DC-DC isolated converter device

Abstract

The invention discloses DC-DC isolation converter equipment. The DC-DC isolation converter equipment comprises a full-bridge circuit, a transformer and a voltage doubling circuit, the transformer comprises a primary winding and a secondary winding, and the primary winding and the secondary winding are electromagnetically coupled; the input end of the full-bridge circuit is connected with a direct-current input power supply, the output end of the full-bridge circuit is connected with the primary winding, and the secondary winding is connected with the input end of the voltage doubling circuit; the full-bridge circuit is used for converting electric energy of the direct-current input power supply into high-frequency alternating driving voltage and outputting the high-frequency alternating driving voltage to the primary winding; the transformer is used for transmitting the electric energy input by the full-bridge circuit to the secondary winding through electromagnetic coupling of the primary winding and the secondary winding; and the voltage doubling circuit comprises a rectifier diode and an energy storage capacitor and is used for carrying out rectification and voltage doubling amplification on the voltage output by the secondary winding and outputting the amplified voltage.

Description

Technical Field

[0001] This application relates to the field of power electronic conversion technology, and more specifically, to a DC-DC isolation converter device. Background Technology

[0002] In electronic equipment applications such as switching power supplies and power conversion, the converter is the core component for power conversion. Its miniaturization and integration design are important development requirements of the industry. At the same time, it is necessary to ensure the stability of the device and avoid problems such as overcurrent and device burnout caused by magnetic core saturation. Therefore, while reducing the size of the magnetic core, it is necessary to take into account the utilization efficiency of the magnetic core and prevent magnetic saturation.

[0003] In the existing technology, conventional solutions for miniaturizing converter cores mostly adopt single-quadrant circuit topologies such as forward and flyback converters, or combine push-pull or half-bridge topologies with ordinary rectifier circuits. Some solutions simply increase the number of coil turns to try to improve core utilization.

[0004] However, topologies such as forward and flyback only utilize the magnetic core in a single quadrant, resulting in low core utilization and a high risk of magnetic saturation after miniaturization. Push-pull topologies require two sets of coils on the primary side, which cannot effectively increase the number of turns and restricts core miniaturization. Half-bridge topologies halve the primary voltage and require doubling the number of turns on the secondary side, and are prone to magnetic saturation due to bias. Ordinary rectifier circuits require multiple sets of secondary coils, occupying magnetic ring space and failing to increase the number of turns on the primary side, making it difficult to avoid magnetic saturation problems after core miniaturization. Summary of the Invention

[0005] The main objective of this application is to provide a DC-DC isolated converter device to solve the problems of magnetic saturation and low core utilization that easily occur after the miniaturization of the converter core. It can achieve efficient core utilization, effectively avoid magnetic saturation while reducing the core size, and ensure stable operation of the converter.

[0006] To achieve the above objectives, this application proposes a DC-DC isolated converter device, comprising: a full-bridge circuit, a transformer, and a voltage multiplier circuit; the transformer includes a primary winding and a secondary winding, the primary winding and the secondary winding being electromagnetically coupled; the input terminal of the full-bridge circuit is connected to a DC input power supply, the output terminal of the full-bridge circuit is connected to the primary winding, and the secondary winding is connected to the input terminal of the voltage multiplier circuit; the full-bridge circuit is used to convert the electrical energy of the DC input power supply into a high-frequency alternating drive voltage and output it to the primary winding; the transformer is used to transmit the electrical energy input by the full-bridge circuit to the secondary winding through the electromagnetic coupling between the primary winding and the secondary winding; the voltage multiplier circuit includes a rectifier diode and an energy storage capacitor, used to rectify and multiply the voltage output from the secondary winding, and output the amplified voltage.

[0007] According to the DC-DC isolation converter device provided in this application, it further includes: a voltage regulator circuit; the output terminal of the voltage multiplier circuit is connected to the input terminal of the voltage regulator circuit; the voltage regulator circuit is used to regulate the voltage signal output by the voltage multiplier circuit.

[0008] According to the DC-DC isolated converter device provided in this application, the voltage regulator circuit is a linear voltage regulator circuit; the linear voltage regulator circuit includes a fifth switching transistor, a first voltage divider sampling resistor, a second voltage divider sampling resistor, a reference voltage source, and an error amplifier; the input terminal of the fifth switching transistor is connected to the output terminal of the voltage multiplier circuit, the output terminal of the fifth switching transistor is connected to one end of the first voltage divider sampling resistor, and the control terminal of the fifth switching transistor is connected to the output terminal of the error amplifier; the other end of the first voltage divider sampling resistor is connected to one end of the second voltage divider sampling resistor, and the other end of the second voltage divider sampling resistor is grounded; the common connection point of the first voltage divider sampling resistor and the second voltage divider sampling resistor is connected to the non-inverting input terminal of the error amplifier, and the reference voltage source is connected to the inverting input terminal of the error amplifier.

[0009] According to the DC-DC isolated converter device provided in this application, the voltage multiplier circuit includes a charging branch and a discharging branch, which are composed of the rectifier diode and the energy storage capacitor. When the secondary winding outputs a first polarity voltage, the energy storage capacitor is charged through the charging branch. When the secondary winding outputs a second polarity voltage opposite to the first polarity voltage, the charged energy storage capacitor is connected in series with the secondary winding and superimposed, and together they supply power to the load through the discharging branch.

[0010] According to the DC-DC isolated converter device provided in this application, the full-bridge circuit includes a first switch, a second switch, a third switch, a fourth switch, and a drive unit; the first switch and the second switch are connected in series to form a left bridge arm, the third switch and the fourth switch are connected in series to form a right bridge arm, the left bridge arm and the right bridge arm are connected in parallel to the two ends of the input power supply, the control terminals of the first switch, the second switch, the third switch, and the fourth switch are all connected to the drive unit, and the midpoint of the left bridge arm and the midpoint of the right bridge arm are connected to the two ends of the primary winding.

[0011] According to the DC-DC isolated converter device provided in this application, the driving unit is used to alternately turn on a first group of transistors and a second group of transistors according to a preset switching frequency. The first group of transistors includes a second switch and a third switch, and the second group of transistors includes the first switch and a fourth switch. When the driving unit controls the first group of transistors to be in the on state and the second group of transistors to be in the off state, the full-bridge circuit outputs a forward current. When the driving unit controls the second group of transistors to be in the on state and the first group of transistors to be in the off state, the full-bridge circuit outputs a reverse current.

[0012] According to the present application, a DC-DC isolation converter device is provided, wherein the preset switching frequency is greater than 100kHz and less than 1MHz.

[0013] According to the present application, a DC-DC isolation converter device further includes a bus support capacitor; the bus support capacitor is connected in parallel between the input terminal of the full-bridge circuit and the input power supply.

[0014] According to the present application, a DC-DC isolation converter device is provided, wherein the transformer is an embedded transformer.

[0015] According to the present application, a DC-DC isolated converter device includes an embedded transformer comprising: a first insulating substrate having a first side and a second side opposite to the first side, and having a trench in the first insulating substrate having an inner periphery and an outer periphery; a magnetic core being accommodated in the trench and having a first segment and a second segment, and the trench being filled with a resin material; an upper conductive trace structure including a second insulating substrate, wherein an upper conductive trace is formed on a first side of the upper conductive trace structure, and the first side of the upper conductive trace structure is bonded to a first side of the first insulating substrate by a first adhesive layer; and a lower conductive trace structure including a third insulating substrate, wherein a lower conductive trace is formed on a first side of the lower conductive trace structure, and the first side of the lower conductive trace structure is bonded to a first side of the first insulating substrate by a first adhesive layer; and a lower conductive trace structure including a third insulating substrate, wherein a lower conductive trace is formed on a first side of the lower conductive trace structure, and the first side of the lower conductive trace structure is bonded to a first side of the first insulating substrate by a first adhesive layer. One side is bonded to the second side of the first insulating substrate via a second adhesive layer; and a first conductive via structure, the first conductive via structure including an external conductive connector and an internal conductive connector, and the first conductive via structure being formed by distributing conductive material on the sidewall of the first insulating substrate exposed due to the formation of the first via structure, wherein the first via structure penetrates the upper conductive trace structure, the lower conductive trace structure and the first insulating substrate; wherein the upper conductive trace, the internal conductive connector, the external conductive connector and the lower conductive trace formed around the first section of the magnetic core form the primary winding of the transformer device, and the upper conductive trace, the internal conductive connector, the external conductive connector and the lower conductive trace formed around the second section of the magnetic core form the secondary winding of the transformer device.

[0016] The technical solutions provided by the embodiments of this application may include the following beneficial effects: In this application, by employing a full-bridge circuit to provide a high-frequency alternating drive voltage to the primary side of the transformer, the magnetization curve of the transformer core operates in the first and third quadrants of the magnetic field strength-magnetic induction intensity curve. Compared to existing single-quadrant topologies such as forward and flyback converters, this achieves bidirectional magnetization utilization of the core, significantly improving core utilization and solving the problem of low core utilization in traditional single-quadrant topologies. Furthermore, because the secondary winding of the transformer is connected to a voltage multiplier circuit, the secondary output voltage is rectified and amplified through the voltage multiplier circuit. The target output voltage can be obtained without increasing the number of turns in the secondary winding, thereby reducing the number of turns occupied by the secondary winding. The primary winding has ample space reserved for core winding, allowing for a corresponding increase in the number of turns. This effectively suppresses the risk of core saturation and overcomes the limitations of existing push-pull topologies in terms of the number of primary coil groups, the tendency of half-bridge topologies to become magnetically saturated, and the difficulty in balancing core miniaturization and anti-magnetic saturation due to the space occupied by ordinary rectifier circuits. Through the coordinated operation of the full-bridge circuit and the voltage multiplier circuit, the core size is reduced, meeting the needs of converter miniaturization and integration, while ensuring efficient core utilization and anti-magnetic saturation effect. This improves the stability of converter operation and avoids potential hazards such as circuit overcurrent and device burnout caused by magnetic saturation. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings: Figure 1 A schematic diagram of the magnetization curve of the magnetic core provided in this application; Figure 2 This is one of the circuit structure schematic diagrams of the DC-DC isolation converter device provided by the present invention; Figure 3 This is one of the circuit structure schematic diagrams of the DC-DC isolation converter device provided by the present invention; Figure 4 This is a schematic diagram of the embedded transformer provided by the present invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present application.

[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application 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.

[0020] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0021] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0022] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linked," and "socketing" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] This application describes some exemplary embodiments for illustrative purposes. It should be understood that this application may be implemented in other ways not specifically shown in the accompanying drawings.

[0024] The following section will explain in detail the magnetization principle and key parameter relationships of the magnetic core in the DC-DC isolated converter.

[0025] Magnetic field strength H is the fundamental magnetic field generated by the coil current, and magnetic induction intensity B is the actual magnetic field strength after the magnetic core is magnetized. The relationship between magnetic field strength H and magnetic induction intensity B can be expressed as: ; (1) in, air permeability, The relative permeability of the magnetic material. Where is the length of the magnetic circuit, N is the number of turns of the coil, I is the current flowing through the coil, and H is the magnetic field generated by the coil current.

[0026] According to formula (1), the magnetic field strength H can be determined by the number of coil turns N, the current I, and the magnetic circuit length. The magnetic flux density B is determined by multiplying the magnetic field strength H by the permeability of the core material. In other words, the magnetic field can excite the magnetization properties of the core material, thereby further strengthening the magnetic field strength to the actual magnetic flux density B. The strengthening factor is the permeability of the core material.

[0027] like Figure 1 The figure shows the magnetization curve of the magnetic core, with the horizontal axis representing the magnetic field strength H and the vertical axis representing the magnetic flux density B. This magnetization curve describes the cyclic process of the magnetic core from unmagnetized to magnetic saturation: The curve starts at the unmagnetized origin 0. As the coil current increases, the magnetic field strength H increases in the positive direction, the magnetic core is gradually magnetized, and the magnetic induction intensity B rises accordingly until the magnetic core reaches the positive magnetic saturation point a. At this point, the magnetic field strength H continues to increase, but the magnetic induction intensity B no longer rises significantly. Subsequently, as the coil current decreases, the magnetic field strength H decreases in the positive direction, and the magnetic induction intensity B also decreases accordingly. However, due to the remanent magnetization of the magnetic core, when the magnetic field strength H drops to 0, the magnetic induction intensity B will not return to 0, but will remain at the remanent magnetization point b. If the coil current increases in the reverse direction, the magnetic field strength H increases in the reverse direction, the magnetic core begins to demagnetize, and the magnetic induction intensity B continues to decrease until the magnetic field strength H reaches the reverse coercivity point c. At this point, the magnetic induction intensity B drops to 0, canceling the remanence. If the reverse current is further increased, the magnetic field strength H increases further in the reverse direction, the magnetic core is reverse magnetized, and the magnetic induction intensity B rises in the reverse direction, eventually reaching the reverse magnetic saturation point d, thus completing one complete magnetization cycle.

[0028] It should be noted that remanence refers to the phenomenon where, due to the hysteresis properties of magnetic materials, after the core is magnetized, although the magnetic field strength becomes zero, a portion of the core remains magnetized, and the magnetic flux density is not zero. Coercivity refers to the strength of the reverse magnetic field applied to reduce the magnetic flux density of the core back to zero. Magnetic saturation refers to the point at which the energy stored or converted by the magnetic core reaches its maximum value.

[0029] It should be noted that when the magnetic core is in a magnetic saturation state, the coil wound on the magnetic core is no longer regarded as an inductor, but as a wire. At this time, the coil current will rise sharply, triggering the circuit overcurrent protection, or directly burning out the circuit components. Therefore, magnetic saturation is an operating state that must be avoided.

[0030] Faraday's law of electromagnetic induction describes the relationship between a magnetic field and an induced electromotive force: ; (2) in, For magnetic flux, The cross-sectional area of ​​the magnetic circuit is... For switching frequency, This represents the change in magnetic flux density within half a switching cycle. To induce electromotive force. This represents the number of turns of the primary coil.

[0031] It is understandable that once the power supply design requirements are determined, the induced electromotive force U remains constant. That is, in a converter design with a fixed input voltage U, reducing the core volume will lead to a decrease in the magnetic circuit cross-sectional area. To reduce the change in magnetic flux density, the change ΔB can be calculated using Faraday's law of electromagnetic induction. It is also important to ensure that the range of change in magnetic flux density B corresponding to the change ΔB does not exceed the unsaturated region of the magnetization curve, i.e., it is far from the saturation value Bs.

[0032] Based on the aforementioned magnetization principle, magnetization curve characteristics, and Faraday's law of electromagnetic induction, in the miniaturization design of DC-DC isolation converters, reducing the core volume will lead to a decrease in the magnetic circuit cross-sectional area. When the input voltage U is fixed, the magnetic circuit cross-sectional area decreases, and according to the above formula (2), the magnetic circuit cross-sectional area is... A decrease in ΔB will directly lead to an increase in the change in magnetic flux density, which can easily cause the magnetic flux density B to approach the saturation value Bs, thus triggering magnetic saturation problems.

[0033] In existing technologies, single-quadrant topologies such as forward and flyback converters only utilize the first quadrant of the magnetization curve, resulting in insufficient core utilization and a narrow usable range for the change in magnetic induction intensity ΔB. Furthermore, reducing the volume significantly increases the risk of saturation. Push-pull topologies require two sets of coils on the primary side, limiting the increase in the number of turns N and making it impossible to compensate for the magnetic circuit cross-sectional area through the number of coil turns. To reduce the impact, the primary voltage of the half-bridge topology is only 1 / 2 of the input voltage, so the number of secondary turns needs to be increased to obtain the target output voltage, which occupies the magnetic core space and makes it difficult to meet the requirements of miniaturization and anti-magnetic saturation.

[0034] To solve the above problems, such as Figure 2As shown, this application embodiment provides a DC-DC isolated converter device suitable for scenarios with stringent requirements for miniaturization, high integration, low power consumption, and power supply stability. The DC-DC isolated converter device may include: a full-bridge circuit 10, a transformer 20, and a voltage multiplier circuit 30; the transformer 20 includes a primary winding 21 and a secondary winding 22, and the primary winding and the secondary winding are electromagnetically coupled; the input terminal of the full-bridge circuit 10 is connected to the DC input power supply VIN, the output terminal of the full-bridge circuit 10 is connected to the primary winding 21, and the secondary winding 22 is connected to the input terminal of the voltage multiplier circuit 30.

[0035] The full-bridge circuit 10 is used to convert the electrical energy of the DC input power supply VIN into a high-frequency alternating drive voltage and output it to the primary winding 21; the transformer 20 is used to transmit the electrical energy input by the full-bridge circuit 10 to the secondary winding 22 through the electromagnetic coupling between the primary winding 21 and the secondary winding 22, and to realize voltage transformation and electrical isolation between the primary winding 21 and the secondary winding 22; the voltage multiplier circuit 30 includes a rectifier diode and an energy storage capacitor, used to rectify and multiply the voltage output by the secondary winding 22, and output the amplified voltage.

[0036] Specifically, this application first receives DC power from the DC input power supply VIN through a full-bridge circuit 10, converts the DC power into a high-frequency alternating drive voltage, and then outputs it to the primary winding 21 of the transformer 20. Based on the electromagnetic coupling characteristics of the transformer 20, the alternation of the current direction in the primary winding 21 will cause the magnetic field strength H to change periodically between +H and -H, thereby causing the magnetization curve of the magnetic core to cycle between the first and third quadrants of the magnetization curve. This not only reduces the risk of magnetic saturation but also realizes the bidirectional magnetization utilization of the magnetic core.

[0037] With a fixed input voltage U, this application can optimize the winding turns configuration through a voltage multiplier circuit 30 after completing the electrical isolation and preliminary voltage transformation of the primary and secondary sides via transformer 20. As a secondary-side rectifier circuit, the voltage multiplier circuit 30 only requires one set of secondary windings 22 to achieve voltage rectification and voltage multiplication, without needing to increase the number of secondary turns to boost the output voltage as in traditional topologies. This minimizes the space occupied by the secondary windings 22 on the magnetic core, reserving sufficient winding space for the primary windings 21. Based on the quantitative relationship of the above formula (2), it can be seen that when the magnetic core volume shrinks, the magnetic circuit cross-sectional area... When the magnetic field area decreases, it can be compensated by increasing the number of turns N of the primary winding 21. Increasing the number of turns N can offset the magnetic field area decrease. To reduce the impact on the change in magnetic flux density ΔB, ensure that the change in magnetic flux density ΔB always remains within the unsaturated range of the magnetization curve, and avoid the change in magnetic flux density B approaching the saturation value Bs due to the decrease of Ae.

[0038] Furthermore, the full-bridge circuit 10 can avoid the shortcomings of push-pull topology requiring two sets of coils on the primary side and half-bridge topology being prone to magnetization. It eliminates the need for additional primary coils, further freeing up the core winding space. At the same time, the primary winding 21 can obtain the complete input power supply voltage VIN, without having to bear the voltage limit of 1 / 2VIN as in the half-bridge topology. It also eliminates the need to compensate for voltage loss by increasing the number of secondary turns, thus structurally ensuring the compensation space for the number of primary turns N.

[0039] Finally, by using the dual-quadrant magnetization design of the full-bridge circuit and the number of turns optimization of the voltage multiplier circuit, combined with the parameter coordination of formula (1) and formula (2), this application can effectively control the range of change of magnetic induction intensity B while realizing the reduction of magnetic core volume and meeting the miniaturization requirements of converter. This solves the problem that magnetic core miniaturization and anti-magnetic saturation are difficult to balance in the prior art, and ensures the stable operation of converter.

[0040] Optionally, continue to refer to Figure 2 The full-bridge circuit 10 may include a first switch Q1, a second switch Q2, a third switch Q3, a fourth switch Q4, and a drive unit. The first switch Q1 and the second switch Q2 are connected in series to form the left bridge arm, and the third switch Q3 and the fourth switch Q4 are connected in series to form the right bridge arm. The left bridge arm and the right bridge arm are connected in parallel to the two ends of the input power supply VIN. The control terminals of the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4 are all connected to the drive unit. The midpoint of the left bridge arm and the midpoint of the right bridge arm are connected to the two ends of the primary winding 21.

[0041] The aforementioned driving unit is used to alternately turn on the first transistor group and the second transistor group according to a preset switching frequency. The first transistor group includes the third switch Q3 and the second switch Q2, and the second transistor group includes the first switch Q1 and the fourth switch Q4. When the driving unit controls the first transistor group to be in the on state and the second transistor group to be in the off state, the full-bridge circuit outputs a forward current. When the driving unit controls the second transistor group to be in the on state and the first transistor group to be in the off state, the full-bridge circuit outputs a reverse current.

[0042] Specifically, the drive unit incorporates bridge arm interlocking logic to ensure that the two switches on the same bridge arm do not conduct simultaneously. That is, when the first switch Q1 is on, the second switch Q2 is off; when the third switch Q3 is on, the fourth switch Q4 is off, preventing short circuits and device burnout. When the drive unit controls the second switch Q2 and the third switch Q3 to be on, and the first switch Q1 and the fourth switch Q4 to be off, the current from the input power supply VIN flows through the midpoint of the right bridge arm and the primary winding 21. A loop is formed at the midpoint of the left bridge arm, and the full-bridge circuit 10 outputs a forward current. When the driving unit controls the first switch Q1 and the fourth switch Q4 to be in the on state and the second switch Q2 and the third switch Q3 to be in the off state, the current of the input power supply VIN forms a reverse loop through the midpoint of the left bridge arm, the primary winding 21, and the midpoint of the right bridge arm, and the full-bridge circuit 10 outputs a reverse current. Through the alternating output of forward and reverse currents, a high-frequency alternating drive voltage can be provided to the primary winding 21.

[0043] Optionally, the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4 are all NMOS transistors.

[0044] Optionally, the preset switching frequency is greater than 100kHz and less than 1MHz.

[0045] It should be noted that the on-resistance of an NMOS transistor is much lower than that of a PMOS transistor of the same specification, resulting in a smaller voltage drop at the same operating current. This significantly reduces the conduction losses of the full-bridge circuit and improves the overall energy conversion efficiency of the DC-DC isolated converter. As a voltage-controlled device, its gate drive requires no large current, and its turn-on and turn-off response time is in the nanosecond range. This allows it to match the preset switching frequency requirements of the full-bridge circuit from 100kHz to 1MHz, reducing transition losses during switching and avoiding signal delays at high frequencies. Furthermore, the NMOS transistor has a lower drive threshold voltage, making it highly compatible with the output characteristics of conventional driver chips, eliminating the need for complex... The current amplification circuit reduces the design complexity and hardware cost of the drive unit; moreover, its inter-electrode parasitic capacitance (gate-source capacitance and drain-source capacitance) is smaller, and the interference such as oscillation and voltage spikes caused by parasitic parameters is weaker during high-frequency alternating switching, which can ensure the stability of the high-frequency alternating drive voltage output of the full-bridge circuit and avoid affecting the magnetization effect of the transformer core; in addition, under the same voltage and current rating, the NMOS transistor has a smaller package size and better high-temperature operating stability, which is conducive to the integrated design of the full-bridge circuit, meets the development needs of miniaturization of DC-DC isolation converter equipment, and also reduces the risk of device failure under long-term high-frequency operation.

[0046] Optionally, a current sampling resistor can be connected in series between the source of each NMOS transistor and the negative terminal of the input power supply VIN to detect the operating current of the switching transistor in real time. The signal output terminal of the current sampling resistor is connected to the current detection terminal of the drive unit. When the detected current exceeds a preset threshold, the drive unit can immediately turn off the corresponding switching transistor to achieve overcurrent protection. A freewheeling diode can also be connected in parallel between the drain and source of each NMOS transistor to absorb the reverse spike voltage generated during the switching process and protect the switching transistor from breakdown damage.

[0047] Optionally, continue to refer to Figure 2 The DC-DC isolated converter device provided in this application embodiment also includes a bus support capacitor C1; the bus support capacitor C1 is connected in parallel between the input terminal of the full-bridge circuit 10 and the input power supply VIN.

[0048] Specifically, the bus support capacitor C1 can smooth the DC voltage output from the input power supply VIN, suppress the bus voltage ripple and current surge caused by the high-frequency alternating switching of the switching transistors in the full-bridge circuit, and prevent voltage fluctuations from affecting the stability of the high-frequency alternating drive signal output by the full-bridge circuit. At the same time, the bus support capacitor C1 can quickly release stored energy at the moment the switching transistor is turned on, providing a large instantaneous current for the primary winding 21, compensating for the dynamic response delay of the input power supply, and ensuring the stable change of the magnetic field strength H during the magnetization process of the transformer core. In addition, the capacitor can also absorb high-frequency harmonics and spike interference in the circuit, reduce electromagnetic radiation, improve the overall electromagnetic compatibility and operational reliability of the DC-DC isolation converter, and provide a stable power foundation for the coordinated operation of the full-bridge circuit, the transformer, and the subsequent voltage multiplier circuit.

[0049] Optionally, continue to refer to Figure 2 The voltage multiplier circuit 30 includes a charging branch and a discharging branch, which are composed of rectifier diodes and energy storage capacitors. When the secondary winding 22 outputs a first polarity voltage, the energy storage capacitor is charged through the charging branch. When the secondary winding 22 outputs a second polarity voltage opposite to the first polarity voltage, the charged energy storage capacitor is connected in series with the secondary winding and supplied to the load through the discharging branch.

[0050] It should be noted that the first polarity voltage can be a reverse voltage, and the second polarity voltage can be a forward voltage.

[0051] Optionally, the voltage multiplier circuit 30 can be a voltage multiplier circuit with a 2x, 3x, or higher multiplier, and the number of rectifier diodes can be adjusted accordingly. The specific configuration can be determined based on actual usage, and this embodiment does not impose any limitations on this.

[0052] Specifically, such as Figure 2As shown, taking the voltage multiplier circuit 30 using a voltage multiplier rectifier circuit as an example, its operation is synchronized with the high-frequency alternating voltage output by the secondary winding 22 of the transformer, which can realize the synergistic effect of rectification and voltage multiplication.

[0053] When the secondary winding 22 outputs a reverse voltage, the second diode D2 is turned on and the first diode D1 is turned off. The secondary winding 22, the second diode D2, and the first capacitor C2 form a charging branch. The voltage across the first capacitor C2 is charged to the peak voltage of the secondary winding 22 through this charging branch. During this stage, the second capacitor C3 independently forms a discharge branch to supply power to the load. When the secondary winding 22 outputs a positive voltage, the second diode D2 is cut off and the first diode D1 is turned on. The secondary winding 22, the first capacitor C2, the first diode D1, and the second capacitor C3 together form a charging branch, which makes the voltage of the secondary winding 22 and the voltage stored in the first capacitor C2 in series superimposed. The second capacitor C3 is charged through this charging branch, so that the voltage across the second capacitor C3 is stabilized to about twice the peak voltage of the secondary winding 22. At the same time, the secondary winding 22, the first capacitor C2, the first diode D1, the second capacitor C3, and the load together form a discharging branch, which supplies power to the load while charging.

[0054] Through the aforementioned alternating charging operation, the voltage multiplier circuit 30 does not require additional turns in the secondary winding. It achieves voltage multiplication by using only one winding in conjunction with the diode and capacitor, significantly reducing the space occupied by the secondary winding on the magnetic core. This leaves ample winding space for the primary winding 21, facilitating the compensation of the magnetic circuit cross-sectional area A resulting from core miniaturization by increasing the number of primary turns. e The reduction in voltage reduces the risk of magnetic saturation from a structural perspective. At the same time, the unidirectional conduction characteristic of the diode enables the rectification of alternating voltage, allowing the voltage multiplier circuit to output a stable DC voltage signal, providing smooth power to the subsequent load or voltage regulator circuit. This ensures both voltage amplification and simplifies the circuit structure.

[0055] Optionally, in order to meet the requirements of high output voltage accuracy and low output ripple voltage, a voltage regulator circuit can be connected after the voltage multiplier circuit, with the output terminal of the voltage multiplier circuit connected to the input terminal of the voltage regulator circuit; the voltage regulator circuit is used to regulate the voltage signal output by the voltage multiplier circuit.

[0056] Specifically, such as Figure 3 As shown, the DC-DC isolation converter power converter provided in this application embodiment may further include: a linear voltage regulator circuit 40; the Vin terminal of the linear voltage regulator circuit 40 is connected to the positive Vout terminal of the voltage multiplier circuit 30, the ground terminal is connected to the negative Vout terminal of the voltage multiplier circuit 30, and the VOUT terminal of the linear voltage regulator circuit 40 is connected to the load.

[0057] The linear voltage regulator circuit includes a fifth switch Q5, a first voltage divider sampling resistor R2, a second voltage divider sampling resistor R3, a reference voltage source Vref, and an error amplifier EA. The input terminal of the fifth switch Q5 is connected to the output terminal of the voltage multiplier circuit 30, the output terminal of the fifth switch Q5 is connected to one end of the first voltage divider sampling resistor R2, and the control terminal of the fifth switch Q5 is connected to the output terminal of the error amplifier EA. The other end of the first voltage divider sampling resistor R2 is connected to one end of the second voltage divider sampling resistor R3, and the other end of the second voltage divider sampling resistor R3 is grounded. The common connection point of the first voltage divider sampling resistor R2 and the second voltage divider sampling resistor R3 is connected to the non-inverting input terminal of the error amplifier EA, and the reference voltage source Vref is connected to the inverting input terminal of the error amplifier EA.

[0058] It should be noted that when the output voltage of the voltage multiplier circuit 30 increases due to load fluctuations, interference from the preceding circuit, etc., the voltage at the common connection point of the first voltage divider sampling resistor R2 and the second voltage divider sampling resistor R3 increases accordingly. This sampling signal is input to the non-inverting input terminal of the error amplifier EA, making the voltage at the non-inverting input terminal higher than the reference voltage Vref at the inverting input terminal. The output voltage of the error amplifier EA decreases accordingly, thereby reducing the conduction degree of the fifth switch Q5 and increasing the voltage drop of the fifth switch Q5 itself, offsetting the rise in output voltage, and accurately pulling VOUT back to the preset stable value. When the output voltage of the voltage multiplier circuit 30 decreases, the sampling node voltage decreases accordingly, causing the voltage at the non-inverting input of the error amplifier EA to be lower than the reference voltage Vref at the inverting input. The output voltage of the error amplifier EA increases accordingly, thereby increasing the conduction level of the fifth switch Q5, reducing the voltage drop of the fifth switch Q5, quickly compensating for the drop in output voltage, and ensuring that the output voltage VOUT is always stable at the target value.

[0059] The linear voltage regulator circuit 40 can further process the amplified voltage output by the voltage multiplier circuit 30 into a DC voltage with low ripple and high precision. At the same time, the linear voltage regulator circuit has a fast response speed and can suppress voltage fluctuations instantly. In addition, due to its simple structure and low noise, it will not introduce additional electromagnetic interference, which can ensure the stable operation of the device under long-term high-frequency and small-scale chemical conditions.

[0060] Optionally, the transformer 20 can be an embedded transformer. This embedded transformer features a compact structure, high integration, and concentrated magnetic circuit, which can improve the utilization rate of the magnetic core and heat dissipation efficiency while reducing the overall size, thereby meeting the design requirements of miniaturization and high efficiency of DC-DC isolation converter equipment.

[0061] Furthermore, the embedded transformer can be implemented using various stacked structures. For example, the embedded transformer may include a first insulating layer, a second insulating layer, an insulating substrate, and a magnetic core. The insulating substrate has an annular groove, and the magnetic core is accommodated in the annular groove. The first insulating layer and the second insulating layer are respectively bonded to two side planes of the insulating substrate to form a stable stacked packaging structure.

[0062] Optionally, such as Figure 4 As shown, this application embodiment also provides an embedded transformer, the embedded transformer comprising: a first insulating substrate 101 having a first side and a second side opposite to the first side, and having a trench 102 in the first insulating substrate 101, the trench 102 having an inner periphery and an outer periphery; a magnetic core 103 being accommodated in the trench 102 and having a first segment and a second segment, and the trench 102 being filled with a resin material 104; an upper conductive trace structure 200 including a second insulating substrate 201, an upper conductive trace 202 being formed on a first side of the upper conductive trace structure 200, the first side of the upper conductive trace structure 200 being bonded to the first side of the first insulating substrate 101 by a first adhesive layer 401; and a lower conductive trace structure 300 including a third insulating substrate 301, a lower conductive trace 302 being formed on a first side of the lower conductive trace structure 300, the lower conductive trace structure 300 being... The first side of the trace structure 300 is bonded to the second side of the first insulating substrate 101 via the second adhesive layer 402; and the first conductive through-hole structure 411 includes an external conductive connector 405 and an internal conductive connector 406, and the first conductive through-hole structure 411 is formed by arranging conductive material on the sidewall of the first insulating substrate 101 exposed due to the formation of the first through-hole structure 410, wherein the first through-hole structure 410 penetrates the upper conductive trace structure 200, the lower conductive trace structure 300 and the first insulating substrate 101; wherein the upper conductive trace 202, the internal conductive connector 406, the external conductive connector 405 and the lower conductive trace 302 formed around the first section of the magnetic core 103 form the primary winding of the transformer device; the upper conductive trace 202, the internal conductive connector 406, the external conductive connector 405 and the lower conductive trace 302 formed around the second section of the magnetic core 103 form the secondary winding of the transformer device.

[0063] It should be noted that, Figure 4The embedded transformer shown uses resin material to fill the grooves housing the magnetic core. This resin material serves two purposes: firstly, it secures the magnetic core within the grooves; secondly, it provides insulation, thereby increasing the creepage distance. In other words, without changing the creepage distance, the thickness of the relevant area in the first insulating substrate can be further reduced, which is beneficial for transformer miniaturization. That is, by selecting… Figure 4 The embedded transformer shown can further adapt to the core requirements of miniaturization, integration and anti-magnetic saturation of DC-DC isolation converter equipment. It should be noted that, in addition, the DC-DC isolation converter equipment provided in this application can also use ordinary transformers, which can be determined according to the application requirements. This application does not limit this.

[0064] In this embodiment, by employing a full-bridge circuit to provide a high-frequency alternating drive voltage to the primary side of the transformer, the magnetization curve of the transformer core operates in the first and third quadrants of the magnetic field strength-magnetic induction intensity curve. Compared to existing single-quadrant topologies such as forward and flyback converters, this achieves bidirectional magnetization utilization of the core, significantly improving core utilization and solving the problem of low core utilization in traditional single-quadrant topologies. Furthermore, because the secondary winding of the transformer is connected to a voltage multiplier circuit, the secondary output voltage is rectified and amplified through the voltage multiplier circuit. This eliminates the need to increase the number of turns in the secondary winding to obtain the target output voltage, thereby reducing the number of turns occupied by the secondary winding. Sufficient space is reserved for the primary winding, allowing for a corresponding increase in the number of turns. This effectively suppresses the risk of core saturation and overcomes the limitations of existing push-pull topologies in terms of the number of primary coil groups, the tendency of half-bridge topologies to become magnetically saturated, and the difficulty in balancing core miniaturization and anti-magnetic saturation due to the space occupied by ordinary rectifier circuits. Through the coordinated operation of the full-bridge circuit and the voltage multiplier circuit, the core size is reduced, meeting the needs of converter miniaturization and integration, while ensuring efficient core utilization and anti-magnetic saturation effect. This improves the stability of converter operation and avoids potential hazards such as circuit overcurrent and device burnout caused by magnetic saturation.

[0065] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A DC-DC isolation converter device, characterized in that, include: A full-bridge circuit, a transformer, and a voltage multiplier circuit; the transformer includes a primary winding and a secondary winding, and the primary winding and the secondary winding are electromagnetically coupled. The input terminal of the full-bridge circuit is connected to a DC input power supply, the output terminal of the full-bridge circuit is connected to the primary winding, and the secondary winding is connected to the input terminal of the voltage multiplier circuit. The full-bridge circuit is used to convert the electrical energy of the DC input power supply into a high-frequency alternating drive voltage and output it to the primary winding. The transformer is used to transmit the electrical energy input from the full-bridge circuit to the secondary winding through electromagnetic coupling between the primary winding and the secondary winding. The voltage multiplier circuit includes a rectifier diode and an energy storage capacitor, which are used to rectify and multiply the voltage output from the secondary winding, and output the amplified voltage.

2. The DC-DC isolation converter device according to claim 1, characterized in that, Also includes: A voltage regulator circuit; the output terminal of the voltage multiplier circuit is connected to the input terminal of the voltage regulator circuit; The voltage regulator circuit is used to regulate the voltage signal output by the voltage multiplier circuit.

3. The DC-DC isolation converter device according to claim 2, characterized in that, The voltage regulator circuit is a linear voltage regulator circuit; the linear voltage regulator circuit includes a fifth switching transistor, a first voltage divider sampling resistor, a second voltage divider sampling resistor, a reference voltage source, and an error amplifier; The input terminal of the fifth switch is connected to the output terminal of the voltage multiplier circuit, the output terminal of the fifth switch is connected to one end of the first voltage divider sampling resistor, and the control terminal of the fifth switch is connected to the output terminal of the error amplifier. The other end of the first voltage divider sampling resistor is connected to one end of the second voltage divider sampling resistor, and the other end of the second voltage divider sampling resistor is grounded; the common connection point of the first voltage divider sampling resistor and the second voltage divider sampling resistor is connected to the non-inverting input terminal of the error amplifier, and the reference voltage source is connected to the inverting input terminal of the error amplifier.

4. The DC-DC isolation converter device according to claim 1, characterized in that, The voltage multiplier circuit includes a charging branch and a discharging branch, which are composed of the rectifier diode and the energy storage capacitor. When the secondary winding outputs the first polarity voltage, the energy storage capacitor is charged through the charging branch; When the secondary winding outputs a second polarity voltage opposite to the first polarity, the charged energy storage capacitor is connected in series with the secondary winding and supplies power to the load through the discharge branch.

5. The DC-DC isolation converter device according to claim 1, characterized in that, The full-bridge circuit includes a first switching transistor, a second switching transistor, a third switching transistor, a fourth switching transistor, and a driving unit; The first and second switching transistors are connected in series to form the left bridge arm, and the third and fourth switching transistors are connected in series to form the right bridge arm. The left and right bridge arms are connected in parallel to the two ends of the input power supply. The control terminals of the first, second, third, and fourth switching transistors are all connected to the drive unit. The midpoint of the left bridge arm and the midpoint of the right bridge arm are connected to the two ends of the primary winding.

6. The DC-DC isolation converter device according to claim 5, characterized in that, The driving unit is used to alternately turn on the first transistor group and the second transistor group according to a preset switching frequency. The first transistor group includes the second switching transistor and the third switching transistor, and the second transistor group includes the first switching transistor and the fourth switching transistor. When the driving unit controls the first transistor group to be in the on state and the second transistor group to be in the off state, the full-bridge circuit outputs a positive current; When the driving unit controls the second transistor group to be in the on state and the first transistor group to be in the off state, the full-bridge circuit outputs a reverse current.

7. The DC-DC isolation converter device according to claim 6, characterized in that, The preset switching frequency is greater than 100kHz and less than 1MHz.

8. The DC-DC isolation converter device according to claim 1, characterized in that, It also includes a bus support capacitor; the bus support capacitor is connected in parallel between the input terminal of the full-bridge circuit and the input power supply.

9. The DC-DC isolation converter device according to claim 1, characterized in that, The transformer is an embedded transformer.

10. The DC-DC isolation converter device according to claim 9, characterized in that, The embedded transformer includes: A first insulating substrate has a first side and a second side opposite to the first side, and has a trench in the first insulating substrate, the trench having an inner periphery and an outer periphery; A magnetic core, the magnetic core being housed in a trench and having a first section and a second section, the trench being filled with a resin material; An upper conductive trace structure includes a second insulating substrate, an upper conductive trace is formed on a first side of the upper conductive trace structure, and the first side of the upper conductive trace structure is bonded to a first side of the first insulating substrate through a first adhesive layer. A lower conductive trace structure, the lower conductive trace structure including a third insulating substrate, a lower conductive trace formed on a first side of the lower conductive trace structure, the first side of the lower conductive trace structure being bonded to a second side of the first insulating substrate via a second adhesive layer; and A first conductive via structure, comprising an external conductive connector and an internal conductive connector, wherein the first conductive via structure is formed by distributing conductive material on the sidewall of the first insulating substrate exposed due to the formation of the first via structure, wherein the first via structure penetrates the upper conductive trace structure, the lower conductive trace structure and the first insulating substrate; The upper conductive trace, the inner conductive connector, the outer conductive connector, and the lower conductive trace formed around the first section of the magnetic core form the primary winding of the embedded transformer, and the upper conductive trace, the inner conductive connector, the outer conductive connector, and the lower conductive trace formed around the second section of the magnetic core form the secondary winding of the embedded transformer.

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