Transformer and power supply device using the same

Abstract

The power supply device of the embodiment includes a substrate, a switching unit arranged on the substrate for alternately switching an input DC power supply to convert it into an AC power supply, a transformer arranged on the substrate for converting the level of the AC power supply, a rectification unit arranged on the substrate for rectifying the AC power supply having a level converted by the transformer, and an output inductor arranged adjacent to the transformer and having one end connected to the transformer, wherein the multiple terminals included in the transformer include first and third terminals, a second terminal located between the first terminal and the third terminal, and an additional terminal arranged to extend from the second terminal to the outside of the first or third terminal, and one end of the output inductor is connected to the additional terminal of the transformer.

Description

[Technical field]

[0001] The embodiments relate to a transformer and a power supply device using the transformer. [Background technology]

[0002] Recently, there has been an increasing demand for higher power sources for servers and vehicle power supplies (eg, direct current / direct current (DC-DC) converters or on-board chargers (OBCs)).

[0003] Full-bridge circuits are used rather than half-bridge circuits for high power power supplies. For example, a Phase Shift Full Bridge (PSFB) circuit can be used as a power supply for a high power power module of about 2kW or more (e.g., 4kW). PSFB circuits are widely used as power supplies because they can perform Zero Voltage Switching (ZVS) operation through soft switching of active elements, minimizing switching losses. However, such PSFB circuits have poor EMI (Electro Magnetic Interference) performance, and research is ongoing to improve this. Summary of the Invention [Problem to be solved by the invention]

[0004] The embodiments provide a transformer with improved noise performance and a power supply device using the same. [Means for solving the problem]

[0005] A transformer according to one embodiment includes a plurality of terminals, and the plurality of terminals may include a first and a third terminal, a second terminal located between the first terminal and the third terminal, and an additional terminal extending from the second terminal to an outside of the first or third terminal.

[0006] A power supply device according to another embodiment includes a substrate, a switching unit arranged on the substrate for alternately switching an input DC power supply to convert it into an AC power supply, a transformer arranged on the substrate for converting a level of the AC power supply, a rectification unit arranged on the substrate for rectifying the AC power supply having a level converted by the transformer, and an output inductor arranged adjacent to the transformer and having one end connected to the transformer, the transformer including a plurality of terminals, the plurality of terminals including first and third terminals, a second terminal located between the first terminal and the third terminal, and an additional terminal arranged to extend from the second terminal to an outside of the first or third terminal, and the one end of the output inductor may be connected to the additional terminal of the transformer.

[0007] For example, the additional terminal may include a terminal body disposed on the substrate outside the first terminal or the third terminal, and a connecting portion connecting the second terminal and the terminal body.

[0008] For example, the connecting portion may horizontally bypass the first terminal or the third terminal to connect the second terminal and the terminal body.

[0009] For example, the connecting portion may vertically bypass the first terminal or the third terminal to connect the second terminal and the terminal body.

[0010] For example, the connector may have a rounded shape.

[0011] For example, the output inductor may be disposed on the substrate, and at least a portion of the output inductor may be disposed facing the terminal body.

[0012] For example, the rectifier unit may include a first switch disposed between the first terminal and a first ground and switched on, and a second switch disposed between the third terminal and a second ground and switched on, and the first ground and the second ground may be connected to each other.

[0013] For example, the first switch and the second switch may be disposed opposite each other, and the output inductor may be disposed outside the first or second switch.

[0014] For example, the power supply device may further include an output terminal connected to the other end of the output inductor.

[0015] For example, the output terminal may include a first capacitor disposed between the other end of the output inductor and the second ground, a filter inductor having one end connected to the other end of the output inductor, and the Filters A second capacitor may be disposed between the other end of the inductor and the second ground.

[0016] For example, the maximum separation distance between the first, second or third terminal and the first capacitor may be 10 mm.

[0017] For example, the lower end of the second terminal may extend to the substrate or may be spaced apart from the substrate.

[0018] According to yet another embodiment, a power supply device includes a substrate, a switching unit disposed on the substrate and configured to alternately switch an input DC power source to convert it into an AC power source, a transformer disposed on the substrate and configured to convert a level of the AC power source, a rectifier disposed on the substrate and configured to rectify the AC power source having a level converted by the transformer, and an output inductor disposed adjacent to the transformer and connected to the transformer, the transformer including a plurality of terminals, the plurality of terminals including first and third terminals, a second terminal located between the first terminal and the third terminal, and an additional terminal disposed extending from the second terminal to an outside of the first or third terminal, the rectifier including a first switch connected between the first terminal of the transformer and a first ground, and a second switch connected between a second ground connected to the first ground and the third terminal, the output inductor being connected to the additional terminal of the transformer. Effect of the Invention

[0019] The transformer according to the embodiment and the power supply device using the same have improved power module operating characteristics and EMI noise performance. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a circuit diagram of a power supply device using a transformer according to an embodiment.

[0021] [Figure 2a] FIG. 2 is a plan view of an embodiment of a power supply device using the transformer shown in FIG.

[0022] [Figure 2b] 1. FIG. 4 is a plan view of another embodiment of a power supply device using the transformer shown in FIG.

[0023] [Diagram 3]FIG. 13 is a perspective view of a transformer included in a power supply device according to another embodiment.

[0024] [Figure 4a] FIG. 2b is a front view of the embodiment of the transformer shown in FIG. 2a. [Figure 4b] FIG. 2b is a front view of the embodiment of the transformer shown in FIG. 2a.

[0025] [Diagram 5] 2 is a diagram conceptually illustrating a secondary current path of the transformer illustrated in FIG. 1.

[0026] [Figure 6] FIG. 1 shows a circuit diagram of a power supply device according to a comparative example.

[0027] [Figure 7] 7 is a diagram conceptually showing a secondary current path of the transformer shown in FIG. 6.

[0028] [Figure 8] FIG. 1 is a plan view illustrating a power supply device according to a comparative example.

[0029] [Figure 9] FIG. 9 is a front view of the transformer shown in FIG. 8.

[0030] [Figure 10] 11 is a graph showing the results of testing the electromagnetic compatibility of a power supply device according to a comparative example.

[0031] [Figure 11] 11 is a graph showing the results of testing the electromagnetic compatibility of a power supply device according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] In the following, in order to specifically explain the present invention, a description will be given based on an embodiment, and a detailed description will be given with reference to the accompanying drawings to help understand the invention. However, the embodiment according to the present invention can be modified into various other forms, and the scope of the present invention should not be interpreted as being limited to the embodiment described below. The embodiment of the present invention is provided to more completely explain the present invention to those having average knowledge in the art.

[0033] In the description of the embodiments of the present invention, when an element is described as being formed "on" or "under" an element, "on" or "under" includes not only the case where the two elements are in direct contact with each other, but also the case where one or more other elements are indirectly disposed between the two elements. In addition, when "on" or "under" is used, it can include not only the upper direction but also the lower direction based on one element.

[0034] Additionally, as used hereinafter, relational terms such as "first" and "second," "top / upper / upper side" and "bottom / lower / lower," etc. do not necessarily require or imply a certain physical or logical relationship or order between such entities or elements, but may be used to distinguish one entity or element from another entity or element.

[0035] Hereinafter, a transformer and a power supply device using the transformer according to an embodiment will be described using a Cartesian coordinate system, but the embodiment is not limited thereto. That is, in the Cartesian coordinate system, the x-axis, the y-axis, and the z-axis are mutually orthogonal, but the embodiment is not limited thereto. That is, the x-axis, the y-axis, and the z-axis may cross each other rather than being orthogonal.

[0036] FIG. 1 shows a circuit diagram of a power supply device 100 using a transformer according to an embodiment.

[0037] 1 may include a switching unit 110, a transformer 120, a rectifier unit 130, an output inductor LO, and a control unit 150. The power supply unit 100 may further include an input terminal. The power supply unit 100 may further include an output terminal (or a filter) 140.

[0038] The power supply device shown in FIG. 1 may be a type of Phase Shift Full Bridge (PSFB) circuit.

[0039] The switching unit 110 may alternately switch the input DC power VI to convert it into AC power and output the converted AC power to the transformer 120. To this end, the switching unit 110 may alternately perform switching operations in a complementary manner using four switching elements.

[0040] For example, the switching unit 110 may include four switching elements Q1, Q2, Q3, and Q4. The first switching element Q1 may be turned on or off in response to a first gate signal S1, the second switching element Q2 may be turned on or off in response to a second gate signal S2, the third switching element Q3 may be turned on or off in response to a third gate signal S3, and the fourth switching element Q4 may be turned on or off in response to a fourth gate signal S4. In order to control such switching operations, the control unit 150 may generate first to fourth gate signals S1 to S4 and provide them to the first to fourth switching elements Q1, Q2, Q3, and Q4, respectively. In addition, the switching unit 110 may include a first inductor L1 and first and second diodes D1 and D2.

[0041] The switching operation of the switching unit 110 having the configuration shown in Fig. 1 is a common matter, so a detailed description will be omitted. Also, as long as the input DC power supply VI can be alternately switched and converted into AC power supply, the switching unit 110 of the power supply device 100 according to the embodiment may have a configuration different from that shown in Fig. 1. That is, the configuration of the switching unit 110 shown in Fig. 1 may be replaced with the configuration of a common switching unit included in a PSFB.

[0042] The input DC power supply VI may be provided to the switching unit 110 from an input terminal.

[0043] For example, the input may include an input capacitor CO and a load (not shown) coupled in parallel to the input capacitor CO. The input may be a high voltage energy storage device or a bus, or may be omitted.

[0044] Meanwhile, the transformer 120 according to the embodiment converts the level of the AC power output from the switching unit 110 .

[0045] Fig. 2a shows a plan view of an embodiment 100A of the power supply device 100 using the transformer 120 shown in Fig. 1, and Fig. 2b shows a plan view of another embodiment 100B of the power supply device 100 using the transformer 120 shown in Fig. 1. For convenience of explanation, the input capacitor CO, the switching unit 110, and the output terminal 140 shown in Fig. 1 are omitted in Figs. 2a and 2b.

[0046] The power supply devices 100A and 100B according to the embodiments shown in FIGS. 2a and 2b may include a transformer 120, rectifier sections Q5 and Q6, an output inductor LO, and a substrate (or printed circuit board (PCB)) 160.

[0047] The transformer 120, the rectifier units Q5 and Q6, and the output inductor LO shown in FIGS. 2a and 2b correspond to the transformer 120, the rectifier unit 1 shown in FIG. 30 and the output inductor LO respectively.

[0048] The transformer 120, the rectifier units Q5 and Q6, and the output inductor LO may be disposed on the substrate 160. In addition, for example, although not shown, the switching unit 110 and the output terminal 140 may also be disposed on the substrate 160. In addition, the control unit 150 may also be disposed on the substrate 160.

[0049] According to an embodiment, as shown in Figures 2a and 2b, the transformer 120 may include a plurality of terminals. The plurality of terminals may include a first terminal T1, a second terminal T2, a third terminal T3, and an additional terminal AT. The first terminal T1 shown in Figures 2a and 2b may be connected to the first output pin P1 of the transformer 120 shown in Figure 1, the second terminal T2 shown in Figures 2a and 2b may be connected to the second output pin P2 of the transformer 120 shown in Figure 1, and the third terminal T3 shown in Figures 2a and 2b may be connected to the third output pin P3 of the transformer 120 shown in Figure 1. Referring to Figures 2a and 2b, the second terminal T 2 is located between the first terminal T1 and the third terminal T3, and may be disposed, for example, in the center between the first terminal T1 and the third terminal T3.

[0050] Also, the additional terminals AT: AT1, AT2 may be disposed extending from the second terminal T2 to the outside of the first terminal T1 or the third terminal T3. Here, the outside of the first terminal T1 may mean a position closer to the first terminal T1 than the third terminal T3 among positions other than the space between the first terminal T1 and the third terminal T3 aligned in the first direction (e.g., the y-axis direction). Also, the outside of the third terminal T3 may mean a position closer to the third terminal T3 than the first terminal T1 among positions other than the space between the first terminal T1 and the third terminal T3 aligned in the first direction (e.g., the y-axis direction).

[0051] For example, as shown in FIGS. 2a and 2b, the additional terminals AT: AT1, AT2 may be arranged to extend outside the third terminal T3.

[0052] FIG. 3 shows a perspective view of a transformer 120 included in a power supply device according to yet another embodiment.

[0053] The additional terminals AT: AT1, AT2, AT3 may include a terminal body TB and a connecting portion CP.

[0054] The terminal body TB may be disposed outside the first terminal T1 or the third terminal T3 on the substrate 160. For example, as shown in Figures 2a, 2b, and 3, respectively, the terminal body TB may be disposed outside the third terminal T3.

[0055] The connecting portion CP serves to connect the second terminal T2 and the terminal body TB.

[0056] According to an embodiment, the connecting part CP may bypass the first terminal T1 or the third terminal T3 in a vertical direction (e.g., z-axis direction) to connect the second terminal T2 to the terminal body TB. For example, as illustrated in Fig. 2a and Figs. 4a and 4b described below, the connecting part CP may bypass the third terminal T3 in a vertical direction to connect the second terminal T2 to the terminal body TB.

[0057] According to another embodiment, the connecting portion CP may bypass the first terminal T1 or the third terminal T3 in a horizontal direction (e.g., in the x-axis and y-axis directions) to connect the second terminal T2 to the terminal body TB. For example, as illustrated in Fig. 2b and Fig. 3, the connecting portion CP may bypass the third terminal T3 in a horizontal direction to connect the second terminal T2 to the terminal body TB.

[0058] The connecting portion CP may have at least one of a twist shape, a rounding shape, or a folding shape, but the embodiment is not limited to a specific shape of the connecting portion CP. For example, the connecting portion CP may have a rounding shape as illustrated in FIG. 3 and later-described FIG. 4A and FIG. 4B.

[0059] If the shape of the additional terminals AP can be simplified and the area in which the additional terminals AP are formed can be minimized to reduce resistance and processing costs, the connecting portion CP is not limited to the above-mentioned shape and can be embodied in various ways.

[0060] The second inductor L2 included in the transformer 120 may be an inductor formed by a leakage inductance, a commutating inductor, or an inductor that is intentionally added.

[0061] 4a and 4b show front views of embodiments 120A, 120B of the transformer 120 shown in FIG. 2a.

[0062] The transformers 120A, 120B shown in Figures 4a and 4b may include a Zero Voltage Switching (ZVS) inductor 210 and a primary side and a secondary side 220A or 220B.

[0063] The ZVS inductor 210 serves to return the residual current to the input side so that there is no FET operation loss, and may correspond to the second inductor L2 shown in Fig. 1. The ZVS inductor 210 may include a first core 212 and a first coil 214. The first core 212 may induce electromagnetism, and the first coil 214 may generate an induced electromotive force by a change in magnetic flux.

[0064] The primary and secondary sides 220A and 220B serve to convert the input power (voltage or current) according to a turn ratio and transmit it to the output side. For example, the primary and secondary sides 220A shown in FIG. 4a include a transformer core 222, a transformer primary coil 224, a transformer secondary coil 226, first to third terminals T1, T2, T3, and an additional terminal AT, and the primary and secondary sides 220B shown in FIG. 4b include a transformer core 222, a transformer primary coil 224, a transformer secondary coil 226, first to third terminals T1, T2, T3, and an additional terminal AT. FIGS. 4a and 4b are the same except that the positions of the lower ends BS1 and BS2 of the second terminal T2 are different from each other.

[0065] The transformer core 222 induces electromagnetism, the transformer primary coil 224 generates magnetic flux and transmits current, the transformer secondary coil 226 generates magnetic flux in the opposite direction to the primary coil 224 and transmits current, and the first to third terminals T1, T2, and T3 are connected to the transformer secondary coil 226. Also, the additional terminal AT, as described above, connects the second terminal T2 to the output inductor LO.

[0066] According to an embodiment, as shown in Fig. 4a, a lower end BS1 of the second terminal T2 may be disposed to extend to the substrate 160. Here, the lower end BS1 may be in contact with the substrate 160. When the second terminal T2 is embodied as shown in Fig. 4a, the heat dissipation characteristics of the transformer 120 may be improved, and durability against vibration may also be improved.

[0067] According to another embodiment, as shown in Fig. 4b, the lower end BS2 of the second terminal T2 may be spaced apart from the substrate 160. That is, the lower end BS2 may be spaced apart a certain distance from the substrate 160. When the second terminal T2 is implemented as shown in Fig. 4b, a margin of the PCB pattern can be secured.

[0068] 1 again, the rectifier 130 is connected to the first terminal T1 and the third terminal T3 of the transformer 120 and can rectify the AC power having a level converted by the transformer 120. That is, the rectifier 130 can have a center-tap type.

[0069] FIG. 5 is a diagram conceptually showing a secondary current path of transformer 120 shown in FIG.

[0070] For example, the rectifier 130 may include a first switch SW1 and a second switch SW2.

[0071] The first switch SW1 can be arranged between the first terminal T1 and a first ground (or a "first ground") G1 and switched, and the second switch SW2 can be arranged between the third terminal T3 and a second ground (or a "second ground") G2 and switched. That is, as shown in Fig. 5, the first switch SW1 can be arranged between the first output pin P1 connected to the first terminal T1 and the first ground G1, and the second switch SW2 can be arranged between the third output pin P3 connected to the third terminal T3 and the second ground G2.

[0072] An output inductor LO may be disposed between the second output pin P2 of the transformer 120 and an output node NO, where the output node NO is the output terminal 110 as shown in FIG. 1 This may correspond to 40 input nodes.

[0073] According to an embodiment, as shown in FIG. 1 and FIG. 5, the first ground G1 and the second ground G2 can be connected to each other and integrated.

[0074] Each of the first and second switches SW1 and SW2 may be implemented by a bipolar transistor or a field effect transistor (FET).

[0075] 1, the first switch SW1 may be implemented by a fifth FET Q5. The fifth FET Q5 may be turned on or off in response to a fifth gate signal S5 and may be disposed between a first output pin P1 of the transformer 120 and a first ground G1.

[0076] The second switch SW2 may be implemented by a sixth FET Q6. The sixth FET Q6 may be turned on or off in response to a sixth gate signal S6 and may be disposed between the third output pin P3 of the transformer 120 and a second ground G2.

[0077] To perform the above-described operations, the controller 150 may generate fifth and sixth gate signals S5 and S6 and provide them to the first and second switches SW1 and SW2.

[0078] Alternatively, as shown in FIGS. 2a and 2b, the first switch SW1 can be realized by No. 5-1 and No. 5-2 FETs Q51 and Q52, and the second switch SW2 can be realized by No. 6-1 and No. 6-2 FETs Q61 and Q62.

[0079] Also, the first and second switches SW1 and SW2 shown in FIG. 5 may be implemented in various forms other than those shown in the drawings.

[0080] The output inductor LO is disposed adjacent to the transformer 120 and has one end connected to the transformer 120. One end of the output inductor LO may be connected to an additional terminal AT of the transformer 120. In this manner, one end of the output inductor LO may be connected to a second terminal T2 of the transformer 120 via the additional terminal AT. The output inductor LO may be mounted on the substrate 160 by various methods such as soldering, SMD, or screws. For example, in FIGS. 2a and 2b, a lead may pass through the substrate 160, and the output inductor LO may be mounted on the substrate 160 by a soldering method.

[0081] Also, depending on the position or structure of the secondary coil 226 of the transformer and the pattern of the substrate 160, the output inductor LO can be tilted by 90° or 180°.

[0082] 2a and 2b, at least a portion of the output inductor LO may be disposed facing the terminal body TB in a second direction (e.g., the x-axis direction) on the substrate 160. For example, although not shown, the output inductor LO is electrically connected to the terminal body TB in the substrate 160 shown in FIGS. 2a and 2b.

[0083] 2a and 2b, the first switch Q5 and the second switch Q6 may be disposed opposite each other in a first direction (e.g., the y-axis direction) on the substrate 160. Here, the output inductor LO may be disposed outside the first or second switch Q5, Q6. Here, the outside of the first switch Q5 may mean a position closer to the first switch Q5 than the second switch Q6 among positions other than the space between the first switch Q5 and the second switch Q6 facing each other in the first direction (e.g., the y-axis direction). Also, the outside of the second switch Q6 may mean a position closer to the second switch Q6 than the first switch Q5 among positions other than the space between the first switch Q5 and the second switch Q6 facing each other in the first direction (e.g., the y-axis direction).

[0084] The output terminal 140 may be connected to the other end of the output inductor L0. For example, the output terminal 140 may filter a signal between the output node N0 and the second ground G2 and output the filtered result V0.

[0085] The output terminal 140 is a kind of filter and can include various types of capacitors and inductors.

[0086] For example, referring to FIG. 1, the output stage 140 may include first and second capacitors C1, C2 and a filter inductor L3.

[0087] The first capacitor C1 can be arranged between the other end of the output inductor LO and the second ground G2, the filter inductor L3 has one end connected to the other end of the output inductor LO, and the second capacitor C2 can be arranged between the other end of the filter inductor L3 and the second ground G2.

[0088] When the distance between the first terminal T1, the second terminal T2, or the third terminal T3 and the output node NO (e.g., the first capacitor C1) is smallest, the electromagnetic interference (EMI) performance can be improved. For example, the maximum value of the distance between the first terminal T1, the second terminal T2, or the third terminal T3 and the first capacitor C1 may be 10 mm, but the embodiment is not limited thereto.

[0089] A power supply device according to a comparative example and a power supply device according to an embodiment will be described below with reference to the accompanying drawings.

[0090] FIG. 6 shows a circuit diagram of a power supply device according to a comparative example.

[0091] The power supply device according to the comparative example shown in Fig. 6 can include an input end including an input capacitor CO, a switching unit 10, a transformer 20, a rectifier unit 30, an output inductor LO, an output end 40, and a control unit 50. The input end, switching unit 10, transformer 20, rectifier unit 30, output inductor LO, output end 40, and control unit 50 shown in Fig. 6 correspond to the input end, switching unit 110, transformer 120, rectifier unit 130, output inductor LO, output end 140, and control unit 150 shown in Fig. 1, respectively, and therefore overlapping explanations will be omitted.

[0092] FIG. 7 is a diagram conceptually showing a secondary current path of the transformer 20 shown in FIG.

[0093] The first switch SW1 and the second switch SW2 shown in FIG. 7 correspond to the rectifier unit 30 shown in FIG. 6 and perform the same functions as the first switch SW1 and the second switch SW2 shown in FIG. 5, respectively, and therefore will not be described again.

[0094] FIG. 8 is a schematic plan view of a power supply device according to a comparative example.

[0095] The power supply device according to the comparative example shown in Fig. 8 can include a transformer 20, a first switch Q5, a second switch Q6, an output inductor LO, and a substrate 60. The transformer 20, the first switch Q5, the second switch Q6, the output inductor LO, and the substrate 60 shown in Fig. 8 perform the same functions as the transformer 120, the first switch Q5, the second switch Q6, the output inductor LO, and the substrate 160 shown in Fig. 2a or 2b, respectively, and therefore a duplicated description of the same parts will be omitted.

[0096] The transformer 20 according to the comparative example includes first, second and third terminals T1, T2, T3 respectively connected to the first, second and third output pins P1, P2 and P3. The second terminal T2 is disposed between the first terminal T1 and the third terminal T3, but unlike the embodiment, it is directly connected to the output inductor LO without passing through an additional terminal AP, and the output inductor LO is disposed between the first switch Q5 and the second switch Q6.

[0097] FIG. 9 is a front view of the transformer 20 shown in FIG.

[0098] As shown in Fig. 9, the transformer 20 can include a first core 12, a first coil 14, a transformer core 22, a transformer primary coil 24, a transformer secondary coil 26, and first to third terminals T1, T2, and T3. The first core 12, the first coil 14, the transformer core 22, the transformer primary coil 24, the transformer secondary coil 26, and the first to third terminals T1, T2, and T3 shown in Fig. 9 perform the same functions as the first core 212, the first coil 214, the transformer core 222, the transformer primary coil 224, the transformer secondary coil 226, and the first to third terminals T1, T2, and T3 shown in Fig. 4a or 4b, respectively, so that a duplicated description will be omitted. However, unlike the embodiment shown in Fig. 4a and Fig. 4b, the transformer 20 shown in Fig. 9 does not include an additional terminal AT.

[0099] 5 and 7, the first secondary output pin P1 of the transformer 120, 20 is connected to the first ground G1 via the first switch SW1, and the third secondary output pin P3 is connected to the second ground G2 via the second switch SW2.

[0100] With this configuration, the large current I2 passes through the second output pin P2 of the transformer 120 and flows into the output inductor LO, and currents I1 and I3 having half the level of the large current I2 can flow through the first and third output pins P1 and P3, respectively, to grounds G1 and G2 via the switches SW1 and SW2.

[0101] Here, as shown in FIGS. 6 and 7, when the first output pin P1 and the third output pin P3 are spaced apart with the second output pin P2 therebetween, energy levelling becomes unbalanced, and when the first ground G1 and the second ground G2 are spaced apart and not connected to each other as shown in FIGS. 6 and 7, a potential difference may occur between the grounds as shown in the following mathematical formula 1.

[0102]

number

[0103] Here, ΔVg indicates the potential difference between the grounds, Vg1 indicates the potential of the first ground G1, and Vg2 indicates the potential of the second ground G2.

[0104] The potential difference ΔVg of Equation 1 may increase EMI noise in the power supply device according to the comparative example, relatively increase the current density in the path through which a large current flows, and increase the heat generation temperature of FETs Q5 and Q6 embodying switches SW1 and SW2, respectively.

[0105] One method for reducing such EMI noise is to form the first and second grounds G1, G2 as close as possible to each other or to gather on one side. However, since the second output pin P2, through which a large current flows, is located between the first output pin P1 and the third output pin P3, there is a limit to the pattern width of the printed circuit board PCB.

[0106] In order to improve this, if the position of the second output pin P2 of the transformer 20 is changed, the shape of the transformer secondary coil 26 becomes complicated, which may increase the processing cost and reduce the assembly yield.

[0107] Therefore, in the case of the power supply device according to the embodiment, the position of the second output pin P2 is the same as that of the comparative example, but the second terminal T2 connected to the second output pin P2 is not directly connected to the output inductor LO but is connected via an additional terminal AT to the first ground G. 1 and the second ground G2 are connected to each other. Therefore, a potential difference ΔVg between the grounds does not occur as in the comparative example, so that the EMI noise is smaller than in the comparative example, the current density in the path through which a large current flows is relatively low, and the operating characteristics and EMI performance of the power module can be improved.

[0108] Fig. 10 is a graph showing the results of testing the ElectroMagnetic Compatibility (EMC) of a power supply device according to a comparative example, and Fig. 11 is a graph showing the results of testing the ElectroMagnetic Compatibility of a power supply device according to an embodiment. In each graph, the horizontal axis indicates frequency, and the vertical axis indicates noise intensity (dB).

[0109] 10, in the case of the power supply device according to the comparative example, a noise peak value 310 exceeds the peak upper limit line PUL, and a noise average value 312 exceeds the average upper limit line AUL.

[0110] On the other hand, referring to FIG. 11, in the case of the power supply device according to the embodiment, the noise peak value 410 does not exceed the peak upper limit line PUL, and the noise average value AV does not exceed the average upper limit line AUL.

[0111] The maximum value PKO of the peak value 410 shown in Fig. 11 can be reduced by 10 dB or more compared to the maximum value PKO of the noise peak value 310 shown in Fig. 10. In this way, it can be seen that the noise performance of the power supply device according to the embodiment is improved.

[0112] The above description is based on the embodiments, but these are merely illustrative and do not limit the present invention. Those skilled in the art will understand that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the present embodiments. For example, each component specifically shown in the embodiments can be modified and implemented. Such modifications and differences in applications should be interpreted as being included in the scope of the present invention defined in the appended claims. MODE FOR CARRYING OUT THEINVENTION

[0113] The embodiment of the invention has been fully described in the above detailed description. [Industrial Applicability]

[0114] The transformer and the power supply device using the transformer according to the embodiment can be applied to servers and vehicles.

Claims

1. A plurality of terminals are included. The plurality of terminals include First and third terminals; a second terminal located between the first terminal and the third terminal; an additional terminal disposed extending from the second terminal to an outside of the first terminal or the third terminal.

2. A substrate; A switching unit that is disposed on the substrate and that converts an input DC power source into an AC power source by alternately switching the input DC power source; a transformer disposed on the substrate for converting a level of the AC power; a rectification unit disposed on the substrate and configured to rectify AC power having a level converted by the transformer; an output inductor disposed adjacent to the transformer and having one end coupled to the transformer; the transformer includes a plurality of terminals; The plurality of terminals include First and third terminals; a second terminal located between the first terminal and the third terminal; an additional terminal disposed extending from the second terminal to an outside of the first terminal or the third terminal; The one end of the output inductor is coupled to the additional terminal of the transformer.

3. The additional terminal is a terminal body disposed on the substrate at the outer side of the first terminal or the third terminal; The power supply device according to claim 2 , further comprising a coupling portion coupling the second terminal and the terminal body.

4. The power supply device according to claim 3 , wherein the connecting portion connects the second terminal and the terminal body by bypassing the first terminal or the third terminal in a horizontal or vertical direction.

5. The power supply device according to claim 3 , wherein the output inductor is disposed on the substrate, and at least a portion of the output inductor is disposed facing the terminal body.

6. The rectifying unit includes: a first switch that is arranged between the first terminal and a first ground and switches; a second switch arranged between the third terminal and a second ground to be switched; The power supply device according to claim 2 , wherein the first ground and the second ground are connected to each other.

7. The first switch and the second switch are disposed opposite to each other, The power supply device of claim 6 , wherein the output inductor is disposed outside the first or second switch.

8. an output terminal connected to the other end of the output inductor, The output terminal is a first capacitor disposed between the other end of the output inductor and the second ground; a filter inductor having one end connected to the other end of the output inductor; 7. The power supply device of claim 6, further comprising: a second capacitor disposed between the other end of the output inductor and the second ground.

9. The power supply device according to claim 2 , wherein a lower end of the second terminal extends to the substrate or is spaced apart from the substrate.

10. A substrate; A switching unit that is disposed on the substrate and that converts an input DC power source into an AC power source by alternately switching the input DC power source; a transformer disposed on the substrate for converting a level of the AC power; a rectification unit disposed on the substrate and configured to rectify AC power having a level converted by the transformer; an output inductor disposed adjacent to the transformer and coupled to the transformer; the transformer includes a plurality of terminals; The plurality of terminals include First and third terminals; a second terminal located between the first terminal and the third terminal; an additional terminal disposed extending from the second terminal to an outside of the first terminal or the third terminal; The rectifying unit includes: a first switch coupled between the first terminal of the transformer and a first ground; a second switch connected between a second ground connected to the first ground and the third terminal; The output inductor is coupled to the additional terminal of the transformer.

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