Control device, control method, power supply, and computer-readable storage medium

Abstract

A control device, control method, power supply, and computer-readable storage medium are disclosed. The control device includes a controller operable to: i) monitor a resonant voltage associated with a primary winding magnetically coupled to a secondary winding; ii) control a current flow through the primary winding to generate an output voltage at the secondary winding; and iii) control a magnetization of the primary winding with respect to a detected zero-crossing event associated with the monitored resonant voltage. The controller also controls a duration of activation of a switch coupled to an auxiliary winding (which is magnetically coupled to the primary winding) based on an amplitude of the monitored resonant voltage and / or an amplitude of an input voltage provided to the primary winding. The controller operates in different modes of magnetizing the primary winding depending on the amplitude of the input voltage, for example operating at a peak or valley of the monitored resonant voltage.

Description

Technical Field

[0001] This invention relates to the field of electronics, and more specifically to power generation and ZVS (zero voltage switching) control in power supplies. Background Technology

[0002] Conventional switching-mode power supplies are widely used to convert input voltage into output voltage to supply power to loads.

[0003] One type of power supply is the flyback converter. A flyback converter is a specific type of switch-mode voltage converter that includes a transformer with primary and secondary windings. Typically, an electronic switch is connected in series with the primary winding to control the flow of a corresponding current through it. The energy derived from the current flowing through the primary winding causes a voltage to be generated from the secondary winding.

[0004] Typically, during operation, the transformer windings are magnetized when the electronic switch is closed and demagnetized when the electronic switch is opened. Magnetizing the transformer involves storing energy in the windings, and demagnetizing the transformer involves transferring the energy stored in the primary winding to the secondary winding and the corresponding load.

[0005] Flyback converters can operate in so-called discontinuous conduction mode (DCM). In this case, there is a time delay between the time it takes for the transformer to be fully demagnetized and the time it takes for the corresponding electronic switch coupled to the primary winding to be reactivated to store energy in the primary winding. During this delay, parasitic oscillations in the voltage across the electronic switch may occur because the winding is not fully demagnetized. Summary of the Invention

[0006] The implementation methods described herein include novel approaches to reducing losses associated with ZVS (zero voltage switching) pulse generation.

[0007] More specifically, embodiments of this document include an apparatus comprising a controller operable to: i) monitor a resonant voltage associated with a primary winding magnetically coupled to a secondary winding; ii) control current flow through the primary winding to generate an output voltage at the secondary winding; and iii) control magnetization of the primary winding in response to detecting a zero-crossing event associated with the monitored resonant voltage. In one embodiment, controlling magnetization includes pre-magnetizing or demagnetizing the primary winding.

[0008] In one embodiment, the resonant voltage of the primary winding is generated at least due to the parasitic capacitance and inductance associated with the primary winding and the first switch, which is operated to control the flow of current through the primary winding.

[0009] In one operating mode, the controller is configured to select any one of a plurality of zero-crossing events as the basis for triggering the magnetization of the primary winding. For example, in one embodiment, the controller is operated to select which of a plurality of zero-crossing events (or conditions) of the monitored resonant voltage is used as a trigger to control the activation of the switch through which control current flows to the primary winding, based on the amount of output current supplied to the load by the output voltage.

[0010] In yet another example implementation, the controller controls the magnetization of the primary winding using the subsequent peak voltage of the monitored resonant voltage after the zero-crossing event is detected. In one implementation, the subsequent peak voltage is the next peak voltage of the monitored resonant voltage after the zero-crossing event is detected.

[0011] Another implementation of this document includes interrupting the execution of a first operating mode of magnetizing the primary winding via a controller in response to detecting that the input voltage of the primary winding is below a threshold.

[0012] In another embodiment, the controller activates the switch after a predetermined delay time relating to the detection of a zero-crossing event. The activation of the switch controls the magnetization of the primary winding. In one embodiment, the predetermined delay time (regarding the detected zero-crossing event) is substantially 75% (e.g., between 70% and 80%) of the period of the monitored resonant frequency. In such a case, the magnetization substantially coincides with the peak voltage of the monitored resonant voltage.

[0013] In yet another embodiment, the controller controls the duration for which the activation switch magnetizes the primary winding based on any suitable one or more parameters. For example, in one embodiment, the controller controls the duration for which one or more switches, as described herein, are activated based on the amplitude of the monitored resonant voltage.

[0014] According to another example implementation, the controller controls the duration of activation of one or more switches as described herein based on multiple parameters, such as the amplitude of the monitored resonant voltage and the amplitude of the input voltage supplied to the primary winding.

[0015] Another embodiment of this document includes operating in different modes based on the amplitude of the input voltage. For example, when the amplitude of the input voltage is above a corresponding threshold, the controller operates in a first mode; when the amplitude of the input voltage is below the corresponding threshold, the controller operates in a second mode.

[0016] Another embodiment of this document includes a power supply comprising a switch controlled by a controller, the state of which controls the flow of a current through a primary winding. The power supply also includes a transformer comprising a primary winding and a secondary winding.

[0017] As previously discussed, the implementation described herein is more useful than conventional techniques. For example, the switching described herein reduces the corresponding power losses associated with ZVS (zero-voltage switching) pulse generation.

[0018] These implementation methods and other more specific implementation methods are disclosed in more detail below.

[0019] Note that while the implementations discussed herein are applicable to power converters, the concepts disclosed herein can be advantageously applied to any other suitable topology as well as general power control applications.

[0020] Note that any resources discussed herein may include one or more computerized devices, mobile communication devices, servers, base stations, wireless communication equipment, communication management systems, workstations, user equipment, handheld or laptop computers, etc., to perform and / or support any or all of the methods disclosed herein. In other words, one or more computerized devices or processors may be programmed and / or configured to operate as described herein to perform the different implementations as illustrated herein.

[0021] Other embodiments of this document include software programs for performing the steps and operations outlined above and detailed below. One such embodiment includes a computer program product comprising a non-transitory computer-readable storage medium (i.e., any computer-readable hardware storage medium) on which software instructions are encoded for subsequent execution. When executed in a computerized device (hardware) having a processor, the instructions and / or program cause the processor (hardware) to perform the operations disclosed herein. Such arrangements are typically provided as software, code, instructions, or other data (e.g., data structures) arranged or encoded on firmware in a non-transitory computer-readable storage medium such as optical media (e.g., CD-ROM), floppy disk, hard disk, memory stick, storage device, etc., or as application-specific integrated circuits (ASICs), etc. Software or firmware or other such configurations may be installed on a computerized device to cause the computerized device to perform the techniques described herein.

[0022] Therefore, the embodiments described herein are for methods, systems, computer program products, etc., that support the operations discussed herein.

[0023] One embodiment of this document includes a computer-readable storage medium and / or system having instructions stored thereon. These instructions, when executed by computer processor hardware (e.g., one or more processor devices located at the same or different locations), cause the computer processor hardware (e.g., one or more processor devices located at the same or different locations) to: monitor a resonant voltage associated with a primary winding magnetically coupled to a secondary winding; control current flow through the primary winding to generate an output voltage at the secondary winding; and control the magnetization of the primary winding (e.g., pre-magnetization, demagnetization, etc.) in response to detecting a zero-crossing event associated with the monitored resonant voltage.

[0024] For clarity, the order of the steps above has been added. Note that any processing steps discussed in this article can be performed in any suitable order.

[0025] Other embodiments of this disclosure include software programs and / or corresponding hardware to perform any of the method implementation steps and operations outlined above and detailed below.

[0026] It should be understood that the systems, methods, devices, instructions on computer-readable storage media discussed herein may also be strictly implemented as software programs, firmware, a mixture of software, hardware and / or firmware, or simply as hardware, such as within a processor (hardware or software) or within an operating system or software application.

[0027] As discussed herein, the techniques described are well-suited for applications supporting switching power supplies. However, it should be noted that the implementations described herein are not limited to such applications, and the techniques discussed herein are also well-suited for other applications.

[0028] Furthermore, it should be noted that although each of the different features, techniques, configurations, etc., described herein may be discussed in different places within this disclosure, it is intended that each of these concepts may optionally be implemented independently of each other or in combination with each other, where appropriate. Therefore, one or more of the inventions described herein can be practiced and viewed in many different ways.

[0029] Additionally, it should be noted that the preliminary discussion of embodiments (Summary of the Invention) herein intentionally does not specify every embodiment and / or additional novel aspect of this disclosure or the claimed invention. Instead, the Summary of the Invention presents only general embodiments and corresponding points of novelty relative to conventional technology. For further details and / or possible perspectives (alternatives) of the invention, the reader will be directed to the “Detailed Description” section (which is also an overview of the embodiments) and the corresponding drawings of this disclosure, as further discussed below. Attached Figure Description

[0030] Figure 1This is an example overall diagram of a power supply that supports switch control and voltage generation according to the embodiments described herein.

[0031] Figure 2 This is a detailed diagram illustrating the power supply and switching control according to the embodiments described herein.

[0032] Figure 3 This is an example diagram illustrating the operation of the power supply in a first mode according to the embodiments described herein.

[0033] Figure 4 This is an example diagram illustrating the operation of the power supply in a first mode according to the embodiments described herein.

[0034] Figure 5 This is an example diagram illustrating the operation of the power supply in a second mode according to an embodiment of this document.

[0035] Figure 6 This is an example diagram illustrating the operation of the power supply in a second mode according to an embodiment of this document.

[0036] Figure 7 This is an example theoretical graph illustrating the increased efficiency of different modes of operation of the corresponding power supply according to the embodiments described herein.

[0037] Figure 8 This is an example diagram illustrating computer processor hardware and related software instructions for performing the methods according to embodiments of this document.

[0038] Figure 9 This is an example diagram illustrating a method according to an embodiment of this document.

[0039] Figure 10 This is an example diagram illustrating the fabrication of a circuit according to an embodiment of this document.

[0040] The above and other objects, features, and advantages of the present invention will become apparent from the following more detailed description of the preferred embodiments illustrated in the accompanying drawings, in which similar reference numerals refer to the same parts throughout the various drawings. The drawings are not necessarily drawn to scale, but are intended to illustrate embodiments, principles, concepts, etc. Detailed Implementation

[0041] Now, specifically, Figure 1 This is an example general diagram illustrating a power supply according to an embodiment of this document.

[0042] As shown in this general example implementation, the power supply 100 (e.g., device, electronic apparatus, hardware, circuit, etc.) includes a controller 140, a transformer 130, a switch S0, a switch S1, an output capacitor 136, and a load 118.

[0043] Transformer 130 includes a primary winding 131, a secondary winding 132, and an auxiliary winding 133. Transformer 130 may include any number of additional windings as discussed further herein.

[0044] In this example embodiment, the primary winding 131 is magnetically coupled to the secondary winding 132 and one or more other windings in the transformer 130. The transformer 130 also includes an auxiliary winding 133. The auxiliary winding 133 is also magnetically coupled to the primary winding 131 and the secondary winding 132.

[0045] As further shown, the primary winding 131 and switch S0 are coupled in series between the input voltage source Vin and the ground reference. Additionally, the input voltage source Vin provides an input voltage 121 to the primary winding 131 of transformer 130.

[0046] The auxiliary winding 133 and the switch S1 are coupled in series. In one embodiment, activation of the switch S0 causes magnetic energy to be stored in or removed from the primary winding 131. As discussed further herein, activation of the switch S1 at an appropriate time during the control cycle magnetizes (e.g., pre-magnetizes) the primary winding 131, thereby reducing the magnitude of the voltage at node 125 of the primary winding 131.

[0047] Furthermore, in this example embodiment, the input voltage source Vin provides an input voltage 121 (e.g., essentially a DC voltage value) to the primary winding 131 of the transformer 130.

[0048] During operation, the activation of switch S0 causes current to flow through the primary winding 13, resulting in the storage of corresponding magnetic energy E in the primary winding 131 and / or the transfer of corresponding magnetic energy E to the secondary winding 132, as well as the generation of output voltage 129 and corresponding output current 128 to load 118.

[0049] After activating the primary winding 131 for the first part of the corresponding control cycle, the controller 140 monitors voltage 161 or a derivative thereof (e.g., the voltage associated with the auxiliary winding 133 of the transformer 130). In one embodiment, the monitored voltage 161 tracks voltage 162 at node 125 or a copy thereof.

[0050] For at least a portion of the corresponding control cycle, after activating switch S0, the amplitude of voltage 161 resonates according to the resonant frequency. As further discussed herein, if the amplitude of input voltage 121 is less than the threshold TV1, then as in Figure 3 and Figure 4 The controller 140 discussed herein operates in the first operating mode. If the amplitude of the input voltage 121 is greater than the threshold TV1, then as in Figure 5 and Figure 6The controller 140 discussed herein operates in the second operating mode.

[0051] Refer again Figure 1 When operating in the first mode, the controller monitors voltage 161 to identify one or more corresponding zero-crossing conditions. Depending on one or more parameters being monitored, such as the magnitude of output voltage 129, the amount of power or current consumed by load 118, the controller 140 controls the timing of activation of switch S0 by generating control signal 105 (GD0).

[0052] In one implementation, when operating in the second mode, the controller 140: i) monitors a resonant voltage 161 (a copy of voltage 162) associated with the primary winding 131 magnetically coupled to the secondary winding 132; ii) controls current 127 to flow through the primary winding 131 to generate an output voltage 129 at the secondary winding 132; and iii) controls the magnetization of the primary winding 131 in relation to one or more zero-crossing events detected that are associated with the monitored resonant voltage 161.

[0053] As shown, in one embodiment, the controller 140 receives voltage 161 from the auxiliary winding 133, although voltage 161 can be received from any suitable entity.

[0054] In one implementation, the resonance associated with the voltage 161 of the primary winding 131 is caused by the parasitic capacitance and inductance associated with the primary winding 131 and the first switch S0. This will be discussed in more detail below.

[0055] Figure 2 This is a detailed diagram illustrating the power supply and switching control according to the embodiments described herein.

[0056] In this example embodiment, power supply 100 includes filter 205, rectifier 210 (e.g., diodes D1, D2, D3 and D4), diode D6, diode D7, Zener diode D8, transformer 130, controller 140, switch S0 and switch S1.

[0057] As the name suggests, filter 205 filters the received AC input voltage 221. Rectifier 210 rectifies the filtered input voltage 221 to produce input voltage 121 (also known as Vbulk, such as a DC voltage value).

[0058] As further shown, the primary winding 131 of transformer 130 receives the input voltage 121 output from rectifier 210. Switch S0 controls the corresponding current 127 to flow through the primary winding 131.

[0059] Repeatedly switching the current 127 flowing through the primary winding 131 causes the corresponding magnetic energy to be transferred from the primary winding 131 to the secondary winding 132. As previously discussed, the secondary winding 132 generates an output voltage 129 to power the corresponding load 118 using the energy received from the primary winding 131.

[0060] As previously discussed, transformer 130 also includes auxiliary winding 133 and auxiliary winding 134.

[0061] The auxiliary winding 133 generates a corresponding power supply voltage, which is provided to the VCC pin of the controller 140. For example, the voltage from the winding 133 powers the controller 140 through diode D5.

[0062] The controller 140 includes a corresponding ZCD pin and corresponding circuitry to monitor one or more zero-crossing conditions associated with the voltage 162 at node 125 via a replica resonant voltage 161 from the auxiliary winding 133.

[0063] Series resistors R1 and R2 generate a resonant voltage 161-1 that is input to controller 140. The amplitude of the resonant voltage 161-1 is proportional to the setting of resistors R1 and R2.

[0064] In one embodiment, the controller 140 includes a comparator 241 that compares the voltage 161-1 with a corresponding zero-crossing threshold (ZCTV) to determine the zero-crossing condition associated with the voltage 162.

[0065] Therefore, in one implementation, voltages 161 and 161-1 are (proportionally) copies of tracking voltage 162. Thus, monitoring voltage 161 is similar to monitoring voltage 162.

[0066] As further discussed herein, controller 140 (via derived voltage 161-1) monitors voltage 161 to control the state of switches S0 and S1.

[0067] In this example implementation, as further shown, controller 140 includes multiple input / output pins. Each different pin of controller 140 supports a different function.

[0068] For example, as the name suggests, the ZCD pin of controller 140 is coupled to a zero-crossing detector (comparator 241) in controller 140. The ZCD pin is connected to resistors R1 and R2 and essentially to auxiliary winding 133 for zero-crossing detection and positive pin voltage measurement associated with voltage 161-1, which, as previously discussed, is a copy of voltage 162 at node 125 of primary winding 131.

[0069] The MFIO pin of controller 140 provides multi-function input / output priority information. In one embodiment, the MFIO pin is connected to an optocoupler in monitor 240, which provides an amplified error signal for PWM mode operation that generates the corresponding output voltage 129. Note that monitor 240 provides any suitable feedback 225, such as the error signal of the output voltage 129 relative to the setpoint voltage value, the amount of current consumed by load 118, etc.

[0070] The GPIO pins of controller 140 are general-purpose digital input / output pins. The GPIO pins provide a UART interface up to brown-in. During normal operation, they are switched to weak pull-down mode and the UART function is disabled.

[0071] The CS pin of controller 140 is a current sensing pin. The CS pin is connected in series with an external shunt resistor and the source of a switch S0 (e.g., a power MOSFET) via a resistor.

[0072] The HV pin of controller 140 is a high-voltage input pin. Connect the HV pin to receive a rectified bulk voltage (also known as input voltage 121, such as a DC input voltage).

[0073] The GD1 pin of controller 140 is the gate driver output. The GD1 pin provides a gate driver pulse signal (control signal 106) to initiate forced frequency resonant mode operation.

[0074] The GD0 pin of controller 140 is the gate driver output. The GD0 pin provides the control signal 105 for directly driving the switch S0 (e.g., a power MOSFET).

[0075] The VCC pin of controller 140 is a positive voltage power supply that receives power generated by auxiliary winding 134.

[0076] The GND pin of controller 140 is the power and signal ground.

[0077] As further shown, the secondary side of power supply 100 includes a monitor 240. As the name suggests, monitor 240 monitors one or more parameters associated with the secondary side of power supply 100, such as the amplitude of output voltage 129, the amplitude of output current 128, error voltage, etc. Controller 140 receives feedback 225 from monitor 240.

[0078] The controller 140 also receives feedback from the primary side of the power supply 100, for example via feedback 226 from resistor R8. In one embodiment, feedback 226 is the voltage across the corresponding resistor R8, indicating the amount of current 127 flowing through the primary winding 131 when switch S0 is turned on (ON).

[0079] As further discussed herein, controller 140 operates in different modes depending on the amplitude of input voltage 121 (Vbulk). For example, when input voltage 121 is below the corresponding threshold TV1, controller 140 operates in the first mode (see...). Figure 3 and Figure 4 Operating under these conditions, in the first mode, switch S0 is activated during the control cycle, but switch S1 is not activated at all during the control cycle. The first mode supports frequency modulation and switching at the valley of the monitored resonant voltage.

[0080] When the input voltage 121 is above the corresponding threshold TV1, the controller 140 is in the second mode (see...). Figure 5 and Figure 6 In the second mode, switches S1 and S0 are activated at different times during the corresponding control cycles. The second mode supports switching at the peak of the monitored resonant voltage.

[0081] Figure 3 This is an example diagram illustrating the operation of the power supply in a first mode according to the embodiments described herein.

[0082] In this example implementation, graph 300 illustrates the operation of controller 140 and the corresponding power supply 100 in a first mode. In one implementation, zero threshold 390 is the amplitude of input voltage 121 (or Vbulk). Threshold V31 is equal to input voltage 121 plus (Npri / Nsec) x output voltage 129 (also called Vsec), where Npri is the number of windings on primary winding 131 and Nsec is the number of windings on secondary winding 132. Signal 361 represents the magnetizing current associated with transformer 130.

[0083] Note that the controller 140 can be configured to select any of a plurality of zero-crossing events as the basis for triggering the magnetization of the primary winding 131.

[0084] For example, in one implementation, when operating in the first mode, if the input voltage 121 is below the threshold TV1, the controller 140 selects which of a plurality of zero-crossing events associated with the monitored resonant voltage 162 to use as the activation switch S0 and the triggering of the current through the primary winding 131.

[0085] In one implementation, a zero-crossing condition among a plurality of zero-crossing conditions associated with voltage 162 is selected based on the magnitude of load 118, for example, based on the amount of output current 127 supplied to load 118 by output voltage 129.

[0086] In this example implementation, between time T31 and time T32, controller 140 activates switch S0 to the on state, thereby allowing current 127 to flow through primary winding 131. Between time T32 and time T33, power supply 100 operates in free-wheeling mode.

[0087] As previously discussed, controller 140 determines the magnitude of the load (e.g., based on the power consumed). Assume that in this example embodiment, controller 140 detects that the load 118 is greater than a threshold or is at full load. In such a case, controller 140 initiates activation of switch S0 at time T35, following the zero-crossing condition detected at time T34, with a first valley voltage (soonerin time). Time T35 occurs after time T34, at one-quarter of the resonant period associated with the resonant frequency of the monitored voltage 161.

[0088] The resonant periods of voltages 161 and 162 can be determined in any suitable manner.

[0089] In one implementation, the resonant period is determined by... Defined, where Lp is the magnetizing inductance associated with winding 131, and the value Clumped (lumped capacitor) includes both the capacitance Coss of switch S0 (MOSFET) and the parasitic capacitance of transformer 130.

[0090] In this example implementation, the controller 140 activates the switch S0 at time T35 with a first valley voltage, where time T35 is a predetermined time delay of 1 / 4 of the resonant period after time T34.

[0091] Therefore, when the line input voltage 121 is low and the load 118 consumes high current or power, the controller 140 only turns on GD0 to control the switch S0. The control signal GD1 and the switch S1 are not activated in the first mode.

[0092] As previously discussed, zero-crossing conditions (events) are detected by monitoring the voltage 161 from the auxiliary winding 134, because, as previously discussed, the voltages 161 and 161-1 of the auxiliary winding 134 are copies of Vds and the corresponding voltage 162 at node 125, but potentially have different turns ratios due to their proportionality to resistors R1 and R2, etc.

[0093] Therefore, after detecting a zero-crossing condition, the controller 140 turns on the switch S0 after 1 / 4 of the resonant cycle for each of the multiple cycles in the first mode.

[0094] In one implementation, feedback 225 represents, for example, load information. It is used to identify, among a sequence of multiple zero-crossing conditions, the specific zero-crossing condition that will be used to activate switch S0. When the power supply operates in a so-called discontinuous conduction mode, the controller selects which zero-crossing condition to use to control the switching frequency of control switch S0. In other words, depending on the load 118 and the corresponding power consumption, controller 140 changes (modulates) the frequency at which switch S0 is activated.

[0095] As discussed further below, for the light load 118 condition, the controller 140 selects the later zero-crossing condition from a sequence of multiple zero-crossing conditions as the trigger for activating the switch S0.

[0096] Figure 4 This is an example diagram illustrating the operation of the power supply in a first mode according to the embodiments described herein.

[0097] In this example implementation, graph 400 illustrates operation in the first mode. Zero threshold 390 is the amplitude of the input voltage 121 (or Vbulk). Threshold V31 is equal to the input voltage 121 plus (Npri / Nsec) x output voltage 129 (also called Vsec), where Npri is the number of windings on the primary winding 131 and Nsec is the number of windings on the secondary winding 132. Signal 461 represents the magnetizing current associated with transformer 130.

[0098] As previously discussed, controller 140 can be configured to select any one of a plurality of zero-crossing events as the basis for triggering the magnetization of primary winding 131.

[0099] In this example implementation, between time T41 and time T42, controller 140 activates switch S0 to the on state, thereby allowing current 127 to flow through primary winding 131.

[0100] Between time T42 and time T43, power supply 100 operates in free-wheeling mode.

[0101] The first zero-crossing condition was detected at time T44; the second zero-crossing condition was detected at time T45; the third zero-crossing condition was detected at time T46; and the fourth zero-crossing condition was detected at time T47.

[0102] As previously discussed, controller 140 determines the magnitude of load 118 (e.g., based on power consumption) or other suitable parameters and uses such information to determine which zero-crossing condition to use as the basis for the frequency of control operation.

[0103] More specifically, suppose that in this example embodiment, controller 140 detects that load 118 is less than a threshold or is a light load (e.g., less than the maximum load or approximately 25% of the maximum load). In such a case, controller 140 activates switch S0 at the fourth valley voltage (time T48) one-quarter (1 / 4) of the resonant cycle after the zero-crossing condition detected at time T47. Time T48 occurs at 3¼ of the resonant cycle from T44 or one-quarter of the resonant cycle from the zero-crossing condition detected at time T47.

[0104] As previously discussed, the resonant periods of voltages 161 and 162 can be determined in any suitable manner. In one embodiment, the resonant period is determined by... Defined, where Lp is the magnetizing inductance associated with winding 131, and the value of Clumped (lumped capacitor) includes both the capacitance Coss of switch S0 (MOSFET) and the parasitic capacitance of transformer 130.

[0105] In this example implementation, the controller 140 activates the switch S0 with a fourth valley voltage at time T48, which is 1 / 4 of the resonant cycle after time T47.

[0106] Therefore, when the online input voltage 121 is low, the controller 140 only allows GD0 to be turned on. In other words, in the first operating mode, the controller 140 does not activate GD1 in the corresponding control cycle.

[0107] In one implementation, zero-crossing conditions (events) are detected by monitoring voltages 161 and / or 161-1 from the auxiliary winding 134, since, as previously discussed, the auxiliary winding 134 is a copy of Vds (voltage 162) but with a different turns ratio.

[0108] As previously discussed, in one implementation, the resonant period is determined by... Defined as follows, where Lp is the magnetizing inductance of winding 131, and the value of Clumped (lumped capacitor) includes both the capacitance Coss of switch S0 (MOSFET) and the parasitic capacitance of transformer 130.

[0109] Another embodiment of this document includes, in response to detecting that the amplitude of the input voltage 121 to the primary winding 131 is higher than a threshold TV1, interrupting the execution of a first operating mode via controller 140 and operating in a second mode. In the second operating mode, the controller activates both GD0 and GD1 in the corresponding control cycle.

[0110] Therefore, when the amplitude of the input voltage 121 is below the corresponding threshold, such as TV1, the controller 140... Figure 3 and Figure 4As shown, it operates in the first mode; when the amplitude of the input voltage 121 is above the corresponding threshold TV1, the controller 140 operates in the following... Figure 5 and Figure 6 It operates in the second mode.

[0111] Figure 5 This is an example diagram illustrating the operation of the power supply in a second mode according to an embodiment of this document.

[0112] In this embodiment, it is assumed that the controller 140 detects that the amplitude of the input voltage 121 is above a threshold TV1 (e.g., above 180 VDC or other suitable value). In this case, the controller 140 operates in a second operating mode, in which the controller 140 generates control signals 106 (GD1) and 105 (GD0) at different times during the corresponding control cycle. Signal 561 represents the magnetizing current associated with the transformer 130.

[0113] Between time T51 and time T52, controller 140 activates switch S0 to the on state, thereby allowing current 127 to flow through primary winding 131 as previously discussed. Energy from winding 131 is transferred to secondary winding 132, which generates the corresponding output voltage 129.

[0114] In this example implementation, a zero-crossing event is triggered by monitoring a voltage 161 (or 161-1) from the auxiliary winding 134. As previously discussed, voltage 161 (161-1) is typically a proportional copy of voltage 162 at node 125 (e.g., the drain node of switch S0). The ratio of voltage 162 to voltage 161 (161-1) depends on the number of turns associated with winding 131 and the number of turns associated with winding 134.

[0115] When a zero-crossing condition of voltage 161-1 (161) is detected via pin ZCD of controller 140 at time T54, controller 140 activates the GD1 signal (control signal 106) after 3 / 4 of the resonant period of voltage 161 (161-1) or the peak voltage at time T57. The resonant period of voltage 161 between time T53 and time T57 is determined by... Defined, where Lp is the magnetizing inductance associated with winding 134, and the value of Clumped (lumped capacitor) includes both the capacitance Coss of switch S0 (MOSFET) and the parasitic capacitance of transformer 130.

[0116] After GD1 (control signal 106) is turned on for a predetermined amount of time (e.g., between time T57 and time T58), the controller 140 sets GD1 (control signal 106) low again at time T58, thereby turning off switch S1. Therefore, the controller 140 activates switch S1 to the on state between time T57 and T58 to pre-magnetize the primary winding 131.

[0117] After the dead time between T58 and T59 (during which the voltage at node 125 decreases by, for example, 30 to 40 volts), controller 140 activates control signal 105 (GD0) at time T59, thereby starting a new control cycle.

[0118] In one implementation, as previously discussed, controller 140 receives load information (e.g., the magnitude of load 118). Controller 140 uses the load information to determine which of a series of zero-crossing events associated with voltage 161-1 (and therefore voltage 162) will be used to control the activation of switch S0 to the on state. In other words, the load information (e.g., the amount of output current 128, percentage of full load, etc.) affects the switching frequency of the operating power supply 100 because turning on switch S0 earlier increases the operating frequency while delaying the turning on of switch S0 decreases the switching frequency.

[0119] As previously discussed, in light load conditions where the power or current consumed by load 118 is less than the threshold, the controller delays the switching on of switch S0 until a later zero-crossing condition; in heavier load conditions, such as when the power or current consumed by load 118 exceeds the threshold, the controller... Figure 5 As shown, the controller 140 turns on the switch S0 earlier in the corresponding control cycle.

[0120] Note that another embodiment of this document includes adjusting the width of the on-time associated with the control signal 105 based on the line voltage (input voltage 121) and the output voltage 129.

[0121] For example, in one implementation, the on-time width (ZVS width) of the control signal 105 in the second mode is as follows:

[0122] ZVS width = k_bulk × BULK_VOLTAGE + k_vout × ZCD_voltage + c_offset

[0123] Here, k_bulk (also known as input voltage 121) and k_vout are configurable parameters that vary depending on the corresponding system design, C_offset is a fixed parameter used to compensate for any linear effects, and ZCD_voltage is the voltage 161-1 detected via the ZCD pin of controller 140.

[0124] The introduction of this scheme will enable the adjustment of the ZVS pulse width based on the AC line (input voltage 121) and different output voltages.

[0125] As another example, in one implementation, the controller 140 determines the ZVS width as follows:

[0126] ZVS width = k_bulk / 65536 × BULK_VOLTAGE + k_vout / 65536 × ZCD_voltage +c_offset

[0127] 1. The controller 140 detects the voltage of the large-capacity capacitor (i.e., BULK_VOLTAGE or input voltage 121) via the HV pin or indirectly from the ZCD winding 134. Since the ZCD pin will be clamped to almost zero, the controller 140 (e.g., an integrating circuit) will sense the current flowing from the ZCD pin to determine the voltage of the large-capacity capacitor.

[0128] 2. Although the positive signal of ZCD includes output voltage information, the controller 140 senses the output voltage 129 from the ZCD pin, for example, by (Vaux / [Vsec×Vsec]).

[0129] Figure 6 This is an example diagram illustrating the operation of the power supply in a second mode according to the embodiments described herein.

[0130] In this example implementation, controller 140 detects that input voltage 121 is above the corresponding threshold TV1 and operates in mode #2. In the manner previously discussed, controller 140: i) monitors voltage 161 (161-1) associated with primary winding 131, since voltage 161 (161-1) is a copy of voltage 162; ii) controls current 127 to flow through primary winding 131 to generate output voltage 129 at secondary winding 132; and iii) controls magnetization of primary winding 131 in response to the detection of a zero-crossing event associated with the monitored resonant voltage at time T64.

[0131] As previously discussed, voltages 161 and 162 resonate due to the parasitic capacitance and inductance associated with the primary winding 131 and the first switch S0, which controls the current 127 flowing through the primary winding 131.

[0132] Between times T61 and T62, controller 140 activates switch S0 to the on state. The time between T62 and T63 represents the continuous current phase of operation.

[0133] At or near time T63, controller 140 monitors voltage 161 to detect the corresponding zero-crossing condition, which is detected at time T64.

[0134] In one implementation, the controller 140 initiates magnetization of the primary winding 131 at a first subsequent peak voltage (time T67) following the detection of a zero-crossing event at time T64 of the monitored resonant voltage 161. For example, the subsequent peak voltage occurs at time T67, which is the next peak voltage of the monitored resonant voltage 161 after the detection of a zero-crossing event at time T64.

[0135] In this example implementation, controller 140 activates switch S1 after a delay time relating to the detection of a zero-crossing event at time T64. Switch S1 is activated between times T67 and T68 to pre-magnetize the primary winding 131. In one implementation, the predetermined delay time (regarding the detection of the zero-crossing event at time T64) is substantially 75% (e.g., between 70% and 80%) of the resonant frequency of the monitored voltage during the period between times T63 and T68. In such a case, the magnetization is substantially consistent with the peak voltage at time T67.

[0136] As previously discussed, controller 140 controls the duration for which activation switch S1 magnetizes the primary winding based on any suitable one or more parameters. For example, in one embodiment, controller 140 controls the duration for which activation switch S0 is activated based on the amplitude of the monitored resonant voltage 161.

[0137] According to another example implementation, the controller 140 controls the duration of the activation switch S0 based on a plurality of parameters, such as the amplitude of the monitored resonant voltage 161 and the amplitude of the input voltage 121 supplied to the primary winding 131.

[0138] Note again that controller 140 selects the appropriate peak voltage after one or more zero-crossing conditions based on the load 118. For example, if the load 118 is less than a threshold or is a light load (e.g., less than the maximum load or about 25% of the maximum load), controller 140 initiates activation of switch S0 at a later zero-crossing condition, such as the fourth valley voltage at a quarter (1 / 4) of the resonant cycle after the fourth zero-crossing condition is detected.

[0139] As previously discussed, the implementation described herein is more useful than conventional techniques. For example, the zero-voltage switching described herein reduces the corresponding power losses associated with ZVS pulse generation.

[0140] Figure 7 This is an example graph illustrating the theoretically increased efficiency of implementing the corresponding power supply in different modes according to the embodiments described herein.

[0141] Graph 710 shows the efficiency of power supply 100 operating in modes #1 and #2 at a 90V DC input voltage. The X-axis indicates the size of load 118 and the percentage of power dissipation; the Y-axis indicates the corresponding efficiency of power supply 100 in converting input voltage 121 to output voltage 129. Under such conditions, as shown in graph 710, power supply 100 operates in... Figure 3 and Figure 4 The control signal 105 or GD0 and the corresponding switch S0 shown are more effective in mode #1, where the control cycle is disabled.

[0142] Graph 720 shows the efficiency of power supply 100 operating in modes #1 and #2 at a 115V DC input voltage. The X-axis indicates the size of load 118 and the percentage of power dissipation; the Y-axis indicates the corresponding efficiency of power supply 100 in converting input voltage 121 to output voltage 129. Under such conditions, as shown in graph 720, power supply 100 operates in... Figure 3 and Figure 4 The control signal 105 or GD0 and the corresponding switch S0 shown are more effective in mode #1, where the control cycle is disabled.

[0143] Graph 730 shows the efficiency of power supply 100 operating in modes #1 and #2 at a 230V DC input voltage. The X-axis indicates the size of load 118 and the percentage of power dissipation; the Y-axis indicates the corresponding efficiency of power supply 100 in converting input voltage 121 to output voltage 129. Under such conditions, as shown in graph 730, power supply 100 operates in... Figure 5 and Figure 6 The control signal 105 or GD0 and the corresponding switch S0 shown are more effective in mode #1 when they are enabled in the corresponding control cycle.

[0144] Graph 740 shows the efficiency of power supply 100 operating in modes #1 and #2 at a 264V DC input voltage. The X-axis indicates the magnitude of load 118 and the percentage of power dissipation; the Y-axis indicates the corresponding efficiency of power supply 100 in converting input voltage 121 to output voltage 129. In such cases, as shown in graph 740, the operation of power supply 100 is as follows... Figure 5 and Figure 6The control signal 105 or GD0 and the corresponding switch S0 shown are more effective in mode #1 when they are enabled in the corresponding control cycle.

[0145] Therefore, the implementation methods described herein are more useful than conventional techniques. For example, such as Figure 7 As shown in the graph, the power supply 100 supports the more efficient conversion of the input voltage 121 to the output voltage 129 in different operating modes.

[0146] Figure 8 This is an example block diagram of a computer system for implementing any of the operations previously discussed, according to embodiments of this document.

[0147] Any resource discussed herein (such as controller 140, etc.) can be configured to include computer processor hardware and / or corresponding executable instructions to perform the different operations discussed herein.

[0148] For example, as shown, the computer system 850 of this example includes an interconnect 811, which is coupled to a computer-readable storage medium 812, such as a non-transitory type medium (which may be any suitable type of hardware storage medium capable of storing and retrieving digital information), a processor 813 (computer processor hardware), an I / O interface 814, and a communication interface 817.

[0149] I / O interface 814 supports connection with switches S0 and S1.

[0150] The computer-readable storage medium 812 can be any hardware storage device, such as a memory, optical storage device, hard disk drive, floppy disk, etc. In one embodiment, the computer-readable storage medium 812 stores instructions and / or data.

[0151] As shown, the computer-readable storage medium 812 may be encoded with a controller application 140-1 (e.g., including instructions) to perform any operation as discussed herein.

[0152] During operation in one implementation, processor 813 accesses computer-readable storage medium 812 via interconnect 811 to initiate, run, execute, interpret, or otherwise perform instructions in controller application 140-1 stored on computer-readable storage medium 812. Execution of controller application 140-1 produces controller process 140-2 to perform any operations and / or processes as discussed herein.

[0153] Those skilled in the art will understand that the computer system 850 may include other processes and / or software and hardware components, such as an operating system that controls the allocation and use of hardware resources to execute the controller application 140-1.

[0154] Note that, depending on the implementation, the computer system can reside in any of a variety of devices, including but not limited to: power supplies, switched-capacitor converters, power converters, mobile computers, personal computer systems, wireless devices, wireless access points, base stations, telephone devices, desktop computers, laptop computers, netbook computers, mainframe computers, handheld computers, workstations, network computers, application servers, storage devices, consumer electronics devices (e.g., cameras, camcorders, set-top boxes, mobile devices, video game consoles, handheld video game devices), peripheral devices (e.g., switches, modems, routers, set-top boxes, content management devices, handheld remote controls), and any type of computing or electronic device. The computer system 850 can reside anywhere or can be included in any suitable resource in any network environment to achieve the functions discussed herein.

[0155] Now will be passed Figure 9 The flowcharts below discuss the features supported by different resources. Note that the steps in the flowcharts below can be performed in any suitable order.

[0156] Figure 9 This is a flowchart 900 illustrating an example method according to an embodiment of this document. Note that there will be some overlap with the concepts discussed above.

[0157] In processing operation 910, controller 140 monitors the resonance of voltage 161 associated with primary winding 131 magnetically coupled to secondary winding 132.

[0158] In processing operation 920, controller 140 controls the current flow through primary winding 131 via switch S0 to generate output voltage 129 at secondary winding 132.

[0159] In processing operation 930, controller 140 controls the magnetization of primary winding 131 in response to detecting a zero-crossing event associated with monitored voltage 161.

[0160] Figure 10 This is an example diagram illustrating the assembly of a circuit board including a current monitor and a controller according to an embodiment of this document.

[0161] In this example embodiment, the assembly machine 1040 receives the substrate 1010 (e.g., a circuit board).

[0162] The assembly machine 1040 further fixes (couples) the components of the power supply 100 (such as controller 140, switch S0, switch S1, transformer 120, etc.) to the substrate 1010.

[0163] The assembly machine 1040 or other suitable entity couples the power supply 100 to the load 118 via one or more circuit paths 1022 (e.g., one or more traces, conductors, cables, wires, etc.). In one embodiment, one or more circuit paths provide connectivity between the power supply 100 and the corresponding transformer 120 to the load 118.

[0164] Note that components such as transformer 120, controller 140, switch S0, switch S1, etc., can be fixed or coupled to the base plate 1010 in any suitable manner. For example, each of one or more components of the power supply 100 can be soldered to the base plate, inserted into one or more corresponding sockets on the base plate 1010, etc.

[0165] Additionally, note that substrate 1010 is optional. If substrate 1010 is required, the components of power supply 100 and the corresponding circuit paths can be arranged in cables or other suitable resources.

[0166] As previously discussed, the assembler 1040 provides connectivity from power supply 100 to load 118 via one or more circuit paths 1022 (e.g., one or more traces, cables, connectors, wires, conductors, conductive paths, etc.). In one embodiment, circuit path 1022 delivers output voltage 129 and / or output current 128 from power supply 100 to load 118.

[0167] Therefore, embodiments of this document include a system comprising: a substrate 1010 (e.g., a circuit board, a standalone board, a motherboard, a standalone board intended to be coupled to a motherboard, a host, etc.); a power supply 100 including corresponding components as described herein; and a load 118. As previously discussed, the load 118 is powered based on an output voltage 129 transmitted through one or more paths 1022.

[0168] It should be noted again that the techniques described in this article are well-suited for power supply applications. However, it should be understood that the implementations described herein are not limited to such applications, and the techniques discussed herein are also well-suited for other applications.

[0169] Although the invention has been specifically shown and described with reference to preferred embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of the invention as defined by the appended claims. Such changes are intended to be covered by the scope of this application. Similarly, the foregoing description of embodiments of this application is not intended to be limiting. Rather, any limitations on the invention are presented in the appended claims.

Claims

1. A control device, comprising: The controller is capable of operating as follows: Monitor the resonant voltage associated with the primary winding magnetically coupled to the secondary winding, the resonant voltage being received from the auxiliary winding coupled to the primary winding; A control current flows through the primary winding to generate an output voltage at the secondary winding; as well as In response to a detected zero-crossing event associated with the monitored resonant voltage, a second switch connected in series with the auxiliary winding is used to control the current flowing through the auxiliary winding, thereby controlling the magnetization of the primary winding.

2. The control device according to claim 1, wherein, The resonant voltage is generated due to the parasitic capacitance and inductance associated with the primary winding and a first switch connected in series with the primary winding, the first switch being operable to control the flow of current through the primary winding.

3. The control device according to claim 1, wherein, The controller is also operable to select which of a plurality of zero-crossing events of the monitored resonant voltage is used as a trigger after the first zero-crossing event is detected to control the magnetization of the primary winding, the triggering depending on the size of the load powered by the output voltage.

4. The control device according to claim 1, wherein, The controller is also operable to control the magnetization of the primary winding using the subsequent peak voltage of the monitored resonant voltage after the detected zero-crossing event.

5. The control device according to claim 4, wherein, The subsequent peak voltage is the next peak voltage of the monitored resonant voltage after the detected zero-crossing event.

6. The control device according to claim 1, wherein, The controller is also operable to magnetize the primary winding with the peak amplitude of the monitored resonant voltage after the zero-crossing event.

7. The control device according to claim 1, wherein, The controller can also be operated to: The second switch is activated after a predetermined delay time following the detection of the zero-crossing event, and the activation of the second switch pre-magnetizes the primary winding.

8. The control device according to claim 7, wherein, The predetermined delay time is 75% of the resonant period of the monitored resonant voltage.

9. The control device according to claim 7, wherein, The controller is operable to control the duration of activation of the second switch based on the amplitude of the monitored resonant voltage.

10. The control device according to claim 7, wherein, The controller is operable to control the duration of activation of the second switch based on the amplitude of the monitored resonant voltage and the amplitude of the input voltage supplied to the primary winding.

11. The control device according to claim 1, wherein, The controller can also be operated to: The flow of current through the primary winding is controlled by a first switch arranged in series with the primary winding.

12. The control device according to claim 7, wherein, The predetermined delay time corresponds to the peak amplitude of the resonant voltage.

13. The control device according to claim 1, wherein, The controller is also operable to select which of the plurality of zero-crossing events of the monitored resonant voltage is used as a trigger after the first zero-crossing event is detected, in order to control the magnetization of the primary winding.

14. The control device according to claim 1, wherein, The control of the current through the auxiliary winding is achieved by pre-magnetizing the primary winding through energy storage in the primary winding.

15. The control device according to claim 1, wherein, The controller can also be operated to: The second switch is activated to pre-magnetize the primary winding by means of energy storage in the primary winding; and After the primary winding is pre-magnetized and the second switch is deactivated, the first switch is activated to control the current flow through the primary winding and generate the output voltage. The first switch is arranged in series with the primary winding.

16. The control device according to claim 15, wherein, The controller can also be operated to: At the time when the amplitude of the resonant voltage is at its trough, the first switch is switched from the off state to the on state.

17. The control device according to claim 1, wherein, The auxiliary winding is a first auxiliary winding; and The control of the current through the first auxiliary winding includes controlling the current through the second auxiliary winding, which is magnetically coupled to both the first auxiliary winding and the primary winding.

18. A power supply controlled by the control device according to any one of claims 1 to 17, comprising: A first switch controlled by the controller of the control device, wherein the state of the first switch is operated to control the flow of current through the primary winding; as well as A transformer, comprising the primary winding and the secondary winding.

19. A control device, comprising: The controller is capable of operating as follows: Monitor the resonant voltage associated with the primary winding that is magnetically coupled to the secondary winding; A control current flows through the primary winding to generate an output voltage at the secondary winding, and the current flows through the primary winding is controlled by a first switch arranged in series with the primary winding. as well as In response to a detected zero-crossing event associated with the monitored resonant voltage, a second switch connected in series with the first auxiliary winding is used to control current flow through the first auxiliary winding, thereby controlling the magnetization of the primary winding. The first auxiliary winding is magnetically coupled to the primary winding, and the monitored resonant voltage is generated by the first auxiliary winding. The controller is also operable to control current flow through the primary winding at the valley amplitude of the monitored resonant voltage after the zero-crossing event. The primary winding is pre-magnetized by controlling current flow through a second auxiliary winding magnetically coupled to the primary winding. The control current flow through the second auxiliary winding occurs during the period when the first switch is deactivated to the off state.

20. A control device, comprising: The controller is capable of operating as follows: Monitor the resonant voltage associated with the primary winding that is magnetically coupled to the secondary winding; A control current flows through the primary winding to generate an output voltage at the secondary winding; as well as In response to a detected zero-crossing event associated with the monitored resonant voltage, the magnetization of the primary winding is controlled. The controller is operable to execute a first mode of valley voltage switching on a first switch through which control current flows in the primary winding in response to a condition where the amplitude of the input voltage supplied to the primary winding is less than a threshold. The controller is operable to perform a second mode of peak voltage switching on a second switch coupled to an auxiliary winding, which is magnetically coupled to the primary winding, in response to a condition where the amplitude of the input voltage provided to the primary winding is greater than the threshold.

21. A control method, comprising: Monitor the resonant voltage associated with the primary winding magnetically coupled to the secondary winding, the resonant voltage being received from an auxiliary winding coupled to both the primary and secondary windings; A control current flows through the primary winding to generate an output voltage at the secondary winding; as well as In response to a detected zero-crossing event associated with the monitored resonant voltage, a second switch connected in series with the auxiliary winding is used to control the current flowing through the auxiliary winding, thereby controlling the magnetization of the primary winding.

22. The control method according to claim 21, wherein, The resonant voltage is generated due to the parasitic capacitance and inductance associated with the primary winding and a first switch arranged in series with the primary winding, the first switch being operable to control the flow of current through the primary winding.

23. The control method according to claim 22, wherein, Controlling the magnetization of the primary winding in response to the detection of a zero-crossing event associated with the monitored resonant voltage includes: Controls the activation of the second switch.

24. The control method according to claim 21, wherein, Controlling the magnetization of the primary winding includes: Selecting which of the multiple zero-crossing events of the monitored resonant voltage is used as a trigger to control the switching of current flow through the primary winding.

25. The control method according to claim 21, wherein, Controlling the magnetization of the primary winding includes: At the peak voltage following the detected zero-crossing event of the monitored resonant voltage, pre-magnetization of the primary winding is initiated, the pre-magnetization comprising storing energy in the primary winding by allowing current to flow through the auxiliary winding.

26. A computer-readable storage medium having instructions stored thereon, the instructions causing the computer processor hardware to perform the control method according to any one of claims 21 to 25 when executed by computer processor hardware.

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