Single-stage isolated DC-DC converter
By adopting a single-stage isolated DC-DC converter design in the power converter, using the interleaved arm structure of the rectifier circuit and the buck-boost circuit, the power converter in the prior art has solved the component size, cost and efficiency of the power converter in the prior art. The challenge of achieving high power density and wide range of voltage conversion effects.
Patent Information
- Application Number
- CN202411644541.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2019-06-20
- Filing Date
- 2020-06-18
- Publication Date
- 2025-02-18
AI Technical Summary
In the prior art, power converters have challenges in component size, cost, noise introduction, power consumption and thermal load, especially in point-of-load applications of electronic devices, where power density and voltage conversion ratios are required.
Using a single-stage isolated DC-DC converter, including rectifier circuit and buck-boost circuit, the circuit output is controlled through multiple switches to achieve wide gain range and efficient power conversion using inductors with central taps and interleaved arm structures. .
Achieve higher power density, wider voltage gain range and higher efficiency, reduce component count and size, reduce noise and thermal loads, suitable for applications requiring high power density and wide range of voltage conversion.
Smart Images
Figure CN119483272A_ABST
Abstract
Description
[0001] Divisional Application Information
[0002] This application is a divisional application of the invention patent application with the application date of June 18, 2020, application number "202010558602.4", and invention name "Single-stage isolated DC-DC converter". Technical Field
[0003] The present disclosure relates to power conversion and, more particularly, to single-stage isolated DC-DC converters. Background Art
[0004] Typically, electronic devices and other applications require power characteristics that are different from the available power sources. Converters, transformers and / or combinations thereof solve the problem of mismatching power sources and power requirements. Converters include electronic circuits and electromechanical devices that convert a direct current (DC) source from one voltage level to another. Transformers are conventionally used to increase or decrease AC voltages in power applications. However, power conversion can be expensive in terms of component size, cost, noise introduction, power consumption, thermal load, etc. Converters located near electronic applications, so-called point-of-load (POL) converters, may be more susceptible to these challenges. In addition, wider and wider input and / or output operating ranges are increasingly frequently applied. Moreover, in particular for POL applications, it is necessary to increase power density. In this way, a single-stage converter with a wide gain range and effective control, such as disclosed below, represents an improvement in the art.
[0005] The descriptions provided in this background section should not be considered to be prior art merely because they are mentioned in or related to the background section.The background section may include information describing one or more aspects of the subject technology. Summary of the invention
[0006] According to one aspect of the present disclosure, a single-stage converter includes a rectifier circuit and a buck-boost circuit. The buck-boost circuit includes an inductor having a center tap, which is configured to supply the output of the buck-boost circuit to the rectifier circuit. The buck-boost circuit also includes a first interleaved arm and a second interleaved arm arranged in parallel with the voltage input of the single-stage converter. The first interleaved arm and the second interleaved arm are each coupled to the inductor and include a plurality of switches operable to control the output of the buck-boost circuit.
[0007] According to another aspect of the present disclosure, a power circuit includes a rectifier having an energy storage resonator, a transformer, and at least one active element. According to this aspect, the power circuit also includes a buck-boost circuit having: an inductor operable to generate an AC output to the rectifier; and an interleaved arm coupled to the inductor such that the interleaved arm includes a plurality of switches operable to control power supplied to the inductor.
[0008] Another aspect of the present disclosure describes a method of operating a converter, the method comprising: operating a plurality of switches disposed in a first interleaved arm and a second interleaved arm of the converter to generate an AC voltage in an inductor of the converter coupled to the first interleaved arm and the second interleaved arm; and rectifying the AC voltage using an LLC resonant circuit of the converter and at least one diode of the converter.
[0009] Other aspects and advantages of the present disclosure will become apparent by consideration of the following detailed description and accompanying drawings, wherein like numerals designate like structures throughout the specification. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The following detailed description refers to the accompanying drawings, in which:
[0011] Figure 1 is a schematic circuit diagram showing a single-stage converter capable of producing a wide gain range;
[0012] Figure 2 Yes means Figure 1 A diagram of the operating modes and switching patterns of a single-stage converter and the resulting output voltage;
[0013] Figure 3 is a graph showing differential mode output with a duty cycle less than 50% and a circuit diagram showing a changing output of the differential mode;
[0014] Figure 4 is a graph showing differential mode output with a duty cycle greater than 50% and a circuit diagram showing a changing output of the differential mode;
[0015] Figure 5 is a graph showing the common mode output with a duty cycle less than 50% and a circuit diagram showing the changing output of the common mode;
[0016] Figure 6 is a graph showing common mode output with a duty cycle greater than 50% and a circuit diagram showing a changing output of the common mode;
[0017] Figure 7 Several schematic circuit diagrams showing a single-stage converter with a modified buck-boost circuit arrangement; and
[0018] Figure 8Several schematic circuit diagrams of single-stage converters with modified rectifier circuit arrangements are shown.
[0019] In one or more implementations, all elements depicted in each figure may not be required, and one or more implementations may include additional elements not shown in the figures. The arrangement and type of elements may be changed without departing from the scope of the present disclosure. Additional elements, different elements, or fewer elements may be utilized within the scope of the disclosed subject matter. DETAILED DESCRIPTION
[0020] The detailed description set forth below is intended as a description of various implementations, rather than being intended to represent a unique implementation in which the subject technology may be practiced. As will be appreciated by those skilled in the art, the described implementations may be modified in various ways, all without departing from the scope of the present disclosure. Further, without departing from the scope of the present disclosure, the depicted modules and processes may be combined in whole or in part, and / or divided into one or more different parts, to be applicable to a specific implementation. Therefore, the drawings and descriptions are considered to be illustrative rather than restrictive in nature.
[0021] Traditionally, two-stage solutions including a non-isolated buck or boost converter and an LLC DC transformer have been widely used in POL and similar applications to facilitate improved step-up / step-down conversion and a relatively wide voltage gain range. However, traditional two-stage solutions require complex circuits. This increased circuit complexity leads to practical limitations on power density, efficiency, and cost. Figure 1-Figure 8 , a single-stage converter 100 presented as an integrated buck-boost LLC converter is shown and described, which includes a buck-boost circuit 102 and a rectifier circuit 104 (including, for example, a resonant energy storage, an LLC resonant circuit, an LC circuit, a CLLC circuit, a rectifier diode, a synchronous rectifier and / or suitable electronic components). The single-stage isolated DC-DC converter 100 is characterized by improved efficiency, greater power density and a wide range of voltage gain. The extended operating range of the single-stage converter 100 facilitates the use of the single-stage converter 100 for DC-DC power conversion requiring high power density and a wide range of voltage conversion ratios. For example, the single-stage converter 100 is required for electric vehicle charging, POL power supply and other similar applications. The buck-boost circuit 102 includes a multiplexing switching unit (MSC) 106 that provides soft switching. In addition, in an example embodiment, the single-stage converter 100 integrates all or most of the magnetic elements disposed therein. The integration of magnetic elements can result in a reduction in the size of the transformer and / or inductor of the single-stage converter 100. However, it is possible to impose an asymmetric current stress on the MSC 106 .
[0022] An illustrative embodiment of a single-stage converter 100 and its basic operating principle are respectively Figure 1 and Figure 2-Figure 6 shown in . Specifically, Figure 1 The example single-stage converter 100 illustrated in FIG. 1 is a half-bridge LLC converter configuration 108 (see also Figure 8 ). Now refer to Figure 1 , the first arm 110 and the second arm 112 of the buck-boost circuit 102 are connected to the voltage input V in The first arm 110 comprises a first capacitor C1 and a first half bridge 114. The first half bridge 114 further comprises a first complementary switch S1 and a second complementary switch S2 arranged around a first node 116. The first capacitor C1 is arranged in series with the first switch S1 of the first half bridge 114.
[0023] The second arm 112 includes a second capacitor C2 and a second half bridge 118. The second half bridge 118 includes a third complementary switch S3 and a fourth complementary switch S4 arranged around a second node 120. The second capacitor C2 is arranged in series with the third switch S3 of the second half bridge 118. In this example embodiment, the first arm 110 and the second arm 112 can be staggered (i.e., phase-shifted by 180°). The first switch S1 and the third switch S3 can be configured to be switched in series with each other according to the duty cycle D (see Figure 2-Figure 6 ) operation. In addition, the first half bridge 114 and the second half bridge 118 are coupled to the DC inductor L via the first node 116 and the second node 120 of the respective first half bridge 114 and the second half bridge 118. dc It is contemplated that the switches including the first to fourth switches S1-S4 may include one or more diodes and / or other active electronic / semiconductor components. In an example embodiment, ultra-fast devices such as silicon carbide (SiC) and / or gallium nitride (GaN) diodes may be used as switches S1-S4 disposed within the buck-boost circuit 102.
[0024] DC Inductor L dc A center tap 122 is included that generates a single AC output of the buck-boost circuit 102. In this example configuration, the common mode output voltage 124 of the first arm 110 and the second arm 112 (see Figure 5 and Figure 6 ) generates an AC output voltage, and the differential output voltage 126 of the two arms 110 and 112 (see Figure 3 and Figure 4 ) generates a DC inductor L dc According to this configuration, the positive phase buck-boost converter 102 is integrated between the first arm 110 and the second arm 112. The buck-boost circuit 102 is connected to the inductor L dc The two ends form a switching power supply. Therefore, the inductor L dcOperates according to the volt-second balance of the magnetic components. Voltage and inductor L dc The relationship between the duty cycle D at both ends is:
[0025] V in +V c =0.5*V in / D
[0026] Then, the interleaved first arm 110 and second arm 112 can be used as phase legs to construct a half-bridge, single-phase and / or multi-phase LLC converter. As described above, Figure 1 The example embodiment illustrated in FIG. 1 is a half-bridge LLC converter configuration 108. The current in each of the first half-bridge 114 and the second half-bridge 118 is asymmetrical. As a result, each of the first switch S1 and the third switch S3, which are connected in series with the first capacitor C1 and the second capacitor C2, respectively, only carries AC current. As a result, the AC output voltage of the buck-boost circuit 102 is symmetrical.
[0027] Still reference Figure 1 The buck / boost circuit 102 is operatively coupled to a rectifier circuit 104. The rectifier circuit 104 is configured to connect a DC inductor L dc The center tap 122 and voltage input V in The rectifier circuit 104 may be an LLC resonant converter / energy storage resonator, which includes a resonant inductor L r and the resonant capacitor C set on both sides of the transformer T r . Resonant inductor L r The resonant capacitor C is operably coupled to the center tap 122 and receives the AC output of the buck / boost circuit 102 as its input. r operably coupled to a voltage input V in One or more rectifier diodes 134 may be operably coupled between the transformer T and the output capacitor Co, and / or the resistive load R, and / or another suitable load. The present disclosure contemplates a rectifier power supply topology that includes at least one diode and one capacitor. Figure 1 In the example shown in , a single rectifier diode 134a rectifies half a cycle of the AC signal. In addition, in example embodiments, one or more synchronous rectifiers may be combined with or replaced with one or more rectifier diodes 134, and the one or more synchronous rectifiers may include active electronic components such as one or more metal oxide semiconductor field effect transistors (MOSFETs), bipolar junction transistors (BJTs), and / or other suitable transistors. As a result, the output capacitor C oIt may be relatively large to properly filter and / or compensate the output DC signal and desirably prevent ripple in the output voltage. In an example embodiment, a switching device (e.g., a mechanical switch, a high-speed switch, other suitable active element switches, etc.) may replace one or more diodes 134 in the rectifier circuit 104.
[0028] Reference now Figure 2-Figure 6 , the operation of the single-stage converter 100 facilitates increased voltage gain and direct control. The single-stage converter 100 can be operated according to a pulse width modulation (PWM) mode, a pulse frequency modulation (PFM) mode, and / or a hybrid mode combining PWM and PFM control schemes. The voltage gain can be adjusted by modifying the duty cycle D. Figure 1 In the example embodiment, the AC voltage applied to the rectifier circuit 104 is:
[0029] 0.5*(Vin+Vc)=0.25*Vin / D
[0030] In the example where the duty cycle D is selected to be a 50% duty cycle, the single-stage converter 100 produces a unity voltage gain similar to a conventional half-bridge LLC circuit. However, when the example embodiment is operated with the duty cycle D set to a value other than 0.5 (i.e., other than 50%), the AC voltage across the rectifier circuit 104 produces a gain of 0.5 / D. For example, when the duty cycle D varies between 0.25 and 0.75, the integrated buck-boost LLC converter 100 provides a voltage gain between 2 and 2 / 3 at each duty cycle D. In addition, further voltage gain can be obtained by adjusting the switching frequency. If the single-stage converter 100 generates an additional voltage gain of a factor of 1 to 2 through PFM, the cumulative voltage gain can range from about 2 / 3 to about 4. Therefore, this example represents a voltage gain range of about 6 or more. Such relatively wide gains are desirable for any number of modern applications discussed throughout the examples disclosed herein. In addition, duty cycle changes and switching frequency control can be optimized to ensure smooth transitions between switching states.
[0031] In addition, if Figure 2 As shown in , the single-stage converter 100 can operate according to zero voltage conduction (ZVS) of all primary switching devices (e.g., first to fourth switches S1-S4) and zero current shutdown (ZCS) of all secondary devices (e.g., one or more diodes 134) over the entire operating range. This will result in lower voltage device ratings compared to traditional two-stage solutions. In addition, compared to traditional buck-boost and LLC resonator cascade converters, the single-stage converter 100 produces a symmetrical AC voltage.
[0032] Reference again Figure 2, indicating the ZVS switching point of the first switch S1 and the second switch S2. In addition, Figure 2 Also shown in FIG. 1 are ZCS switching points of one or more rectifier diodes 134. Here, ZVS and ZCS switching points are indicated when the duty cycle D is less than 50% and when the duty cycle D is greater than 50%. In addition, single-stage integration of the buck-boost circuit 102 and the rectifier circuit 104 according to differential and common-mode voltage gain outputs is facilitated by interleaving the interleaved arms 110, 112 and their switching arrangements.
[0033] Figure 3 and Figure 4 The buck-boost circuit 102 is shown integrated by the interleaved arms 110, 112 according to the differential mode gain of the converter 100 (ie, the voltage difference in the first arm 110 and the second arm 112 is amplified). Figure 3 , the voltage across the first arm 110 and the second arm 112 of the single-stage converter 100 is shown when the duty cycle D is less than 50%. When the duty cycle D is less than 50%, the inductor L dc The battery is charged through the second switch S1 of the first arm 110 and the fourth switch S4 of the second arm 112 . Figure 4 The voltage across the first arm 110 and the second arm 112 is depicted when the duty cycle D is greater than 50%. Therefore, when the duty cycle is greater than 50%, the inductor L dc The first switch S1 of the first arm 110 connected to the second capacitor C2 and the third switch S3 of the second arm 112 are charged.
[0034] Whether the duty cycle D is less than or greater than 50%, the inductor L dc are discharged according to the same topology. In particular, the inductor L dc The first switch S1 from the first arm 110 is discharged through the first capacitor C1 and connected to the fourth switch S4 from the second arm 112. dc The first arm 110 is discharged through the second switch S2 connected to the second capacitor C2 and the third switch S3 of the second arm 112 .
[0035] Figure 3 and Figure 4 The voltage diagram indicates the charging and discharging status during the progression of the duty cycle D. Figure 3 In the example, stage I indicates charging, while stages III and IV indicate discharging. Figure 4 Charging at stage II is shown, while stages III and IV indicate discharging.
[0036] Figure 5 and Figure 6Further illustrated is the integration of the buck-boost circuit 102 by the interleaved arms 110, 112 according to the common mode gain of the converter 100 (i.e., the amplification of the voltage present on both arms 110, 112 relative to the common / ground). Figure 5 In FIG. 1 , the neutral state with a duty cycle D less than 50% is shown as activating the second switch S2 and the fourth switch S4. Figure 6 In FIG. 1 , when the duty cycle D is greater than 50%, the neutral state activates the first capacitor C1 and the first switch S1 of the first arm 110 , which corresponds to the second capacitor C2 and the third switch S3 of the second arm 112 .
[0037] Figure 5 and Figure 6 The same topology is shown for the inverting and non-inverting states of phases III and IV, respectively, whether the duty cycle D is less than or greater than 50%. Figure 5 and Figure 6 The voltage graph of indicates the change between the neutral, reverse and positive phases during the progression of the duty cycle D. Figure 5 In the embodiment, level I indicates a neutral state, while levels III and IV indicate an inverting state and a non-inverting state, respectively. Figure 6 In the diagram, the neutral state is II, while the inverting and non-inverting states correspond to stages III and IV.
[0038] Reference now Figure 7 and Figure 8 , several embodiments and variations of the single-stage converter 100 are shown. Figure 7 In FIG. 1 , half-bridge DC-DC converters 200 a, 200 b are shown each having a single buck-boost circuit 102. Figure 7 In FIG. 1 , the single-phase DC-DC converters 200 c , 200 d are shown as having a combination of a half-bridge buck-boost circuit 102 and a hybrid buck-boost phase circuit 202 including a fifth switch S5 and a sixth switch S6 . Figure 7 1 and 2 are single-phase or multi-phase DC-DC converters 200e, 200f having two (or more in the example embodiment) buck-boost phase circuits 102. In the example circuit configurations 200e, 200f, the capacitors of each of the buck-boost phase circuits 102 may be arranged individually or in parallel. Figure 7 Each of the circuit configurations 200a-200f further includes an isolated rectifier circuit 204. The isolated rectifier circuit 204 may be one of the LLC resonant converters / circuit 104 or another suitable non-resonant converter (eg, a full-bridge phase-shift converter, a dual active bridge converter, etc.).
[0039] exist Figure 8, an example circuit configuration including a buck-boost circuit 102 is combined with a half-bridge LLC converter. The circuit configuration 300a is a single-stage converter 100 in a half-bridge LLC converter configuration 108 (see also Figure 1 ). In addition, the circuit structure 300b includes a first resonant capacitor C operably coupled in parallel with one end of the transformer T. r1 and the second resonant capacitor C r2 .and Figure 1 The resonant capacitor C of the LLC resonant circuit 104 shown in FIG. r This adds an additional capacitor. In circuit configuration 300c, the first resonant capacitor C r1 and the second resonant capacitor C r2 is operably coupled to either end of the transformer T, and the resonant inductor L r A center tap 302 operably coupled to a primary winding 304 of a transformer T.
[0040] The embodiments described in detail above may be combined in whole or in part with any of the alternative embodiments described.
[0041] Industrial Applicability
[0042] The above disclosure can represent an improvement in the art by providing a reliable, efficient and economical single-stage wide gain converter. Compared with the prior art two-stage converter with similar voltage range capability, the subject matter of the present disclosure provides greater power density and direct control. The single-stage converter can allow a wide gain range with fewer and smaller electronic components.
[0043] While certain embodiments have been shown and described, numerous modifications are conceivable without departing significantly from the spirit of the present disclosure, and the scope of protection is limited solely by the scope of the appended claims.
[0044] To the extent that the terms "include," "have," and the like are used, such terms are intended to be inclusive in a manner similar to the term "comprise" when used as a transitional term in a claim. Relational terms such as first and second, and the like may be used to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions.
[0045] For example, aspects, the aspects, another aspect, some aspects, one or more aspects, implementations, the implementations, another implementation, some implementations, one or more implementations, embodiments, the embodiments, another embodiment, some embodiments, one or more embodiments, configurations, the configurations, another configuration, some configurations, one or more configurations, subject technology, the present disclosure, the present disclosure, other variations thereof, etc. are for convenience and do not mean that the disclosure involving such phrases is necessary for the subject technology, or that such disclosures apply to all configurations of the subject technology. Disclosures involving such phrases can apply to all configurations or one or more configurations. Disclosures involving such phrases can provide one or more examples. For example, a phrase of one aspect or some aspects can refer to one or more aspects, and vice versa, and this applies similarly to the other aforementioned phrases.
[0046] The disclosed systems and methods are well suited to achieve the objects and advantages mentioned and those inherent therein. The specific implementations disclosed above are illustrative only, as the teachings of the present disclosure may be modified and practiced in different but equivalent ways apparent to those skilled in the art who benefit from the teachings herein. In addition, except as described in the claims below, it is not intended to limit the details of the structure or design shown herein. Therefore, it is apparent that the specific illustrative implementations disclosed above may be changed, combined or modified, and all such variations are considered to be within the scope of the present disclosure. The systems and methods illustratively disclosed herein may be appropriately implemented in the absence of any element not specifically disclosed herein and / or any optional element disclosed herein.
[0047] It should be understood that the described instructions, operations, and systems may generally be integrated together in a single software / hardware product or packaged into multiple software / hardware products.
[0048] In the context of describing the subject matter of the present disclosure (particularly in the context of the appended claims), the use of the terms "a" and "an", "the" and "said" and similar references should be interpreted as covering both the singular and the plural, unless otherwise indicated herein or clearly contradictory to the context. In the absence of further restrictions, elements starting with "a", "an", "the" and "said" do not exclude the presence of other identical elements. Unless otherwise specified in this article, the enumeration of numerical ranges herein is only intended to be used as a shorthand method for individually referring to each individual value falling within the range, and each individual value is incorporated into the specification as if it is individually listed in this article. All methods described herein can be carried out in any suitable order, unless otherwise indicated herein or clearly contradictory to the context. The use of any and all examples or exemplary language (e.g., "such as") provided herein is only intended to better illustrate the present disclosure, and does not limit the scope of the present disclosure, unless otherwise stated. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure.
Claims
1. A method for operating a converter, comprising: operating a plurality of switches disposed in a first interleaved arm and a second interleaved arm of the converter to generate an AC voltage in an inductor of the converter coupled to the first interleaved arm and the second interleaved arm; and The AC voltage is supplied to an LLC resonant circuit of the converter from a center-tapped output of the inductor, the inductor being connected in parallel with a resonant capacitor of the LLC resonant circuit. 2 . The method of claim 1 , wherein operating the plurality of switches comprises zero voltage switching the plurality of switches. 3 . The method of claim 1 , wherein operating the plurality of switches comprises controlling switching of the plurality of switches using pulse width modulation. The method of claim 1 , wherein operating the plurality of switches comprises controlling switching of the plurality of switches using frequency modulation.
5. The method according to claim 1, further comprising: The AC voltage is rectified using the LLC resonant circuit of the converter and at least one diode of the converter.
6. A power circuit, comprising: Rectifier; and A buck-boost circuit comprising: an inductor operable to generate an AC output to the rectifier; and an interleaved arm coupled to the inductor, the interleaved arm including a plurality of switches operable to control power supplied to the inductor; wherein each of the interlaced arms comprises: at least two switches of the plurality of switches connected directly in series; at least one capacitor connected in series with the at least two switches; and A node is disposed between the at least two switches and coupled to the inductor of the buck-boost circuit. 7 . The power circuit of claim 6 , wherein the plurality of switches are operable by one of pulse width modulation and frequency modulation to control a voltage gain of the power circuit.
8. The power circuit of claim 6, wherein the interleaved arms include (i) a first interleaved arm coupled to a first end of the inductor and (ii) a second interleaved arm coupled to a second end of the inductor.
9. The power circuit of claim 8, wherein a first node of the first interleaved arm is coupled to a first side of the inductor, and a second node of the second interleaved arm is coupled to a second side of the inductor.
10. The power circuit of claim 6, wherein the inductor of the buck-boost circuit is operable to generate the AC output through a center tap of the inductor, the center tap being coupled to another inductor of the rectifier.
11. The power circuit of claim 6, wherein the rectifier comprises a tank resonator. 12 . The power circuit of claim 11 , wherein the rectifier further comprises at least one of a rectifying diode and a synchronous rectifier.
13. The power circuit of claim 11, wherein the rectifier further comprises at least one rectifier diode operably coupled to a filtering output capacitor.
14. A system comprising: A buck-boost circuit comprising: an inductor operable to generate an AC output; and an interleaved arm coupled to the inductor, the interleaved arm including a plurality of switches operable to control power supplied to the inductor; wherein each of the interlaced arms comprises: at least two switches of the plurality of switches connected directly in series; at least one capacitor connected in series with the at least two switches; and A node is disposed between the at least two switches and coupled to the inductor.
15. The system of claim 14, wherein the plurality of switches are operable by one of pulse width modulation and frequency modulation to control a voltage gain by the buck-boost circuit.
16. The system of claim 14, wherein the interleaved arms include (i) a first interleaved arm coupled to a first end of the inductor and (ii) a second interleaved arm coupled to a second end of the inductor.
17. The system of claim 16, wherein a first node of the first interlaced arm is coupled to a first side of the inductor and a second node of the second interlaced arm is coupled to a second side of the inductor.
18. The system of claim 14, wherein the inductor of the buck-boost circuit is operable to generate the AC output through a center tap of the inductor.
19. The system of claim 14, further comprising: An LLC resonant circuit is configured to receive the AC output from the inductor, wherein the inductor is connected in parallel with a resonant capacitor of the LLC resonant circuit.
20. The system of claim 19, wherein the inductor comprises a center tap configured to supply the AC output to the LLC resonant circuit.