CN111899962A - Magnetic integration system of DC-DC converter based on GaN - Google Patents

Abstract

The invention discloses a magnetic integration system of a GaN-based DC-DC converter. A first plane inductance coil and a second plane inductance coil are both hexagonal structures, and the middle of the first plane inductance coil passes through the first plane magnetic field. Between the column and the fourth plane magnetic column and between the second plane magnetic column and the third plane magnetic column, and the second plane magnetic column is located at the opening position on one side of the first plane inductance coil, and the fourth plane magnetic column is located on the first plane magnetic column. At the opening position on the other side of the two-plane inductance coil, the middle of the second plane inductance coil passes between the first plane magnetic column and the second plane magnetic column and between the third plane magnetic column and the fourth plane magnetic column, and The third plane magnetic column is located at the opening position on one side of the second plane inductance coil, and the first plane magnetic column is located at the opening position on the other side of the second plane inductance coil. The system can be decoupled and integrated through discrete inductors to increase the Power density of large converters.

Description

A GaN-based magnetic integration system for DC-DC converters

technical field

The invention relates to a magnetic integration system, in particular to a magnetic integration system of a GaN-based DC-DC converter.

Background technique

High efficiency, high power density and miniaturization are the development trends of data center voltage regulator modules. Typically, these DC-DC converters are built on the motherboard directly next to the load and are therefore also known as point-of-load (POL) converters. To achieve the goal, two approaches can be used to reduce the size of the converter. The first is to drastically increase the switching frequency to reduce the size of passive components. The other is integrated passive components, the basic principle of which is to integrate discrete inductor windings on a magnetic core.

Gallium nitride transistors (GaN), a wide-bandgap power semiconductor device, are a promising POL converter device with high electron mobility, offering potential advantages for high-frequency power conversion. Coupled with the advent of advanced ferrite material technology, it is possible to use PCB planar transformers and inductors, which can achieve greater power density of VRMs due to their low profile advantages. At the same time, PCB planar inductors and transformers are easier to automate, since traditional transformers and inductors require manual winding of coils, requiring a lot of manual intervention. This also highlights the advantages of PCB planar inductors and transformers. In the field of VRMs, magnets occupy a relatively high volume of volume. At the same time, the space for voltage modules on the server motherboard of the data center is very limited. Integrated magnetics are a necessary option.

At present, the 12V to 1.xV polyphase buck in VRMs is a relatively recognized solution. Professor Li Zeyuan proposed an inductive and magnetic integration solution for a reverse-coupled polyphase buck circuit. Compared with discrete inductors, this reverse-coupled inductor not only effectively reduces the volume of the magnetic core, but also improves efficiency. This is also the most popular magnetic integration solution at present.

Although reverse coupling is a generally accepted method of magnetic integration, its application is limited to interleaved operation, such as multiphase buck circuits, and not all DC-DC converters or other directions can be used. Therefore, a more widely applicable discrete inductor integration solution needs to be proposed.

Referring to Figure 1, for a 48V-1.xV POL converter, the traditional buck converter has an extremely low duty cycle, which limits its development. Hossein Ardi et al. proposed a new type of converter with simple structure and high buck gain, which is an ideal topology for 48V to 1.xV converters. This topology consists of one or two capacitors, two inductors, and four active devices. The positive pole of the topology input power supply is connected to one end of the first inductor and one end of the first switch tube through the fourth switch tube, and the other end of the first switch tube is connected to one end of the third switch tube and the negative end of the first capacitor. The positive end of the first capacitor is connected to one end of the second inductor and one end of the second switch tube, and the positive end of the second capacitor is connected to the other end of the second inductor, the other end of the first inductor and the positive end of the load. The negative end of the second capacitor is connected to the other end of the second switch tube, the other end of the third switch tube and the negative end of the load. The two inductor currents of the above topology do not run interleaved and the inductance values are not consistent. Therefore, the traditional inverse coupling magnetic integration method will increase the magnetic loss of the iron core.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art, and to provide a magnetic integration system of a GaN-based DC-DC converter, which can be decoupled and integrated through discrete inductors to increase the power density of the converter.

In order to achieve the above object, the magnetic integrated system of the GaN-based DC-DC converter of the present invention includes a first planar magnetic column, a second planar magnetic column, a third planar magnetic column, a fourth planar magnetic column, and a first planar magnetic column. an inductor coil and a second planar inductor coil;

The first plane magnetic column, the second plane magnetic column, the third plane magnetic column and the fourth plane magnetic column are located at the positions of the four corners of the square in turn, and the first plane inductance coil and the second plane inductance coil are all of a hex-shaped structure, and the middle of the first planar inductance coil passes between the first planar magnetic column and the fourth planar magnetic column and between the second planar magnetic column and the third planar magnetic column, and the second planar magnetic column is located in the first planar inductance coil At the opening position on one side, the fourth plane magnetic column is located at the opening position on the other side of the second plane inductance coil, and the middle of the second plane inductance coil passes through between the first plane magnetic column and the second plane magnetic column and the second plane magnetic column. Between the three plane magnetic column and the fourth plane magnetic column, and the third plane magnetic column is located at the opening position on one side of the second plane inductance coil, and the first plane magnetic column is located at the opening position on the other side of the second plane inductance coil .

It also includes a substrate, wherein the first plane magnetic column, the second plane magnetic column, the third plane magnetic column and the fourth plane magnetic column are all located on the substrate.

The first planar inductor coil is located between the second planar inductor coil and the substrate.

The present invention has the following beneficial effects:

During the specific operation of the magnetic integrated system of the GaN-based DC-DC converter according to the present invention, the first plane magnetic column, the second plane magnetic column, the third plane magnetic column and the fourth plane magnetic column are located in four squares in sequence. At the corner position, the middle of the first planar inductance coil passes between the first planar magnetic column and the fourth planar magnetic column and between the second planar magnetic column and the third planar magnetic column, and the second planar magnetic column is located at the first planar magnetic column. At the opening position on one side of a planar inductor coil, the fourth planar magnetic column is located at the opening position on the other side of the second planar inductor coil, and the middle of the second planar inductor coil passes through the first planar magnet column and the second planar magnet column between the third plane magnetic column and the fourth plane magnetic column, and the third plane magnetic column is located at the opening position on one side of the second plane inductance coil, and the first plane magnetic column is located on the other side of the second plane inductance coil. At the opening position of the inductance, according to the inductance magnetic flux distribution, the magnetic flux directions of the first plane inductance coil and the second plane inductance coil are in an orthogonal relationship to achieve decoupling, thereby increasing the power density of the converter and expanding its application range. , to avoid the increase of the magnetic loss of the iron core, and the present invention is more suitable for the converter from 48V to 1.xV, which is beneficial to reduce the number of components of the converter, increase the power density, and reduce the volume. It saves manpower and material resources and is more conducive to mass production.

Description of drawings

Figure 1 is a topology diagram of a 48V-1.xV VRMs converter;

Fig. 2 is the structural representation of the present invention;

Fig. 3a is a distribution diagram of the first planar inductor coil L1;

FIG. 3b is a distribution diagram of the second planar inductance coil L2;

Fig. 4a is a magnetic flux distribution diagram of the first planar inductor coil L1;

Fig. 4b is a magnetic flux distribution diagram of the second planar inductor coil L2;

5a is a decoupling reluctance model diagram of the first planar inductor coil L1;

Fig. 5b is a decoupling reluctance model diagram of the second planar inductor coil L2;

Fig. 6 is the coupling coefficient simulation result diagram of the present invention;

Figure 7 is the LGA package diagram of the EPC2020.

Wherein, 1 is the first planar magnetic column, 2 is the second planar magnetic column, 3 is the third planar magnetic column, and 4 is the fourth planar magnetic column.

Detailed ways

Below in conjunction with accompanying drawing, the present invention is described in further detail:

Referring to FIG. 2, the magnetic integration system of the GaN-based DC-DC converter according to the present invention includes a first planar magnetic column 1, a second planar magnetic column 2, a third planar magnetic column 3, a fourth planar magnetic column 4, The first plane inductance coil L1 and the second plane inductance coil L2; the first plane magnetic column 1, the second plane magnetic column 2, the third plane magnetic column 3 and the fourth plane magnetic column 4 are located at the four corners of the square in turn , the first planar inductance coil L1 and the second planar inductance coil L2 are all hexagonal structures, and the middle of the first planar inductance coil L1 passes between the first planar magnetic column 1 and the fourth planar magnetic column 4 and the second plane Between the magnetic column 2 and the third plane magnetic column 3, the second plane magnetic column 2 is located at the opening position on one side of the first plane inductance coil L1, and the fourth plane magnetic column 4 is located on the other side of the second plane inductance coil L2 At the opening position of , the middle of the second planar inductance coil L2 passes through between the first planar magnetic column 1 and the second planar magnetic column 2 and between the third planar magnetic column 3 and the fourth planar magnetic column 4, and the third The planar magnetic column 3 is located at the opening position on one side of the second planar inductor coil L2, and the first planar magnetic column 1 is located at the opening position on the other side of the second planar inductor coil L2.

The present invention also includes a substrate, wherein the first planar magnetic column 1, the second planar magnetic column 2, the third planar magnetic column 3 and the fourth planar magnetic column 4 are all located on the substrate, and the first planar inductance coil L1 is located on the between the two planar inductor coils L2 and the substrate.

Referring to FIG. 3, the first plane magnetic column 1 is located at the coordinate origin of the three-dimensional rectangular coordinate system, the second plane magnetic column 2 is located at the positive half-axis of the X-axis, and the fourth plane magnetic column 4 is located at the positive half-axis of the Y-axis. The first plane magnetic column 1 is at the same appropriate fixed distance, the third plane magnetic column 3 is located in the first quadrant of the XY plane, and the winding methods of the first plane inductance coil L1 and the second plane inductance coil L2 are shown in Figure 2 , Figure 3a and Figure 3b.

4a and 4b, according to the inductance magnetic flux distribution, it can be known that the magnetic flux directions of the first planar inductor coil L1 and the second planar inductor coil L2 are in an orthogonal relationship, so that decoupling can be achieved.

The present invention models the equivalent inductances of the first planar inductance coil L1 and the second planar inductance coil L2 respectively, and the modeling results are shown in FIG. 5 a and FIG. 5 b .

Referring to Fig. 6, the finite element simulation results of the above magnetic decoupling structure are carried out. It should be noted that the magnetic vectors of the first planar inductance coil L1 and the second planar inductance coil L2 are orthogonal, and the coupling coefficient is 0.0128, which proves that the decoupling structure is effective. correctness and validity.

A 60W 48V-1.xV, GaN-based device prototype operating at 1MHz switching frequency will be built and tested to further validate the proposed magnetic structure, the GaN device uses EPC2020 as the power switch, refer to Figure 7, Feather Magnetics Oxygen 3F4 will be used as the material for the proposed magnetic structure.

Finally, it should be noted that the present invention can be applied to the integration of two inductors of the LCL filter, the integration of polyphase bucks, and the magnetic integration of any two discrete inductors, which can greatly increase the power density of the converter.

Claims (3)

1. A magnetic integrated system of a GaN-based DC-DC converter, characterized in that it comprises a first planar magnetic column (1), a second planar magnetic column (2), a third planar magnetic column (3), a Four-plane magnetic column (4), a first plane inductance coil (L1) and a second plane inductance coil (L2); The first plane magnetic column (1), the second plane magnetic column (2), the third plane magnetic column (3) and the fourth plane magnetic column (4) are located at the four corners of the square in sequence, and the first plane inductance coil (L1) and the second planar inductance coil (L2) are both hex-shaped structures, and the middle of the first planar inductance coil (L1) passes between the first planar magnetic column (1) and the fourth planar magnetic column (4) and between the second plane magnetic column (2) and the third plane magnetic column (3), and the second plane magnetic column (2) is located at the opening position on the side of the first plane inductance coil (L1), and the fourth plane magnetic column (3) The column (4) is located at the opening position on the other side of the second plane inductance coil (L2), and the middle of the second plane inductance coil (L2) passes through the first plane magnetic column (1) and the second plane magnetic column (2) between the third plane magnetic column (3) and the fourth plane magnetic column (4), and the third plane magnetic column (3) is located at the opening position on the side of the second plane inductance coil (L2), the first The plane magnetic column (1) is located at the opening position on the other side of the second plane inductance coil (L2). 2. The magnetic integrated system of the GaN-based DC-DC converter according to claim 1, further comprising a substrate, wherein the first planar magnetic column (1) and the second planar magnetic column (2) , the third plane magnetic column (3) and the fourth plane magnetic column (4) are all located on the substrate. 3. The magnetic integrated system of the GaN-based DC-DC converter according to claim 2, characterized in that the first planar inductor coil (L1) is located between the second planar inductor coil (L2) and the substrate.

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