configured to perform bottom detection and quantization on the detected bottom, and send the detected number of the bottoms to the bottom selected state latch and operation circuit.
Example 6: on the basis of embodiment 2, the FB interval comparison circuit compares the voltage detected by the FB pin with a set interval threshold, and sends the comparison result to the valley selection circuit.
Example 7: on the basis of the embodiment 1, the valley bottom selection circuit selects the valley bottom at which the quasi-resonant switch is turned on according to the result given by the FB interval comparison circuit, and sends the current state to the valley bottom selected state latch and operation circuit after the valley bottom is selected.
Example 8: on the basis of the embodiment 1, the FB interval threshold selecting circuit selects a threshold for FB voltage comparison according to the valley bottom selected by the valley bottom selecting circuit, where the threshold includes a maximum threshold and a minimum threshold; this threshold interval determines the range of variation of the FB voltage when the system is operating at the current valley.
Example 9: in embodiment 1, the valley bottom selected state latch and operation circuit is configured to latch the valley bottom state selected by the previous valley bottom selected circuit, compare the latched valley bottom number with the valley bottom number detected by the valley bottom detection circuit, and send a signal to the PWM on logic circuit when the latched valley bottom number and the latched valley bottom number are equal to each other.
Example 10: on the basis of embodiment 1, the PWM on logic circuit is configured to generate a PWM wave on signal.
Other embodiments than the above examples may be devised by those skilled in the art based on the foregoing disclosure, or by adapting and using knowledge or techniques of the relevant art, and features of various embodiments may be interchanged or substituted and such modifications and variations that may be made by those skilled in the art without departing from the spirit and scope of the present invention are intended to be within the scope of the following claims.
Claims (10)
1. A silence valley bottom locking control circuit of a high-frequency valley bottom jumping mode flyback switching power supply is characterized by comprising: the peak current detection circuit comprises a valley bottom filter circuit, a valley bottom detection and quantization circuit, an FB interval comparison circuit, a valley bottom selection circuit, an FB interval threshold selection circuit, a valley bottom selection state latch and operation circuit, a PWM (pulse width modulation) starting logic circuit, a peak current setting circuit, a PWM (pulse width modulation) turn-off logic circuit, a PWM generating circuit and a driving circuit;
the valley bottom filtering circuit is connected with the valley bottom detection and quantization circuit, the valley bottom detection and quantization circuit is connected with the valley bottom selected state latch and operation circuit, the valley bottom selected state latch and operation circuit is connected with the PWM opening logic circuit, the PWM opening logic circuit is connected with the PWM generating circuit, and the PWM generating circuit is connected with the driving circuit;
the FB interval comparison circuit is connected with the valley bottom selection circuit, the valley bottom selection circuit is connected with the valley bottom selection state latch and operation circuit, and the valley bottom selection state latch and operation circuit is connected with the PWM starting logic circuit;
the FB interval threshold value selection circuit is connected with the valley bottom selection circuit and the FB interval comparison circuit, the FB interval comparison circuit is connected with the peak current setting circuit, and the peak current setting circuit is connected with the PWM turn-off logic circuit.
2. The muting valley locking control circuit of the flyback switching power supply with the high-frequency valley-skipping mode as claimed in claim 1, comprising a ZCD pin, an FB pin and a CS pin, wherein the ZCD pin is connected with the valley-skipping filter circuit, the FB pin is connected with the FB interval comparison circuit, and the CS pin is connected with the PWM turn-off logic circuit.
3. The mute valley locking control circuit of the high-frequency valley-jumping mode flyback switching power supply as claimed in claim 2, wherein the ZCD pin is used for detecting a drain terminal voltage VD of the driving power tube; the FB pin is used for detecting the size of the output load of the power supply and is in direct proportion to the size of the output load; the CS pin is used to detect the magnitude of the peak current Ipk.
4. The mute valley bottom locking control circuit of the high-frequency valley bottom mode flyback switching power supply of claim 2, wherein the valley bottom filter circuit is used for filtering the ZCD pin voltage and filtering out high-frequency components higher than the valley bottom resonant frequency so as to ensure that the valley bottom detection circuit can accurately detect the valley bottom.
5. The mute valley bottom locking control circuit of a high-frequency valley bottom mode flyback switching power supply of claim 1, wherein the valley bottom detection and quantization circuit is configured to perform valley bottom detection and quantization on the detected valley bottoms and to send the detected valley bottom number to the valley bottom selected state latch and operation circuit.
6. The muting valley locking control circuit of the flyback switching power supply with the high-frequency valley-skipping mode as claimed in claim 2, wherein the FB interval comparator circuit compares the voltage detected by the FB pin with a set interval threshold and sends the comparison result to the valley selection circuit.
7. The mute valley bottom locking control circuit of the flyback switching power supply with the high-frequency valley bottom mode as claimed in claim 1, wherein the valley bottom selection circuit selects which valley bottom the quasi-resonant switch is turned on according to the result given by the FB interval comparison circuit, and sends the current state to the valley bottom selected state latch and operation circuit after the valley bottom is selected.
8. The muting valley locking control circuit of the flyback switching power supply with the high-frequency valley-skipping mode according to claim 1, wherein the FB interval threshold selecting circuit selects the threshold for FB voltage comparison according to the valley selected by the valley selecting circuit, and the threshold comprises a maximum threshold and a minimum threshold; this threshold interval determines the range of variation of the FB voltage when the system is operating at the current valley.
9. The mute valley bottom locking control circuit of the high-frequency valley bottom mode flyback switching power supply of claim 1, wherein the valley bottom selected state latch and operation circuit is configured to latch the valley bottom state selected by the previous valley bottom selected circuit, compare the latched valley bottom number with the valley bottom number detected by the valley bottom detection circuit, and send a signal to the PWM on logic circuit when the two are equal.
10. The muting valley locking control circuit of the high-frequency valley-skipping mode flyback switching power supply as claimed in claim 1, wherein the PWM on logic circuit is configured to generate a PWM wave on signal.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210180971.3A CN114825896A (en) | 2022-02-25 | 2022-02-25 | Mute valley bottom locking control circuit of high-frequency valley bottom jumping mode flyback switching power supply |
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| CN202210180971.3A CN114825896A (en) | 2022-02-25 | 2022-02-25 | Mute valley bottom locking control circuit of high-frequency valley bottom jumping mode flyback switching power supply |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115065254A (en) * | 2022-08-19 | 2022-09-16 | 深圳英集芯科技股份有限公司 | Control device and method of flyback switching power supply and charger |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115065254A (en) * | 2022-08-19 | 2022-09-16 | 深圳英集芯科技股份有限公司 | Control device and method of flyback switching power supply and charger |
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