Multiphase interleaved switching power supply circuit

Abstract

The utility model discloses a multiphase interlaced switching power supply circuit, which comprises an input voltage, at least two switching tubes, a current sampling resistor and an output voltage, the high end of the input voltage is connected with the input end of one switching tube, the two switching tubes are connected in series, and the current sampling resistor is connected with the output voltage. The output ends of the two switching tubes are connected with the first end of the current sampling resistor, and the second end of the current sampling resistor is connected with the low end of the output voltage. The second end of the current sampling resistor is connected with the low end of the output voltage, the potential of the current sampling resistor and the potential of the output voltage can be in the same horizontal line, isolation sampling is not needed, the cost is reduced, and the performance of the system can be remarkably improved.

Description

Technical Field

[0001] The utility model relates to the technical field of switching power supplies, and more specifically to a multi-phase interleaved switching power supply circuit. Background Art

[0002] Switching power supplies are widely used in the field of advanced manufacturing and high-performance intelligent instruments. However, with the continuous improvement of the requirements for power supply performance in modern electronic systems, especially in applications that require large current output and low ripple, such as test power supplies and laboratory power supplies, the requirements for current accuracy and response speed are relatively high. However, traditional switching power supplies usually require the use of isolation devices such as optocouplers and magnetic couplers to achieve isolated sampling. These devices often have disadvantages such as nonlinear distortion and temperature drift, and the response speed will be limited.

[0003] Therefore, in applications that require high-precision current sampling and fast response, traditional isolation sampling methods often cannot meet the requirements. Utility Model Content

[0004] In order to overcome the problem that existing switching power supplies usually need to use isolation devices such as optical couplers and magnetic couplers to achieve isolated sampling, these devices often have shortcomings such as nonlinear distortion and temperature drift, resulting in slow response speed of the switching power supply, the utility model provides a multi-phase interleaved switching power supply circuit.

[0005] The technical solution of the utility model is as follows:

[0006] A multi-phase interleaved switching power supply circuit comprises an input voltage, at least two switching tubes, a current sampling resistor and an output voltage, wherein the high end of the input voltage is connected to the input end of one of the switching tubes, two of the switching tubes are connected in series, and the output ends of the two switching tubes are connected to the first end of the current sampling resistor, and the second end of the current sampling resistor is connected to the low end of the output voltage.

[0007] The utility model according to the above scheme also includes an output inductor, a first end of the output inductor, an output end of one of the switch tubes and an input end of another of the switch tubes are interconnected, and a second end of the output inductor is connected to a first end of the current sampling resistor.

[0008] The utility model according to the above scheme also includes a clamping diode, the anode of the clamping diode, the output end of another switch tube and the low end of the input voltage are interconnected, and the cathode of the clamping diode, the first end of the current sampling resistor and the second end of the output inductor are interconnected.

[0009] According to the above scheme of the utility model, the plurality of switch tubes are divided into multiple groups, the number of switch tubes in each group is two, the two switch tubes in each group are connected in series, and the switch tubes in each group are connected in parallel.

[0010] According to the above-mentioned solution of the utility model, a support capacitor C1 is provided between the high end of the input voltage and the low end of the input voltage.

[0011] According to the above-mentioned solution of the utility model, a filter capacitor C2 is provided between the high end of the output voltage and the low end of the output voltage.

[0012] The utility model according to the above scheme has the beneficial effect that the second end of the current sampling resistor of the utility model is connected to the low end of the output voltage, and the potential of the current sampling resistor can be on the same horizontal line as the potential of the output voltage, thereby avoiding the need for isolated sampling, which not only reduces the cost but also significantly improves the performance of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 It is a schematic diagram of the circuit structure of the utility model. DETAILED DESCRIPTION

[0015] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0016] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present utility model are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. Terms such as "setting" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. The directions or positions indicated by the terms "upper", "lower", "left", "right", "front", "back", "bottom", etc. are based on the directions or positions shown in the drawings, which are only for the convenience of description and cannot be understood as limitations on the present technical solution.

[0017] It should be noted that switching power supplies are widely used in the field of advanced manufacturing / high-performance intelligent instrumentation. However, with the continuous improvement of the requirements for power supply performance in modern electronic systems, especially in applications that require large current output and low ripple, such as test power supplies and laboratory power supplies, the requirements for current accuracy and response speed are relatively high. However, existing switching power supplies usually require the use of isolation devices such as optocouplers and magnetic couplers to achieve isolated sampling. These devices often have disadvantages such as nonlinear distortion and temperature drift, resulting in slow response speed of the switching power supply.

[0018] like Figure 1 As shown, this embodiment provides a multi-phase interleaved switching power supply circuit, the second end of the current sampling resistor is connected to the low end of the output voltage, the potential of the current sampling resistor can be on the same horizontal line as the potential of the output voltage, and isolated sampling is not required, which not only reduces the cost but also significantly improves the performance of the system.

[0019] Specifically, it includes an input voltage, at least two switching tubes, a current sampling resistor and an output voltage, the high end of the input voltage is connected to the input end of one of the switching tubes, the two switching tubes are connected in series, and the output ends of the two switching tubes are connected to the first end of the current sampling resistor, and the second end of the current sampling resistor is connected to the low end of the output voltage.

[0020] When the current passes through the switch tube and the current sampling resistor, the voltage drop generated will be directly reflected at both ends of the current sampling resistor. The potential of the current sampling resistor is on the same horizontal line as the output voltage potential. The current size can be directly obtained by measuring the voltage across the current sampling resistor without using a complex isolation sampling circuit.

[0021] The bandwidth of the current loop is no longer limited by isolated sampling, and the circuit can respond to changes in input voltage and load more quickly, thereby ensuring the stability and accuracy of the output voltage.

[0022] In one embodiment, an output inductor is also included, and the output inductor is used to smooth the output current, reduce the output ripple, and improve the stability of the power supply.

[0023] Specifically, the first end of the output inductor, the output end of one of the switch tubes, and the input end of another of the switch tubes are interconnected. When the switch tube is turned on, current will flow through the switch tube and the output inductor, and the inductor will store energy. When the switch tube is turned off, the inductor will release the stored energy to maintain the continuity of the current, thereby reducing the ripple of the output current. The second end of the output inductor is connected to the first end of the current sampling resistor. The second end of the output inductor is connected to the first end of the current sampling resistor. Due to the existence of the output inductor, a voltage drop will be generated when the current passes through the output inductor. This voltage drop can be measured by the current sampling resistor to obtain the size of the output current.

[0024] In one embodiment, a clamping diode is also included. The main function of the clamping diode is to protect the switch tube from being damaged due to overvoltage.

[0025] Specifically, the anode of the clamping diode, the output end of another of the switching tubes, and the low end of the input voltage are interconnected. When the switching tube is turned off, if the output voltage is too high, the anode voltage of the clamping diode will exceed its conduction voltage. At this time, the diode will be turned on and the output voltage will be clamped within a safe range, thereby protecting the switching tube.

[0026] The cathode of the clamping diode, the first end of the current sampling resistor and the second end of the output inductor are interconnected. When the diode is turned on, it will guide the excessive voltage to the current sampling resistor and the output inductor instead of directly acting on the switch tube, further protecting the switch tube.

[0027] In one embodiment, the plurality of switch tubes are divided into multiple groups, each group includes two switch tubes, the two switch tubes in each group are connected in series, and the switch tubes in each group are connected in parallel.

[0028] Preferably, taking three-phase interleaving as an example, the number of switch tubes is six, namely Q1-Q6, the six switch tubes are staggered-phase controlled, the number of output inductors is three, namely L1, L2, and L3, the number of current sampling resistors is three, namely R1, R2, and R3, and the number of clamping diodes is one, namely D1.

[0029] It should be noted that the three-phase interleaving of the buck circuit is used as an example for explanation, but it does not mean that it can only be implemented on the buck topology. The circuit of this patent is also applicable to other topologies; similarly, taking the three-phase interleaving as an example, it is not just three-phase interleaving, other interleaving numbers are also applicable.

[0030] In one embodiment, a support capacitor C1 is provided between the high end of the input voltage and the low end of the input voltage, which is mainly used to stabilize the input voltage and filter out high-frequency noise in the input power supply. When the input power supply fluctuates or the load changes, the support capacitor C1 can provide additional charge to maintain a stable input voltage, thereby ensuring the normal operation of the power supply. In addition, the support capacitor C1 can also reduce electromagnetic interference (EMI) at the input end of the power supply and improve the performance of the power supply.

[0031] A filter capacitor C2 is provided between the high end of the output voltage and the low end of the output voltage, which is mainly used to smooth the output voltage and reduce the output ripple. Since the rapid switching of the switch tube will generate high-frequency noise and ripple, the filter capacitor C2 can absorb these high-frequency components, thereby providing a stable output voltage. The capacitance and type of the filter capacitor C2 can be selected to effectively reduce the output ripple and improve the quality of the power supply.

[0032] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to the utility model.

[0033] The above is an exemplary description of the utility model patent in conjunction with the accompanying drawings. It is obvious that the implementation of the utility model patent is not limited to the above-mentioned method. As long as various improvements are made by adopting the method concept and technical solution of the utility model patent, or the concept and technical solution of the utility model patent are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims

1. A multi-phase interleaved switching power supply circuit, characterized in that: It includes an input voltage, at least two switching tubes, a current sampling resistor and an output voltage, wherein the high end of the input voltage is connected to the input end of one of the switching tubes, the two switching tubes are connected in series, and the output ends of the two switching tubes are connected to the first end of the current sampling resistor, and the second end of the current sampling resistor is connected to the low end of the output voltage.

2. A multi-phase interleaved switching power supply circuit according to claim 1, characterized in that: It also includes an output inductor, a first end of the output inductor, an output end of one of the switch tubes and an input end of another of the switch tubes are interconnected, and a second end of the output inductor is connected to a first end of the current sampling resistor.

3. A multi-phase interleaved switching power supply circuit according to claim 2, characterized in that: It also includes a clamping diode, the anode of the clamping diode, the output end of another switch tube and the low end of the input voltage are interconnected, and the cathode of the clamping diode, the first end of the current sampling resistor and the second end of the output inductor are interconnected.

4. A multi-phase interleaved switching power supply circuit according to any one of claims 1 to 3, characterized in that: The plurality of switch tubes are divided into a plurality of groups, each group includes two switch tubes, the two switch tubes in each group are connected in series, and the switch tubes in each group are connected in parallel.

5. A multi-phase interleaved switching power supply circuit according to claim 4, characterized in that: A support capacitor C1 is provided between the high end of the input voltage and the low end of the input voltage.

6. A multi-phase interleaved switching power supply circuit according to claim 1, 2, 3 or 5, characterized in that: A filter capacitor C2 is provided between the high end of the output voltage and the low end of the output voltage.

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