Power conversion device

Abstract

The invention provides further optimization for the circuit topology and layout of the six-switch flying capacitor step-down conversion circuit applied to the intermediate bus converter. An aspect provides a layout of the transformer and the inductor such that parasitic resistance of windings within the magnetic core assembly is minimized. And on the other hand, an auxiliary switch and an auxiliary winding are additionally arranged on the six-switch flying capacitor step-down conversion circuit and are used for providing enough energy for the output end when the input voltage is four times lower than the output voltage. And on the other hand, a switch layout is provided, so that parasitic parameters and power loss of a transformer winding alternating current loop and parasitic parameters and power loss on a switch bridge arm path are reduced. And on the other hand, a flying capacitor layout is provided, so that the loop area of the input capacitor and the switch bridge arm is reduced, the loop area defined by the input capacitor, the corresponding upper switch, the flying capacitor and the corresponding lower switch is reduced, parasitic parameters on the loop are reduced, and the power loss of the power conversion device is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of high-frequency power supply, and in particular relates to a power conversion device. Background Art

[0002] With the development of artificial intelligence, the power requirements of intelligent data processing chips, such as GPU / CPU / NPU, etc. (collectively referred to as xPU) are getting higher and higher, which has greatly increased the power of servers, and the input voltage of servers has gradually changed from 12V to 48V. The operating voltage of xPU is getting lower and lower with the advancement of technology, gradually moving from 0.8V to 0.65V. Therefore, the gain ratio of output voltage to input voltage is getting lower and lower, making the two-stage buck circuit architecture gradually become the mainstream; and in order to obtain high 48V input to 0.65V output conversion efficiency, the intermediate bus voltage moves from 12V to 6.75V or even 3.3V.

[0003] The present invention provides a solution for a power conversion device with a 48V input and a 12V to 3.3V regulated output. By adding an auxiliary winding and an auxiliary switch, sufficient energy is provided to the output end when the input voltage Vin is lower than 4 times the output voltage Vo; and by improving the layout of the transformer, inductor and other power devices, the parasitic parameters of the power conversion device are further reduced. Summary of the invention

[0004] In view of this, one of the objects of the present invention is to provide a power conversion device, which provides sufficient energy to the output end by adding auxiliary windings and auxiliary switches when the input voltage Vin is lower than 4 times the output voltage Vo; and reduces the parasitic parameters on the power transmission path and improves the conversion efficiency of the power conversion device by optimizing the layout of key components such as transformers and inductors.

[0005] In one aspect, the present invention provides a power conversion device, including a circuit substrate, an upper switch, a middle switch, a lower switch, a first flying capacitor, an input capacitor, an output capacitor, and a transformer;

[0006] The circuit substrate comprises a first surface and a second surface opposite to each other, two transformer side column holes, a transformer middle column hole, a lower switch area, a first flying capacitor area, a first upper middle switch area and an output area;

[0007] The lower switch area, the first flying capacitor area, the first upper middle switch area and the output area are arranged on the first surface of the circuit substrate;

[0008] The two transformer side column holes and the transformer center column hole penetrate the first surface and the second surface, and are respectively used for the transformer side column and the transformer center column to pass through; between each transformer side column hole and the transformer center column hole is a transformer winding area, the transformer winding area is used for the transformer winding to pass through, and the transformer winding area includes a first side and a second side opposite to each other;

[0009] The lower switch region is disposed adjacent to a first side of the transformer winding region, the output region is disposed adjacent to a second side of the transformer winding region, the lower switch is disposed in the lower switch region, and the output capacitor is disposed in the output region;

[0010] The first flying capacitor is arranged in the first flying capacitor area, and the lower switch area is arranged between the first flying capacitor area and the transformer winding area;

[0011] The upper switch and the middle switch are arranged in the first upper-middle switch area, and the first upper-middle switch area is arranged adjacent to the first flying capacitor area and the lower switch area.

[0012] Preferably, the first surface further includes an input region, and the input capacitor is arranged in the input region; and the first flying capacitor region is arranged between the input region and the lower switch region.

[0013] Preferably, the first surface further includes a second upper-middle switch area, the power conversion device further includes a second upper switch and a second middle switch, and the second upper switch and the second middle switch are arranged in the second upper-middle switch area.

[0014] Preferably, the first surface also includes a second flying capacitor area, a third flying capacitor area and a fourth flying capacitor area; the power conversion device also includes a second flying capacitor, a third flying capacitor and a fourth flying capacitor, and they are respectively arranged in the second flying capacitor area, the third flying capacitor area and the fourth flying capacitor area in sequence; the second flying capacitor area is arranged between the lower switch area and the input area, and the third flying capacitor area and the fourth flying capacitor area are respectively arranged on the outside of the first upper-middle switch area and the second upper-middle switch area.

[0015] Preferably, the second surface includes a fifth flying capacitor area, a lower switch area, an input area and an output area; the power conversion device also includes a fifth flying capacitor, another lower switch, an input positive terminal, an output positive terminal and an output negative terminal; the input positive terminal is arranged in the input area, the output positive terminal and the output negative terminal are arranged in the output area, the other lower switch is arranged in the lower switch area, and the fifth flying capacitor is arranged in the fifth flying capacitor area; the lower switch area is arranged adjacent to one side of the transformer winding area, and the output area is arranged adjacent to the other side of the transformer winding area; the fifth flying capacitor area is arranged between the input area and the lower switch area.

[0016] Preferably, the projection of the lower switch area set on the second surface on the first surface at least partially overlaps with the lower switch area set on the first surface; the projection of the input area set on the second surface on the first surface at least partially overlaps with the input area set on the first surface; the projection of the output area set on the second surface on the first surface at least partially overlaps with the output area set on the first surface.

[0017] Preferably, it further comprises a heat sink block and a grounding metal block, wherein the heat sink block is welded to the first surface; the grounding metal block is welded to the second surface and is electrically connected to the output negative terminal.

[0018] Another aspect of the present invention provides a power conversion device, comprising an input positive terminal, an input negative terminal, an output positive terminal and an output negative terminal, wherein the input negative terminal and the output negative terminal are electrically connected;

[0019] The power conversion device also includes a first bridge arm, a second bridge arm, two flying capacitors, an output capacitor, two transformer windings, an output inductor, an auxiliary switch and an auxiliary winding; the first bridge arm and the second bridge arm are electrically connected in parallel between the input positive terminal and the input negative terminal, the first bridge arm and the second bridge arm both include an upper switch, a middle switch and a lower switch, the upper switch and the middle switch are electrically connected to the upper node, and the middle switch and the lower switch are electrically connected to the lower node; one end of each flying capacitor is electrically connected to the upper node of one bridge arm, and the other end is electrically connected to the lower node of another bridge arm; the second end of the transformer winding is electrically connected to one end of the output inductor, the first end of the transformer winding is electrically connected to one of the lower nodes respectively, and the other end of the output inductor is electrically connected to the output positive terminal; the output capacitor is connected across the output positive terminal and the output negative terminal;

[0020] One end of the auxiliary winding is electrically connected to the input positive terminal, and the other end is electrically connected to the drain of the auxiliary switch. The source of the auxiliary switch is electrically connected to the output positive terminal.

[0021] Preferably, it also includes a first control signal, a second control signal, a third control signal, a fourth control signal and a fifth control signal, and the switching cycles of the first control signal, the second control signal, the third control signal, the fourth control signal and the fifth control signal are the same; the first control signal is used to control the opening and closing of the upper switch of the first bridge arm and the middle switch of the second bridge arm, and the second control signal is used to control the opening and closing of the middle switch of the first bridge arm and the upper switch of the second bridge arm; the third control signal is used to control the opening and closing of the lower switch of the first bridge arm, and the fourth control signal is used to control the opening and closing of the lower switch of the second bridge arm; the fifth control signal is used to control the opening and closing of the auxiliary switch.

[0022] Preferably, when the input voltage of the power conversion device is less than four times the output voltage, the duty cycles of the first control signal and the second control signal are equal and both are less than or equal to 0.5, and the first control signal and the second control signal are 180 degrees out of phase; the third control signal is the same as the second control signal, and the fourth control signal is the same as the first control signal; the switching cycle includes two half-cycles, within one half-cycle, the fifth control signal is complementary to the first control signal, and within the other half-cycle of the same switching cycle, the fifth control signal is complementary to the second control signal.

[0023] Preferably, when the input voltage of the power conversion device is greater than or equal to four times the output voltage, the duty cycles of the first control signal and the second control signal are equal and both are less than or equal to 0.5, and the first control signal and the second control signal are 180 degrees out of phase; the third control signal is complementary to the first control signal, and the fourth control signal is complementary to the second control signal; the fifth control signal is at a low level, and the auxiliary switch is in an off state.

[0024] Another aspect of the present invention provides a power conversion device, comprising: a circuit substrate, an input end, an output end, a switch element, a magnetic component and a grounded metal block; the input end comprises an input positive end and an input negative end, the output end comprises an output positive end and an output negative end; the magnetic component comprises a winding and a magnetic core, the winding is arranged in the circuit substrate; the magnetic component is bridged between the input end and the output end through the switch element, and the magnetic component is arranged between the input end and the output end;

[0025] The grounding metal block is arranged on the surface of the circuit substrate and is used to short-circuit the input negative terminal and the output negative terminal;

[0026] The grounding metal block is arranged adjacent to one side of the magnetic component.

[0027] Preferably, it further comprises a heat dissipation block, wherein the heat dissipation block is welded to the first surface; and the grounding metal block is welded to the second surface.

[0028] Preferably, the height of the heat dissipation block is equal to the height of the switch element.

[0029] Preferably, the grounding metal block is connected in parallel with a grounding wire in the circuit substrate.

[0030] Preferably, the magnetic component includes a first side and a second side opposite to each other, the input end is arranged adjacent to the first side, the output end is arranged adjacent to the second side, and the grounding metal block extends from the first side to the second side along the other side of the magnetic component.

[0031] The beneficial effects of the present invention are:

[0032] (1) The present invention can reduce the loop area formed by the input capacitor and the switch bridge arm by setting the layout of the power conversion device, and further reduce the loop area formed by the input capacitor, the upper switch, the flying capacitor and the lower switch, thereby reducing the inductance of the parasitic inductance and the resistance of the parasitic resistance in each loop, effectively reducing the voltage peak value at both ends of the switch and the power loss of the power conversion device;

[0033] (2) By adding auxiliary circuits and adopting different control timings, the present invention can satisfy the requirement that when the input voltage is greater than or equal to 4 times the output voltage, the auxiliary circuit does not affect the operation of the six-switch flying capacitor step-down converter circuit; and when the input voltage is less than 4 times the output voltage, only by changing the control timing, the input voltage can provide energy to the output end through the auxiliary circuit within the working range of the auxiliary switch, and the circuit structure is simple and easy to implement.

[0034] (3) The present invention realizes the drive control of six switches by adopting three independently packaged drivers and simple peripheral circuits, thereby reducing the area of ​​the drive circuit on the circuit substrate in the power conversion device. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 is a schematic diagram of a six-switch power conversion circuit;

[0037] Figure 2 It is a three-dimensional exploded diagram of a power conversion device;

[0038] Figure 3a It is a schematic diagram of the top layout of the power conversion device;

[0039] Figure 3b It is a schematic diagram of the bottom layout of the power conversion device.

[0040] Figures 4a to 4c is a schematic diagram of an extended embodiment of a layout;

[0041] Figure 5 Schematic diagram of a six-switch power conversion circuit with additional auxiliary switches and auxiliary windings

[0042] Figure 6a This is a control timing diagram when Vin≥4*Vo;

[0043] Figure 6bThis is the control timing diagram when Vin<4*Vo;

[0044] Figure 7 This is the control timing diagram when D>0.5;

[0045] Figure 8 Another control timing diagram when D>0.5;

[0046] Fig. 9 is a circuit diagram of another embodiment;

[0047] Fig.10 A schematic diagram of the driving power supply circuit;

[0048] in:

[0049] 1a / 1b / 1c / 2a power conversion circuit; 10 circuit substrate; 10a first switch bridge arm; 10b second switch bridge arm; 20 transformer core; 21 / 22 transformer side column; 23 transformer center column; 24 / 25 transformer winding channel; 30 output inductor core; 31 / 32 output inductor side column; 33 output inductor winding channel; 101 first surface; 102 second surface; 121 / 122 transformer side column hole; 123 transformer center column hole; 124 / 125 transformer winding area; 131 output inductor side column hole; 132 output inductor side column slot; 133 output inductor winding area; 140 first Flying capacitor area; 141 second flying capacitor area; 142 third flying capacitor area; 143 fourth flying capacitor area; 151 lower switch area; 152 first upper middle switch area; 153 second upper middle switch area; 161 input area; 162 output area; 171 heat sink; 200 transformer magnetic substrate 201 first transformer side; 202 second transformer side; 240 fifth flying capacitor area; 241 sixth flying capacitor area; 251 lower switch area; 261 input area; 262 output area; 271 grounding metal block; 281 / 282 input positive end; 283 input negative end; 184 / 284 output negative end; 185 / 28 5 output positive end; 300 output inductor magnetic substrate; 301 first output inductor side; 302 second output inductor side; A1 / A2 upper node; B1 / B2 lower node; Cd1 / Cd2 / Cd3 / Cd4 drive capacitor; Cin input capacitor; Co output capacitor; C1 / C2 flying capacitor; Dd1 / Dd2 / Dd3 / Dd4 drive diode; Dr1 / Dr2 / Dr3 driver; E1 / E2 / F1 / F2 connection point; L1 middle column line; Lin input inductor; LW1 output inductor winding; LW2 auxiliary winding; PWM1 first control signal; PWM2 second control signal; PWM3 first Three control signals; PWM4 fourth control signal; PWM5 fifth control signal; Q1 / Q3 upper switch; Q2 / Q4 middle switch; QSX auxiliary switch; SR1 / SR2 lower switch; TL1 winding short point; TW11 / TW12 high voltage winding; TW21 / TW22 transformer winding; Vin+ input positive terminal; Vin- input negative terminal; Vo+ output positive terminal; Vo- output negative terminal; HB / HS pin; HS1 / HS2 floating pin; HB1 / HB2 floating power supply pin; HO1 / HO2 drive pin; Hl1 / Hl2 input signal pin; GND ground pin; VDD power supply pin. DETAILED DESCRIPTION

[0050] One of the core aspects of the present invention is to provide a power conversion device, which reduces parasitic parameters on the power transmission path and improves the conversion efficiency of the power conversion device by optimizing the layout of key components such as transformers and inductors; another core aspect of the present invention is to provide an auxiliary circuit, when the input voltage is less than four times the output voltage, the input voltage can directly power the output end through the auxiliary circuit.

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] Figure 1 The six-switch flying capacitor step-down power conversion circuit shown can be applied to the intermediate bus power conversion device with 54V or 48V input and 12V regulated output. It includes an input positive terminal, an input negative terminal, an output positive terminal, an output negative terminal, two three-switch bridge arms, two flying capacitors, two transformer windings, an output inductor, and input and output capacitors. Figure 1In the power conversion circuit 1a shown, the input negative terminal Vin- and the output negative terminal Vo- are short-circuited; the two three-switch bridge arms are respectively the first switch bridge arm 10a and the second switch bridge arm 10b, wherein the first switch bridge arm 10a includes an upper switch Q1, a middle switch Q2 and a lower switch SR1, the upper switch Q1 and the middle switch Q2 are electrically connected to the upper node A1, the middle switch Q2 and the lower switch SR1 are electrically connected to the lower node B1, the drain of the upper switch Q1 is electrically connected to the input positive terminal Vin+, and the source of the lower switch SR1 is electrically connected to the input negative terminal Vin-; the second switch bridge arm 10b includes an upper switch Q3, a middle switch Q4 and a lower switch SR2, the upper switch Q3 and the middle switch Q4 are electrically connected to the upper node A2, the middle switch Q4 and the lower switch SR2 are electrically connected to the lower node B2, the drain of the upper switch Q3 is electrically connected to the input positive terminal Vin+, and the source of the lower switch SR2 is electrically connected to the input negative terminal Vin-; the input capacitor Cin is connected between the input positive terminal Vin+ and the input negative terminal Vin-, and the output capacitor Co is connected between the output positive terminal Vo+ and the output negative terminal Vo+; the flying capacitor C1 is connected between the upper node A1 of the first switch bridge arm 10a and the lower node B2 of the second switch bridge arm 10b, and the flying capacitor C2 is connected between the upper node A2 of the second switch bridge arm 10b and the lower node B1 of the first switch bridge arm 10a; the first end of the transformer winding TW21 is electrically connected to the lower node B1, the first end of the transformer winding TW22 is electrically connected to the lower node B2, the second end of the transformer winding TW21 and the second end of the transformer winding TW22 are electrically connected to the winding short-circuit point TL1, the transformer winding TW21 and the transformer winding TW22 are coupled on a magnetic core, and the first end of the transformer winding TW21 and the second end of the transformer winding TW22 are the same-name terminals (that is, the same polarity), marked as point terminals. The coupling coefficient of the transformer winding TW21 and the transformer winding TW22 is close to that of an ideal transformer (i.e., the coupling coefficient is close to 1), and the output inductor winding LW1 is connected between the winding short-circuit point TL1 and the output positive terminal Vo+; the end of the output inductor winding LW1 and the winding short-circuit point TL1 short-circuited is the input end of the output inductor winding LW1; the end of the output inductor winding LW1 and the output positive terminal Vo+ short-circuited is the output end of the output inductor winding LW1. The output capacitor Co is connected between the output positive terminal Vo+ and the output negative terminal Vo-.

[0053] The three-dimensional exploded view of the power conversion device disclosed in the present invention is as follows Figure 2As shown, it includes a circuit substrate 10, a transformer core 20 and an output inductor core 30, and the circuit substrate 10 includes a first surface 101 and a second surface 102 opposite to each other. The transformer core 20 includes two transformer magnetic substrates 200, transformer side columns 21 and 22 and a transformer center column 23, wherein the transformer side columns 21 and 22 and the transformer center column 23 are arranged between the two transformer magnetic substrates 200; the transformer center column 23 is arranged between the transformer side columns 21 and 22; a transformer winding channel 24 is formed between the transformer center column 23 and the transformer side column 21, and a transformer winding channel 25 is formed between the transformer center column 23 and the transformer side column 22 for the transformer winding to pass through. The output inductor core 30 includes two output inductor magnetic substrates 300, output inductor side columns 31 and 32, wherein the output inductor side columns 31 and 32 are arranged between the two output inductor magnetic substrates 300; an output inductor winding channel 33 is formed between the output inductor side columns 31 and 32 for the output inductor winding to pass through.

[0054] The circuit substrate 10 includes transformer side column holes 121 and 122 and a transformer center column hole 123. The transformer side column holes 121 and 122 and the transformer center column hole 123 penetrate the first surface 101 and the second surface 102. The transformer side column holes 121 and 122 are respectively used for the transformer side columns 21 and 22 to pass through, and the transformer center column hole 123 is used for the transformer center column 23 to pass through. The circuit substrate 20 also includes an output inductor hole 131 and an output inductor slot 132. The output inductor hole 131 and the output inductor slot 132 penetrate the first surface 101 and the second surface 102. The output inductor hole 131 is used for the output inductor side column 31 to pass through, and the output inductor slot 132 is used for the output inductor side column 32 to pass through. The output inductor slot 132 here can also be an output inductor hole, and the hole can also be designed as a slot according to actual needs, but is not limited thereto. On the circuit substrate 10, the transformer side column hole 121 and the transformer center column hole 123 are the transformer winding area 124, and the area between the transformer side column hole 122 and the transformer center column hole 123 is the transformer winding area 125, and the transformer winding areas 124 and 125 are for the transformer winding to pass through; the transformer center column and the side column pass through the corresponding holes respectively, so that the transformer magnetic substrate is buckled with the circuit substrate 10 from the first surface 101 and the second surface 102 respectively, and coupled with the transformer winding to form the required transformer; the transformer core 20 also includes a first transformer side 201 and a second transformer side 202 opposite to each other, wherein the transformer winding channels 24 and 25 pass through the first transformer side 201 and the second transformer side 202. The output inductor winding area 133 is located between the output inductor hole 131 and the output inductor slot 132. The output inductor winding area 133 is for the output inductor winding to pass through. The output inductor side columns pass through the corresponding holes and slots respectively, so that the output inductor magnetic substrate is buckled with the circuit substrate 20 from the first surface 101 and the second surface 102 respectively, and is coupled with the output inductor winding to form an output inductor; the output inductor magnetic core 30 also includes a first output inductor side edge 301 and a second output inductor side edge 302 opposite to each other, wherein the output inductor winding channel 33 passes through the first output inductor side edge 301 and the second output inductor side edge 302.

[0055] Figure 3aThe top surface layout schematic diagram of the power conversion device 1a is disclosed, and the first surface 101 of the circuit substrate 10 includes a first flying capacitor area 140, a second flying capacitor area 141, a lower switch area 151, a first upper middle switch area 152, a second upper middle switch area 153, an input capacitor area 161 and an output area 162; the lower switch area 151 is used to set the lower switches SR1 and SR2; the lower switches SR1 and SR2 are placed side by side along the y-axis direction, and the lower switch area 151 is arranged adjacent to the first transformer side 201, the lower switch SR1 is arranged adjacent to the transformer winding area 125, and the lower switch SR2 is arranged adjacent to the transformer winding area 124, so that the drains of the lower switches SR1 and SR2 can be electrically connected to the first end of the transformer winding TW21 and the first end of TW22 respectively by the shortest path. The above layout can minimize the AC loop formed by the transformer winding and the lower switch, reduce the parasitic resistance and parasitic leakage inductance of the AC loop, and effectively reduce the voltage spike value at both ends of the switch and the power loss of the power conversion device.

[0056] The first flying capacitor area 140 is used to set the flying capacitor C1, and the second flying capacitor area 141 is used to set the flying capacitor C2; the first flying capacitor area 140 and the second flying capacitor area 141 are arranged side by side, and the first flying capacitor area 140 is arranged adjacent to the lower switch SR1, and the second flying capacitor area 141 is arranged adjacent to the lower switch SR2; there is a center column line L1 on the first surface 101 of the circuit substrate 10, and the center column line L1 passes through the transformer center column hole 123 along the x-axis direction shown in the figure, and the lower switches SR1 and SR2 are respectively arranged on both sides of the center column line L1, and the first flying capacitor area 140 and the second flying capacitor area 141 are also respectively arranged on both sides of the center column line L1. The first upper middle switch region 152 is used to set the upper switch Q1 and the middle switch Q2, and the second upper middle switch region 153 is used to set the upper switch Q3 and the middle switch Q4; the first upper middle switch region 152 is arranged adjacent to the first flying capacitor region 140, and the middle switch Q2 is arranged adjacent to the lower switch SR1; in this layout, the source of the upper switch Q1 is arranged adjacent to the drain of the middle switch Q2, the source of the middle switch Q2 is arranged adjacent to the drain of the lower switch SR1, and one end of the flying capacitor C1 is arranged adjacent to the source of the upper switch Q1 and the drain of the middle switch Q2; similarly, the second upper middle switch region 153 is arranged adjacent to the second flying capacitor region 141, and the middle switch Q4 is arranged adjacent to the lower switch SR2; the source of the upper switch Q3 is arranged adjacent to the drain of the middle switch Q4, the source of the middle switch Q4 is arranged adjacent to the drain of the lower switch SR2, and one end of the flying capacitor C2 is arranged adjacent to the source of the upper switch Q3 and the drain of the middle switch Q4. The first upper middle switch area 152 and the second upper middle switch area 153 are respectively placed on both sides of the middle column line L1; the input capacitor area 161 is arranged adjacent to the first flying capacitor area 140, the second flying capacitor area 141, the first upper middle switch area 152 and the second upper middle switch area 153. With this layout, the loop area formed by the input capacitor Cin and the first switch bridge arm 10a can be reduced, and the loop area formed by the input capacitor Cin and the second switch bridge arm 10b can be reduced; the loop area formed by the input capacitor Cin, the upper switch Q1, the flying capacitor C1 and the lower switch SR2 can be further reduced; and the loop area formed by the input capacitor Cin, the upper switch Q3, the flying capacitor C2 and the lower switch SR1 can be further reduced; thereby reducing the inductance of the parasitic inductance and the resistance of the parasitic resistance in each loop, and effectively reducing the voltage spike value at both ends of the switch and the power loss of the power conversion device.

[0057] The first surface 101 of the circuit substrate 10 also includes an output area 162, and the output area 162 is used to set the output capacitor Co, the output positive end 185 and the output negative end 184. The transformer core 20 and the output inductor core 30 are placed side by side along the y-axis direction to form a magnetic assembly; the first transformer side 201 and the first output inductor side 301 are located on the same side of the magnetic assembly, that is, the first side of the magnetic assembly; the second transformer side 202 and the second output inductor side 302 are located on the same side of the magnetic assembly, that is, the second side of the magnetic assembly; the first side of the magnetic assembly is opposite to the second side. The first side of the magnetic assembly is adjacent to the lower switch area 151, so that the lower switch area 151 is adjacent to the first transformer side 201. The second side of the magnetic assembly is adjacent to the output area 162, so that the output positive end 185 is adjacent to the second output inductor side 302. The detailed winding method of the transformer winding and the inductor winding (not shown) is as follows: the first end of the transformer winding TW21, the first end of the transformer winding TW22 and the winding short-circuit point TL1 are arranged adjacent to the first transformer side 201. The transformer winding starts from the first end of the transformer winding TW21, passes through the transformer winding area 125 to the second transformer side 202, and then passes through the transformer winding area 124 to the winding short-circuit point TL1 adjacent to the first transformer side 201; then continues to pass through the winding area 125 to the second transformer side 202, and then passes through the transformer winding area 124 to the first end of the transformer winding TW22 arranged on the first transformer side 201. The input end of the output inductor winding LW1 is adjacent to the first output inductor side 301, and the output end of the output inductor winding LW1 is adjacent to the second output inductor side 302. The output inductor winding LW1 starts from the input end, passes through the output inductor winding area 133 and reaches the second output inductor side 302, forming the output end of the output inductor winding LW1, and short-circuiting with the output positive end 185. In the layout method of the transformer core 20 and the output inductor 30, the first end of the transformer winding TW21, the first end of the transformer winding TW22, the winding short-circuit point TL1 and the input end of the output inductor winding LW1 are all arranged on the first side of the magnetic component, so that the winding short-circuit point TL1 and the input end of the output inductor winding LW1 can be short-circuited at the shortest distance; at the same time, the output end of the output inductor winding LW1 is arranged on the second side of the magnetic component, and short-circuited with the output positive end 185 at the shortest distance; the parasitic resistance of the winding of the magnetic core component is effectively reduced.

[0058] The first surface 101 of the circuit substrate 10 further includes a third flying capacitor area 142 and a fourth flying capacitor area 143, which are respectively arranged on both sides of the middle column line L1. The third flying capacitor area 142 is used to set the flying capacitor C1, and the third flying capacitor 142 and the first upper middle switch area 152 are located on the same side of the middle column line L1, so that the first upper middle switch area 152 is arranged between the first flying capacitor area 140 and the third flying capacitor area 142; the fourth flying capacitor area 143 is used to set the flying capacitor C2, and the fourth flying capacitor area 143 and the second upper middle switch area 153 are located on the same side of the extension line L1, so that the second upper middle switch area 153 is arranged between the second flying capacitor area 141 and the fourth flying capacitor area 143. The first surface 101 of the circuit substrate 10 also includes at least one heat sink 171, which is welded on the first surface 101 and is adjacent to the heat generating components (such as the upper switch Q1 / Q3, the middle switch Q2 / Q4 and the lower switch SR1 / SR2); the height of the heat sink 171 is close to the height of the heat generating components, and the soldering pads of the heat sink 171 are electrically connected to the heat dissipation pads of the heat generating components, so that the thermal resistance between the two is small and the temperature difference is low, so as to more effectively allow part of the loss of the heat generating components to pass through the heat sink 171 and reach the temperature equalizing plate or radiator on the top of the heat sink 171.

[0059] Figure 3bThe bottom layout diagram of the power conversion device 1a is disclosed, and the second surface 102 of the circuit substrate 10 includes a lower switch area 251, a fifth flying capacitor area 240, a sixth flying capacitor area 241, an input area 261, a first input capacitor area 263, a second input capacitor area 264 and an output area 262. The lower switch area 251 is arranged adjacent to the first transformer side 201 and is used to arrange the lower switches SR1 and SR2; the lower switches SR1 and SR2 are arranged side by side along the y-axis direction. The lower switch SR1 is disposed adjacent to the transformer winding region 125, and the lower switch SR2 is disposed adjacent to the transformer winding region 124, so that the drains of the lower switches SR1 and SR2 are electrically connected to the first end of the transformer winding TW21 and the first end of TW22 respectively through the shortest path; the fifth flying capacitor region 240 is used to set the flying capacitor C1, and the fifth flying capacitor region 240 is disposed adjacent to the lower switch SR1; the sixth flying capacitor region 241 is used to set the flying capacitor C2, and the sixth flying capacitor region 241 is disposed adjacent to the lower switch SR2; the input region 261 is used to set the input capacitor Cin, the input positive end 281 / 282 and the input negative end 283, and the input inductor 286 is disposed adjacent to the input positive end 281 or 282. The first input capacitor region 263 is disposed adjacent to the sixth flying capacitor region 241 and the input region 261, and the second input capacitor region 264 is disposed adjacent to the fifth flying capacitor region 240 and the input region 261. The output region 262 is provided with an output capacitor Co, an output positive end 285 and an output negative end 284, and the output region 262 is provided adjacent to the second transformer side 202 and the second output inductor side 302, so that the output capacitor Co and the output positive end 285 are provided adjacent to one end of the inductor winding, thereby reducing parasitic parameters on the power transmission path and reducing power loss.

[0060] The second surface 102 of the circuit substrate 10 also includes a grounding metal block 271 , which is welded on the second surface 102 and connected in parallel with the corresponding traces on the inner layer of the circuit substrate 10 to reduce the short-circuit resistance between the input negative end 283 and the output negative end 284 .

[0061] Also refer to Figure 3a and Figure 3b, the lower switch SR1 disposed on the first surface 101 is electrically connected in parallel with the lower switch SR1 disposed on the second surface 102, and the projection of the lower switch SR1 disposed on the first surface 101 on the first surface 101 and the projection of the lower switch SR1 disposed on the second surface 102 on the first surface at least partially overlap; the lower switch SR2 disposed on the first surface 101 is electrically connected in parallel with the lower switch SR2 disposed on the second surface 102, and the projection of the lower switch SR2 disposed on the first surface 101 on the first surface 101 and the projection of the lower switch SR2 disposed on the second surface 102 on the first surface at least partially overlap. The projection of the fifth flying capacitor region 240 on the first surface 101 at least partially overlaps with the first flying capacitor region 140; the projection of the sixth flying capacitor region 241 on the first surface 101 at least partially overlaps with the second flying capacitor region 141. The projection of the input region 261 on the first surface 101 at least partially overlaps with the input region 161. The projection of the output area 262 on the first surface 101 at least partially overlaps with the output area 162 .

[0062] The layout shown in the above embodiment is also applicable to Figure 4a The six-switch flying capacitor buck circuit shown in Figure 4a The circuit shown in Figure 1 The circuit shown is different in that it has high voltage windings TW11 and TW12. Figure 1 The circuit shown is the same and can also be used Figure 3a and Figure 3b The layout method shown, especially the layout method of the transformer and the output inductor, can also obtain the benefits brought by the layout of the aforementioned embodiment, which will not be described in detail here. Figure 3a and Figure 3b The layout method shown also applies to Figure 4b and Figure 4c The four-switch flying capacitor buck circuit shown in Figure 4b The circuit shown is Figure 1 The circuit shown differs in that an upper switch, a middle switch, and a flying capacitor are removed; Figure 4b The circuit layout shown can be Figure 3a and Figure 3b Based on the layout shown in the figure, the second upper middle switch area, the second flying capacitor area, the fourth flying capacitor area and the sixth flying capacitor area can be removed, and the rest can be adopted. Figure 3a and Figure 3b The layout shown; Figure 4c The circuit shown is Figure 4b The circuit shown is different in that a high voltage winding TW11 is added. The layout can also be Figure 4b The layout of the circuit shown can also obtain the advantages brought by the layout of the aforementioned embodiment, which will not be described in detail here.

[0063] In order to solve the problem that the input voltage of the power conversion device has a large variation range and the input voltage is lower than four times the output voltage, the output energy is insufficient, resulting in the output voltage being too low and failing to reach the target setting value, the present invention is Figure 1 Based on the six-switch flying capacitor step-down power conversion circuit shown in the figure, an auxiliary switch QSX and an auxiliary winding LW2 are added, as shown in FIG. Figure 5 As shown. The auxiliary winding LW2 and the inductor winding LW1 are wound on a magnetic core, and one end of the auxiliary winding LW2 is electrically connected to the input positive terminal Vin+, and the other end is electrically connected to the drain of the auxiliary switch QSX, and the source of the auxiliary switch QSX is electrically connected to the output positive terminal Vo+. The end of the auxiliary winding LW2 connected to the input positive terminal Vin+ has the same name as the input end of the inductor winding LW1, marked as *. The power conversion device also includes a first control signal PWM1, a second control signal PWM2, a third control signal PWM3 and a fourth control signal PWM4; when the input voltage Vin is greater than or equal to 4 times the output voltage, as shown Figure 6a As shown, the first control signal PWM1 is used to control the on and off of the upper switch Q1 and the middle switch Q4; the second control signal PWM2 is used to control the on and off of the upper switch Q3 and the middle switch Q2; the duty ratios of the first control signal PWM1 and the second control signal PWM2 are equal and less than or equal to 50%, and the first control signal PWM1 and the second control signal PWM2 are 180 degrees out of phase. The third control signal PWM3 is complementary to the first control signal PWM1 (ignoring the dead time between PWM1 and PWM3), and is used to control the on and off of the lower switch SR2; the fourth control signal PWM4 is complementary to the second control signal PWM2 (ignoring the dead time between PWM4 and PWM2), and is used to control the on and off of the lower switch SR1. The power conversion device also includes a fifth control signal PWM5, which is used to control the on and off of the auxiliary switch QSX. When the input voltage Vin is greater than or equal to 4 times the output voltage, the fifth control signal PWM5 is always at a low level, and the auxiliary switch QSX is in an off state, that is, the auxiliary switch QSX is in a non-operating state. At this time, the gain relationship between the output voltage Vo and the input voltage Vin satisfies Vo=Vin*D / 2; the duty cycle D here is the duty cycle of the first control signal PWM1, and the duty cycle D that appears below is the duty cycle of the first control signal PWM1, which will not be repeated. When the duty cycle D is equal to the maximum value of 0.5, the output voltage Vo reaches the maximum value Vin / 4.

[0064] When the input voltage Vin is less than 4 times the output voltage, the control timing disclosed by the present invention is as follows: Figure 6bAs shown, the first control signal PWM1 is used to control the on and off of the upper switch Q1 and the middle switch Q4; the second control signal PWM2 is used to control the on and off of the upper switch Q3 and the middle switch Q2; the duty cycle of the first control signal PWM1 and the second control signal PWM2 are equal and less than or equal to 50%, and the first control signal PWM1 is 180 degrees out of phase with the second control signal PWM2. The third control signal PWM3 is the same as the second control signal PWM2, and is used to control the on and off of the lower switch SR2; the fourth control signal PWM4 is the same as the first control signal PWM1, and is used to control the on and off of the lower switch SR1. Figure 6b In a switching cycle Ts (such as the interval between time 0 and time t4) shown in the figure, in the first half of the switching cycle, that is, in the interval 0-t2, the fifth control signal PWM5 is complementary to the first control signal PWM1 (ignoring the dead time between PWM5 and PWM1); in the second half of the switching cycle, that is, in the interval t2-t4, the fifth control signal PWM5 is complementary to the second control signal PWM2 (ignoring the dead time between PWM5 and PWM2); the fifth control signal PWM5 is used to control the on and off of the auxiliary switch QSX. In the interval where the fifth control signal PWM5 is at a high level, that is, in the interval t1-t2 and the interval t3-t4, the input voltage Vin directly provides energy to the output end through the auxiliary winding LW2 and the auxiliary switch QSX, which can solve the problem that when the input voltage Vin is lower than 4 times the output voltage, the output energy is insufficient, resulting in the output voltage being too low and failing to reach the target setting value. Specifically, if the number of turns of the inductor winding LW1 is 1, the number of turns of the auxiliary winding LW2 is also 1. At this time, the gain relationship between the output voltage Vo and the input voltage Vin satisfies Vo=(Vin / 2)-(Vin*D / 2). According to the above relationship, when the input voltage Vin decreases, the required output voltage Vo value can be obtained by reducing the duty cycle D of the first control signal PWM1; that is, when the duty cycle D is equal to the maximum value of 0.5, the output voltage Vo reaches the minimum value Vin / 4. The method of adding an auxiliary circuit (auxiliary winding LW2 and auxiliary switch QSX series circuit) disclosed in the present invention can meet the requirements that when the input voltage Vin is greater than or equal to 4 times the output voltage, the auxiliary circuit does not affect the operation of the six-switch flying capacitor buck converter circuit by adopting different control timings; and when the input voltage Vin is less than 4 times the output voltage, only by changing the control timing, the input voltage can provide energy to the output end through the auxiliary circuit within the working range of the auxiliary switch QSX. The circuit structure is simple and easy to implement.

[0065] like Figure 1 The circuit topology 1a shown can solve the problem of output voltage reduction caused by too low input voltage by adjusting the duty cycle D so that the duty cycle D of the power conversion device is greater than 0.5. Figure 7 As shown, the duty ratio of the first control signal PWM1 and the second control signal PWM2 is greater than 0.5, and the first control signal PWM1 and the second control signal PWM2 are 180 degrees out of phase; the third control signal PWM3 is complementary to the first control signal PWM1, and the fourth control signal PWM4 is complementary to the first control signal PWM1. The first control signal PWM1 is used to control the opening and closing of the upper switch Q1, the second control signal PWM2 is used to control the opening and closing of the upper switch Q3, the third control signal PWM3 is used to open and close the middle switch Q2 and the lower switch SR2, and the fourth control signal PWM4 is used to open and close the middle switch Q4 and the lower switch SR1. The above control strategy can make the output voltage value meet the demand when the input voltage decreases; however, at the moment when the upper switch Q1 is disconnected, the flying capacitors C1 and C2 are connected in series, and the voltage sum V_C1+V_C2 across the flying capacitor is greater than the voltage V_Cin across the input capacitor, so that the voltage across the flying capacitor produces a voltage impact on the voltage across the input capacitor, resulting in additional capacitor voltage impact loss; similarly, the same problem exists at the moment when the upper switch Q3 is disconnected.

[0066] In order to solve the problems caused by the above control strategies, the present invention discloses a new control strategy, such as Figure 8 The control strategy shown is similar to Figure 7 The difference of the control strategy shown is that at time t1, when the upper switch Q3 is turned off, the upper switch Q1 is also turned off. At this time, only the middle switch Q4 and the lower switch SR1 are in the on state, and the flying capacitor C2 discharges to the output end, and the voltage across the flying capacitor C2 decreases, as shown in FIG. Figure 8 As shown, in the interval t1 to t2, the value of V_C1+V_C2 decreases; at the same time, because the upper switches Q1 and Q3 are disconnected, the input capacitor Cin stops discharging and starts charging at time t1, as shown in the figure, V_cin starts to rise at time t1. When V_Cin equals V_C1+V_C2 (i.e., time t2), the upper switch Q1 is turned on again to avoid the voltage shock to the input capacitor Cin caused by the series connection of the flying capacitors C1 and C2. Similarly, in the interval t4 to t5, when the upper switch Q1 is turned off, the upper switch Q3 is also turned off, and the flying capacitor C1 discharges to the output end. When V_Cin=V_C1+V_C2 (i.e., time t5), the upper switch Q3 is turned on again. The upper switches Q1 and Q3 in this embodiment can select SiMOSFET, but GaNMOSFET is the best. The body diode of GaNMOSFET has a large conduction voltage drop. During the period when Q1 and Q3 are both turned off, the voltage impact on the input capacitor Cin caused by the series connection of the flying capacitors C1 and C2 can be completely avoided, thereby reducing the loss caused by the capacitor voltage impact to zero.

[0067] The present invention also discloses another circuit topology 3a and a corresponding control strategy for solving the problem of output voltage reduction when the input voltage is too low. Fig. 9 As shown, combined with Figure 7 The control strategy shown; the circuit topology 3a is different from the circuit topology 1a in that it includes two input inductors Lin1 and Lin2, two input capacitors Cin1 and Cin2, and auxiliary switches Qa and Qb. The first end of the two input inductors Lin1 and the first end of Lin2 are electrically connected to the input positive terminal Vin+, the second end of the input inductor Lin1 is electrically connected to the positive end of the input capacitor Cin1 and the drain of the upper switch Q1, and the second end of the input inductor Lin2 is electrically connected to the positive end of the input capacitor Cin2 and the drain of the upper switch Q3; the negative ends of the input capacitors Cin1 and Cin2 are electrically connected to the input negative terminal Vin-. The auxiliary switches Qa and Qb can be connected to a common source or a common drain. Here, the common source connection is used as an example. The drain of the auxiliary switch Qa is electrically connected to the drain of the upper switch Q1, and the drain of the auxiliary switch Qb is electrically connected to the drain of the upper switch Q3. If the auxiliary switches Qa and Qb are connected with a common drain, the source of the auxiliary switch Qa is electrically connected to the drain of the switch Q1 , and the source of the auxiliary switch Qb is electrically connected to the drain of the switch Q3 .

[0068] Fig. 9 In the circuit topology 3a shown in FIG. 1 , when the duty cycle is less than or equal to 0.5, the auxiliary switches Qa and Qb are in the normally-on state. Figure 6a The control strategy shown in the figure works in combination with circuit topology 1a. Figure 6a The first control strategy to the fourth control strategy shown are the same. When the duty cycle is greater than 0.5, the auxiliary switches Qa and Qb are in a normally closed state. At this time, the drive waveforms of the switches of the power conversion device are as follows: Figure 7As shown. The duty ratios of the first control signal PWM1 and the second control signal PWM2 are the same and greater than 0.5, and the first control signal PWM1 and the second control signal PWM2 are 180 degrees out of phase; the third control signal PWM3 is complementary to the first control signal PWM1, and the fourth control signal PWM4 is 180 degrees out of phase with the first control signal PWM1. The first control signal PWM1 is used to control the opening and closing of the upper switch Q1, the second control signal PWM2 is used to control the opening and closing of the upper switch Q3, the third control signal PWM3 is used to open and close the middle switch Q2 and the lower switch SR2, and the fourth control signal PWM4 is used to open and close the middle switch Q4 and the lower switch SR1. In the interval t1-t2, the upper switch Q1, the middle switch Q4 and the lower switch SR1 are in the on state, the input capacitor Cin1 discharges to the output end, and the voltage V_Cin1 across the input capacitor Cin1 decreases; at the same time, the upper switch Q3 is in the off state, the input capacitor Cin2 is in the charging state, and the voltage V_Cin2 across the input capacitor Cin2 increases; in the interval t2-t3, the upper switch Q1 and the upper switch Q3 are both in the on state, so that the input capacitor Cin1 and the input capacitor Cin2 discharge to the output end; the voltages across the input capacitor Cin1 and the input capacitor Cin2, V_Cin1 and V_Cin2, both decrease; at time t3, the upper switch Q3, the middle switch Q2 and the lower switch SR2 are turned on, and the upper switch Q1 is turned off, the flying capacitors C1 and C2 are connected in series again, and the voltages across the flying capacitors C1 and C2 and V_C1+V_C2 have an impact on the input capacitor Cin2; compared with the circuit topology 1a combined Figure 7 Control strategy, circuit topology 3a combined Figure 7 Control strategy, the voltage drop amplitude V_Cin2 across the input capacitor Cin2 is greatly reduced, so the amplitude of the impact voltage is also greatly reduced, which greatly reduces the capacitor voltage impact loss. Similarly, at time t1, when the upper switch Q3 is turned off, the upper switch Q1, the middle switch Q4 and the lower switch SR1 are turned on, the voltage across the flying capacitors C1 and C2 and V_C1+V_C2 impact the input capacitor Cin1; also compared to the circuit topology 1a combined Figure 7 Control strategy, circuit topology 3a combined Figure 7 Control strategy, the voltage V_Cin1 across the input capacitor Cin1 decreases significantly, so the amplitude of the impulse voltage is also greatly reduced, so that the capacitor voltage impulse loss is also greatly reduced.

[0069] All circuit topologies disclosed in the present invention include six switches, namely, two upper switches, two middle switches and two lower switches. The present invention discloses a driving circuit for driving and controlling six switches, the driving circuit including three drivers, four driving diodes and four driving capacitors. Driver Dr1 is used to drive two upper switches Q1 and Q3, driver Dr2 is used to drive the middle switch Q2 and the lower switch SR1 of one bridge arm, and driver Dr3 is used to drive the middle switch Q4 and the lower switch SR2 of the other bridge arm.

[0070] Drivers Dr2 and Dr3 are half-bridge drivers, the positive electrode of the driving diode Dd1 is electrically connected to the power supply pin VDD of the driver Dr2, the negative electrode of the driving diode Dd1 is electrically connected to the pin HB, the driving capacitor Cd1 is electrically connected between the pin HB and the pin HS of the driver Dr2, wherein the pin HS is electrically connected to the lower node B1, the pin HB is electrically connected to the connection point E1, and the input terminals HB and HO are electrically connected to two control signals from the first control signal to the fourth control signal respectively; similarly, the positive electrode of the driving diode Dd2 is electrically connected to the power supply pin VDD of the driver Dr3, the negative electrode of the driving diode Dd2 is electrically connected to the pin HB of the driver Dr3, the driving capacitor Cd2 is electrically connected between the pin HB and the pin HS of the driver Dr2, wherein the pin HS is electrically connected to the lower node B2, the pin HB is electrically connected to the connection point E2, and the pin HB and HO are electrically connected to two control signals from the first control signal to the fourth control signal respectively. The driver Dr1 is a floating driver, comprising two floating driving circuits and a ground pin GND, the two floating driving circuits are used to output two floating driving signals to drive two upper switches; specifically, the driver Dr1 comprises two floating pins HS1 and HS2, two driving pins HO1 and HO2, two floating power supply pins HB1 and HB2, a power supply pin VDD with the ground pin GND as a reference ground, and two input signal pins Hl1 and Hl2 with the ground pin GND as a reference ground. They are short-connected to upper nodes A1 and A2 respectively, the two floating pins HS1 and HS2 are short-connected to upper nodes A1 and A2 respectively, the two driving pins HO1 and HO2 are electrically connected to the gates of the two upper switches respectively, the two floating power supply pins HB1 and HB2 are referenced to the floating pins HS1 and HS2 respectively, and power is supplied to the two driving pins HO1 and HO2, and the input signal pins Hl1 and Hl2 are used to receive two control signals from the first control signal to the fourth control signal. The positive electrode of the driving diode Dd3 is electrically connected to the connection point E1, the negative electrode of the driving diode Dd3 is electrically connected to the floating power supply pin HB1 of the driver Dr1, and the driving capacitor Cd3 is electrically connected between the floating power supply pin HB1 and the floating pin HS1; wherein the floating power supply pin HB1 is electrically connected to the connection point F1, and the floating pin HS1 is electrically connected to the upper node A1. Similarly, the positive electrode of the driving diode Dd4 is electrically connected to the connection point E2, the negative electrode of the driving diode Dd2 is electrically connected to the floating power supply pin HB2 of the driver Dr1, and the driving capacitor Cd4 is electrically connected between the floating power supply pin HB2 and the floating pin HS2; wherein the floating power supply pin HB2 is electrically connected to the connection point F2, and the floating pin HS2 is electrically connected to the upper node A2. The driving circuit disclosed in the present invention only includes three independently packaged drivers to complete the driving control of six switches, reducing the number of independently packaged drivers; and the number of devices in the peripheral circuit is small, further reducing the area of ​​the driving circuit on the circuit substrate in the power conversion device.

[0071] in addition, Figures 2 to 3b The disclosed layout is also applicable to the use of Figure 5 , Figure 6a to Figure 6b , Figure 7 , Figure 8 and Fig. 9 The disclosed circuit and the power conversion device for controlling the timing, and the power conversion device comprising Fig.10 A power conversion device of the driving circuit shown.

[0072] The magnetic columns (side columns and middle columns) in the transformer core or inductor core disclosed in the present invention can be independently formed with two magnetic substrates, or the magnetic columns can be integrally formed with one of the magnetic substrates, or each magnetic column can be divided into two parts, each part is integrally formed with one magnetic substrate; the transformer core material and the driving core material can both be ferrite. The cross section of the connection between the magnetic column of the transformer core or inductor core and the magnetic substrate and the cross section of the magnetic substrate can be rectangular, square, circular or elliptical, etc., but are not limited thereto.

[0073] The switch disclosed in the present invention can be SiMOSFET, SiCMOSFET, GaNMOSFET or IGBTMOSFET, etc., all of which can realize the function of the switch disclosed in the present invention.

[0074] The power conversion device described in the above embodiments may be a part of an electronic device or an independent power module, as long as it meets the technical features and benefits disclosed by the present invention.

[0075] The "equal", "same" or "equal" disclosed in the present invention must take into account the parameter distribution of the project, and the error distribution is within ±30%; the definition of "parallel" of two line segments or two center columns is that the angle between the two line segments or two center columns is less than or equal to 45 degrees; the definition of "perpendicular" of two line segments or two center columns is that the angle between the two line segments or two center columns is within the range of [60, 120] degrees; the definition of "phase mismatch" also needs to take into account the parameter distribution of the project, and the error distribution of the degree of phase mismatch is within ±30%.

[0076] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0077] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power conversion device, characterized in that: It includes a circuit substrate, an upper switch, a middle switch, a lower switch, a first flying capacitor, an input capacitor, an output capacitor and a transformer; The circuit substrate comprises a first surface and a second surface opposite to each other, two transformer side column holes, a transformer middle column hole, a lower switch area, a first flying capacitor area, a first upper middle switch area and an output area; The lower switch area, the first flying capacitor area, the first upper middle switch area and the output area are arranged on the first surface of the circuit substrate; The two transformer side column holes and the transformer center column hole penetrate the first surface and the second surface, and are respectively used for the transformer side column and the transformer center column to pass through; between each transformer side column hole and the transformer center column hole is a transformer winding area, the transformer winding area is used for the transformer winding to pass through, and the transformer winding area includes a first side and a second side opposite to each other; The lower switch region is disposed adjacent to a first side of the transformer winding region, the output region is disposed adjacent to a second side of the transformer winding region, the lower switch is disposed in the lower switch region, and the output capacitor is disposed in the output region; The first flying capacitor is arranged in the first flying capacitor area, and the lower switch area is arranged between the first flying capacitor area and the transformer winding area; The upper switch and the middle switch are arranged in the first upper-middle switch area, and the first upper-middle switch area is arranged adjacent to the first flying capacitor area and the lower switch area.

2. The power conversion device according to claim 1, characterized in that: The first surface further includes an input region, the input capacitor is arranged in the input region; and the first flying capacitor region is arranged between the input region and the lower switch region.

3. The power conversion device according to claim 1, characterized in that: The first surface further includes a second upper-middle switch area, and the power conversion device further includes a second upper switch and a second middle switch, and the second upper switch and the second middle switch are arranged in the second upper-middle switch area.

4. The power conversion device according to claim 2, characterized in that: The first surface also includes a second flying capacitor area, a third flying capacitor area and a fourth flying capacitor area; the power conversion device also includes a second flying capacitor, a third flying capacitor and a fourth flying capacitor, and they are respectively arranged in the second flying capacitor area, the third flying capacitor area and the fourth flying capacitor area in sequence; the second flying capacitor area is arranged between the lower switch area and the input area, and the third flying capacitor area and the fourth flying capacitor area are respectively arranged on the outside of the first upper middle switch area and the second upper middle switch area.

5. The power conversion device according to claim 2, characterized in that: The second surface includes a fifth flying capacitor area, a lower switch area, an input area and an output area; the power conversion device also includes a fifth flying capacitor, another lower switch, an input positive terminal, an output positive terminal and an output negative terminal; the input positive terminal is arranged in the input area, the output positive terminal and the output negative terminal are arranged in the output area, the other lower switch is arranged in the lower switch area, and the fifth flying capacitor is arranged in the fifth flying capacitor area; the lower switch area is arranged adjacent to one side of the transformer winding area, and the output area is arranged adjacent to the other side of the transformer winding area; the fifth flying capacitor area is arranged between the input area and the lower switch area.

6. The power conversion device according to claim 5, characterized in that: The projection of the lower switch area disposed on the second surface on the first surface at least partially overlaps with the lower switch area disposed on the first surface; The projection of the input area disposed on the second surface on the first surface at least partially overlaps with the input area disposed on the first surface; The projection of the output area disposed on the second surface on the first surface at least partially overlaps with the output area disposed on the first surface.

7. The power conversion device according to claim 1, characterized in that: It also includes a heat sink and a grounding metal block. The heat sink is welded to the first surface; the grounding metal block is welded to the second surface and is electrically connected to the output negative terminal.

8. A power conversion device, characterized in that: It includes an input positive terminal, an input negative terminal, an output positive terminal and an output negative terminal, wherein the input negative terminal and the output negative terminal are electrically connected; The power conversion device also includes a first bridge arm, a second bridge arm, two flying capacitors, an output capacitor, two transformer windings, an output inductor, an auxiliary switch and an auxiliary winding; the first bridge arm and the second bridge arm are electrically connected in parallel between the input positive terminal and the input negative terminal, the first bridge arm and the second bridge arm both include an upper switch, a middle switch and a lower switch, the upper switch and the middle switch are electrically connected to the upper node, and the middle switch and the lower switch are electrically connected to the lower node; one end of each flying capacitor is electrically connected to the upper node of one bridge arm, and the other end is electrically connected to the lower node of another bridge arm; the second end of the transformer winding is electrically connected to one end of the output inductor, the first end of the transformer winding is electrically connected to one of the lower nodes respectively, and the other end of the output inductor is electrically connected to the output positive terminal; the output capacitor is connected across the output positive terminal and the output negative terminal; One end of the auxiliary winding is electrically connected to the input positive end, and the other end is electrically connected to the drain of the auxiliary switch. The source of the auxiliary switch is electrically connected to the output positive end.

9. The power conversion device according to claim 8, characterized in that: It also includes a first control signal, a second control signal, a third control signal, a fourth control signal and a fifth control signal, wherein the switching cycles of the first control signal, the second control signal, the third control signal, the fourth control signal and the fifth control signal are the same; the first control signal is used to control the opening and closing of the upper switch of the first bridge arm and the middle switch of the second bridge arm, and the second control signal is used to control the opening and closing of the middle switch of the first bridge arm and the upper switch of the second bridge arm; The third control signal is used to control the on and off of the lower switch of the first bridge arm, and the fourth control signal is used to control the on and off of the lower switch of the second bridge arm; The fifth control signal is used to control the on and off of the auxiliary switch.

10. The power conversion device according to claim 9, characterized in that: When the input voltage of the power conversion device is less than four times the output voltage, the duty cycles of the first control signal and the second control signal are equal and both are less than or equal to 0.5, and the first control signal and the second control signal are 180 degrees out of phase; the third control signal is the same as the second control signal, and the fourth control signal is the same as the first control signal; the switching cycle includes two half-cycles, within one half-cycle, the fifth control signal is complementary to the first control signal, and within the other half-cycle of the same switching cycle, the fifth control signal is complementary to the second control signal.

11. The power conversion device according to claim 9, characterized in that: When the input voltage of the power conversion device is greater than or equal to four times the output voltage, the duty cycles of the first control signal and the second control signal are equal and both are less than or equal to 0.5, and the first control signal and the second control signal are 180 degrees out of phase; the third control signal is complementary to the first control signal, and the fourth control signal is complementary to the second control signal; the fifth control signal is at a low level, and the auxiliary switch is in an off state.

12. A power conversion device, characterized in that: It includes an input positive terminal, an input negative terminal, an output positive terminal and an output negative terminal, wherein the input negative terminal and the output negative terminal are electrically connected; The power conversion device further includes a first bridge arm and a second bridge arm; the first bridge arm and the second bridge arm are electrically connected in parallel between the input positive terminal and the input negative terminal, the first bridge arm and the second bridge arm both include an upper switch, a middle switch and a lower switch, the upper switch and the middle switch are electrically connected to the upper node, and the middle switch and the lower switch are electrically connected to the lower node; The power conversion device also includes a first drive unit, a second drive unit, a third drive unit and four control signals; each of the drive units receives two corresponding control signals among the four control signals; the first drive unit is used to drive the opening and closing of the upper switch of the first bridge arm and the upper switch of the second bridge arm, the second drive unit is used to drive the opening and closing of the middle switch and the lower switch of the first bridge arm, and the third drive unit is used to drive the opening and closing of the middle switch and the lower switch of the second bridge arm.

13. The power conversion device according to claim 12, characterized in that: The four control signals are respectively a first control signal, a second control signal, a third control signal and a fourth control signal; the first control signal is used to control the opening and closing of the upper switch of the first bridge arm and the middle switch of the second bridge arm, and the second control signal is used to control the opening and closing of the middle switch of the first bridge arm and the upper switch of the second bridge arm; The third control signal is used to control the on and off of the lower switch of the first bridge arm, and the fourth control signal is used to control the on and off of the lower switch of the second bridge arm.

14. The power conversion device according to claim 12, characterized in that: The second driving unit and the third driving unit are half-bridge driving units.

15. The power conversion device according to claim 13, characterized in that: The first driving unit receives a first control signal and a second control signal, wherein the first control signal and the second control signal have equal duty cycles and are 180 degrees out of phase with each other.

16. The power conversion device according to claim 12, characterized in that: The second driving unit and the third driving unit both include a power supply pin, a pin HB, a pin HS, a pin HO, a pin LO, a driving diode and a driving capacitor; the anode of each driving diode is electrically connected to the power supply pin of the first driving unit or the second driving unit; the cathode of each driving diode is electrically connected to the pin HB of the first driving unit or the second driving unit; each driving capacitor is bridged between the pin HB and the pin HS; the pin HS is electrically connected to the corresponding lower node; the pin HO is electrically connected to the gate of the middle switch, and the pin LO is electrically connected to the gate of the lower switch.

17. The power conversion device according to claim 16, characterized in that: The first driving unit includes a pin HB1, a pin HS1, a pin HO1, a pin HB2, a pin HS2, a pin HO2, a first driving diode, a second driving diode, a first driving capacitor and a second driving capacitor; the anode of the first driving diode is electrically connected to the pin HB of the second driving unit, and the cathode of the first driving diode is electrically connected to the pin HB1; the anode of the second driving diode is electrically connected to the pin HB of the third driving unit, and the cathode of the second driving diode is electrically connected to the pin HB2; the first driving capacitor is connected between the pin HB1 and the pin HS1; the second driving capacitor is connected between the pin HB2 and the pin HS2; the pin HO1 is used to drive the switch on the first bridge arm to be turned on and off; The pin HO2 is used to drive the switch on the second bridge arm to be turned on and off.

18. A power conversion device, characterized in that: It includes an input positive terminal, an input negative terminal, an output positive terminal and an output negative terminal, wherein the input negative terminal and the output negative terminal are electrically connected; The power conversion device also includes a first bridge arm, a second bridge arm, two flying capacitors, an output capacitor, two transformer windings, an output inductor, two input inductors, two input capacitors and two auxiliary switches; the first bridge arm and the second bridge arm are electrically connected in parallel between the input positive end and the input negative end, and the first bridge arm and the second bridge arm both include an upper switch, a middle switch and a lower switch, the upper switch and the middle switch are electrically connected to the upper node, and the middle switch and the lower switch are electrically connected to the lower node; one end of each flying capacitor is electrically connected to the upper node of one bridge arm, and the other end is electrically connected to the lower node of another bridge arm; the second end of the transformer winding is electrically connected to one end of the output inductor, the first end of the transformer winding is electrically connected to one of the lower nodes respectively, and the other end of the output inductor is electrically connected to the output positive end; the output capacitor is connected across the output positive end and the output negative end; each input capacitor is connected across the two ends of the corresponding bridge arm; one end of each input inductor is electrically connected to the input positive end, and the other end is electrically connected to the corresponding bridge arm upper end; The two auxiliary switches are connected in series between the upper end of the first bridge arm and the upper end of the second bridge arm; the sources or drains of the two auxiliary switches are short-circuited.

19. The power conversion device according to claim 18, characterized in that: It also includes a first control signal, a second control signal, a third control signal and a fourth control signal; the first control signal is used to control the on and off of the switch on the first bridge arm, and the second control signal is used to control the on and off of the switch on the second bridge arm; The first control signal and the second control signal have equal duty cycles and are 180 degrees out of phase.

20. The power conversion device according to claim 19, characterized in that: When the duty cycle is less than or equal to 0.5, the two auxiliary switches are in a normally on state; the first control signal is also used to control the opening and closing of the switch in the second bridge arm, and the second control signal is also used to control the opening and closing of the switch in the first bridge arm; the third control signal is complementary to the first control signal and is used to control the opening and closing of the switch under the second bridge arm; the fourth control signal is complementary to the second control signal and is used to control the opening and closing of the switch under the first bridge arm.

21. The power conversion device according to claim 19, characterized in that: When the duty cycle is greater than 0.5, the two auxiliary switches are in a normally closed state; the third control signal is complementary to the first control signal and is used to control the on and off of the switch in the first bridge arm and the switch under the second bridge arm; The fourth control signal is complementary to the second control signal and is used to control the on and off of the switch in the second bridge arm and the switch under the first bridge arm.

22. A power conversion device, characterized in that: include: A circuit substrate, an input terminal, an output terminal, a switch element, a magnetic component and a grounded metal block; the input terminal includes an input positive terminal and an input negative terminal, the output terminal includes an output positive terminal and an output negative terminal; the input negative terminal is electrically connected to the output negative terminal; the magnetic component includes a winding and a magnetic core, the winding is arranged in the circuit substrate; the magnetic component is bridged between the input terminal and the output terminal through the switch element, and the magnetic component is arranged between the input terminal and the output terminal; The grounding metal block is arranged on the surface of the circuit substrate and is used to short-circuit the input negative terminal and the output negative terminal; The grounding metal block is arranged adjacent to one side of the magnetic component.

23. The power conversion device according to claim 22, characterized in that: It also includes a heat sink block, which is welded to the first surface; and the grounding metal block is welded to the second surface.

24. The power conversion device according to claim 23, characterized in that: The height of the heat sink is equal to the height of the switch element.

25. The power conversion device according to claim 22, characterized in that: The grounding metal block is connected in parallel with the grounding line in the circuit substrate.

26. The power conversion device according to claim 22, characterized in that: The magnetic component includes a first side and a second side opposite to each other. The input end is disposed adjacent to the first side, the output end is disposed adjacent to the second side, and the grounding metal block extends from the first side to the second side along the other side of the magnetic component.

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