阅读说明：本技术 混合开关电容转换器 (Hybrid switched capacitor converter ) 是由 C·雷纳 R·里佐拉蒂 O·威登鲍尔 于 2020-01-07 设计创作，主要内容包括：本公开涉及混合开关电容转换器。例如,一种电源系统包括开关电容转换器、变压器和电压转换器。开关电容转换器包括多个电容器。多个电容器在包括变压器的初级绕组的电路路径中被可控地切换,以将第一电压转换为第二电压。电压转换器将由开关电容转换器产生的第一电压转换成为负载供电的第二电压。(The present disclosure relates to hybrid switched-capacitor converters. For example, a power supply system includes a switched capacitor converter, a transformer, and a voltage converter. The switched-capacitor converter includes a plurality of capacitors. A plurality of capacitors are controllably switched in a circuit path including a primary winding of the transformer to convert the first voltage to a second voltage. The voltage converter converts a first voltage generated by the switched-capacitor converter into a second voltage supplied by the load.)

1. An apparatus, comprising:

a switched-capacitor converter operative to generate a first voltage, the switched-capacitor converter comprising a plurality of capacitors;

a transformer comprising a primary winding, the plurality of capacitors being controllably switched in a circuit path comprising the primary winding to convert the first voltage to a second voltage; and

a voltage converter coupled to the secondary winding of the transformer, the voltage converter operative to convert the second voltage to an output voltage.

2. The apparatus of claim 1, wherein the voltage converter is a rectifier circuit operative to convert the second input voltage to the output voltage.

3. The apparatus of claim 1, further comprising: an inductor connected across a node of the primary winding of the transformer.

4. The apparatus of claim 3, wherein the inductor is operative to provide zero voltage switching of a switch in the switched-capacitor converter.

5. The apparatus of claim 1, wherein the primary winding comprises a first node and a second node, the apparatus further comprising:

a first capacitor;

a second capacitor;

a first switching circuit path extending from the first node of the primary winding to an input voltage source that provides power for the switched-capacitor converter, the first switching circuit path including the first capacitor; and

a second switched circuit path extending from the second node of the primary winding to the input voltage source providing power for the switched-capacitor converter, the second switched circuit path including the second capacitor.

6. The apparatus of claim 5, wherein the first capacitor is a first flying capacitor, and wherein the second capacitor is a second flying capacitor.

7. The apparatus of claim 1, wherein the switched-capacitor converter comprises a first capacitor and a second capacitor, the apparatus further comprising:

a controller operative to switch the switched-capacitor converter between a first resonant frequency mode and a second resonant frequency mode, wherein: i) the first resonant frequency mode is operative to charge the first capacitor via an input voltage and discharge the second capacitor through the primary winding, and ii) the second resonant frequency mode is operative to charge the second capacitor via the input voltage and discharge the first capacitor through the primary winding.

8. The apparatus of claim 7, wherein operation in the first resonant frequency mode comprises activation of a first switch in the switched-capacitor converter, the activation of the first switch connecting the first capacitor in series with the primary winding of the transformer; and

wherein operation in the second resonant frequency mode comprises activation of a second switch in the switched-capacitor converter, the activation of the second switch connecting the second capacitor in series with the primary winding of the transformer.

9. The apparatus of claim 1, further comprising:

a controller operative to adjust a frequency at which the first switch and the second switch in the switched-capacitor converter are switched, the adjustment of the frequency being used to control a magnitude of the output voltage.

10. The apparatus of claim 1, wherein the transformer further comprises a secondary winding that is center tapped to produce the output voltage.

11. The apparatus of claim 1, wherein the switched-capacitor converter comprises a first capacitor and a second capacitor;

wherein the switched-capacitor converter comprises a first switch and a second switch, the apparatus further comprising:

a controller operative to: i) activating the first switch while the second switch is deactivated; and ii) activating the second switch while the first switch is deactivated.

12. The apparatus of claim 1, wherein the switched-capacitor converter comprises a multi-switch network of switches coupled to the primary winding of the transformer.

13. The apparatus of claim 12, wherein the switched-capacitor converter comprises first and second capacitors coupled to the multi-switch network of switches, the apparatus further comprising:

a controller operative to switch the switched-capacitor converter between a first resonant frequency mode and a second resonant frequency mode, wherein: i) the first resonant frequency mode is operative to charge the first capacitor via an input voltage and discharge the second capacitor through the primary winding, and ii) the second resonant frequency mode is operative to charge the second capacitor via the input voltage and discharge the first capacitor through the primary winding.

14. The apparatus of claim 1, further comprising:

a controller operative to switch the switched-capacitor converter between operating the switched-capacitor converter at the same resonant frequency during each of a plurality of different switching modes that controllably switch the plurality of capacitors.

15. A method, comprising:

controllably switching a plurality of capacitors in a switched-capacitor converter, the plurality of capacitors controllably switched in a circuit path including a primary winding of a transformer, the controllable switching of the plurality of capacitors converting a first voltage to a second voltage;

receiving the second voltage as an input to the primary winding of the transformer; and

controlling a voltage converter coupled to a secondary winding of the transformer to convert the second voltage into a load-powered output voltage.

16. The method of claim 15, wherein controlling the voltage converter comprises: rectifying the second voltage to generate the output voltage.

17. The method of claim 15, further comprising:

providing zero voltage switching of a switch in the switched-capacitor converter for controllably switching the plurality of capacitors in the circuit path via an inductor across the primary winding of the transformer.

18. The method of claim 15, wherein the plurality of capacitors comprises a first capacitor and a second capacitor, the method further comprising:

control, via the plurality of switches in the switched-capacitor converter:

in a first mode, providing a first switching circuit path extending from a first node of the primary winding to an input voltage source providing power for the switched-capacitor converter, the first switching circuit path including the first capacitor; and

in a second mode, a second switched circuit path is generated that extends from a second node of the primary winding to the input voltage source that provides power for the switched-capacitor converter, the second switched circuit path including the second capacitor.

19. The method of claim 18, wherein the first capacitor is a first flying capacitor; and is

Wherein the second capacitor is a second flying capacitor.

20. The method of claim 15, wherein the switched-capacitor converter comprises a first capacitor and a second capacitor; and is

Wherein selectively switching the plurality of capacitors in the switched-capacitor converter comprises: switching the switched-capacitor converter between a first resonant frequency mode and a second resonant frequency mode, wherein: i) operation of the switched-capacitor converter in the first resonant frequency mode charges the first capacitor via the first voltage and discharges the second capacitor through the primary winding, and ii) operation in the second resonant frequency mode charges the second capacitor via the first voltage and discharges the first capacitor through the primary winding.

21. The method of claim 20, wherein operation in the first resonant frequency mode comprises activating a first switch in the switched-capacitor converter; and is

Wherein operation in the second resonant frequency mode comprises activating a second switch in the switched-capacitor converter.

22. The method of claim 15, further comprising:

adjusting a frequency at which a first switch and a second switch in the switched-capacitor converter are switched, the adjustment of the frequency for controlling the magnitude of the second voltage.

23. The method of claim 15, further comprising:

the output voltage is output from a center tap of a secondary winding of the transformer.

24. The method of claim 15, wherein the plurality of capacitors comprises a first capacitor and a second capacitor, the method further comprising:

in a first mode, activating a first switch in the switched-capacitor converter while a second switch in the switched-capacitor converter is deactivated; and

in a second mode, a second switch in the switched-capacitor converter is activated while the first switch is deactivated.

25. The method of claim 15, wherein the switched-capacitor converter comprises a multi-switch circuit coupled to a primary winding of the transformer, the method further comprising:

controlling a plurality of switches in the multi-switch circuit in the switched-capacitor converter to generate the first voltage.

26. The method of claim 25, wherein the plurality of capacitors comprises a first capacitor and a second capacitor, the first capacitor and the second capacitor coupled to the multi-switch circuit, the method further comprising:

switching the switched-capacitor converter between a first resonant frequency mode and a second resonant frequency mode, wherein: i) operation of the switched-capacitor converter in the first resonant frequency mode charges the first capacitor via an input voltage and discharges the second capacitor through the primary winding, and ii) operation in the second resonant frequency mode charges the second capacitor via the input voltage and discharges the first capacitor through the primary winding.

27. The method of claim 15, further comprising:

controlling the switched-capacitor converter to operate in different switching modes in which the switched-capacitor converter operates at the same resonance frequency.

28. Computer-readable storage hardware having stored thereon instructions that, when executed by computer processor hardware, cause the computer processor hardware to:

controllably switching a plurality of capacitors in a switched-capacitor converter, the plurality of capacitors controllably switched in a circuit path of a primary winding of a transformer, controllable selective switching of the plurality of capacitors converting a first voltage to a second voltage;

converting, via the transformer, the first voltage to a second voltage; and

controlling a voltage converter to convert the second voltage generated by the transformer into an output voltage supplied by a load.

29. The apparatus of claim 1, further comprising:

an inductor integrated in the transformer, the inductor operative to provide zero voltage switching in the switched-capacitor converter.

Technical Field

The present disclosure relates to the field of circuits, and more particularly, to hybrid switched capacitor converters.

Background

As the name implies, conventional switched capacitor DC-DC converters convert a received DC input voltage into a DC output voltage.

In one conventional application, the input voltage of a conventional switched-capacitor converter falls within a range between 40VDC and 60 VDC. In this case, for a so-called 4:1 switched-capacitor converter, the switches in the switched-capacitor converter are controlled to transfer the charge stored in the capacitor, thereby converting an input voltage (such as 48VDC) to an output voltage (such as 12 VDC). In other words, a conventional switched-capacitor converter may be configured to convert a 48VDC voltage to a 12VDC voltage.

To avoid so-called hard switching in a switched capacitor converter, the switches in a switched capacitor converter are preferably switched when they have a near zero voltage across them and a near zero current through them.

By placing a separate inductor in series with a corresponding capacitor in each stage of a switched capacitor converter, undesirable hard switching in conventional switched capacitor converters can be mitigated. This results in a resonant (or semi-resonant) switching converter. Such a switched capacitor converter is sometimes referred to as a Switched Tank Converter (STC). The resonant tank circuit formed by the series connection of the inductor and the capacitor has an associated resonant frequency based on the inductance and capacitance of these components.

The switching of the switches in conventional switched capacitor converters at the respective resonant frequencies results in so-called Zero Current Switching (ZCS), which reduces switching losses and provides good power conversion efficiency.

Disclosure of Invention

The present disclosure includes the observation that the power conversion efficiency of conventional switched capacitor converters can be improved. For example, to this end, embodiments herein include novel ways of providing improved performance of switched-capacitor converters and efficient generation of respective output voltages.

More specifically, according to one embodiment, an apparatus (such as a power supply) includes: switched capacitor converters, transformers and voltage converters. The switched-capacitor converter includes a plurality of capacitors and is operative to generate a first voltage. The transformer includes a primary winding and a secondary winding. A controller of the apparatus controllably switches a plurality of capacitors in respective circuit paths including the primary winding to convert the first voltage to a second voltage. A subsequent stage of the power supply, such as a voltage converter, is coupled to the secondary winding of the transformer and converts the second voltage to an output voltage.

It should be noted that any of the one or more components of the power supply, such as the switched capacitor converter, the transformer, the voltage converter, the controller, etc., may be implemented as hardware, such as a circuit arrangement, software, or a combination of hardware and software.

In one embodiment, the voltage converter is a rectifier or other suitable converter circuit operative to convert the second input voltage to the output voltage. As previously discussed, the transformer may be configured to include a secondary winding inductively coupled to the primary winding. The secondary winding may be center tapped, if desired, to produce an output voltage from the voltage converter.

According to a further embodiment, a power supply as described herein comprises an inductor connected across a node of a primary winding of a transformer. The inductor provides Zero Voltage Switching (ZVS) of the switches in the switched-capacitor converter. Additionally or alternatively, it should be noted that the zero voltage switching capability may be provided by the magnetizing inductance of the transformer.

According to still further embodiments, the primary winding of the transformer comprises a first node and a second node. A switched-capacitor converter includes a first capacitor (such as a first flying capacitor) and a second capacitor (such as a second flying capacitor). The switched-capacitor converter also includes a first switched-circuit path and a second switched-circuit path. In one embodiment, a first switched circuit path (including a first capacitor) of the switched-capacitor converter extends from a first node (for a first duration) of the primary winding to an input voltage source that provides power to the switched-capacitor converter; a second switched circuit path extends (for a second duration of time) from a second node of the primary winding to an input voltage source that provides power to the switched-capacitor converter. The first switching circuit path and the second switching circuit path may be activated at different times to generate a voltage input to the transformer.

Further embodiments herein include a controller operative to control the switched-capacitor converter and/or the voltage converter.

As a more specific example, the controller is operative to switch the switched-capacitor converter between a first resonant frequency mode and a second resonant frequency mode, wherein: i) a first resonant frequency mode operative to charge the first capacitance via the input voltage and discharge the second capacitance through the primary winding, and ii) a second resonant frequency mode operative to charge the second capacitor via the input voltage and discharge the first capacitor through the primary winding.

According to a further embodiment, the operation in the first resonant frequency mode comprises an activation of a first switch in the switched-capacitor converter, the activation of the first switch connecting or creating a circuit path comprising a combination of at least a first capacitor and a primary winding of a transformer in series; operation in the second resonant frequency mode includes activation of a second switch in the switched-capacitor converter, the activation of connecting the combined second switch or creating a circuit path including at least a second capacitor and a primary winding of a transformer in series.

According to still further embodiments, the controller is operative to switch the switched-capacitor converter between operating the switched-capacitor converter at the same resonant frequency during each of a plurality of different switching modes that controllably switch the plurality of capacitors in different circuit paths.

According to a further embodiment, the controller is operative to adjust a frequency of switching different sets of switches (such as a first switch and a second switch in a switched capacitor converter); the adjustment of the frequency controls the amplitude of the output voltage. To switch between resonant frequency modes, the controller is operative to: i) activating the first switch while deactivating the second switch, and ii) activating the second switch while deactivating the first switch. Further embodiments herein include so-called dead time when no switch is activated.

In the manner previously discussed, operation in the first resonant frequency mode includes activation of the first switch resulting in a unique connection of the combination of the first capacitor, the primary winding of the transformer and the second capacitor. Operation in the second resonant frequency mode includes the sole connection of the combination of the first capacitor, the primary winding of the transformer, and the second capacitor.

Further embodiments herein implement a switched-capacitor converter to include a multi-switch circuit coupled to a primary winding of a transformer. Each branch of the multi-switch circuit optionally includes a plurality of switches connected in series.

In one example embodiment, a switched-capacitor converter includes a first capacitor and a second capacitor coupled to a multi-switch circuit. The apparatus also includes a controller operative to switch the switched-capacitor converter between a first resonant frequency mode and a second resonant frequency mode, wherein: i) a first resonant frequency mode operative to charge the first capacitor via the input voltage and discharge the second capacitor through the primary winding, and ii) a second resonant frequency mode operative to charge the second capacitor via the input voltage and discharge the first capacitor through the primary winding.

Embodiments herein are useful over conventional techniques. For example, new power supplies including switched capacitor converters, transformers, and voltage converters provide greater efficiency in converting an input voltage to a corresponding output voltage than conventional techniques. Such an embodiment provides improved efficiency (lower energy loss) in generating the respective output voltages.

These and other more specific embodiments are disclosed in more detail below.

It should be noted that any resource discussed herein may include one or more computerized devices, apparatus, hardware, etc., performing and/or supporting any or all of the method operations disclosed herein. In other words, one or more computerized devices or processors may be programmed and/or configured to operate as explained herein to perform the different embodiments described herein.

Still other embodiments herein include software programs that perform the steps and/or operations outlined above and disclosed in detail below. One such embodiment includes a computer program product that includes a non-transitory computer-readable storage medium (i.e., any computer-readable hardware storage medium) having software instructions encoded thereon for subsequent execution. When executed in a computerized device (hardware) having a processor, the instructions program and/or cause the processor (hardware) to perform the operations disclosed herein. Such arrangements are typically provided as software, code, instructions and/or other data (e.g., data structures) arranged or encoded on a non-transitory computer readable storage medium such as an optical medium (e.g., CD-ROM), floppy disk, hard disk, memory stick, storage device, etc., or other medium such as firmware in one or more ROMs, RAMs, PROMs, etc., or as an Application Specific Integrated Circuit (ASIC), etc.

Accordingly, embodiments herein aim to provide methods, systems, computer program products, etc. that support operation as discussed herein.

One embodiment includes a computer-readable storage medium and/or system having instructions stored thereon to facilitate generating an output voltage to power a load. When executed by computer processor hardware, the instructions cause the computer processor hardware (such as one or more co-located or differently located processor devices or hardware): controllably switching a plurality of capacitors in a switched-capacitor converter, the plurality of capacitors controllably switching in a circuit path of a primary winding of a transformer, the controlled selective switching of the plurality of capacitors converting the first voltage to a second voltage; converting the first voltage to a second voltage via a transformer; and controlling the voltage converter to convert the second voltage generated by the transformer into an output voltage supplied by the load.

The order of the above steps is added for clarity. It should be noted that any of the process steps discussed herein may be performed in any suitable order.

Other embodiments of the present disclosure include software programs and/or corresponding hardware to perform any of the method embodiment steps and operations summarized above and disclosed in detail below.

It should be understood that the systems, methods, apparatus, instructions on a computer-readable storage medium, etc. discussed herein may also be implemented strictly as a software program, firmware, software, a mixture of hardware and/or firmware, or hardware-only, such as within a processor (hardware or software) or within an operating system or within a software application.

It should also be noted that although the embodiments discussed herein are suitable for controlling the operation of a switched capacitor converter, the concepts disclosed herein may be advantageously applied to any other suitable voltage converter topology.

Additionally, it should be noted that although each of the different features, techniques, configurations, etc. herein may be discussed in different places of this disclosure, each concept may alternatively be performed independently of each other or in combination with each other, where appropriate. Thus, one or more of the inventions described herein can be practiced and observed in many different ways.

Additionally, it should be noted that the preliminary discussion of embodiments herein (summary of the invention) is not intended to specify each embodiment and/or the incremental novel aspects of the disclosure or claimed invention. Rather, this brief description presents only general embodiments and corresponding novel points relative to conventional techniques. For additional details and/or possible perspectives (permutations) of the invention, the reader is directed to the specific embodiments section of the disclosure (which is an abstract of embodiments) and corresponding figures discussed further below.

Drawings

Fig. 1 is an example diagram illustrating a power supply including a switched capacitor converter according to embodiments herein.

Fig. 2 is an example diagram illustrating a more detailed reproduction of a controller and a power supply including a switched-capacitor converter, a transformer, and a voltage converter according to embodiments herein.

Fig. 3 is an example timing diagram illustrating signals controlling switches in a switched capacitor converter and a voltage converter according to embodiments herein.

Fig. 4 is an example diagram illustrating a timing diagram of an output signal according to embodiments herein.

Fig. 5 is an example diagram illustrating a first mode of controlling switches in a switched capacitor converter and a voltage converter according to embodiments herein.

Fig. 6 is an example diagram illustrating dead time or deactivation of switches in a power supply according to embodiments herein.

Fig. 7 is an example diagram illustrating a second mode of controlling switches in a switched capacitor converter and a voltage converter according to embodiments herein.

Fig. 8 is an example diagram illustrating dead time or deactivation of switches in a power supply according to embodiments herein.

Fig. 9 is an exemplary diagram illustrating a circuit equivalent of the first mode of operation (fig. 5) according to embodiments herein.

Fig. 10 is an exemplary diagram illustrating a circuit equivalent of the second mode of operation (fig. 7) according to embodiments herein.

Fig. 11 is an example diagram illustrating an implementation of a voltage converter according to embodiments herein.

Fig. 12 is an example diagram illustrating an implementation of a switched-capacitor converter including a multi-switch circuit according to embodiments herein.

Fig. 13 is an example diagram illustrating a first mode of controlling switches in a switched capacitor converter and a voltage converter according to embodiments herein.

Fig. 14 is an example diagram illustrating dead time or deactivation of switches in a switched capacitor converter and a voltage converter according to embodiments herein.

Fig. 15 is an example diagram illustrating a second mode of controlling switches in a switched capacitor converter and a voltage converter according to embodiments herein.

Fig. 16 is an example diagram illustrating dead time or deactivation of switches in a switched capacitor converter and a voltage converter according to embodiments herein.

Fig. 17 is an exemplary diagram illustrating a computer architecture for performing one or more operations according to embodiments herein.

Fig. 18 is an example diagram illustrating a general method according to embodiments herein.

The foregoing and other objects, features and advantages of the embodiments herein will be apparent from the following more particular descriptions, as illustrated in the accompanying drawings wherein like reference numbers represent the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments, principles, concepts, etc.

Detailed Description

According to one embodiment, an apparatus, such as a power supply system, includes a switched capacitor converter, a transformer, and a voltage converter, as discussed further herein. The switched-capacitor converter includes a plurality of capacitors. A plurality of capacitors are controllably switched in a circuit path including a primary winding of the transformer to convert the first voltage to a second voltage. The voltage converter converts a first voltage generated by the switched-capacitor converter into a second voltage supplied by the load.

A power supply as described herein provides more efficient conversion of an input voltage to an output voltage that powers a load.

Now, more specifically, fig. 1 is an example diagram illustrating a power supply including a switched capacitor converter according to embodiments herein.

As shown in this example embodiment, a power supply 100 (such as an apparatus, electronic device, etc.) includes a controller 110, a switched-capacitor converter 150, a transformer 160, and a voltage converter 170.

It should be noted that each of the sources described herein may be instantiated in a suitable manner. For example, each of the controller 110, the switched-capacitor converter 150, the transformer 160, the voltage converter 170, and the like may be instantiated as or include hardware (such as circuitry), software (executed instructions), or a combination of hardware and software resources.

During operation, the controller 110 generates control signals 105 (such as one or more pulse width modulated signals) that control the state of corresponding control switches in the switched-capacitor converter 150.

As further shown, the switched-capacitor converter 150 receives an input voltage 120(Vin, such as a DC input voltage) and converts it to a first voltage 121. The transformer 160 includes a primary winding 161 and a secondary winding 162. The secondary winding is inductively coupled to the primary winding.

As discussed further herein, the controller 110 of the power supply 100 controllably switches a plurality of capacitors in respective circuit paths including the primary winding 161 of the transformer 160 to convert the input voltage to the first voltage 121.

It should also be noted that the voltage converter 170 is coupled to the secondary winding 162 of the transformer 160 and receives the second voltage 122. The voltage converter 170 converts the second voltage 122 into an output voltage 123 that powers the load 118.

Fig. 2 is an example diagram illustrating a switched-capacitor converter according to embodiments herein.

As shown, the power supply 100 includes a voltage source Vin, a switched capacitor converter 150, a transformer 160, and a voltage converter 170.

The switched-capacitor converter 150 (a device such as hardware, circuit device, etc.) includes a plurality of switches Q1, Q2, Q3, Q4, Q5, and Q6. in addition, the switched-capacitor converter 150 includes a plurality of circuit components, including an inductor L zvs, a capacitor Cres1, and a capacitor Cres 2.

In this embodiment, the drain node (D) of switch Q1 and the drain node (D) of switch Q4 are connected to an input voltage source Vin.

In addition, the source node (S) of the switch Q1 is coupled to the drain node (D) (node 213) of the switch Q2. The source node (S) of the switch Q4 is coupled to the drain node (D) (node 214) of the switch Q5. The source node (S) of switch Q2 is coupled to node 211. The source node (S) of switch Q5 is coupled to node 212.

Capacitor Cres1 is connected between node 213 and node 212. Capacitor Cres2 is connected between node 214 and node 211.

Inductor L zvs is coupled in parallel with primary winding 161 and is disposed between nodes 211 and 212.

As further shown, the transformer 160 includes a primary winding 161 (such as N1 turns) and a secondary winding 162. The number of windings associated with primary winding 161 and/or secondary winding 162 may vary depending on the embodiment.

In the exemplary embodiment, secondary winding 162 includes a first secondary winding 162-1(N2 turns) and a second secondary winding 162-2(N2 turns). According to a further embodiment, it is noted that the secondary winding may be a single winding.

As shown, the drain (D) of switch Q3 is connected to node 211; the source (S) of switch Q3 is connected to ground. The drain (D) of switch Q6 is connected to node 212; the source (S) of switch Q6 is connected to ground.

The voltage converter 170 includes switches Q7 and Q8. As further shown, the drain (D) of switch Q7 is connected to the first secondary winding 162-1; the drain (D) of switch Q8 is connected to the second secondary winding 162-2. The center tap of secondary winding 162 outputs a current Iout and generates an output voltage 123 to drive load 118.

In one embodiment, the magnitude of the output voltage 123 is Vin/8. Thus, if Vin is 48VDC, the magnitude of the output voltage 123 is 6 volts. However, as discussed herein, the settings of the components in the power supply 100 may be adjusted to produce any suitable value of the output voltage 123 (Vout). Typically, the output voltage 123, Vout is Vin (N2/(2 × N1)), where N1 is the number of turns on the primary winding and N2 is the number of turns on each secondary winding.

As further shown, during operation, controller 110 generates control signals 105-1 and 105-2.

In this example embodiment, the control signal 105-1 generated by the controller drives the gates (G) of the respective switches Q1, Q3, Q5, and Q7. Thus, the control signal 105-1 controls the state of each of the switches Q1, Q3, Q5, and Q7.

The control signal 105-2 drives the respective gates (G) of the switches Q2, Q4, Q6, and Q8. Thus, the control signal 105-2 controls the state of each switch Q2, Q4, Q6, and Q8.

It should be noted that each of the switches described herein may be any suitable device, such as a (metal oxide semiconductor) field effect transistor, a bipolar junction transistor, or the like.

The arrangement of capacitors Cres1 and Cres2 may be any suitable value, for example, the voltage converter described herein provides better performance when Cres1 ≠ Cres2, and works well even though Cres1 ≠ Cres 2. inductor L zvs may be any suitable value-see discussion in fig. 4 below, which illustrates an example arrangement of inductor L zvs that provides zero-voltage switching to switches in power supply 100.

Referring again to fig. 2, according to a further embodiment, as shown, the power supply 100 is a switched-capacitor converter (such as a zero-voltage switching hybrid switched-capacitor converter or ZVS hybrid SCC), as shown in fig. 2 including an interleaved switched-capacitor converter 150 on the primary side and a transformer 160 with a center-tapped (CT) rectifier (secondary winding and/or voltage converter 170) on the secondary side.

In one embodiment, there is optionally an additional inductance (such as inductor L ZVS) in parallel with the transformer 160 to enable Zero Voltage Switching (ZVS) of the one or more switches Q1-Q8.

An inductance (inductor) L zvs is optionally integrated in the primary winding of the transformer 160 to achieve higher power density, if desired.

As previously discussed, the switches in the power supply 100 are divided into two switch groups: the first switch set includes switches Q1, Q3, Q5, and Q7 (controlled by control signal 105-1), and the second switch set includes switches Q2, Q4, Q6, and Q8 (controlled by control signal 105-2, control signal 105-2 typically being a 180 ° phase shift of control signal 105-1).

In one embodiment, the pulse width modulation of the control signal 105 is approximately 50% to achieve a minimum RMS current.

The magnitude of the output voltage 123 depends on the number of turns (winding ratio of primary to secondary N1/N2 #) and the switching frequency of the control signal 105.

In one embodiment, controller 110 achieves regulation (such as maintaining the amplitude of output voltage 123 within a desired range) by varying the switching frequency (or period) of control signal 105. In this case, the output voltage 123 may be regulated inversely to the output current (Iout) variation with narrow switching frequency variation (i.e., depending on the power capacity and resonant tank components such as capacitors Cres1 and Cres 2). Accordingly, the proposed power supply 100 (such as a ZVS hybrid switched-capacitor converter) can be extended to different conversion ratios by merely changing the transformer turns ratio.

Embodiments herein include utilizing the leakage inductance L k of the transformer 160 to (soft) charge the capacitors Cres1 and Cres2 for example, in one embodiment, the capacitors Cres1 and Cres2 act as flying capacitors, enabling the use of lower voltage field effect transistors at the primary side (switched-capacitor converter 150) compared to the classical LL C topology.

In one embodiment, switches Q1, Q3, Q4, and Q6 typically block half of the input voltage Vin/2, switches Q2 and Q5 block all of the input voltage, and switches Q7 and Q8 block the 2xVout voltage in their off state.

It should be noted that a further advantage of the switched-capacitor converter 150 as described herein is the symmetrical behavior of such a circuit. For example, via implementation of power supply 100: i) the switched capacitor converter 150 is almost continuously powered from the input power Vin, reducing input current ripple compared to other techniques; ii) the equivalent resonant tank switching circuit path of the switched-capacitor converter 150 is the same in two resonant modes of operation, such as a first mode between time T0 and time T1 and a second mode between time T2 and time T3, where the resonant capacitors Cres1 and Cres2 are in parallel. As discussed further herein, this provides a natural balance that does not take into account tolerances of the respective circuit components.

It should be noted that one contributing factor to the high efficiency and high power density of the proposed power supply 100 is the ability to implement lower voltage rated field effect transistors and implement class II ceramic capacitors (such as capacitors Cres1 and Cers2, which inherently provide high capacitance density).

Further, as previously discussed, the additional inductor L ZVS provides inductive energy to ensure ZVS conversion (such as during all switching conditions) of all field effect transistors in the switched-capacitor converter 150-for example, the energy stored in the inductor L ZVS provides charge to the parasitic capacitor of the respective switch.

In one embodiment, to increase the output power of the power supply 100, it should be noted that additional Synchronous Rectifier (SR) MOSFETs may be implemented in parallel to reduce conduction losses at the secondary side of the power supply 100.

Fig. 3 is an example diagram illustrating generation of control signals for controlling a switched-capacitor converter and a corresponding voltage converter according to embodiments herein.

Generally, as shown in diagram 300, controller 110 generates control signal 105-2 as an inverse of control signal 150-1. The pulse width of each control signal is approximately 49% or other suitable pulse width modulation value.

Between time T0 and time T1, when control signal 105-1 (logic high) controls the set of switches Q1, Q3, Q5, and Q7 to the ON state (low impedance or short circuit), control signal 105-2 (logic low) controls the set of switches Q2, Q4, Q6, and Q8 to the OFF state (very high impedance or open circuit).

Conversely, between time T2 and time T3, when control signal 105-2 (logic high) controls the set of switches Q2, Q4, Q6, and Q8 to the ON state, control signal 105-1 (logic low) controls the set of switches Q1, Q3, Q5, and Q7 to the OFF state.

It should be noted that the duration between time T1 and time T2, the duration between time T3 and time T4, the duration between time T5 and time T6, and the like represent so-called dead times during which each switch (Q1-Q8) in the power supply 100 is deactivated to an OFF state (high impedance or open circuit).

As further shown, the control signal 105 is periodic. For example, the setting of the control signal 105 for the subsequent cycle is the same as the setting for the cycle between time T0 and time T4. More specifically, the setting of the control signal 105 generated by the controller 110 between time T3 and time T7 is the same as the setting of the control signal 105 between time T0 and time T3.

In one embodiment, the controller 110 controls the frequency of the control signal (the period is the time between T0 to time T4) which may be generated at any suitable frequency.

In addition, as previously mentioned, the controller 110 controls the pulse duration of the control signal 105 to be around 49%, although the control signal 105 may be generated at any suitable pulse width modulation value.

In one non-limiting exemplary embodiment, as mentioned, the power supply provides an 8:1 reduction of the input voltage Vin (such as about 48VDC) to the output voltage 123. In this case, when the input voltage Vin is 48VDC, the switching of the respective switches converts the 48VDC input voltage to an output voltage (such as an unregulated output voltage) of Vout-6 volts. The output voltage can be adjusted, if necessary, to produce the output voltage 123 within a desired range.

As previously discussed, the magnitude of the output voltage 123(Vout) depends on the number of turns (winding ratio N1/N2 #) of the primary winding to the secondary winding and the switching frequency of the control signal 105.

It should be noted that the properties of the switched-capacitor converter 120 may be modified to convert any input voltage level to a corresponding desired (regulated or unregulated) output voltage level.

Fig. 4 is an example diagram illustrating a timing diagram of an output signal according to embodiments herein.

In this example embodiment, voltage Vx represents the voltage at node 211 of primary winding 161; voltage Vy represents the voltage at node 212 of primary winding 161.

Icres1 represents the current through capacitor Cres 1; icres2 represents the current through capacitor Cres 2. Ip represents the amount of current through the primary winding 161, which is equal to Icres 2-Icresl.

I L zvs represents the current through inductor L zvs.

Vcresl represents the voltage across capacitor Cresl; vcres2 represents the voltage across capacitor Cres 2.

Iout represents the output current provided to the load by the center tap of the secondary winding l62 of transformer l 60.

Fig. 5 is an example diagram illustrating a first mode (phase # l) of controlling switches in a switched capacitor converter and a voltage converter according to embodiments herein.

Between times T0 and Tl, controller l40 activates (turns on) switches Ql, Q3, Q5, and Q7.

As previously discussed, the primary winding l6l of the transformer l60 includes a first node 2ll and a second node 2l 2. During time T0 to time Tl (first resonant frequency mode), controller ll0 creates a first switched circuit path connecting capacitor Cresl to input voltage Vin; the controller 110 further creates a first switched circuit path by connecting the capacitor Cres2 to the node 212 of the primary winding 160, effectively connecting the capacitors Cres1 and Cres2 in parallel (see fig. 9 for an equivalent circuit).

Zero Voltage Switching (ZVS) and Zero Current Switching (ZCS) and resonant switching occur between the capacitors Cres1 and Cres2 (effectively in parallel between time T0 and time T1) and the leakage inductance (L k) of the transformer, where the resonant frequency is:

an equivalent resonant tank associated with the operation of the switched-capacitor converter 150 of fig. 5 is shown in fig. 9. In this (first or phase #1) mode, the first capacitor Cres1 is (soft) charged from the input voltage source Vin, while the capacitor Cres2 is (soft) discharged.

It should be noted that when the capacitance Cres1 is Cres2, the current through each capacitor is half of the primary current Ip of the transformer 160. In other words, as previously described, the current Ip through the primary winding is equal to the current icars 2-icarsl. This is illustrated in fig. 4, where Ip represents the amount of current through primary winding 161.

Fig. 6 is an example diagram illustrating dead time or deactivation of all switches in a switched capacitor converter and a voltage converter according to embodiments herein.

Between times Tl and T2, controller ll0 generates control signals l05-l to deactivate (turn off) switches Ql, Q3, Q5 and Q7, in which case the parasitic capacitances of Ql and Q3 are charged to half the input voltage (Vin/2), respectively, the parasitic capacitance of Q5 is charged to the input voltage Vin, the parasitic capacitance of Q7 is charged to 2xVout, and the parasitic capacitances of Q2, Q4, Q6 and Q8 are discharged to zero volts, respectively, using the inductive energy stored in inductor L zvs (the inductance at time Tl).

The current i L ZVS at time T1, at which ZVS operation can be achieved, is represented as i L ZVS, pk in FIG. 4, which is determined by the following equation:

fig. 7 is an example diagram illustrating a second mode of controlling switches in a switched capacitor converter and a voltage converter according to embodiments herein.

As previously discussed, the primary winding 161 of the transformer 160 includes a first node 211 and a second node 212. During time T2 to time T3 (second resonant frequency mode), the controller 110 creates a switched circuit path that connects the capacitor Cres2 to the input voltage Vin; the controller 110 further creates this switched circuit path by connecting the capacitor Cres1 to the node 211 of the primary winding 160, effectively connecting the capacitors Cres1 and Cres2 in parallel (see fig. 10 for an equivalent circuit).

In one embodiment, the resonant frequency at which the switched-capacitor converter 150 is operated in the second resonant frequency mode is the same as the resonant frequency at which the switched-capacitor converter 150 is operated in the first resonant frequency mode.

Zero Voltage Switching (ZVS) and Zero Current Switching (ZCS) and resonant switching occur between the capacitors Cres1 and Cres2 (effectively in parallel between time T2 and time T3) and the leakage inductance (L k) of the transformer, where the resonant frequency is:

an equivalent resonant tank associated with the operation of the switched-capacitor converter 150 of fig. 7 is shown in fig. 10. In this (second or phase #2) mode, the second capacitor Cres2 is (soft) charged from the input voltage source Vin, while the capacitor Cres1 is (soft) discharged. The resonant frequency operating in phase #2 is the same as the resonant frequency operating in phase # 1.

Thus, between time T2 and time T3, controller 110 generates control signal 105-2 to turn on switches Q2, Q4, Q6, and Q8. with ZVS after time T2, in a manner opposite to that discussed above, resonant switching occurs between capacitor Cres1 and capacitor Cres2 and the leakage inductance (L k) of transformer 160, capacitor Cres2 is soft charged from input voltage source Vin, and capacitor Cres1 is soft discharged.

Fig. 8 is an example diagram illustrating dead time or deactivation of all switches in a switched capacitor converter and a voltage converter according to embodiments herein.

Between T3 and T4, switches Q2, Q4, Q6, and Q8 are off, and the parasitic capacitances of switches Q4 and Q6 are charged to half Vin/2 of the input voltage; switch Q2 charges at the input voltage Vin; switch Q8 charges to 2 xVout; while the parasitic capacitances of switches Q1, Q3, Q5, and Q7 discharge to zero.

The topological state is shown in FIG. 8. the current that can achieve ZVS in the switched-capacitor converter 150 is i (L _ ZVS) (T3), which corresponds to [ (L (ZVS, pk)). therefore, i (L (ZVS, pk)) is a good indicator of when all switches reach the ZVS condition.

At T4, switches Q1, Q3, Q5, and Q7 turn on in ZVS, ending the switching cycle (i.e., time T0 to time T4).

As highlighted in the different phases of operation of the power supply 100 (in fig. 5-8), the power supply 100 converter achieves ZVS conditions under all load conditions, regardless of component tolerances.

In one embodiment, if the expected ZVS conditions are designed for the worst case (Vin — V _ (In, min)) and L — ZVS +' tolerance (L ZVS)), the switched-capacitor converter 150 can achieve soft-switching operation under all load conditions for different input voltages, which makes the power supply 100 useful In many applications.

Fig. 9 is an exemplary diagram illustrating an equivalent circuit of a first mode of operation (fig. 5) (phase #1) according to embodiments herein.

In this example embodiment, the operation of the power supply 100 shown in fig. 5 results in the equivalent circuit 900 of fig. 9, in this case, the capacitor Cres1 is effectively in parallel with the capacitor Cres2 as shown in fig. 4, the current Ip through the primary winding 161 (Icres 2-icrasl) is based on the combination of Icres1 and Icres2 during phase #1, as shown and as previously discussed, the leakage inductance L k of the primary winding l6l provides for the (soft) charging of the capacitor Cresl and the (soft) discharging of the capacitor Cres 2.

In one embodiment, leakage inductance L k of transformer l60 represents the additional series inductance impedance of primary winding l6l of transformer l60 that does not support the conversion of voltage l2l to voltage l 22.

In one example embodiment, L zvs ═ l.2 microhenries +/-20%; Fsw ═ 6l0 kilohertz embodiments herein include ensuring that the energy stored in the resonant inductor (L zvs) is greater than the energy stored in the MOSFET output capacitors (intrinsic capacitors across transistors Ql, Q2, Q3, etc., as shown in fig. 6 and 8).

Ipk-pk ═ (V L zvs _ min/L zvs _ max) xT ═ (10V/1.44 microhenry) x (l/Fsw) x 0.5 ═ 5.69 amps

ELzvs＝0.5Lzvs(Ipk-pk/2)²Not equal to 0.5x l.2 microHenx (11.66A)²5.83 microjoules, where E L zvs is the energy stored in inductor L zvs;

E_LZVS>E_{COSS_MAX}in which E_{COSS_MAX}Energy stored in the intrinsic capacitor of the switch;

5.83 microJoule >5.2 microJoule

Fig. 10 is an exemplary diagram illustrating an equivalent circuit of a second mode of operation (fig. 7) (stage #3) according to embodiments herein.

In this example embodiment, the operation of the power supply l00 shown in fig. 7 (stage #3) produces the equivalent circuit 1000 of fig. 10. in this case, the capacitor Cresl is effectively connected in parallel with the capacitor Cres2 as shown in fig. 4, the current Ip through the primary winding 161 (Icres2-Icresl) is based on a combination of Icresl and Icres2, during stage #3, the leakage inductance L k of the primary winding 161 provides a (soft) charging of the capacitor Cres2 and a (soft) discharging of the capacitor Cres 1.

Fig. 11 is an example diagram illustrating an implementation of a voltage converter according to embodiments herein.

To further improve the performance of the power supply 100 as described herein, embodiments herein include implementing the voltage converter 170 of the power supply 100 in fig. 2 and 12 as a rectifier as shown in fig. 11.

The proposed rectifier 1170 allows the use of low voltage field effect transistors for the switches Q11, Q12, Q13, and Q14. Furthermore, the total copper loss at the secondary side (secondary winding) of the transformer 160 is lower compared to a center-tapped transformer, because a full-bridge rectifier implements one secondary winding, rather than the two windings that are present when a center-tapped rectifier is used.

Furthermore, in full-bridge rectification, the secondary side leakage energy is recycled rather than dissipated as in center-tap rectification.

According to the converter proposed in fig. 12 (which is also applicable to the converter proposed in fig. 2), the switches Q11 and Q14 are controlled by the control signal 105-1; switches Q12 and Q13 are controlled by control signal 105-2.

Fig. 12 is an example diagram illustrating an implementation of a switched-capacitor converter including a multi-switch circuit according to embodiments herein.

In this example embodiment, the power supply 1200 includes a switched-capacitor converter 150, a transformer 160, and a voltage converter 170.

The switched-capacitor converter 150 includes a capacitor Cres1, a capacitor Cres2, a switch Q21, a Q22, a Q23, a Q24, a Q25, a Q26, a Q27, a Q28, and an inductor L zvs.

In this example embodiment, referring to the switched-capacitor converter 150, the drain node (D) of the switch Q21 and the drain node (D) of the switch Q25 are connected to the input voltage source Vin.

Further, the source node (S) of the switch Q21 is coupled to the drain node (D) of the switch Q22 and to the node 1215. The source node (S) of switch Q25 is coupled to the drain node (D) of switch Q26 and to node 1216.

The source node (S) of switch Q22 is coupled to the drain node (D) of switch Q23 and node 1213; the source node (S) of switch Q26 is coupled to the drain nodes (D) and 1214 of switch Q27.

Circuit path 1225 provides coupling between node 1213 and node 1214.

The source node (S) of switch Q23 is coupled to node 1211. The source node (S) of switch Q27 is coupled to node 1212.

Capacitor Cres1 is coupled between node 1211 and node 1215. Capacitor Cres2 is coupled between node 1212 and node 1216.

Inductor L zvs is coupled in parallel with primary winding 161 and is connected between nodes 1211 and 1212.

As further shown, the transformer 160 includes a primary winding 161 (such as N1 turns) and a secondary winding 162. In the exemplary embodiment, the secondary winding includes a first secondary winding 162-1(N2 turns) and a second secondary winding 162-2(N2 turns). The number of windings may vary depending on the embodiment. In one embodiment, the secondary winding 162 is a single winding rather than multiple windings.

As shown, the drain (D) of switch Q24 is connected to node 1211; the source of switch Q24 is connected to ground. The drain (D) of switch Q28 is connected to node 1212; the source of switch Q28 is connected to ground.

The voltage converter 170 in this example embodiment includes switches Q29 and Q30.

The drain (D) of switch Q29 is connected to the first secondary winding 162-1; the drain (D) of switch Q30 is connected to the second secondary winding 162-2. The center tap of secondary winding 162 generates output voltage 123 to drive load 118.

As further shown, during operation, controller 110 generates control signals 105-1 and 105-2. In this example embodiment, the control signal 105-1 generated by the controller drives the gates (G) of the respective switches Q21, Q23, Q26, Q28, and Q30. Thus, the control signal 105-1 controls the state of each switch Q21, Q23, Q26, Q28, and Q30.

The control signal 105-2 drives the respective gates (G) of the switches Q22, Q24, Q25, Q27, and Q29. Thus, the control signal 105-2 controls the state of each switch Q22, Q24, Q25, Q27, and Q29.

The combination of series switches Q22 and Q23 in the first circuit path (first leg), the combination of series switches Q26 and Q27 in the second circuit path (second leg), and circuit path 1225 (connecting the first and second legs) extending between nodes 1213 and 1214 represent a multi-switch circuit. As shown, the multi-switch circuit is coupled across primary winding 161 of transformer 160 to nodes 1211 and 1212 via switches Q23 and Q27.

Accordingly, further embodiments herein implement the switched-capacitor converter 150 to include a multi-switch circuit of switches coupled to the primary winding 161 of the transformer 160. As discussed further below, the multi-switch circuit in the switched-capacitor converter 150 (the circuit path 1225 and the supplemental network of switches including the switches Q22, Q23, Q26, Q27) provides an alternative way of blocking the input voltage Vin when the switches are OFF.

As previously discussed, in one example embodiment, the switched-capacitor converter 150 includes a first capacitor Cres1 connected between nodes 1211 and 1215 and a second capacitor Cres2 connected between nodes 1212 and 1216. Thus, the capacitor is coupled to the multi-switch circuit.

The apparatus further comprises a controller 110, the controller 110 being operative to switch the switched-capacitor converter 150 between a first resonance frequency mode and a second resonance frequency mode, wherein: i) the first resonant frequency mode is operative to charge the first capacitor Cres1 via the input voltage and to discharge the second capacitor Cres2 through the primary winding 161, and ii) the second resonant frequency mode is operative to charge the second capacitor Cres2 via the input voltage and to discharge the first capacitor Cres1 through the primary winding.

Embodiments herein are useful over conventional techniques. For example, new power supplies, including switched capacitor converters and voltage converters, provide greater efficiency in converting an input voltage to a corresponding output voltage.

In addition, it should be noted that the ZVS hybrid SCC (power supply 100) in fig. 2 does not allow the use of low voltage devices (field effect transistors), which have superior FOM (quality factor) because the switches Q2 and Q5 in fig. 2 must block the full amplitude of the input voltage Vin.

To overcome this problem, the alternative circuit in fig. 12 replaces the original switches Q2 and Q5 in fig. 2 with four switches (Q22, Q23, Q26 and Q27 or a multi-switch circuit as previously discussed) and connects capacitor Cres1 and capacitor Cres2 to node 1211(Vx) and node 1212(Vy), respectively, where the switches in the primary side winding in switched capacitor converter 150 need only block half the amplitude of the input voltage (Vin) in its off state. Thus, all switches in the power supply 1200 may be fabricated as low voltage switches.

As previously discussed, all switches of the power supply 1200 in fig. 12 may be divided into two switch groups: the first switch group is formed of Q21, Q23, Q26, Q28, and Q30 controlled by control signal 105-1, and the second switch group Q22, Q24, Q25, Q27, and Q29 is controlled by control signal 105-2, which is a 180 ° phase-shifted PWM signal of control signal 105-1. In one embodiment, the converter 150 of FIG. 12 operates at a fixed duty cycle, ideally close to 50%, to achieve minimum RMS current.

The power supply 1200 in fig. 12 operates in four different stages as shown in fig. 13-16.

Fig. 13 is an example diagram illustrating a first mode (phase #1) of controlling switches in a switched capacitor converter and a voltage converter according to embodiments herein.

In this example embodiment, between times T0 and T1, switches Q21, Q23, Q26, Q28, and Q30 conduct in ZVS and Zero Current Switching (ZCS). resonant switching occurs between capacitors Cres1, Cres2 and the leakage inductance of transformer 160 (labeled L k).

In a similar manner to the previous discussion, in phase #1 associated with fig. 13, capacitor Cres1 is soft charged from input voltage source Vin, while capacitor Cres2 is soft discharged. When the capacitance Cres1 of the capacitor is Cres2, the current through each resonant capacitor is half the primary current Ip of the transformer 160.

Fig. 14 is an example diagram illustrating dead time or deactivation (phase #2) of all switches in a switched capacitor converter and a voltage converter according to embodiments herein.

Between times T1 and T2, switches Q21, Q23, Q26, Q28, and Q30 are off, and the parasitic capacitances of switches Q21, Q23, Q26, Q28 are charged to one-half Vin/2 of the input voltage, switch Q30 is charged to the voltage 2xVout, and the parasitic capacitances of switches Q22, Q24, Q25, Q27, and Q29 are discharged to zero.

Fig. 15 is an example diagram illustrating a second mode (phase #3) of controlling switches in a switched capacitor converter and a voltage converter according to embodiments herein.

Between times T2 and T3, switches Q22, Q24, Q25, Q27, and Q29 are turned on by ZVS after time T2, resonant switching occurs between capacitors Cres1 and Cres2 leakage inductance L k of transformer 160 operates in a similar manner as previously discussed, however, in this example embodiment, capacitor Cres2 is soft charged from input voltage source Vin, while capacitor Cres1 is soft discharged.

Fig. 16 is an example diagram illustrating dead time or deactivation (phase #4) of all switches in a switched capacitor converter and voltage converter according to embodiments herein.

Between times T3 and T4, switches Q22, Q24, Q25, Q27, and Q29 are turned off, and the parasitic capacitances of switches Q21, Q23, Q26, Q28 charge to half Vin/2 of the input voltage; switch Q29 charges to 2 xVout; while the parasitic capacitances of switches Q21, Q23, Q26, Q28, and Q30 discharge to zero. When the capacitances of switches Q21, Q23, Q26, Q28, and Q30 discharge to zero, their body diodes begin to conduct to turn ZVS on. At time T4, switches Q21, Q23, Q26, Q28, and Q30 turn on in ZVS, which ends the switching period Tsw of one cycle (between time T0 and time T4).

Fig. 17 is an example block diagram of a computer system to implement any of the operations previously discussed in accordance with embodiments herein.

Any of the resources discussed herein (such as the controller 110, the switched-capacitor converter 150, the voltage converter 170, etc.) may be configured to include computer processor hardware and/or corresponding executable instructions to perform the various operations discussed herein.

As shown, the computer system 1750 of this example includes an interconnect 1711, the interconnect 1711 coupling a computer readable storage medium 1712 (such as a non-transitory type medium, which may be any suitable type of hardware storage medium that accesses digital information), a processor 1713 (computer processor hardware), I/O interfaces 1714, and a communications interface 1717.

The I/O interface 1714 supports connections to the repository 1780 and input resources 1792.

The computer-readable storage medium 1712 may be any hardware storage device, such as memory, optical storage, hard drives, floppy disks, and the like. In one embodiment, computer-readable storage medium 1712 stores instructions and/or data.

As shown, the computer-readable storage medium 1712 may be encoded with a controller application 110-1 (e.g., comprising instructions) to perform any of the operations discussed herein.

During operation of an embodiment, the processor 1713 accesses the computer-readable storage medium 1712 via use of the interconnect 1711 to launch, run, execute, interpret or otherwise execute instructions in the controller application 110-1 stored on the computer-readable storage medium 1712. Execution of the controller application 110-1 results in a controller process 110-2 to perform any of the operations and/or processes discussed herein.

Those skilled in the art will appreciate that the computer system 1750 may include other processes and/or software and hardware components, such as an operating system that controls allocation and use of hardware resources to execute the controller application 110-1.

According to different embodiments, it should be noted that a computer system may reside in any of a variety of types of devices, including but not limited to a power supply, a switched capacitor converter, a power converter, a mobile computer, a personal computer system, a wireless device, a wireless access point, a base station, a telephony device, a desktop computer, a laptop computer, a netbook, a mainframe computer system, a handheld computer, a workstation, a network computer, an application server, a storage device, a consumer electronics device (such as a camera, a camcorder, a set-top box, a mobile device, a video game console, a handheld video game device), a peripheral device (such as a switch, a modem, a router, a set-top box, a content management device, a handheld remote control device), any type of computing or electronic device, and the like. Computer system 1750 may reside anywhere, or may be included in any suitable resource of any network environment, to implement the functions discussed herein.

The functionality supported by the different resources will now be discussed via the flow diagram in fig. 18. It should be noted that the steps in the following flow charts may be performed in any suitable order.

Fig. 18 is a flow diagram 1800 illustrating an exemplary method according to embodiments herein. It should be noted that there is some overlap of the concepts discussed above.

In a process operation 1810, the controller 110 controllably switches a plurality of capacitors (Cres1 and Cres2) in the switched-capacitor converter 150; controllably switching a plurality of capacitors in a circuit path of a primary winding 161 of a transformer 160; the controllable switching of the plurality of capacitors converts the input voltage 120 into a first voltage 121.

In process operation 1820, the transformer 160 converts the first voltage 121 to the second voltage 122.

In process operation 1830, via control input from controller 110, voltage converter 170 converts second voltage 122 generated by the transformer into output voltage 123 that powers load 118.

Note again that the techniques herein are well suited for use in power supply applications. It should be noted, however, that the embodiments herein are not limited to use in such applications, and that the techniques discussed herein are well suited for other applications as well.

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present application as defined by the appended claims. The scope of the present application is intended to cover such modifications. As such, the foregoing description of the embodiments of the application is not intended to be limiting. Rather, any limitations to the invention are set forth in the following claims.