Power supply circuit of self-coupling transformation structure

Abstract

The invention discloses a power supply circuit of a self-coupling transformation structure. The power supply circuit comprises a first resonance bridge, a second resonance bridge, a third resonance bridge, a fourth resonance bridge, a first coil unit, a second coil unit, a third coil unit and a capacitor. The voltage input end is located between the first resonance bridge and the second resonance bridge, the first resonance bridge is grounded through the third resonance bridge, the second resonance bridge is grounded through the fourth resonance bridge, and the reference ground is connected between the third resonance bridge and the fourth resonance bridge. The first resonance bridge is connected with the second resonance bridge through the capacitor and the first coil unit in sequence, the second coil unit is connected between the third resonance bridge and the third coil unit, and the third coil unit is connected to the fourth resonance bridge. The voltage output end is located between the second coil unit and the third coil unit and used for outputting voltage to a load. By means of the autotransformer structure, high integration level and miniaturization of the power supply circuit are achieved.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and more particularly to a power supply circuit with an autotransformer structure. Background Art

[0002] In traditional full-bridge DC-DC circuits, transformers are typically used for voltage conversion and electrical isolation. However, the parallel winding of the secondary windings causes the transformer to occupy a large space on the PCB. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a power supply circuit with an autotransformer structure to address the defect that the transformer of the full-bridge DCDC circuit in the prior art occupies a large space on the PCB board.

[0004] The technical solution adopted by the present invention to solve the technical problem is: constructing a power supply circuit of an autotransformer structure, including: a first resonant bridge 10, a second resonant bridge 20, a third resonant bridge 30, a fourth resonant bridge 40, a first coil unit, a second coil unit, a third coil unit and a capacitor; The voltage input terminal is connected between the first end of the first resonant bridge 10 and the first end of the second resonant bridge 20. The second end of the first resonant bridge 10 is grounded via the first end of the third resonant bridge 30. The second end of the second resonant bridge 20 is grounded via the first end of the fourth resonant bridge 40. The reference ground is connected between the second end of the third resonant bridge 30 and the second end of the fourth resonant bridge 40. The third end of the first resonant bridge 10 is further connected to the third end of the second resonant bridge 20 through the capacitor and the first coil unit in sequence; The second end of the first resonant bridge 10 is also connected to the second end of the second resonant bridge 20; one end of the second coil unit is connected to the third end of the third resonant bridge 30, and the other end thereof is connected to one end of the third coil unit, and the other end of the third coil unit is connected to the third end of the fourth resonant bridge 40; for realizing voltage conversion; The voltage output end is connected between the second coil unit and the third coil unit, and is used to output the converted voltage to a load.

[0005] In one embodiment, the first resonant bridge 10 includes a first switch SW1 and a second switch SW2; The voltage input end is connected to the first end of the third resonant bridge 30 through the first switch tube SW1 and the second switch tube SW2 in sequence, the first capacitor is connected between the first switch tube SW1 and the second switch tube SW2, and the first switch tube SW1 is connected to the first end of the second resonant bridge 20.

[0006] In one embodiment, the second resonant bridge 20 includes a third switch tube SW3 and a fourth switch tube SW4; The voltage input end is connected to the first end of the fourth resonant bridge 40 through the third switch tube SW3 and the fourth switch tube SW4 in sequence. The first switch tube SW1 is connected to the third switch tube SW3. The first coil unit is connected between the third switch tube SW3 and the fourth switch tube SW4. The second switch tube SW2 is also connected to the fourth switch tube SW4.

[0007] In one embodiment, the third resonant bridge 30 includes a fifth switch tube SW5 and a sixth switch tube SW6; the second switch tube SW2 is grounded through the fifth switch tube SW5 and the sixth switch tube SW6 in sequence, and the second coil unit is connected between the fifth switch tube SW5 and the sixth switch tube SW6.

[0008] In one embodiment, the fourth resonant bridge 40 includes a seventh switch tube SW7 and an eighth switch tube SW8; the fourth switch tube SW4 is grounded through the seventh switch tube SW7 and the eighth switch tube SW8 in sequence, the third coil unit is connected between the seventh switch tube SW7 and the eighth switch tube SW8, and the sixth switch tube SW6 is connected to the eighth switch tube SW8.

[0009] In one embodiment, the power supply circuit further includes a control circuit; the control circuit is connected to the control ends of the first switch tube SW1, the second switch tube SW2, the third switch tube SW3, the fourth switch tube SW4, the fifth switch tube SW5, the sixth switch tube SW6, the seventh switch tube SW7, and the eighth switch tube SW8, respectively.

[0010] In one embodiment, the control circuit performs, in one execution cycle, the following operations: controlling the third switch tube SW3, the second switch tube SW2, the seventh switch tube SW7, and the sixth switch tube SW6 to be turned on; and controlling the first switch tube SW1, the fourth switch tube SW4, the eighth switch tube SW8, and the fifth switch tube SW5 to be turned off.

[0011] In one embodiment, the control circuit performs, in one execution cycle, the following operations: controlling the first switch tube SW1, the fourth switch tube SW4, the eighth switch tube SW8, and the fifth switch tube SW5 to be turned on, and controlling the third switch tube SW3, the second switch tube SW2, the seventh switch tube SW7, and the fifth switch tube SW5 to be turned off.

[0012] In one embodiment, the control circuit includes a PWM generator, which generates corresponding pulse width modulation signals and frequencies according to the operating frequency of the power supply circuit, load conditions, the first coil, the second coil and the capacitor resonant frequency, so as to control the on and off time of each switch tube.

[0013] In one embodiment, the switch tube is any one of a silicon-based MOSFET device, a silicon carbide device, or a gallium nitride device.

[0014] The beneficial effect of the present invention is that the present invention provides a power supply circuit of an autotransformer structure, comprising: a first resonant bridge 10, a second resonant bridge 20, a third resonant bridge 30, a fourth resonant bridge 40, a first coil unit, a second coil unit, a third coil unit and a capacitor; the voltage input end is connected between the first end of the first resonant bridge 10 and the first end of the second resonant bridge 20, the second end of the first resonant bridge 10 is grounded through the first end of the third resonant bridge 30, the second end of the second resonant bridge 20 is grounded through the first end of the fourth resonant bridge 40, and the reference ground is connected to the second end of the third resonant bridge 30 and the fourth resonant bridge The first resonant bridge 10 is connected to the second end of the second resonant bridge 20 via the capacitor and the first coil unit; the second end of the first resonant bridge 10 is also connected to the second end of the second resonant bridge 20; one end of the second coil unit is connected to the third end of the third resonant bridge 30, and the other end is connected to one end of the third coil unit, and the other end of the third coil unit is connected to the third end of the fourth resonant bridge 40; the voltage output end is connected between the second coil unit and the third coil unit, and is used to output the converted voltage to the load. By adopting an autotransformer structure, the present invention achieves high integration and miniaturization of the power supply circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which: Figure 1 This is a circuit diagram of an embodiment of a power supply circuit with an autotransformer structure according to the present invention; Figure 2 It is a schematic diagram of a DCDC circuit in the prior art; Figure 3 This is a schematic diagram of the inductor current flow in an embodiment of a power supply circuit of an autotransformer structure of the invention; Figure 4 This is a circuit diagram of the inductor current flow in another embodiment of the power supply circuit of the autotransformer structure of the invention. DETAILED DESCRIPTION

[0016] The present application is further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core portion of the present application being overwhelmed by excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail. They can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0017] like Figure 1 As shown, Figure 1 FIG. 1 is a circuit diagram of an embodiment of a power supply circuit with an autotransformer structure according to the present invention.

[0018] The technical solution adopted by the present invention is a power supply circuit of an autotransformer structure, comprising: a first resonant bridge 10, a second resonant bridge 20, a third resonant bridge 30, a fourth resonant bridge 40, a first coil unit, a second coil unit, a third coil unit and a capacitor; The voltage input terminal is connected between the first end of the first resonant bridge 10 and the first end of the second resonant bridge 20. The second end of the first resonant bridge 10 is grounded via the third resonant bridge 30. The second end of the second resonant bridge 20 is grounded via the fourth resonant bridge 40. The reference ground is connected between the second end of the third resonant bridge 30 and the second end of the fourth resonant bridge 40. The third end of the first resonant bridge 10 is also connected to the third end of the second resonant bridge 20 through the capacitor and the first coil unit in sequence; the second end of the first resonant bridge 10 is also connected to the second end of the second resonant bridge 20; one end of the second coil unit is connected to the third end of the third resonant bridge 30, and the other end thereof is connected to one end of the third coil unit, and the other end of the third coil unit is connected to the third end of the fourth resonant bridge 40; it is used to achieve voltage conversion; the voltage output end is connected between the second coil unit and the third coil unit, and is used to output the converted voltage to the load.

[0019] like Figure 1 As shown, the present invention employs an autotransformer power supply circuit, which includes multiple resonant bridges and coil units. Specifically, N1A represents the first coil unit, N2A1 represents the second coil unit, and N2A2 represents the third coil unit. N2A1 and N2A2 are symmetrical coils with equal inductance.

[0020] During circuit operation, the input voltage passes through switch SW3, first coil unit N1A, switch SW2, switch SW7, third coil unit N2A2, second coil unit N2A1, and switch SW6, forming a resonant path. The resonant frequency of this path is determined by the total inductance of the first coil unit N1A, second coil unit N2A1, and third coil unit N2A2 (i.e., N1A + N2A1 + N2A2) and the capacitance C.

[0021] During the next switching cycle, the input voltage passes through switch SW1, capacitor C, first coil unit N1A, switch SW4, switch SW5, second coil unit N2A1, third coil unit N2A2, and switch SW8, forming another resonant path. This path not only achieves resonance but also decouples the coils formed by N1A, N2A1, and N2A2.

[0022] Ultimately, the magnitude of the output voltage is determined by the proportional relationship between the inductance of the second coil unit N2A1 (or the third coil unit N2A2) and the total inductance of the entire coil (ie, N1A + N2A1 + N2A2).

[0023] Furthermore, the first resonant bridge 10 includes a first switch tube SW1 and a second switch tube SW2; the voltage input end is connected to the first end of the third resonant bridge 30 through the first switch tube SW1 and the second switch tube SW2 in sequence, the first capacitor is connected between the first switch tube SW1 and the second switch tube SW2, and the first switch tube SW1 is connected to the first end of the second resonant bridge 20.

[0024] In one embodiment, when the circuit is operating, voltage enters from the input terminal and first enters the first resonant bridge 10. The first switch SW1 and the second switch SW2 are alternately turned on and off according to a preset frequency and duty cycle.

[0025] Furthermore, the second resonant bridge 20 includes a third switch tube SW3 and a fourth switch tube SW4; the voltage input end is connected to the first end of the fourth resonant bridge 40 through the third switch tube SW3 and the fourth switch tube SW4 in sequence, the first switch tube SW1 is connected to the third switch tube SW3, the first coil unit is connected between the third switch tube SW3 and the fourth switch tube SW4, and the second switch tube SW2 is also connected to the fourth switch tube SW4.

[0026] Under the control of the switching transistor, the first coil, second coil, and third coil units efficiently resonate and generate electromagnetic induction, further transforming the voltage. This improves energy conversion and transmission efficiency, reduces losses, and optimizes overall performance. Compared to traditional transformer winding structures, this combination simplifies the circuit structure, reduces component and PCB area, lowers costs, and increases integration and miniaturization, meeting the stringent power supply circuit requirements of modern electronic devices.

[0027] Furthermore, the third resonant bridge 30 includes a fifth switch tube SW5 and a sixth switch tube SW6; the second switch tube SW2 is grounded through the fifth switch tube SW5 and the sixth switch tube SW6 in sequence, and the second coil unit is connected between the fifth switch tube SW5 and the sixth switch tube SW6.

[0028] Furthermore, the fourth resonant bridge 40 includes a seventh switch tube SW7 and an eighth switch tube SW8; the fourth switch tube SW4 is grounded through the seventh switch tube SW7 and the eighth switch tube SW8 in sequence, the third coil unit is connected between the seventh switch tube SW7 and the eighth switch tube SW8, and the sixth switch tube SW6 is connected to the eighth switch tube SW8.

[0029] like Figure 2 As shown in the figure, a traditional full-bridge DCDC circuit is shown. A total of four coils N1, N2, N3 and N4 are used. After adopting the idea of ​​implementing the autotransformer, the improved circuit is as follows Figure 3 As shown in the figure. In a specific implementation, assuming N1, N2 are not equal to N3 and N4, the lowest common denominator can be used to ensure that the number of turns N2A1 and N2A2 in the improved diagram is the smallest integer fraction of the number of turns N1, N2, N3, and N4 before the improvement. For example, if N1=N2=2 and N3=N4=1, then after the improvement, N2A1=1, N2A2=1, and N1A=2. The total number of turns before the improvement is 2+2+1+1=6, while the number of turns after the improvement is 2+1+1=4. This saves 2 turns, for a savings rate of 2 / 6=33.3%.

[0030] Furthermore, the power supply circuit also includes a control circuit; the control circuit is connected to the control ends of the first switch tube SW1, the second switch tube SW2, the third switch tube SW3, the fourth switch tube SW4, the fifth switch tube SW5, the sixth switch tube SW6, the seventh switch tube SW7, and the eighth switch tube SW8 respectively.

[0031] It's important to note that the control circuit is responsible for controlling the on / off switching of each switch based on the power circuit's operating status and load requirements. By monitoring circuit parameters such as voltage and current, it adjusts the drive signals to the switches in real time, ensuring optimal operation under varying operating conditions. For example, when the load changes, the control circuit can quickly respond by adjusting the switch's on-time to maintain a stable output voltage. The control circuit also incorporates protection features such as overcurrent and overvoltage protection. When an abnormality is detected, it promptly shuts down the relevant switches to prevent circuit damage.

[0032] like Figure 3 and as shown in 4, where Figure 3 The direction of the inductor current is from left to right. Figure 4 The direction of the inductor current is from right to left, such as Figure 3 and Figure 4 The two phases shown in the figure are converted to each other, and the switch tube is used to realize the current commutation in the inductor to maintain the volt-second balance. Specifically, when the circuit is in Figure 3 In the stage shown, the control circuit turns on the relevant switch tube, forming a current path from left to right, and the inductor stores energy; then the circuit switches to Figure 4 In the stage shown, the control circuit changes the conduction state of the switch, reversing the current flow from right to left, and releasing energy in the inductor. This alternation between the two stages achieves commutation of the inductor current, maintaining the inductor's volt-second balance and ensuring stable circuit operation.

[0033] Furthermore, the control circuit executes in one execution cycle: controlling the third switch tube SW3, the second switch tube SW2, the seventh switch tube SW7 and the sixth switch tube SW6 to be turned on and controlling the first switch tube SW1, the fourth switch tube SW4, the eighth switch tube SW8 and the fifth switch tube SW5 to be turned off.

[0034] It should be noted that this control strategy ensures that current flows along a predetermined path within the circuit. When the third switch SW3 and the second switch SW2 are turned on, current flows from the input terminal through the third switch SW3 to the first coil unit, and then through the second switch SW2 to the subsequent circuit. Simultaneously, the conduction of the seventh switch SW7 and the sixth switch SW6 allows current to flow through the third coil unit to the ground terminal, completing the current loop. At this point, the off state of the first switch SW1, the fourth switch SW4, the eighth switch SW8, and the fifth switch SW5 ensures that current does not flow along other paths, avoiding unnecessary energy loss and circuit interference.

[0035] Furthermore, the control circuit executes in one execution cycle: controlling the first switch tube SW1, the fourth switch tube SW4, the eighth switch tube SW8 and the fifth switch tube SW5 to be turned on, and controlling the third switch tube SW3, the second switch tube SW2, the seventh switch tube SW7 and the fifth switch tube SW5 to be turned off.

[0036] It should be noted that this control strategy ensures that current flows along a predetermined path within the circuit. When the first switch SW1 is turned on, current flows from the input terminal through the first switch SW1 to the first terminal of the second resonant bridge 20. The turning on of the fourth switch SW4 allows the current to continue flowing to the fourth resonant bridge 40, ultimately connecting to ground through the eighth and fifth switches SW8 and SW5. At this point, the off states of the third, second, seventh, and sixth switches SW3, SW2, SW7, and SW6 ensure that current does not flow along other paths, avoiding unnecessary energy loss and circuit interference.

[0037] Furthermore, the control circuit includes a PWM generator, which generates corresponding pulse width modulation signals and frequencies according to the operating frequency of the power supply circuit, the load conditions of the first coil, the second coil and the capacitor resonant frequency, so as to control the on and off time of each switch tube.

[0038] Specifically, the PWM generator monitors the operating status of the power supply circuit in real time, including the operating frequency and load conditions, while also taking into account the resonant frequencies of the first and second coils and the capacitor. These parameters together determine the characteristics of the pulse-width modulation signal. The generated pulse-width modulation signal is then sent to the control terminals of each switch, precisely controlling the on and off moments of the switch. For example, within a single execution cycle, the PWM generator might turn on the first switch SW1, the fourth switch SW4, the eighth switch SW8, and the fifth switch SW5, while turning off the third switch SW3, the second switch SW2, the seventh switch SW7, and the sixth switch SW6. This directs the current along a predetermined path, achieving efficient voltage conversion and current transmission.

[0039] Furthermore, the switch tube is any one of a silicon-based MOSFET device, a silicon carbide device or a gallium nitride device.

[0040] This invention utilizes an autotransformer model to cleverly reuse the transformer primary winding, reducing the number of parallel turns in the secondary winding. Each turn of the transformer primary is used as the minimum unit. The number of secondary windings is designed based on the transformer and switching power supply. N minimum primary units are stacked together to form part of the secondary winding. This reduces the wire diameter of the secondary winding and improves the power density of the non-isolated power supply.

[0041] It is understood that the above embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, which all fall within the scope of protection of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of coverage of the claims of the present invention.

Claims

1. A power supply circuit with an autotransformer structure, characterized in that: include: A first resonant bridge (10), a second resonant bridge (20), a third resonant bridge (30), a fourth resonant bridge (40), a first coil unit, a second coil unit, a third coil unit, and a capacitor; The voltage input end is connected between the first end of the first resonant bridge (10) and the first end of the second resonant bridge (20), the second end of the first resonant bridge (10) is grounded through the first end of the third resonant bridge (30), the second end of the second resonant bridge (20) is grounded through the first end of the fourth resonant bridge (40), and the reference ground is connected between the second end of the third resonant bridge (30) and the second end of the fourth resonant bridge (40); The third end of the first resonant bridge (10) is also connected to the third end of the second resonant bridge (20) via the capacitor and the first coil unit in sequence; The second end of the first resonant bridge (10) is also connected to the second end of the second resonant bridge (20); one end of the second coil unit is connected to the third end of the third resonant bridge (30), and the other end is connected to one end of the third coil unit, and the other end of the third coil unit is connected to the third end of the fourth resonant bridge (40); used to achieve voltage conversion; The voltage output end is connected between the second coil unit and the third coil unit, and is used to output the converted voltage to a load.

2. The power supply circuit of the autotransformer structure according to claim 1, characterized in that: The first resonant bridge (10) comprises a first switching tube (SW1) and a second switching tube (SW2); The voltage input end is connected to the first end (30) of the third resonant bridge via the first switch tube (SW1) and the second switch tube (SW2) in sequence, the first capacitor is connected between the first switch tube (SW1) and the second switch tube (SW2), and the first switch tube (SW1) is connected to the first end of the second resonant bridge (20).

3. The power supply circuit of the autotransformer structure according to claim 2, characterized in that: The second resonant bridge (20) comprises a third switch tube (SW3) and a fourth switch tube (SW4); The voltage input end is connected to the first end of the fourth resonant bridge (40) through the third switch tube (SW3) and the fourth switch tube (SW4) in sequence, the first switch tube (SW1) is connected to the third switch tube (SW3), the first coil unit is connected between the third switch tube (SW3) and the fourth switch tube (SW4), and the second switch tube (SW2) is also connected to the fourth switch tube (SW4).

4. The power supply circuit of the autotransformer structure according to claim 1, characterized in that: The third resonant bridge (30) comprises a fifth switching tube (SW5) and a sixth switching tube (SW6); The second switch tube (SW2) is grounded via the fifth switch tube (SW5) and the sixth switch tube (SW6) in sequence, and the second coil unit is connected between the fifth switch tube (SW5) and the sixth switch tube (SW6).

5. The power supply circuit of the autotransformer structure according to claim 1, characterized in that: The fourth resonant bridge (40) comprises a seventh switching tube (SW7) and an eighth switching tube (SW8); The fourth switch tube (SW4) is grounded in sequence through the seventh switch tube (SW7) and the eighth switch tube (SW8); the third coil unit is connected between the seventh switch tube (SW7) and the eighth switch tube (SW8); and the sixth switch tube (SW6) is connected to the eighth switch tube (SW8).

6. The power supply circuit of the autotransformer structure according to claim 1, characterized in that: The power supply circuit also includes a control circuit; The control circuit is connected to the control ends of the first switch tube (SW1), the second switch tube (SW2), the third switch tube (SW3), the fourth switch tube (SW4), the fifth switch tube (SW5), the sixth switch tube (SW6), the seventh switch tube (SW7), and the eighth switch tube (SW8), respectively.

7. The power supply circuit of the autotransformer structure according to claim 6, characterized in that: The control circuit performs in one execution cycle: Control the third switch tube (SW3), the second switch tube (SW2), the seventh switch tube (SW7) and the sixth switch tube (SW6) to be turned on The first switch tube (SW1), the fourth switch tube (SW4), the eighth switch tube (SW8) and the fifth switch tube (SW5) are controlled to be turned off.

8. The power supply circuit of the autotransformer structure according to claim 6, characterized in that: The control circuit performs in one execution cycle: The first switch tube (SW1), the fourth switch tube (SW4), the eighth switch tube (SW8) and the fifth switch tube (SW5) are controlled to be turned on, and the third switch tube (SW3), the second switch tube (SW2), the seventh switch tube (SW7) and the fifth switch tube (SW5) are controlled to be turned off.

9. The power supply circuit of the autotransformer structure according to claim 6, characterized in that: The control circuit includes a PWM generator, which generates corresponding pulse width modulation signals and frequencies according to the operating frequency of the power supply circuit, load conditions, the first coil, the second coil and the capacitor resonant frequency, so as to control the on and off time of each switch tube.

10. The power supply circuit of the autotransformer structure according to claim 6, characterized in that: The switch tube is any one of a silicon-based MOSFET device, a silicon carbide device or a gallium nitride device.

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