On-off circuit, frequency locking circuit, and DC-DC voltage conversion circuit

Abstract

This application provides a turn-on / off circuit, a frequency lock circuit, and a DC-DC voltage conversion circuit. The turn-on / off circuit includes: a first energy storage module for providing a first energy storage voltage; a first charge / discharge module connected to the first energy storage module for charging or discharging the first energy storage module; a switch connected to the first charge / discharge module and receiving a turn-on duration signal, controlling the first charge / discharge module to charge or discharge the first energy storage module based on the turn-on duration signal; and a comparison module receiving the first energy storage voltage and a first feedback voltage corresponding to the output voltage of the voltage conversion circuit, generating a turn-on / off signal based on the first energy storage voltage and the first feedback voltage. When the load of the DC-DC voltage conversion circuit changes, causing a change in its turn-off duration, its turn-on duration can also be adjusted accordingly, thereby improving the stability of the operating frequency.

Description

Technical Field

[0001] The disclosed embodiments of this application relate to the field of power electronics technology, and more specifically, to a turn-on / turn-off circuit, a frequency lock-in circuit, and a DC-DC voltage conversion circuit. Background Technology

[0002] In voltage conversion circuits, when the load is constant, the circuit has a stable operating frequency. However, when the load changes, the operating frequency may increase or decrease sharply during the adjustment process before the circuit stabilizes again, which will broaden the noise spectrum of the circuit.

[0003] In order to achieve a certain degree of fast dynamic response, the minimum cutoff time of the circuit can be set to be short. When the load of the circuit changes from light load (heavy load) to heavy load (light load), the circuit will shorten (extend) the cutoff time during adjustment. However, since the conduction time is fixed, this will cause the operating frequency of the circuit to increase (decrease) sharply, and the noise spectrum will still become wider.

[0004] Therefore, improving the stability of the operating frequency of voltage conversion circuits has become an urgent problem to be solved. Summary of the Invention

[0005] According to embodiments of this application, the present invention provides a turn-on / turn-off circuit, a frequency lock-in circuit, and a DC-DC voltage conversion circuit to improve the stability of the operating frequency of the voltage conversion circuit.

[0006] According to one aspect of this application, an exemplary on / off circuit is disclosed, applied to a frequency lock circuit of a DC-DC voltage conversion circuit, used to issue an on / off signal to adjust the on-time of the DC-DC voltage conversion circuit. The on / off circuit includes a first energy storage module, a first charge / discharge module, a switching switch, and a comparison module. The first energy storage module provides a first energy storage voltage; the first charge / discharge module is connected to the first energy storage module to charge or discharge the first energy storage module; the switching switch is connected to the first charge / discharge module and receives an on-time signal, controlling the first charge / discharge module to charge or discharge the first energy storage module based on the on-time signal; the comparison module receives the first energy storage voltage and a first feedback voltage corresponding to the output voltage of the voltage conversion circuit, and generates the on / off signal based on the first energy storage voltage and the first feedback voltage; wherein, a controlled power supply is provided on the charging path of the first charge / discharge module, the controlled power supply changing according to the load change of the voltage conversion circuit to change the charging current for charging the first energy storage module, thereby adjusting the on-time of the voltage conversion circuit.

[0007] The second aspect of this application provides a frequency lock-in circuit for use in a DC-DC voltage conversion circuit, the frequency lock-in circuit including the on / off circuit of the first aspect described above.

[0008] A third aspect of this application provides a DC-DC voltage conversion circuit, including the frequency locking circuit described in the second aspect above.

[0009] In the above scheme, the controlled power supply on the charging path of the first charging module of the on / off circuit changes based on the load change of the voltage conversion circuit. Therefore, when the load of the voltage conversion circuit changes, the charging current of the first energy storage module will also change accordingly, causing the time for the first energy storage voltage of the first energy storage module to charge from a lower voltage to a higher voltage that can change the on / off signal of the comparator module will also change. In this way, the on-time of the DC-DC voltage conversion circuit can be adjusted by adjusting the duration of the change in the on / off signal. That is to say, when the load of the DC-DC voltage conversion circuit changes, causing its off-time to change, its on-time can also be adjusted accordingly, thereby improving the stability of the operating frequency. Attached Figure Description

[0010] The present application will be further described below with reference to the accompanying drawings and embodiments. In the drawings:

[0011] Figure 1 This is a schematic diagram of the circuit structure of one embodiment of the DC-DC voltage conversion circuit in this application;

[0012] Figure 2 This is a schematic diagram of the circuit structure of one embodiment of the frequency locking circuit in this application;

[0013] Figure 3 This is a schematic diagram of a module of an embodiment of the on / off circuit of this application;

[0014] Figure 4 These are schematic diagrams of the circuit structure of some embodiments of the on / off circuit of this application;

[0015] Figure 5 This is a schematic diagram of the circuit structure of an embodiment of the controlled power supply voltage generation circuit of this application. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0017] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the application. The singular forms “a,” “said,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless otherwise clearly indicated above. “Multiple” generally includes at least two, but does not exclude the inclusion of at least one.

[0018] It should be understood that the term "and / or" used herein is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Furthermore, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0019] It should be understood that the terms "comprising," "including," or any other variations used herein are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in every place in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] This application provides a DC-DC voltage conversion circuit 100. Please refer to... Figure 1 , Figure 1 This is a schematic diagram of the circuit structure of an embodiment of the DC-DC voltage conversion circuit 100 in this application. Figure 1 The BUCK circuit shown is only one embodiment of the DC-DC voltage conversion circuit 100. Those skilled in the art will know that the DC-DC voltage conversion circuit 100 can have other implementations. This application does not limit the specific circuit structure of the DC-DC voltage conversion circuit 100.

[0022] exist Figure 1In the DC-DC voltage conversion circuit 100 shown, when switch M0 is on, switch M1 is off; when switch M0 is off, switch M1 is on. In this document, turning on switch M0 is referred to as the DC-DC voltage conversion circuit 100 being on, and the duration of switch M0 being on is referred to as the on-time of the DC-DC voltage conversion circuit 100; turning off switch M0 is referred to as the DC-DC voltage conversion circuit 100 being off, and the duration of switch M0 being off is referred to as the off-time of the DC-DC voltage conversion circuit 100. In other words, the on-time of switch M1 is the off-time of the DC-DC voltage conversion circuit 100, and the on-time of switch M1 is the off-time of the DC-DC voltage conversion circuit 100.

[0023] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the circuit structure of an embodiment of the frequency lock circuit 200 in this application; the DC-DC voltage conversion circuit 100 includes the frequency lock circuit 200.

[0024] A second aspect of this application also provides a frequency locking circuit 200. The frequency locking circuit 200 includes a turn-on / turn-off circuit 300, the specific structure of which will be described in detail in the following embodiments.

[0025] The frequency lock circuit 200 may further include a turn-on circuit 210. In the DC-DC voltage conversion circuit 100, the operating frequency of the DC-DC voltage conversion circuit 100 changes accordingly when the load changes. Specifically, when the load increases, the cutoff time will shorten; while when the load decreases, the cutoff time will lengthen. However, while adjusting the cutoff time achieves a fast dynamic response of the circuit, it also degrades the stability of the circuit's operating frequency. This application adjusts the cutoff time when the load changes, and simultaneously adjusts the turn-on time through the turn-off circuit 300, thereby ensuring that the sum of the turn-on time and cutoff time of the DC-DC voltage conversion circuit 100 remains essentially unchanged when the load changes, thus improving the stability of the operating frequency of the DC-DC voltage conversion circuit 100.

[0026] In some embodiments, the frequency lock circuit 200 may further include a flip-flop FF and a driver D. One input of the flip-flop FF may be connected to the on-start circuit 210, and the other input may be connected to the on-stop circuit 300 to receive the on-start signal ON-PULSE from the on-start circuit 210 and the on-stop signal OFF-PULSE from the on-stop circuit 300, and generate an on-duration signal ON based on the on-start and on-stop signals. The on-start signal ON-PULSE and the on-stop signal OFF-PULSE may be logic high or logic low, respectively; based on the states of the on-start signal ON-PULSE and the on-stop signal OFF-PULSE, the on-duration signal ON may be high or low, respectively. The on-duration signal ON of the flip-flop FF is also output to the on-stop circuit 300.

[0027] For example, when the trigger FF receives a high-level ON-PULSE signal and the OFF-PULSE signal is low, the conduction duration signal can be high, thereby driving the driver to turn off switch M1 and turn on switch M0. Those skilled in the art will understand that the correspondence between the ON-PULSE signal, the OFF-PULSE signal, and the conduction duration signal, as well as the correspondence between the conduction duration signal and the conduction state of the switching transistors, is not limited to the correspondence described in the above example. It can be adaptively changed according to the selection of components such as the driver, switching transistors, and triggers. Therefore, the above example is only for illustrative purposes, and the specific control mode can be set according to actual conditions.

[0028] In some embodiments, the turn-on circuit 210 includes a first comparison unit and a second comparison unit. The first comparison unit EA has its first input terminal connected to the output voltage VOUT of the DC-DC voltage converter circuit 100, and its second input terminal connected to a first reference voltage VREF. Based on the output voltage VOUT of the DC-DC voltage converter circuit 100 and the first reference voltage VREF, it outputs a first comparison signal EA_OUT at its output terminal. The second comparison unit CMP has its first input terminal connected to the first comparison signal EA_OUT, and its second input terminal connected to a second reference signal I_L. Based on the first comparison signal EA_OUT and the second reference signal I_L, it generates a turn-on signal ON-PULSE at its output terminal. The second reference signal I_L can be the current flowing through the inductor L in the DC-DC voltage converter circuit 100. The first input terminal of the first comparison unit EA can also be connected to its output terminal through a compensation circuit.

[0029] In such Figure 1In the DC-DC voltage conversion circuit 100 shown, under steady state, when the switch M1 is turned on, the inductor current I_L decreases. When the inductor current I_L decreases below the first comparison signal EA_OUT, the ON-PULSE signal output by the second comparison unit CMP becomes high, thereby triggering the ON-time signal output by the flip-flop FF to a high level. This drives the switch M1 to turn off and the switch M0 to turn on, supplying power to the inductor L, thus increasing the inductor current. When the ON-time signal is triggered to a high level, the on-off circuit 300, based on this high-level ON-time signal, outputs a high-level OFF-PULSE signal after a certain period, thereby triggering the ON-time signal output by the flip-flop FF to a low level. This drives the switch M1 to turn on and the switch M0 to turn off, causing the inductor L to output power, thus decreasing the inductor current.

[0030] Those skilled in the art will understand that if the model of the components in the circuit is changed, or the triggering method is changed, such as changing from high-level triggering to low-level triggering, the control logic can also be changed accordingly. Therefore, the above-described control logic is only an example and is not intended to limit the specific implementation of this application.

[0031] Please refer to the reference. Figures 1-3 ,in Figure 3 This is a schematic diagram of a module of an embodiment of the on / off circuit 300 of this application. In order to improve the operating frequency stability of the DC-DC voltage conversion circuit 100, this application proposes an on / off circuit 300, which is applied to the frequency locking circuit 200 of the DC-DC voltage conversion circuit 100 to issue an on / off signal to adjust the on-time of the DC-DC voltage conversion circuit 100. The on / off circuit 300 includes a first energy storage module 330, a first charge / discharge module 320, a switching switch 310 and a comparison module 340. The first energy storage module 330 provides a first energy storage voltage; the first charge / discharge module 320 is connected to the first energy storage module 330 to charge or discharge the first energy storage module 330; the switch 310 is connected to the first charge / discharge module 320 and receives a conduction duration signal, and controls the first charge / discharge module 320 to charge or discharge the first energy storage module 330 based on the conduction duration signal; the comparison module 340 receives the first energy storage voltage and a first feedback voltage corresponding to the output voltage of the voltage conversion circuit, and generates a conduction cutoff signal based on the first energy storage voltage and the first feedback voltage; wherein, a controlled power supply is provided on the charging path of the first charge / discharge module 320, and the controlled power supply changes based on the load change of the voltage conversion circuit to change the charging current for charging the first energy storage module 330 and adjust the conduction duration of the voltage conversion circuit.

[0032] The on / off circuit 300 of this application can be applied to the frequency lock circuit 200 of the BUCK circuit, and of course, it can also be applied to other DC-DC voltage conversion circuits 100.

[0033] In the above scheme, the controlled power supply on the charging path of the first charging module of the on / off circuit 300 changes based on the load change of the voltage conversion circuit. Therefore, when the load of the voltage conversion circuit changes, the charging current of the first energy storage module 330 will also change accordingly, causing the first energy storage voltage of the first energy storage module 330 to change from a lower voltage to a higher voltage that can change the on / off signal of the comparison module 340. In this way, the on-time of the DC-DC voltage conversion circuit 100 can be adjusted by adjusting the duration of the change in the on / off signal. That is, when the load of the DC-DC voltage conversion circuit 100 changes, causing its off-time to change, its on-time can also be adjusted accordingly, thereby improving the stability of the operating frequency.

[0034] In some embodiments, the ON conduction duration signal can include a high-level state and a low-level state. When the ON conduction duration signal is in a high-level state, switch M1 is turned off and switch M0 is turned on, corresponding to the DC-DC voltage conversion circuit 100 being turned on. The duration of this state is the conduction duration. When the ON conduction duration signal is in a low-level state, switch M1 is turned on and switch M0 is turned off, corresponding to the DC-DC voltage conversion circuit 100 being turned off. The duration of this state is the off-time.

[0035] In such Figure 1 In the DC-DC voltage conversion circuit 100 shown, when the circuit load increases, the cutoff time will be shortened, that is, the duration of switching transistor M1 being turned on and switching transistor M0 being turned off is shortened; at this time, by using the turn-on / cut-off circuit 300, the conduction time is extended, that is, the duration of switching transistor M1 being turned off and switching transistor M0 being turned on is extended, and the operating frequency of the DC-DC voltage conversion circuit 100 can be basically maintained stably.

[0036] When the trigger FF receives a high-level ON-PULSE signal from the turn-on circuit 210, it will cause the DC-DC voltage conversion circuit 100 to enter the conduction state until the trigger receives a high-level OFF-PULSE signal. Therefore, by adjusting the output time of the high-level OFF-PULSE signal, the conduction duration of the DC-DC voltage conversion circuit 100 can be controlled.

[0037] When the trigger receives a high-level ON-PULSE signal, the trigger FF can synchronously output a high-level on-time signal from the on-off circuit 300. Upon receiving this high-level on-time signal, the switch 310 of the on-off circuit 300 can control the first charge / discharge module 320 to charge the first energy storage module 330. Based on the voltage of the first energy storage module 330, it is determined whether an OFF-PULSE signal needs to be output to terminate the conduction of the DC-DC voltage conversion circuit 100. Therefore, the on-time of the DC-DC voltage conversion circuit 100 can be controlled by adjusting the charging / discharging speed of the first energy storage module 330.

[0038] In this embodiment, a controlled power supply can be set on the charging path of the first charging and discharging module 320, and the size of the controlled power supply changes based on the load change of the DC-DC voltage conversion circuit 100. Therefore, when the load changes, the charging speed of the first energy storage module 330 can be adjusted by adjusting the size of the controlled power supply, thereby controlling the conduction time of the DC-DC voltage conversion circuit 100.

[0039] In some embodiments, in response to the load of the voltage conversion circuit switching from light load to heavy load, the off-time of the voltage conversion circuit is shortened, the voltage of the controlled power supply can be reduced, the charging current for charging the first energy storage module 330 is reduced, and the on-time is extended; in response to the load of the voltage conversion circuit switching from heavy load to light load, the off-time of the voltage conversion circuit is extended, the voltage of the controlled power supply is increased, the charging current for charging the first energy storage module 330 is increased, and the on-time is shortened.

[0040] The controlled power supply may have an MCU, which can be connected to the DC-DC voltage conversion circuit 100 to monitor its load changes and adjust the controlled power supply according to the load changes.

[0041] A controlled power source can be a current source or a voltage source.

[0042] In some embodiments, by setting a turn-on / turn-off circuit, the turn-on duration can dynamically change with the load change of the voltage conversion circuit, thereby stabilizing the sum of the turn-on duration and the turn-off duration within the range of (TT*20%, T+T*20%), where T is the sum of the turn-on duration and the turn-off duration. In other words, the frequency change amplitude is within 20%, thereby improving the stability of the operating frequency.

[0043] Please refer to Figure 4 , Figure 4 This is a schematic diagram of the circuit structure of some embodiments of the on / off circuit 300 of this application.

[0044] In some embodiments, the switching switch 310 may include a semiconductor switch, such as a MOSFET, a transistor, an optocoupler, etc., and the switching switch 310 may also include a relay, etc. This application does not limit the specific structure of the switching switch 310.

[0045] The first energy storage module 330 may include a capacitor Cramp, and the comparison module 340 may include a voltage comparator CMP1. One end of the capacitor Cramp is connected to the positive input terminal of the voltage comparator CMP1, and the other end is grounded. The inverting input terminal of the voltage comparator CMP1 is connected to the first feedback voltage MVOUT.

[0046] The first charge / discharge module 320 is connected between the switch 310 and the first energy storage module 330. The first charge / discharge module 320 may include a charging path and a discharging path. A controlled power supply may be provided on the charging path. The discharging path can directly ground the first energy storage module 330 through a wire to achieve rapid discharge.

[0047] In some embodiments, such as Figure 4 As shown, multiple controlled power sources can be configured on the charging path of the first charging / discharging module 320, and these multiple controlled power sources are current sources. At least one controlled power source has a charge level related to the input voltage VIN of the DC-DC voltage conversion circuit 100 (such a controlled power source is labeled as the first controlled power source KVIN in the accompanying drawings and below). It also includes at least one controlled power source that varies based on the load changes of the DC-DC voltage conversion circuit 100 (such a controlled power source is labeled as the second controlled power source NVC in the accompanying drawings and below).

[0048] In some embodiments, except Figure 4 In addition to the embodiments shown, the charging path of the first charging and discharging module 320 may also be provided with only a controlled power supply that varies based on the load changes of the DC-DC voltage conversion circuit 100.

[0049] In some embodiments, the first feedback voltage MVOUT corresponds to the output voltage VOUT of the DC-DC voltage conversion circuit 100. For example, the first feedback voltage MVOUT can be M times the output voltage VOUT, where M is a value that can be adjusted according to actual needs. When at least one first controlled power supply KVIN is provided on the charging path of the first charging and discharging module 320, the charging time of the first charging and discharging module 320 can also be adjusted by adjusting the magnitude of the first controlled power supply KVIN and the first feedback voltage MVOUT, thereby adjusting the conduction time of the DC-DC voltage conversion circuit 100.

[0050] Please refer to Figure 5 , Figure 5This is a schematic diagram of the circuit structure of one embodiment of the controlled power supply voltage generation circuit of this application. In some embodiments, the on / off circuit 300 may further include a controlled power supply voltage generation circuit 500, which receives an on-time signal and generates a controlled power supply voltage based on the on-time signal, wherein the magnitude of the controlled power supply voltage is related to the frequency of the on-time signal.

[0051] In some implementation scenarios, the controlled power supply voltage generation circuit 500 may include an MCU. The MCU can receive the conduction duration signal and detect the frequency of the conduction duration signal, and adjust the voltage of the controlled power supply according to the frequency of the conduction duration signal.

[0052] In some embodiments, the controlled power supply voltage generation circuit 500 may include a trigger circuit 510, a second energy storage module 540, and a second charge / discharge module 530. The trigger circuit 510 may receive an ON conduction duration signal and trigger a periodic signal with a fixed pulse width based on a state switching edge (e.g., a rising edge) of the same type as the ON conduction duration signal. The second energy storage module 540 may be used to provide a second energy storage voltage, and the controlled power supply voltage corresponds to the second energy storage voltage. The second charge / discharge module 530 may be disposed between the trigger circuit 510 and the second energy storage module 540, and charge / discharge the second energy storage module 540 based on the periodic signal to adjust the controlled power supply voltage.

[0053] The second energy storage module 540 may include a capacitor Csource.

[0054] The state switching edge of the same type of conduction duration signal can be a rising edge switching from low level to high level or a falling edge switching from high level to low level. This application does not limit this.

[0055] The fixed pulse width of the periodic signal can be set according to actual needs. For example, it can be half of the steady-state operating cycle of the DC-DC voltage conversion circuit 100 (T0 / 2, where T0 is the steady-state operating cycle of the DC-DC voltage conversion circuit 100). The trigger circuit 510 triggers the fixed pulse width periodic signal based on the same type of state switching edge of the conduction duration signal. For example, the trigger circuit 510 can output a high-level periodic signal when it receives the rising edge of the conduction duration signal switching from low to high, and the pulse width of the high-level periodic signal is half of the steady-state operating cycle of the DC-DC voltage conversion circuit 100. During the remaining time, the output of the trigger circuit 510 remains low. That is, when the rising edge of the conduction duration signal is received, the trigger circuit 510 outputs a high-level periodic signal for a duration of T0 / 2. After T0 / 2, the periodic signal output by the trigger circuit 510 becomes low. In this embodiment, the pulse width of the high-level state of the periodic signal is fixed, while the duration of the low-level state varies accordingly with the operating cycle of the DC-DC voltage conversion circuit 100. In other embodiments, the pulse width of the low-level state of the periodic signal may be fixed, while the duration of the high-level state varies accordingly with the operating cycle of the DC-DC voltage conversion circuit 100.

[0056] In some embodiments, in response to the periodic signal being at a logic high level, the second charge / discharge module 530 discharges the second energy storage module 540; in response to the periodic signal being at a logic low level, the second charge / discharge module 530 charges the second energy storage module 540.

[0057] In other embodiments, the second energy storage module 540 may be charged when the logic level of the periodic signal is high, and discharged when the logic level is low. Specific adjustments can be made based on the component type, connection method, etc.

[0058] For example, at the rising edge of the ON duration signal, the trigger circuit 510 generates a pulse with a pulse width of T0 / 2 (i.e., the high-level state of this pulse signal lasts for T0 / 2 hours), and the second energy storage module 540 is charged while this pulse is in a high-level state. Therefore, as the frequency of the ON duration signal increases, the number of rising edges of the ON duration signal increases accordingly, thereby causing the trigger circuit 510 to generate more pulses, increasing the charging duration of the second energy storage module 540 and decreasing the discharging duration, thus increasing the voltage of the second energy storage module 540. (Refer to...) Figure 4 The second controlled power supply NVC can be a voltage-controlled current source, the magnitude of which can vary with the voltage of the second energy storage module 540. Therefore, the magnitude of the controlled power supply voltage can increase as the frequency of the conduction duration signal increases, and decrease as the frequency of the conduction duration signal decreases.

[0059] In some embodiments, the controlled power supply voltage generation circuit 500 may further include a second switching switch 520, which is disposed between the trigger circuit 510 and the second charge / discharge module 530, and controls the second charge / discharge module 530 to charge and discharge the second energy storage module 540 based on a periodic signal.

[0060] The second switching switch 520 may include semiconductor switches, such as MOSFETs, transistors, optocouplers, etc., and may also include relays, etc. This application does not limit the specific structure of the second switching switch 520.

[0061] In some embodiments, the second charging / discharging module 530 may include a second charging power supply and a second discharging power supply. One end of the second charging power supply is connected to the second energy storage module 540, and the other end is connected to the second switching switch 520; one end of the second discharging power supply is connected to the second energy storage module 540, and the other end is connected to the second switching switch 520; in response to the periodic signal being at a logic high level, the second discharging power supply discharges the second energy storage module 540; in response to the periodic signal being at a logic low level, the second charging power supply charges the second energy storage module 540.

[0062] The following is combined Figures 1-5The working principle of the turn-on / off circuit 300 provided in some embodiments of this application is specifically explained as follows: When the switch M1 is turned on, the current I_L of the inductor L decreases. When the current I_L of the inductor L decreases below the first comparison signal EA_OUT, the ON-PULSE signal output by the second comparison unit CMP becomes high, thereby triggering the ON-duration signal ON output by the trigger FF to a high level. This triggers the switch M1 to turn off and the switch M0 to turn on, allowing the power supply to power the inductor L, thus increasing the inductor current. When the ON-duration signal ON is triggered to a high level, the trigger circuit 510 generates a periodic signal with a fixed pulse width, causing contact 1 of the second switching switch 520 to close, thereby discharging the second energy storage module 540 through the second discharge power supply. After time T0 / 2, contact 0 of the second switching switch 520 closes, and the second energy storage module 540 is charged by the second charging power supply. When the ON duration signal is triggered to a high level, the switch 310 of the on-off circuit 300 is also connected to contact 1, thereby charging the first energy storage module 330 through the charging path. When the voltage VRAMP of the first energy storage module 330 is greater than the first feedback voltage MVOUT, the comparator module 340 generates a high-level on-off signal OFF-PULSE, which triggers the ON duration signal output by the trigger FF to a low level. This drives the switch M1 to turn on and the switch M0 to turn off, causing the inductor L to output current, thus reducing the inductor current. Simultaneously, when the ON duration signal is triggered to a low level, contact 0 of the switch 310 is connected, and the first energy storage module 330 discharges. Since the voltage VRAMP of the first energy storage module 330 is less than the first feedback voltage, the comparator module 340 outputs a low level.

[0063] When the DC-DC voltage conversion circuit 100 is in a stable state, its operating cycle remains stable. Therefore, when the pulse width of the periodic signal output by the trigger circuit 510 is fixed at T0 / 2, the charging and discharging time of the second energy storage module 540 through the second charge and discharge module 530 is the same, that is, the charging and discharging is balanced, thereby generating a stable controlled power supply. That is, the charging current of the first charge and discharge module 320 for charging the first energy storage module 330 remains unchanged. Therefore, the charging time of the first energy storage module 330 remains unchanged. Thus, the conduction time and cutoff time of the DC-DC voltage conversion circuit 100 remain unchanged, and it continues to maintain a steady state. When the load on the DC-DC voltage conversion circuit 100 switches from light load to heavy load, the cutoff time is shortened, thus shortening the duty cycle. Since the pulse width of the periodic signal output by the trigger circuit 510 is fixed at T0 / 2, the discharge time of the second energy storage module 540 through the second charge / discharge module 530 is fixed, remaining at T0 / 2. However, the charging time of the second energy storage module 540 through the second charge / discharge module 530 is correspondingly shortened due to the shortened duty cycle, resulting in an imbalance between charging and discharging. The charging time is less than the discharging time, reducing the charge of the second energy storage module 540, which in turn reduces the charge of the controlled power supply. Consequently, the charging time of the first energy storage module 330 through the first charge / discharge unit is correspondingly extended, thus extending the conduction time. When the load on the DC-DC voltage conversion circuit 100 switches from heavy load to light load, the cutoff time is extended, thus extending the duty cycle. Since the pulse width of the periodic signal output by the trigger circuit 510 is fixed at T0 / 2, the discharge time of the second energy storage module 540 through the second charge / discharge module 530 is also shortened due to the shortened duty cycle. 2. Therefore, the discharge time of the second energy storage module 540 through the second charge / discharge module 530 is fixed and remains at T0 / 2; while the charging time of the second energy storage module 540 through the second charge / discharge module 530 is correspondingly extended due to the shortened working cycle, resulting in an imbalance between charging and discharging, with the charging time exceeding the discharging time. The charge of the second energy storage module 540 increases, which in turn increases the charge of the controlled power supply. Consequently, the charging time of the first energy storage module 330 through the first charge / discharge unit is correspondingly reduced, thereby shortening the conduction time. In other words, when switching from light load to heavy load, the shortened cutoff time leads to a shortened working cycle, and the conduction time is extended by reducing the charge of the controlled power supply; when switching from heavy load to light load, the extended cutoff time leads to a longer working cycle, and the conduction time is reduced by increasing the charge of the controlled power supply. This allows the working cycle to basically recover to the steady-state working cycle, improving the dynamic stability of the DC-DC voltage conversion circuit 100.

[0064] The symbols for the switching switch 310 and the second switching switch 520 in the accompanying drawings, as well as the description of the "contacts" of the switching switches in this specification, are merely for the purpose of describing their working principle and are not intended to limit their actual operation.

[0065] Those skilled in the art will readily recognize that numerous modifications and variations can be made to the apparatus and method while maintaining the teachings of this application. Therefore, the above disclosure should be considered limited only by the scope of the appended claims.

Claims

1. A turn-on / turn-off circuit, applied to a frequency-locked circuit of a DC-DC voltage conversion circuit, used to issue a turn-on / turn-off signal to adjust the conduction duration of the DC-DC voltage conversion circuit, characterized in that, The on / off circuit includes: The first energy storage module is used to provide the first energy storage voltage; The first charging and discharging module is connected to the first energy storage module and charges or discharges the first energy storage module. A switch is used to connect the first charging and discharging module and receive a conduction duration signal. Based on the conduction duration signal, the first charging and discharging module is controlled to charge or discharge the first energy storage module. The comparison module receives the first energy storage voltage and a first feedback voltage corresponding to the output voltage of the voltage conversion circuit, and generates the on / off signal based on the first energy storage voltage and the first feedback voltage. The charging path of the first charging and discharging module is equipped with a controlled power supply. The controlled power supply changes based on the load change of the DC-DC voltage conversion circuit to change the charging current for charging the first energy storage module and adjust the conduction time of the DC-DC voltage conversion circuit.

2. The conduction and cutoff circuit according to claim 1, characterized in that, In response to the load of the voltage conversion circuit switching from light load to heavy load, the off-time of the voltage conversion circuit is shortened, the voltage of the controlled power supply is reduced, the charging current for charging the first energy storage module is reduced, and the on-time is extended. In response to the load of the voltage conversion circuit switching from heavy load to light load, the off-time of the voltage conversion circuit is extended, the voltage of the controlled power supply is increased, the charging current for charging the first energy storage module is increased, and the on-time is shortened.

3. The conduction and cutoff circuit according to claim 2, characterized in that, Further includes: A controlled power supply voltage generation circuit receives the conduction duration signal and generates a controlled power supply voltage based on the conduction duration signal. The magnitude of the controlled power supply voltage is related to the frequency of the conduction duration signal.

4. The conduction and cutoff circuit according to claim 3, characterized in that, The controlled power supply voltage generation circuit includes: A trigger circuit receives the conduction duration signal and triggers a periodic signal with a fixed pulse width based on the same type of state switching edge of the conduction duration signal. The second energy storage module is used to provide a second energy storage voltage, and the controlled power supply voltage corresponds to the second energy storage voltage. The second charging and discharging module is disposed between the trigger circuit and the second energy storage module, and charges and discharges the second energy storage module based on the periodic signal to adjust the controlled power supply voltage.

5. The conduction and cutoff circuit according to claim 4, characterized in that, In response to the periodic signal being at a logic high level, the second charging and discharging module discharges the second energy storage module; In response to the periodic signal being at a logic low level, the second charging and discharging module charges the second energy storage module.

6. The conduction / cutoff circuit according to claim 4 or 5, characterized in that, The controlled power supply voltage generation circuit also includes: The second switching switch is located between the trigger circuit and the second charging / discharging module, and controls the second charging / discharging module to charge and discharge the second energy storage module based on the periodic signal.

7. The conduction / cutoff circuit according to any one of claims 6, characterized in that, The second charge / discharge module includes: The second charging power supply is connected at one end to the second energy storage module and at the other end to the second switching switch; The second discharge power supply is connected at one end to the second energy storage module and at the other end to the second switching switch; In response to the periodic signal being at a logic high level, the second discharge power supply discharges the second energy storage module; In response to the periodic signal being at a logic low level, the second charging power supply charges the second energy storage module.

8. The conduction / cutoff circuit according to any one of claims 1 to 7, characterized in that, The sum of the conduction duration and the cutoff duration is within the range of (TT*20%, T+T*20%), where T is the sum of the conduction duration and the cutoff duration.

9. A frequency lock-in circuit, applied to a DC-DC voltage conversion circuit, characterized in that, include: The on / off circuit as described in any one of claims 1-8.

10. The frequency locking circuit according to claim 9, characterized in that, Further includes: The on / off circuit is used to send an on / off signal. A trigger, connected to the turn-on circuit and the turn-off circuit, generates the turn-on duration signal based on the turn-on signal and the turn-off signal; The driver, connected to the trigger, outputs a drive signal based on the conduction duration signal to drive the DC-DC voltage conversion circuit to turn on or off.

11. The frequency locking circuit according to claim 10, characterized in that, The switching circuit includes: The first comparison unit has its first input terminal connected to the output voltage of the DC-DC voltage conversion circuit, its second input terminal connected to the first reference voltage, and outputs a first comparison signal at its output terminal based on the output voltage of the DC-DC voltage conversion circuit and the first reference voltage. The second comparison unit has a first input terminal connected to the first comparison signal and a second input terminal connected to the second reference signal. Based on the first comparison signal and the second reference signal, it generates a turn-on signal at its output terminal.

12. A DC-DC voltage conversion circuit, characterized in that, Includes the frequency locking circuit as described in claims 9-11.

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