A direct-current step-down circuit, an electronic device, and a direct-current step-down method
By introducing an energy storage unit and a path selection unit into the DC buck circuit and adopting a dual-path hybrid buck structure, the problem of high switching voltage and current overlap loss is solved, and higher conversion efficiency is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTHERN UNIVERSITY OF SCIENCE AND TECHNOLOGY
- Filing Date
- 2026-02-09
- Publication Date
- 2026-06-16
Smart Images
Figure CN122225845A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of voltage conversion technology, and in particular to a DC step-down circuit, electronic device, and DC step-down method. Background Technology
[0002] In related technologies, existing buck converters typically employ a switched Buck topology. In this structure, the voltage across the switch switches between the input voltage and ground during the on / off period. When the switch is off, the voltage across it is higher; when the switch is on, the current is larger. The current and voltage are not completely separated at the moment of switching, resulting in overlap and consequently, higher overlap losses, leading to lower buck efficiency. Therefore, improving the conversion efficiency of buck converters has become a pressing technical problem. Summary of the Invention
[0003] The main objective of this application is to provide a DC-DC step-down circuit, electronic device, and DC-DC step-down method, which aims to improve the conversion efficiency of the DC-DC step-down circuit.
[0004] To achieve the above objectives, a first aspect of this application provides a DC step-down circuit, the circuit comprising: a voltage input module for connecting a DC voltage; A voltage output module, wherein the voltage output module is used to output a target output voltage through a target power transmission path, wherein the target output voltage is lower than the DC voltage; A path switching module, comprising a path selection unit and an energy storage unit, wherein the path selection unit is connected to the voltage input module and the energy storage unit respectively, and the energy storage unit is used to step down the DC voltage to obtain the intermediate voltage of the energy storage unit; An intermediate step-down module is connected to the energy storage unit. The intermediate step-down module is used to convert the intermediate voltage into the target output voltage. The intermediate voltage is lower than the DC voltage and higher than the target output voltage. The first inductor module, the path selection unit is connected to the voltage output module through the first inductor module, so as to determine the first power transmission path between the voltage input module and the voltage output module; The second inductor module, wherein the path selection unit is connected to the voltage output module in sequence through the energy storage unit, the intermediate step-down module and the second inductor module, to determine the second energy transmission path between the voltage input module and the voltage output module; The path selection module is used to determine the target power transmission path from the first power transmission path or the second power transmission path.
[0005] The DC buck converter circuit proposed in this application employs a dual-path hybrid buck structure, introducing an energy storage unit to share the input DC voltage. The path selection unit pre-divides or steps down the DC voltage under different power transmission paths, effectively reducing the actual voltage stress on the power devices and narrowing the voltage swing range across the circuit components. This allows for the selection of power devices with lower withstand voltage and lower on-resistance, reducing switching and conduction losses, and ultimately improving the conversion efficiency of the DC buck converter circuit.
[0006] In some embodiments, the path selection unit includes a first control unit, a first switch, a second switch, a third switch, and a flying capacitor. The first control unit is connected to the first switch, the second switch, the third switch, and the energy storage unit. The voltage input module is connected to the first terminal of the third switch and the first terminal of the flying capacitor via the first switch. The second terminal of the third switch is connected to the energy storage unit. The second terminal of the flying capacitor is connected to the first terminal of the second switch and the first terminal of the first inductor module. The second terminal of the second switch is grounded. The second terminal of the first inductor module is connected to the voltage output module. The first control unit generates a first switch control signal and a second switch control signal based on the intermediate voltage of the energy storage unit. Under the same timing sequence, the levels of the first switch control signal and the second switch control signal are opposite. The first switch is turned on or off according to the first switch control signal, forming the first energy transmission path when on, or disconnecting the first energy transmission path when off. The second switch and the third switch are turned on or off according to the second switch control signal, forming the second energy transmission path when on, or disconnecting the second energy transmission path when off. The flying capacitor is charged according to the DC voltage when the first switch is on.
[0007] In some embodiments, the energy storage unit includes an intermediate capacitor, the first terminal of which is connected to the second terminal of the third switch and the intermediate step-down module, and the second terminal of the intermediate capacitor is grounded.
[0008] In some embodiments, the intermediate step-down module includes a second control unit, a fourth switch, and a fifth switch. The second control unit is connected to the fourth switch, the fifth switch, and the voltage output module, respectively. The first terminal of the fourth switch is connected to the first terminal of the intermediate capacitor, and the second terminal of the fourth switch is connected to the second inductor module and the fifth switch, respectively. The second terminal of the fifth switch is grounded. The second control unit generates a third switch control signal and a fourth switch control signal according to the target output voltage of the voltage output module. Under the same timing, the levels of the third switch control signal and the fourth switch control signal are opposite. The fourth switch is turned on or off according to the third switch control signal, and the fifth switch is turned on or off according to the fourth switch control signal.
[0009] In some embodiments, the first inductor module includes a first inductor, the second inductor module includes a second inductor, a first terminal of the first inductor is connected to the second terminal of the flying capacitor and the first terminal of the second switch, a first terminal of the second inductor is connected to the second terminal of the fourth switch and the first terminal of the fifth switch, and a second terminal of the second inductor is connected to the voltage output module, wherein the inductance value of the first inductor is greater than the inductance value of the second inductor.
[0010] In some embodiments, the voltage output module includes an output capacitor and an output terminal. The first terminal of the output capacitor is connected to the first inductor module, the second inductor module, and the output terminal, respectively. The second terminal of the output capacitor is grounded, and the output terminal is used to connect to an electrical load.
[0011] To achieve the above objectives, a second aspect of this application provides an electronic device, which includes the circuit described in the first aspect.
[0012] The electronic device proposed in this application uses the DC buck circuit described in the first aspect above, which can select power devices with lower withstand voltage and lower on-resistance, reduce switching losses and conduction losses, and improve overall voltage conversion efficiency.
[0013] To achieve the above objectives, a third aspect of this application provides a DC-DC step-down method applied to the circuit described in the first aspect, the method comprising: DC voltage is obtained through a voltage input module; The path selection unit of the path switching module is controlled to obtain the first power transmission path between the voltage input module and the voltage output module. The DC voltage is stepped down according to the first power transmission path to obtain a candidate voltage; The target output voltage is obtained through the voltage output module; The path selection unit performs path switching to obtain a second power transmission path between the voltage input module and the voltage output module, so as to determine the candidate voltage as the intermediate voltage of the power storage unit of the path switching module according to the second power transmission path. A first switch control signal and a second switch control signal are generated based on the intermediate voltage; A third switch control signal and a fourth switch control signal are generated based on the target output voltage; The path selection unit is controlled to switch paths based on the first and second switch control signals, and the intermediate step-down module is controlled to step down based on the third and fourth switch control signals.
[0014] In some embodiments, generating the first switch control signal and the second switch control signal based on the intermediate voltage includes: An initial error signal is generated based on the intermediate voltage and the preset first reference voltage; The initial error signal is amplified to obtain the target error signal; The first switch control signal is obtained by pulse width modulation based on the target error signal; The first switch control signal is inverted to obtain the second switch control signal.
[0015] In some embodiments, generating the third and fourth switch control signals based on the target output voltage includes: The target output voltage and the preset second reference voltage are pulse-width modulated by a preset comparator to obtain the third switching control signal; The third switch control signal is inverted to obtain the fourth switch control signal.
[0016] The proposed DC buck converter method detects and feeds back the intermediate voltage, stabilizing it within a predetermined target voltage range. To meet the dynamic performance requirements under rapid load step changes, the output requires higher loop bandwidth and response speed. Adaptive constant on-time control is more conducive to reducing the output voltage deviation and shortening the recovery time during load transients, thereby achieving comprehensive optimization of the overall buck DC converter performance in terms of low switching withstand voltage, high conversion efficiency, and fast transient response. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the DC buck circuit provided in the embodiments of this application; Figure 2This is an optional circuit structure diagram of the DC buck circuit provided in the embodiments of this application; Figure 3 This is a schematic diagram of the first power transmission path of the DC buck circuit provided in the embodiments of this application; Figure 4 This is a schematic diagram of the second power transmission path of the DC buck circuit provided in the embodiments of this application; Figure 5 This is a flowchart of the DC step-down method provided in the embodiments of this application; Figure 6 This is a waveform diagram of a DC buck circuit according to an embodiment of this application; Figure 7 This is another working waveform diagram of the DC buck circuit in the embodiment of this application.
[0018] Figure description: Voltage input module 100; Voltage output module 200; Path switching module 300; Path selection unit 310; Energy storage unit 320; Intermediate step-down module 400; First inductor module 500; Second inductor module 600. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0020] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.
[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.
[0022] In related technologies, existing buck converters typically employ a switched Buck topology. In this structure, the voltage across the switch switches between the input voltage and ground during the on / off period. When the switch is off, the voltage across it is higher; when the switch is on, the current is larger. The current and voltage are not completely separated at the moment of switching, resulting in overlap and consequently, higher overlap losses, leading to lower buck efficiency. Therefore, improving the conversion efficiency of buck converters has become a pressing technical problem.
[0023] Based on this, embodiments of this application provide a DC-DC step-down circuit, an electronic device, and a DC-DC step-down method, aiming to improve the conversion efficiency of the DC-DC step-down circuit.
[0024] The DC step-down circuit, electronic device, and DC step-down method provided in this application are specifically described through the following embodiments. First, the DC step-down circuit in this application embodiment is described.
[0025] Figure 1 This is a schematic diagram of the DC-DC step-down circuit provided in an embodiment of this application. It also shows the module connection diagram of the DC-DC step-down circuit provided in an embodiment of this application.
[0026] Voltage input module 100, voltage input module 100 is used to connect DC voltage V IN The voltage input module 100 can be a battery or a connector for connecting to a power source.
[0027] Voltage output module 200, the voltage output module 200 is used to output the target output voltage V through the target power transmission path. OUT The target output voltage is lower than the DC voltage. The voltage output module 200 can be an output connector for connecting to a load device to provide the target output voltage to the device.
[0028] The path switching module 300 includes a path selection unit 310 and an energy storage unit 320. The path selection unit 310 is connected to both the voltage input module 100 and the energy storage unit 320. The energy storage unit 320 is used to step down the DC voltage to obtain an intermediate voltage V. MID .
[0029] Intermediate step-down module 400 is connected to energy storage unit 320. Intermediate step-down module 400 is used to convert intermediate voltage V MID Converted to target output voltage, intermediate voltage V MID It is below the DC voltage and above the target output voltage.
[0030] The first inductor module 500 and the path selection unit 310 are connected to the voltage output module 200 through the first inductor module 500 to determine the first power transmission path between the voltage input module 100 and the voltage output module 200.
[0031] The second inductor module 600 and the path selection unit 310 are connected to the voltage output module 200 in sequence through the energy storage unit 320, the intermediate step-down module 400 and the second inductor module 600, so as to determine the second energy transmission path between the voltage input module 100 and the voltage output module 200.
[0032] The path selection module is used to determine the target power transmission path from the first power transmission path or the second power transmission path.
[0033] The DC-DC buck circuit provided in this application adopts a dual-path hybrid buck structure, introducing an energy storage unit to share the input DC voltage. The path selection unit pre-divides or steps down the DC voltage under different power transmission paths, thereby effectively reducing the actual voltage stress on the power devices and narrowing the voltage swing range across the circuit devices. Therefore, power devices with lower withstand voltage and lower on-resistance can be selected, reducing switching and conduction losses, ultimately improving the conversion efficiency of the DC-DC buck circuit.
[0034] In some embodiments, please refer to Figure 2 , Figure 2 This is an optional circuit structure diagram of the DC-DC step-down circuit provided in the embodiments of this application. The path selection unit 310 includes a first control unit (not shown in the figure), a first switch S1, a second switch S2, a third switch S3, and a flying capacitor C. F Furthermore, the first control unit is connected to the first switch S1, the second switch S2, the third switch S3, and the energy storage unit 320, respectively. The voltage input module 100 is connected to the first terminal of the third switch S3 and the flying capacitor C via the first switch S1. F The first terminal is connected, the second terminal of the third switch S3 is connected to the energy storage unit 320, and the flying capacitor C F The second terminal is connected to the first terminal of the second switch S2 and the first terminal of the first inductor module 500, respectively. The second terminal of the second switch S2 is grounded, and the second terminal of the first inductor module 500 is connected to the voltage output module 200. The first control unit is used to adjust the voltage V of the energy storage unit 320 according to the intermediate voltage V. MID A first switch control signal and a second switch control signal are generated. Under the same timing, the levels of the first switch control signal and the second switch control signal are opposite.
[0035] In some embodiments, the first control unit may include a cascaded operational amplifier and a comparator, the operational amplifier adjusting for an intermediate voltage V.MID The difference between the voltage and the preset reference voltage generates an error signal, which is amplified. The amplified error signal is then pulse-width modulated by a comparator to generate a first switch control signal and a second switch control signal. It is understood that the first and second switch control signals can be PWM signals, and the first switch S1, second switch S2, and third switch S3 can be MOSFETs. The first control unit drives the gate of the first switch S1 through the first switch control signal and drives the gates of the second switch S2 and the third switch S3 through the second switch control signal, controlling their turn-on and turn-off.
[0036] Specifically, please refer to Figure 3 , Figure 3 This is a schematic diagram of the first power transmission path of the DC-DC step-down circuit provided in this application embodiment. The blue line in the diagram represents the first power transmission path, and the arrow indicates the direction of power transmission. A first switch is used to turn on or off according to a first switch control signal, so as to form the first power transmission path when on, or to disconnect the first power transmission path when off. When the first power transmission path is on, the DC voltage VIN affects the flying capacitor C. F During charging, some electrical energy is directly transferred to the voltage output module 200 through the first inductor module 500. At this time, the first power transmission path serves as the target power transmission path, realizing step-down transmission from input to output.
[0037] Please see Figure 4 , Figure 4 This is a schematic diagram of the second power transmission path of the DC buck circuit provided in this application embodiment. The red line in the diagram represents the second power transmission path, and the arrow indicates the direction of power transmission. The second switch S2 and the third switch S3 are used to turn on or off according to the second switch control signal, so as to form the second power transmission path when it is turned on, or to disconnect the second power transmission path when it is turned off. At this time, the second power transmission path serves as the target power transmission path to realize the step-down transmission from input to output.
[0038] Furthermore, since the levels of the first and second switch control signals are opposite under the same timing sequence, the duty cycle of the first switch S1 is designated as D1, while the duty cycles of the second switch S2 and the third switch S3 are the same, both being (1-D1). Therefore, the first and second power transmission paths are formed alternately, i.e., within one slow switching cycle 1 / f... sw1 Internally, when the first switch S1 is closed, the second switch S2 and the third switch S3 are open. Conversely, when the second switch S2 and the third switch S3 are closed, the first switch S1 is open. sw1 It is the switching frequency of the first switch S1, the second switch S2, and the third switch S3.
[0039] Furthermore, the flying capacitor CF This is used to charge the capacitor based on the DC voltage when the first switch S1 is turned on. It should be noted that the first power transmission path must be activated before the second power transmission path; the flying capacitor C is activated first. F Charging is performed, thereby allowing the capacitor C to fly across during the formation of the second power transmission path. F Capable of discharging, enabling the flying capacitor C F The charge and discharge balance. Additionally, by adjusting the flying capacitor C... F Charging and discharging, flying capacitor C F A certain voltage exists across the two ends, thus reducing the voltage withstand requirement for the switches in the circuit. Taking the first switch S1 as an example, through the flying capacitor C... F It withstands voltage, and its switching withstand voltage is V IN Reduce to V IN -V CF .
[0040] In some embodiments, the energy storage unit 320 includes an intermediate capacitor C. MID Specifically, the intermediate capacitor C MID The first terminal is connected to the second terminal of the third switch S3 and the intermediate step-down module 400, respectively, and the intermediate capacitor C MID The second terminal is grounded. It is understandable that when the second power transmission path is formed, the flying capacitor C... F Discharge occurs, transferring electrical energy to the intermediate capacitor C. MID Thus, the intermediate capacitor C is obtained. MID The intermediate voltage V at both ends MID .
[0041] In some embodiments, the intermediate step-down module 400 includes a second control unit (not shown), a fourth switch S4, and a fifth switch S5. The second control unit is connected to the fourth switch S4, the fifth switch S5, and the voltage output module 200, respectively. The first terminal of the fourth switch is connected to the intermediate capacitor C. MID The first end of the fourth switch S4 is connected to the second inductor module 600 and the fifth switch S5 respectively. The second end of the fifth switch S5 is grounded.
[0042] In some embodiments, the second control unit determines the target output voltage V of the voltage output module 200. OUT A third switch control signal and a fourth switch control signal are generated. Under the same timing, the levels of the third switch control signal and the fourth switch control signal are opposite. The fourth switch is turned on or off according to the third switch control signal, and the fifth switch is turned on or off according to the fourth switch control signal.
[0043] It is understandable that the second control unit may include a comparator, which directly compares the target output voltage V. OUTThe signal is compared with another preset reference voltage, and a square wave modulation signal is output. The third and fourth switch control signals can be PWM signals, and the fourth switch S4 and the fifth switch S5 can be MOSFETs. The second control unit drives the gate of the fourth switch S4 and the gate of the fifth switch S5 through the third switch control signal. Furthermore, since the levels of the third and fourth switch control signals are opposite under the same timing, the duty cycle of the fourth switch S4 is designated as D2, and the duty cycle of the fifth switch S5 is (1-D2).
[0044] It should be added that the switching frequency f of the fourth switch S4 and the fifth switch S5 sw2 The switching frequency f must be higher than that of the first switch S1, the second switch S2, and the third switch S3. sw1 Since the intermediate step-down module 400 has a higher switching frequency, a low-inductance, small-volume inductor (corresponding to the second inductor module 600) can be selected in this branch, thereby effectively reducing the size of passive components, increasing power density, and improving the load transient response performance by utilizing the high-frequency branch.
[0045] In some embodiments, the first inductor module 500 includes a first inductor L1, and the second inductor module 600 includes a second inductor L2. The first terminal of the first inductor L1 is connected to the flying capacitor C. F The second terminal of the first inductor L1 is connected to the first terminal of the second switch S2. The first terminal of the second inductor L2 is connected to the second terminal of the fourth switch S4 and the first terminal of the fifth switch S5, respectively. The second terminal of the second inductor L2 is connected to the voltage output module 200. The inductance value of the first inductor L1 is greater than that of the second inductor L2. It should be noted that the first inductor L1 and the second inductor L2 are located in the first power transmission path and the second power transmission path, respectively. In this application, the switches in the path selection unit 310 and the intermediate step-down module 400 adopt slow and fast dual switching frequencies, respectively. The first inductor L1 with a large inductance value is designed for the slow frequency switch, and the second inductor L2 with a small inductance value is designed for the fast frequency switch. Thus, in the working process where the first power transmission path and the second power transmission path are alternately formed, on the one hand, the large inductance is used to suppress current ripple and improve steady-state output characteristics, and on the other hand, the small inductance is used to increase the current change rate in the high-frequency path, thereby improving the slew rate of the overall equivalent inductance current. While maintaining controllable output ripple, the size of passive devices can be reduced accordingly, power density can be increased, and the current build-up and recovery process can be accelerated when the load changes rapidly, thus improving transient response speed.
[0046] In some embodiments, the voltage output module 200 includes an output capacitor C. OUT and output terminal V O Output capacitor C OUTThe first terminal is connected to the first inductor module 500, the second inductor module 600, and the output terminal V, respectively. O Connection, output capacitor C OUT The second terminal is grounded, and the output terminal V O Used to connect to electrical loads. Specifically, the output capacitor C OUT The first end is connected to the second end of the first inductor L1, the second end of the second inductor L2, and the output terminal VO, respectively.
[0047] This application also provides an electronic device that includes the DC-DC buck circuit described in the above embodiments. This device can be any smart terminal, including tablet computers, in-vehicle computers, etc. By using the DC-DC buck circuit described in the above embodiments, the electronic device of this application can select power devices with lower voltage ratings and lower on-resistance, thereby reducing switching losses and conduction losses and improving overall voltage conversion efficiency.
[0048] The specific implementation of this electronic device is basically the same as the specific embodiment of the DC buck circuit described above, and will not be repeated here.
[0049] Please see Figure 5 This application also provides a DC step-down method, which may include, but is not limited to, steps S501 to S508: Step S501: Obtain DC voltage through the voltage input module.
[0050] Step S502: Perform path control on the path selection unit of the path switching module to obtain the first power transmission path between the voltage input module and the voltage output module.
[0051] Step S503: The DC voltage is stepped down according to the first power transmission path to obtain a candidate voltage.
[0052] Step S504: Obtain the target output voltage through the voltage output module.
[0053] Step S505: The path selection unit performs path switching to obtain a second power transmission path between the voltage input module and the voltage output module, so as to determine the candidate voltage as the intermediate voltage of the power storage unit of the path switching module according to the second power transmission path.
[0054] Step S506: Generate a first switch control signal and a second switch control signal based on the intermediate voltage.
[0055] Step S507: Generate a third switch control signal and a fourth switch control signal based on the target output voltage.
[0056] Step S508: Perform path switching control on the path selection unit based on the first switch control signal and the second switch control signal, and perform step-down control on the intermediate step-down module based on the third switch control signal and the fourth switch control signal.
[0057] In step S501 of some embodiments, the voltage input module can be a battery, power adapter, or other power supply device, and its function is to connect the DC voltage from the external power source to the DC buck circuit of this embodiment. This DC voltage will serve as the input voltage V in subsequent steps. IN .
[0058] In step S502 of some embodiments, a first power transmission path is first formed, and the flying capacitor C of the path selection unit is... F It is charged to cooperate with the second power transmission path in the subsequent process to achieve charge-discharge balance.
[0059] In step S503 of some embodiments, voltage reduction is achieved through the first power transmission path, and the output is then transmitted through the output terminal. The flying capacitor C... F The voltage across the two ends is used as the candidate voltage.
[0060] In step S504 of some embodiments, the target output voltage can be sampled by a voltage sampling circuit or a voltage sensor, and the sampling result can be transmitted to the second control unit to obtain the target output voltage.
[0061] In step S505 of some embodiments, when the second power transmission path is turned on, the path selection unit is connected to the power storage unit, and at this time the intermediate capacitor C of the power storage unit can be determined based on the candidate voltage. MID intermediate voltage V MID .
[0062] In some embodiments, step S506 specifically includes the following steps: based on the intermediate voltage V MID An initial error signal is generated using a preset first reference voltage. This initial error signal is amplified to obtain a target error signal. Pulse width modulation is performed on the target error signal to obtain a first switching control signal. The first switching control signal is then inverted to obtain a second switching control signal. This process has been described in detail in the aforementioned embodiment of the DC-DC buck circuit and will not be repeated here.
[0063] In some embodiments, step S507 specifically includes the following steps: pulse-width modulation of the target output voltage and a preset second reference voltage using a preset comparator to obtain a third switch control signal. The level of the third switch control signal is then inverted to obtain a fourth switch control signal. This process has been described in detail in the aforementioned embodiments of the DC-DC buck circuit and will not be repeated here.
[0064] In step S508 of some embodiments, the path selection unit is controlled to switch paths via a first switch control signal and a second switch control signal, adjusting the path of electrical energy flow. Simultaneously, the intermediate step-down module is controlled to step down based on a third switch control signal and a fourth switch control signal.
[0065] Steps S501 to S508 as shown in the embodiments of this application detect and feed back the intermediate voltage, stabilizing the intermediate voltage within a predetermined target voltage range. To meet the dynamic performance requirements under rapid load step changes, the output terminal requires higher loop bandwidth and response speed. Adaptive constant on-time control is more conducive to reducing the output voltage deviation and shortening the recovery time during load transients, thereby achieving comprehensive optimization of the overall buck DC converter in terms of low switching withstand voltage, high conversion efficiency, and fast transient response.
[0066] Please see Figure 6 , Figure 6 This is a waveform diagram of a DC buck circuit according to an embodiment of this application. Figure 6 The prerequisite setting is DC voltage V IN The voltage is 5V, the desired output voltage is 1V, and the desired output current is 1A. Please refer to the diagram for the positions of switching nodes SW1 and SW2. Figure 2 The annotation in I L1 I is the inductor current generated by the first inductor. L2 This is the inductance current generated by the second inductor.
[0067] Please see Figure 7 , Figure 7 This is another working waveform diagram of the DC buck circuit in the embodiment of this application. Figure 7 Prerequisites and Figure 6 The same. I Ltot This represents the total inductor current in the circuit. It can be seen that when the load current undergoes a sudden change, the DC buck circuit of this application can quickly recover to a steady state.
[0068] The DC buck circuit of this application embodiment can support high power density and high efficiency DC buck conversion, and has fast transient response performance at the output.
[0069] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.
[0070] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.
[0071] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.
[0072] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.
[0073] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0074] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.
[0075] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.
[0076] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.
[0077] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.
[0078] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0079] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.
Claims
1. A DC step-down circuit, characterized in that, The circuit includes: A voltage input module, wherein the voltage input module is used to connect to a DC voltage; A voltage output module, wherein the voltage output module is used to output a target output voltage through a target power transmission path, wherein the target output voltage is lower than the DC voltage; A path switching module, comprising a path selection unit and an energy storage unit, wherein the path selection unit is connected to the voltage input module and the energy storage unit respectively, and the energy storage unit is used to step down the DC voltage to obtain the intermediate voltage of the energy storage unit; An intermediate step-down module is connected to the energy storage unit. The intermediate step-down module is used to convert the intermediate voltage into the target output voltage. The intermediate voltage is lower than the DC voltage and higher than the target output voltage. The first inductor module, the path selection unit is connected to the voltage output module through the first inductor module, so as to determine the first power transmission path between the voltage input module and the voltage output module; The second inductor module, wherein the path selection unit is connected to the voltage output module in sequence through the energy storage unit, the intermediate step-down module and the second inductor module, to determine the second energy transmission path between the voltage input module and the voltage output module; The path selection module is used to determine the target power transmission path from the first power transmission path or the second power transmission path.
2. The circuit according to claim 1, characterized in that, The path selection unit includes a first control unit, a first switch, a second switch, a third switch, and a flying capacitor. The first control unit is connected to the first switch, the second switch, the third switch, and the energy storage unit. The voltage input module is connected to the first terminal of the third switch and the first terminal of the flying capacitor through the first switch. The second terminal of the third switch is connected to the energy storage unit. The second terminal of the flying capacitor is connected to the first terminal of the second switch and the first terminal of the first inductor module. The second terminal of the second switch is grounded. The second terminal of the first inductor module is connected to the voltage output module. The first control unit generates a first switch control signal and a second switch control signal based on the intermediate voltage of the energy storage unit. Under the same timing sequence, the levels of the first switch control signal and the second switch control signal are opposite. The first switch is turned on or off according to the first switch control signal, forming the first energy transmission path when on, or disconnecting the first energy transmission path when off. The second switch and the third switch are turned on or off according to the second switch control signal, forming the second energy transmission path when on, or disconnecting the second energy transmission path when off. The flying capacitor is charged according to the DC voltage when the first switch is on.
3. The circuit according to claim 2, characterized in that, The energy storage unit includes an intermediate capacitor. The first terminal of the intermediate capacitor is connected to the second terminal of the third switch and the intermediate step-down module, respectively. The second terminal of the intermediate capacitor is grounded.
4. The circuit according to claim 3, characterized in that, The intermediate step-down module includes a second control unit, a fourth switch, and a fifth switch. The second control unit is connected to the fourth switch, the fifth switch, and the voltage output module, respectively. The first terminal of the fourth switch is connected to the first terminal of the intermediate capacitor, and the second terminal of the fourth switch is connected to the second inductor module and the fifth switch, respectively. The second terminal of the fifth switch is grounded. The second control unit generates a third switch control signal and a fourth switch control signal according to the target output voltage of the voltage output module. Under the same timing, the levels of the third switch control signal and the fourth switch control signal are opposite. The fourth switch is turned on or off according to the third switch control signal, and the fifth switch is turned on or off according to the fourth switch control signal.
5. The circuit according to claim 4, characterized in that, The first inductor module includes a first inductor, and the second inductor module includes a second inductor. The first end of the first inductor is connected to the second end of the flying capacitor and the first end of the second switch, respectively. The first end of the second inductor is connected to the second end of the fourth switch and the first end of the fifth switch, respectively. The second end of the second inductor is connected to the voltage output module. The inductance value of the first inductor is greater than the inductance value of the second inductor.
6. The circuit according to any one of claims 1 to 5, characterized in that, The voltage output module includes an output capacitor and an output terminal. The first terminal of the output capacitor is connected to the first inductor module, the second inductor module, and the output terminal, respectively. The second terminal of the output capacitor is grounded. The output terminal is used to connect to an electrical load.
7. An electronic device, characterized in that, The electronic device includes a DC buck circuit as described in any one of claims 1 to 6.
8. A DC step-down method, characterized in that, The method, applied to the DC buck circuit as described in any one of claims 1 to 6, comprises: DC voltage is obtained through a voltage input module; The path selection unit of the path switching module is controlled to obtain the first power transmission path between the voltage input module and the voltage output module. The DC voltage is stepped down according to the first power transmission path to obtain a candidate voltage; The target output voltage is obtained through the voltage output module; The path selection unit performs path switching to obtain a second power transmission path between the voltage input module and the voltage output module, so as to determine the candidate voltage as the intermediate voltage of the power storage unit of the path switching module according to the second power transmission path. A first switch control signal and a second switch control signal are generated based on the intermediate voltage; A third switch control signal and a fourth switch control signal are generated based on the target output voltage; The path selection unit is controlled to switch paths based on the first and second switch control signals, and the intermediate step-down module is controlled to step down based on the third and fourth switch control signals.
9. The method according to claim 8, characterized in that, The generation of the first switch control signal and the second switch control signal based on the intermediate voltage includes: An initial error signal is generated based on the intermediate voltage and the preset first reference voltage; The initial error signal is amplified to obtain the target error signal; The first switch control signal is obtained by pulse width modulation based on the target error signal; The first switch control signal is inverted to obtain the second switch control signal.
10. The method according to claim 8, characterized in that, The generation of the third and fourth switch control signals based on the target output voltage includes: The target output voltage and the preset second reference voltage are pulse-width modulated by a preset comparator to obtain the third switch control signal; The third switch control signal is inverted to obtain the fourth switch control signal.