Power supply circuit and power supply system with hardware compatible with different BUCK chips

Abstract

The invention provides a power supply circuit and a power supply system with hardware compatible with different BUCK chips, and relates to the technical field of BUCK circuits, the circuit comprises a power supply filtering module, a BUCK voltage reduction module and an output filtering module which are connected in sequence; the BUCK step-down module comprises a BUCK chip mounting structure and a charging capacitor; the BUCK chip installation structure can be compatible with BUCK power supply chips of at least two different loads. The output filtering module comprises a load filtering capacitor; the charging capacitor and the load filtering capacitor meet a preset capacitance value condition. According to the embodiment of the invention, the compatible design of the BUCK power supply circuit suitable for different loads can be realized, the hardware development universality is improved, the development and maintenance cost is reduced, and the development and maintenance period is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of BUCK circuits, and in particular to a power supply circuit and a power supply system that are hardware compatible with different BUCK chips. Background Art

[0002] Buck chips are switching power supply integrated circuits used for voltage conversion, stepping down voltage based on the principle of inductive energy storage. Traditional buck chips have poor compatibility, requiring different buck chips for different load sizes and custom buck power supply solutions.

[0003] However, due to structural and theoretical limitations, different buck power supply solutions cannot be compatible on the same printed circuit board (PCB). For example, large-load and small-load power supply solutions require different peripheral capacitor sizes and configurations. Consequently, existing buck power supply solutions are incompatible with buck chips for different loads, resulting in poor compatibility, high development costs, and long development cycles. Summary of the Invention

[0004] To address the above-mentioned issues, an embodiment of the present invention provides a power supply circuit that is hardware-compatible with different buck chips, including a power filter module, a buck step-down module, and an output filter module connected in sequence. The buck step-down module includes a buck chip mounting structure and a charging capacitor. The buck chip mounting structure is compatible with buck power supply chips for at least two different loads. The output filter module includes a load filter capacitor. The charging capacitor and the load filter capacitor meet the following conditions:

[0005]

[0006] Wherein, Ivcc is the internal discharge current of the Vcc terminal of the BUCK chip, Io is the load current, Co is the capacitance of the load filter capacitor, and Cvcc is the capacitance of the charging capacitor.

[0007] The hardware provided by the embodiment of the present invention is compatible with the power circuits of different BUCK chips, which can realize the compatible design of BUCK power circuits suitable for different loads, improve the versatility of hardware development, and reduce the development and maintenance costs and cycles.

[0008] Optionally, the BUCK chip mounting structure is mounted with a BUCK chip suitable for a specific load; the BUCK chip is connected to the charging capacitor; and the discharge speed of the charging capacitor is between 50% and 200% of the full-load discharge speed.

[0009] In the embodiment of the present invention, a BUCK chip suitable for different loads can be installed on a circuit board while meeting the capacitance conditions and can meet the DC step-down working requirements.

[0010] Optionally, the BUCK chip suitable for high load is a plug-in BUCK chip, and the BUCK chip suitable for low load is a surface mount BUCK chip.

[0011] The embodiment of the present invention adopts different types of BUCK chips selected on the PCB, which can be applicable to different loads.

[0012] Optionally, the BUCK step-down module further includes a charge-discharge circuit connected to the BUCK chip; and a loop area of ​​the charge-discharge circuit meets EMC test standards.

[0013] The embodiments of the present invention optimize the routing of the buck charging and discharging circuit to reduce the circuit area while meeting various EMC test standards, thereby enabling the same PCB to be compatible with different types of buck power chips.

[0014] Optionally, one end of the charging capacitor is connected to the Vcc end of the BUCK chip and to one end of the load filter capacitor through a feedback diode, and the other end of the charging capacitor is connected to the GND end of the BUCK chip and to the other end of the load filter capacitor through a first freewheeling diode.

[0015] The embodiment of the present invention provides a specific circuit structure of a BUCK step-down module, which can achieve DC step-down.

[0016] Optionally, the BUCK step-down module further includes a first energy storage inductor, which is connected in parallel with the load filter capacitor.

[0017] The embodiment of the present invention provides a specific circuit structure of a BUCK step-down module, which can achieve DC step-down.

[0018] Optionally, the BUCK step-down module further includes a second energy storage inductor and a second freewheeling diode, one end of the second energy storage inductor is connected to the first energy storage inductor and the feedback diode, and the other end of the second energy storage inductor is connected to one end of a second load filter capacitor; the other end of the second load filter capacitor is connected to the other end of the charging capacitor through the first freewheeling diode.

[0019] The power supply circuit of the embodiment of the present invention can output different DC voltages based on the connection between the second energy storage inductor and the first energy storage inductor, as well as the first load filter capacitor and the second load filter capacitor.

[0020] Optionally, the BUCK step-down module further includes a capacitor connected in parallel with the load filter capacitor.

[0021] In the embodiment of the present invention, the load filter capacitor and the ordinary capacitor are connected in parallel to achieve filtering.

[0022] Optionally, the charging capacitor is a chip capacitor.

[0023] An embodiment of the present invention provides a power supply system, including any of the above-mentioned power supply circuits with hardware compatible with different BUCK chips.

[0024] The power supply system provided by the embodiment of the present invention can achieve the same technical effect as the power supply circuits of the above-mentioned hardware compatible with different BUCK chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the plug-in BUCK circuit structure suitable for large-load power supply solutions;

[0026] Figure 2 This is a schematic diagram of the chip BUCK circuit structure suitable for small load power supply solutions;

[0027] Figure 3 A schematic diagram illustrating the structure of a power supply circuit that is hardware-compatible with different BUCK chips provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0029] Figure 1 The schematic diagram of the plug-in BUCK circuit structure suitable for large-load power supply solutions is shown. The BUCK chip adopts the DIP (Dual In-line Package) packaging method.

[0030] Figure 2 The schematic diagram of the chip BUCK circuit structure suitable for small load power supply solutions is shown. The BUCK chip adopts the SOP (Small Outline Package) packaging method.

[0031] exist Figure 1 and Figure 2 The BUCK circuit structure consists of the following three parts: power supply filter part, BUCK step-down part and output filter part.

[0032] Specifically, the power supply filter includes power supplies L and N, a fuse (FUSE), a varistor (ZNR), a bridge rectifier (BG), a filter circuit (ELQ, C1), and a negative temperature coefficient (NTC) thermistor (NTC). The AC voltage passes through the fuse, is clamped by the varistor (ZNR), rectified by the bridge rectifier, and filtered by the filter circuit.

[0033] The buck step-down part includes: buck chip U1 or U2, charging capacitor C2, electrolytic capacitor E2, feedback diode D1, energy storage inductors L1 and L2, and freewheeling diodes D2 and D3.

[0034] The output filter part includes: the 5V filter part is composed of electrolytic capacitor E3 and capacitor C3, and the 12V filter is composed of electrolytic capacitor E4 and capacitor C4.

[0035] exist Figure 1 and Figure 2 Also shown are an electrolytic capacitor E1, a resistor R2, and a capacitor C4.

[0036] Compare Figure 1 and Figure 2 The circuit in the circuit uses different BUCK chips due to different loads, and the surrounding circuit structure is also different. Figure 1 The charging capacitor C2 and the electrolytic capacitor E2 are connected in parallel, and Figure 2 There is only charging capacitor C2. However, the different BUCK chips mentioned above require different circuit boards for adaptation, and the existing circuit is not compatible with BUCK chips of different loads.

[0037] This embodiment of the present invention proposes a method for achieving hardware compatibility between different buck power supply chips. By adapting peripheral components to a unified principle and optimizing the layout, this method enables hardware compatibility between buck power supply solutions with different loads. For example, a single PCB can be compatible with two power supply solutions, improving product versatility.

[0038] An embodiment of the present invention provides a power supply circuit that is hardware compatible with different BUCK chips, including a power supply filter module, a BUCK step-down module, and an output filter module that are connected in sequence.

[0039] Among them, the BUCK step-down module includes a BUCK chip mounting structure and a charging capacitor. The BUCK chip mounting structure is compatible with the installation of at least two BUCK power chips with different loads. The above-mentioned BUCK chip mounting structure can install a specific type of BUCK chip according to the load requirements, and the installed BUCK chip is connected to other components in the BUCK step-down module. For example, the BUCK chip is mounted on the PCB of the power circuit through packaging. The above-mentioned mounting structure can provide electrical and mechanical connections to ensure that the chip can work stably. Two or more mounting positions for BUCK chips are reserved on the PCB (suitable for BUCK chips of different sizes or packaging methods), and one BUCK chip can be installed in actual applications.

[0040] In this embodiment, the BUCK chip mounting structure and the charging capacitor are compatible with BUCK chips for different loads. The output filter module includes a load filter capacitor.

[0041] In this embodiment, the charging capacitor is used to maintain chip power. When the charging capacitor and the load filter capacitor are properly matched, the output voltage can be stabilized. If the charging capacitor is too small, the Vcc voltage of the buck chip drops faster than the Vout voltage in the no-load state, which can easily cause the no-load output voltage to rise. If the Vcc feedback capacitor is too large, the Vcc voltage of the buck chip drops slower than the Vout voltage in the full-load state, which can easily reduce the maximum stable output load current of the system and the chip's load capacity.

[0042] To ensure system loop stability, the discharge speed of the charging capacitor should not be too slow under full load and not too fast under light load. For example, the discharge speed of the charging capacitor should be between 50% and 200% of the full load discharge speed. Specifically, the capacitance of the above charging capacitor and the load filter capacitor should meet the following conditions:

[0043]

[0044] Where, Ivcc is the internal discharge current of the BUCK chip Vcc terminal, Io is the load current, Co is the capacitance of the load filter capacitor, and Cvcc is the capacitance of the charging capacitor.

[0045] Exemplarily, the charging capacitor is a chip capacitor.

[0046] In this embodiment, a buck chip can be installed based on specific load requirements. Therefore, the buck chip mounting structure described above incorporates a buck chip suitable for a specific load. The buck chip is connected to a charging capacitor, and the charging capacitor's discharge rate is between 50% and 200% of the full-load discharge rate. As long as the aforementioned capacitance conditions are met, buck chips for different loads can be installed on the circuit board and meet DC step-down requirements.

[0047] The hardware provided by the embodiment of the present invention is compatible with the power circuits of different BUCK chips, which can realize the compatible design of BUCK power circuits suitable for different loads, improve the versatility of hardware development, and reduce the development and maintenance costs and cycles.

[0048] Figure 3 The schematic diagram of the power supply circuit of the embodiment of the present invention is shown. Figure 3 As shown, the power supply circuit includes a power supply filter module, a BUCK step-down module and an output filter module.

[0049] Exemplarily, the power supply filter module includes: power supplies L, N, fuse FUSE, varistor ZNR, rectifier bridge BG, filter circuit (ELQ, C1), and negative temperature coefficient thermistor NTC. The AC voltage passes through the fuse, is clamped by the varistor ZNR, rectified by the rectifier bridge, and filtered by the filter circuit. The BUCK step-down module includes: BUCK chips U1, U2, charging capacitor C2, electrolytic capacitor E2, feedback diode D1, energy storage inductors L1, L2, and freewheeling diodes D2, D3. The output filter module includes: the 5V filter part is composed of electrolytic capacitor E3 and capacitor C3, and the 12V filter is composed of electrolytic capacitor E4 and capacitor C4.

[0050] Optionally, one end of the charging capacitor C2 is connected to the Vcc terminal of the BUCK chip and to one end of the load filter capacitor E3 via the feedback diode D1. The other end of the charging capacitor C2 is connected to the GND terminal of the BUCK chip and to the other end of the load filter capacitor E3 via the first freewheeling diode D2. The positive electrode of the feedback diode D1 is connected to one end of the load filter capacitor E3, and the negative electrode is connected to the Vcc terminal of the BUCK chip. The charging capacitor is used to maintain the power supply of the chip and samples the Vout voltage through the feedback diode and feeds it back to the internal reference of the chip. The freewheeling diode allows the current of the inductive load to change more smoothly, avoiding the occurrence of surge voltage.

[0051] Optionally, the buck module also includes a first energy storage inductor L1 connected in parallel with the load filter capacitor E3. The energy storage inductor L1 can store energy and release it when needed to ensure output voltage stability. Working together with the capacitor, it can smooth voltage fluctuations and reduce noise interference.

[0052] Optionally, the buck module also includes a second energy storage inductor L2 and a second freewheeling diode D3. One end of the second energy storage inductor L2 is connected to the first energy storage inductor L1 and the feedback diode D1, and the other end of the second energy storage inductor L2 is connected to one end of the second load filter capacitor E4. The other end of the second load filter capacitor E4 is connected to the other end of the charging capacitor C2 via the first freewheeling diode D2. In this embodiment, the power supply circuit, based on the connection between the second energy storage inductor and the first energy storage inductor, and the first and second load filter capacitors, can output different DC voltages, such as 5V and 12V.

[0053] Optionally, the BUCK step-down module further includes a capacitor connected in parallel with the load filter capacitor. The load filter capacitor may be an electrolytic capacitor with a large capacitance, and the parallel capacitor may be a conventional capacitor with a small capacitance. The two capacitors are connected in parallel to achieve filtering.

[0054] like Figure 3 As shown in the figure, for a buck power supply chip, the Vcc pin capacitor (Vcc capacitor) C2 maintains the chip's power supply and samples the Vout voltage through diode D1, feeding it back to the chip's internal reference. When the Vcc and Vout capacitors are properly matched, Vcc can accurately sample changes in the system's output voltage, thereby stabilizing the output voltage. If the Vcc capacitor is too small, the Vcc voltage drops faster than the Vout voltage in the no-load state, which can easily cause the no-load output voltage to rise. If the Vcc capacitor is too large, the Vcc voltage drops slower than the Vout voltage in the full-load state, which can easily reduce the system's maximum stable output load current and the chip's load capacity.

[0055] Therefore, to ensure system loop stability, the Vcc capacitor discharge speed should not be too slow under full load applications and not too fast under light load conditions. For example, the Vcc capacitor discharge speed should be between 50% and 200% of the full load discharge speed.

[0056] The Vcc capacitor discharge speed must be between 0.5-2 times the full-load discharge speed. The time constant T = RC, where R is the resistance and C is the capacitance. Therefore, the discharge speed is proportional to the capacitance C. Secondly, Ivcc / Cvcc = Io / Co, which means the capacitor discharge rate is the same. If Co is known, Cvcc can be calculated, then Cvcc = Ivcc*Co / Io. Cvcc (i.e. C2) can meet the following formula.

[0057]

[0058] Where, Ivcc is the internal discharge current of the chip Vcc pin, Io is the load current, Co is the capacitance of the load filter capacitor E3, and Cvcc is the capacitance of the Vcc capacitor C2.

[0059] Figure 3 The circuit structure shown is Figure 1 Compared to the circuit shown in Figure 1, the E2 electrolytic capacitor is eliminated, leaving only the C2 chip capacitor (typically 1µF). The BUCK chip only requires the Vcc capacitor value; it doesn't specify whether it's electrolytic or chip-type. This embodiment uses a single-chip solution, based on the specification and confirmation from the chip manufacturer, by selecting the appropriate matching capacitance. Hardware testing and EMC (Electromagnetic Compatibility) testing both meet requirements.

[0060] It should be noted that in this embodiment, different types of BUCK chips are used (corresponding to different loads), and the capacitance of the charging capacitor actually set in the circuit can satisfy the above-mentioned relationship formula between the charging capacitor and the load filter capacitor. That is, the power supply circuit of this embodiment is compatible with different types of BUCK chips.

[0061] For example, this embodiment is compatible with the design plug-in and patch BUCK solutions. Figure 1 Figure 2 The single solution is shown in FIG. 1 . The existing solution is not compatible with dual chips. This embodiment is compatible with dual chips and provides the layout and circuit design of the two chips.

[0062] Therefore, this embodiment enables a single PCB to be compatible with two BUCK power supply solutions, demonstrating a trend toward universalization. This reduces the number of experiments required for R&D and simultaneously reduces costs. In practical applications, two mounting locations are reserved on the PCB to accommodate two different BUCK chips. While installing two BUCK chips satisfies the principle, installing only one is feasible for cost considerations.

[0063] Furthermore, the embodiment of the present invention also optimizes the layout of the circuit.

[0064] Optionally, a plug-in buck chip for high loads can be used, while a surface-mount buck chip for low loads can be used. These plug-in and surface-mount buck chips are mounted on both sides of the circuit board. For example, a plug-in buck chip is mounted on one side of the PCB, while a surface-mount buck chip is mounted on the other side. Using different mounting methods for different buck chips on the PCB can shorten trace lengths, improve signal quality, and reduce power loss.

[0065] Optionally, the BUCK step-down module further includes a charge-discharge circuit connected to the BUCK chip; the loop area of ​​the charge-discharge circuit meets EMC test standards.

[0066] This embodiment optimizes the routing of the buck charging and discharging circuits, reducing the circuit area while meeting tool and electrical safety spacing requirements. This also ensures compliance with various EMC test standards, enabling compatibility with different buck power chip types on the same PCB, enabling customized selection based on load requirements. With dual buck chips compatible, the routing area must be minimized, including the charging and discharging circuits, and the ground wire length, all taking into account the layout requirements of each chip.

[0067] In this embodiment, the routing is optimized to reduce the loop area, and experiments have verified that this can effectively solve the EMI problem.

[0068] The hardware-compatible power supply circuit provided by the embodiments of this invention, which is compatible with different buck chips, has the following advantages: 1. It enables a compatible design of dual-buck power supply circuits, improving the versatility of hardware development and reducing development and maintenance costs; 2. It optimizes buck peripheral components, reduces the buck charge and discharge routing loop area, and reduces EMI interference. These advantages provide universality, ease of implementation, and widespread adoption.

[0069] An embodiment of the present invention provides a power supply system, including the power supply circuit with hardware compatible with different BUCK chips.

[0070] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

[0071] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0072] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0073] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A power supply circuit that is hardware compatible with different BUCK chips, characterized in that: It includes a power filter module, a BUCK step-down module and an output filter module connected in sequence; The BUCK step-down module includes a BUCK chip mounting structure and a charging capacitor; the BUCK chip mounting structure is compatible with mounting at least two BUCK power chips with different loads; The output filter module includes a load filter capacitor; The charging capacitor and the load filter capacitor meet the following conditions: Wherein, Ivcc is the internal discharge current of the Vcc terminal of the BUCK chip, Io is the load current, Co is the capacitance of the load filter capacitor, and Cvcc is the capacitance of the charging capacitor.

2. The power supply circuit according to claim 1, wherein: The BUCK chip mounting structure is mounted with a BUCK chip suitable for a specific load, and the BUCK chip is connected to the charging capacitor; The discharge rate of the charging capacitor is between 50% and 200% of the full-load discharge rate.

3. The power supply circuit according to claim 2, wherein: The BUCK chip suitable for high loads is a plug-in BUCK chip, and the BUCK chip suitable for low loads is a surface mount BUCK chip.

4. The power supply circuit according to claim 3, wherein: The BUCK step-down module further includes a charge-discharge circuit connected to the BUCK chip; The loop area of ​​the charging and discharging loop meets the EMC test standard.

5. The power supply circuit according to claim 2, wherein: One end of the charging capacitor is connected to the Vcc end of the BUCK chip and to one end of the load filter capacitor through a feedback diode, and the other end of the charging capacitor is connected to the GND end of the BUCK chip and to the other end of the load filter capacitor through a first freewheeling diode.

6. The power supply circuit according to claim 5, wherein: The BUCK step-down module further includes a first energy storage inductor, which is connected in parallel with the load filter capacitor.

7. The power supply circuit according to claim 6, wherein: The BUCK step-down module further includes a second energy storage inductor and a second freewheeling diode, one end of the second energy storage inductor is connected to the first energy storage inductor and the feedback diode, and the other end of the second energy storage inductor is connected to one end of a second load filter capacitor; The other end of the second load filter capacitor is connected to the other end of the charging capacitor through the first freewheeling diode.

8. The power supply circuit according to claim 2, wherein: The BUCK step-down module further includes a capacitor connected in parallel with the load filter capacitor.

9. The power supply circuit according to claim 2, wherein: The charging capacitor is a chip capacitor.

10. A power supply system, characterized in that: A power supply circuit comprising the hardware according to any one of claims 1 to 9, which is compatible with different BUCK chips.

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