Electronic device for power supply and control method thereof

Abstract

The electronic device includes: an electromagnetic interference (EMI) filter; a bridge diode connected to an output terminal of the EMI filter; and a power factor correction (PFC) connected to an output terminal of the bridge diode, and including a PFC IC, in which the PFC IC controls an inductor current flowing in an inductor included in the PFC so as to be maintained at or below a predetermined current value, and the predetermined current value may be smaller than a current value of a current flowing in the inductor based on an applied peak voltage.

Description

Technical Field

[0001] The present disclosure relates to an electronic device and a control method thereof, and more particularly, to an electronic device for powering and a control method thereof. Background Art

[0002] The development of electronic technology has led to the development of various types of electronic devices. In particular, electronic devices that consume a large amount of power, such as televisions (TVs) with large screens, have been developed in recent years.

[0003] An electronic device such as this may include a power supply circuit, and the power supply circuit may power each component of the electronic device through a power factor correction (PFC) converter and simultaneously satisfy power factor regulations and harmonic regulations.

[0004] Therefore, the efficiency of the PFC converter can be an important factor in power consumption issues. Summary of the invention

[0005] Provided are an electronic device capable of improving power factor correction (PFC) and reducing an inductor and a method for manufacturing the same.

[0006] Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

[0007] According to one aspect of the present disclosure, an electronic device includes: an electromagnetic interference (EMI) filter; a bridge diode connected to an output terminal of the EMI filter; and a power factor correction (PFC) connected to the output terminal of the bridge diode and including a PFC integrated circuit (IC), wherein the PFC IC is configured to: control an inductor current flowing in an inductor included in the PFC so that the inductor current is maintained less than or equal to a predetermined current value, and wherein the predetermined current value is less than a current value of a current flowing in the inductor based on a peak voltage applied to the PFC.

[0008] The PFC IC may also be configured to control the inductor current by controlling a transistor included in the PFC according to the inductor current.

[0009] The electronic device may further include: a sensing resistor connected between the bridge diode and the PFC, and the PFC IC may further be configured to: turn off the transistor based on an increase in the inductor current and a voltage of the sensing resistor reaching a predetermined voltage value corresponding to a predetermined current value; and turn on the transistor based on a decrease in the inductor current and a voltage of the sensing resistor reaching zero.

[0010] The electronic device may further include: a direct current to direct current (DC / DC) converter connected to an output terminal of the PFC; and a feedback circuit configured to: detect an output voltage of the PFC, and change a voltage of a sensing resistor based on the output voltage of the PFC decreasing below an allowable input range of the DC / DC converter.

[0011] The feedback circuit may be further configured to reduce the voltage of the sense resistor based on the output voltage of the PFC decreasing to less than or equal to the allowable input range, and the PFC IC may be further configured to increase the on-time of the transistor as the voltage of the sense resistor decreases.

[0012] The feedback circuit may further include a sensing circuit configured to output an output value and change the output value from a first output value to a second output value based on a decrease in the output voltage of the PFC; and a variable voltage circuit configured to change a voltage of the sensing resistor based on the output value.

[0013] The PFC IC may also be configured to control the PFC by changing a conduction time of a gate of a transistor included in the PFC so that the inductor current is maintained less than or equal to a predetermined current value.

[0014] The PFC IC may be further configured to maintain an output voltage of the PFC at a predetermined voltage by increasing a turn-on time of the gate of the transistor included in the PFC during a second time interval among the plurality of time intervals based on the inductor current reaching a predetermined current value during a first time interval among a plurality of time intervals in which the gate of the transistor included in the PFC is turned on.

[0015] Based on the gate on-time reaching the on-time limit, the output voltage of the PFC can be reduced.

[0016] The PFC may also include a transistor, a diode and a capacitor, a first end of the inductor may be connected to an output terminal of the bridge diode, a drain of the transistor may be connected to a second end of the inductor, and a source of the transistor may be grounded; an anode of the diode may be connected to the second end of the inductor; and a first end of the capacitor may be connected to a cathode of the diode, and a second end of the capacitor may be grounded.

[0017] According to one aspect of the present disclosure, a method of controlling an electronic device includes: sensing an inductor current flowing in an inductor included in a power factor correction (PFC) of the electronic device through a PFC integrated circuit (IC) included in the PFC; and controlling the inductor current through the PFC IC so that the inductor current is maintained less than or equal to a predetermined current value, wherein the predetermined current value is less than a current value of a current flowing in the inductor based on a peak voltage applied to the PFC.

[0018] Controlling the inductor current may further include controlling a transistor included in the PFC according to the current flowing in the inductor.

[0019] Controlling the transistor may further include turning off the transistor based on the inductor current increasing and the voltage of the sense resistor reaching a predetermined voltage value corresponding to the predetermined current value; and turning on the transistor based on the inductor current decreasing and the voltage of the sense resistor reaching zero.

[0020] The method may further include: detecting an output voltage of the PFC; and changing a voltage of a sensing resistor based on the output voltage of the PFC decreasing below an allowable input range of a direct current to direct current (DC / DC) converter.

[0021] The changing may further include reducing a voltage of a sensing resistor based on an output voltage of the PFC decreasing to be less than or equal to an allowable input range, and the controlling may further include increasing an on-time of the transistor as the voltage of the sensing resistor decreases. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings, in which:

[0023] Figures 1a to 1e is a diagram illustrating the operation of power factor correction (PFC) according to an embodiment;

[0024] Figure 2 is a block diagram showing a configuration of an electronic device according to an embodiment;

[0025] Figure 3 is a diagram showing a circuit structure of an electronic device according to an embodiment;

[0026] Figure 4 is a diagram showing a specific operation of the electronic device 100 according to an embodiment;

[0027] Figure 5 and Figure 6 is a diagram showing an operation waveform according to an embodiment;

[0028] Figure 7 is a diagram showing a feedback operation according to an embodiment; and

[0029] Figure 8 is a flowchart illustrating a control method of an electronic device according to an embodiment. DETAILED DESCRIPTION

[0030] Various modifications may be made to the exemplary embodiments of the present disclosure. Therefore, specific exemplary embodiments are shown in the drawings and are described in detail in the specific embodiments. However, it should be understood that the present disclosure is not limited to specific exemplary embodiments, but includes all modifications, equivalents and substitutions without departing from the scope and spirit of the present disclosure. In addition, if a well-known function or structure would obscure the present disclosure with unnecessary details, it may not be described in detail.

[0031] Embodiments may relate to an electronic device capable of improving power factor correction (PFC) and reducing an inductor and a method of manufacturing the same.

[0032] Embodiments will be described in more detail below with reference to the accompanying drawings.

[0033] The terms used in the present disclosure and claims are general terms determined in consideration of the functions of the embodiments of the present disclosure. However, these terms may vary according to the intentions of technicians in the relevant fields, legal or technical interpretations, the emergence of new technologies, etc. In addition, in some cases, the applicant may select a term, in which case the term will be described in detail in the corresponding disclosed description. Therefore, the terms used in the present disclosure should be defined based on the meaning of the term and the content throughout the present disclosure, rather than being defined based on the simple name of the term.

[0034] In this specification, the expressions “have”, “may have”, “include” or “may include” etc. indicate the existence of corresponding features (for example, components such as quantity, function, operation or part), and do not exclude the existence of additional features.

[0035] The expression “at least one of A or B” should be understood to mean any one of “A” or “B” or “A and B”.

[0036] As used herein, the terms “first,” “second,” and the like may refer to various components regardless of order and / or importance, and may be used to distinguish one component from another without limiting the component.

[0037] Unless otherwise specified, singular expressions include plural expressions. It should be understood that terms such as "including" or "consisting of..." are used herein to indicate the existence of features, quantities, steps, operations, elements, components or combinations thereof, without excluding the possibility of the existence or addition of one or more other features, quantities, steps, operations, elements, components or combinations thereof.

[0038] In the present disclosure, the term “user” may refer to a person who uses an electronic device, or a device (eg, an artificial intelligence (AI) electronic device) that uses the electronic device.

[0039] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0040] Figures 1a to 1e 1 is a diagram showing the operation of power factor correction (PFC) to help understand the present disclosure. As shown in FIG. 1 , the electronic device 10 may include an electromagnetic interference (EMI) filter 110, a bridge diode 120, and a PFC 130. In addition, the electronic device 10 may further include a direct current to direct current (DC / DC) converter 310 connected to the output terminal of the PFC.

[0041] like Figure 1a As shown, for a power supply circuit of, for example, 75 W or greater, power factor correction (PFC) may be used to meet the conditions for power factor regulations and harmonic regulations.

[0042] Figure 1b and Figure 1c The circuit and operating waveforms of a critical conduction mode (CRM) boost PFC are shown. Figure 1b and Figure 1c As shown, when the input voltage and the load current are constant, the conduction time of the transistor 131 is has a fixed value, and the current is During the period, the slope In an embodiment, the transistor 131 may be a field effect transistor (FET), but the embodiment is not limited thereto. The maximum value of the current flowing in the inductor included in the PFC is , and the current is During the period, the slope Therefore, the slope of the inductor current and the operating frequency can be operated according to the input voltage.

[0043] For example, because the input voltage The PFC 130 may be designed to control the output for 90-264 volts of alternating current (VAC) as it may differ for different applications (for example, in devices used in different countries). In this case, as the input current increases at a low alternating current (AC) input voltage (90 to 120 VAC), the efficiency and temperature characteristics may deteriorate, and the PFC may be designed based on the corresponding operating point.

[0044] like Figure 1d As shown in the electronic device 11 shown in the figure, a boost follower 150 can be added to maintain operation with good characteristics at a high AC input voltage and improve the operation characteristics in a low AC input voltage region. The boost follower 150 can adjust the output voltage by sensing the input voltage and changing the feedback voltage level. Specifically, as Figure 1eAs shown, it can be the basic operation that the output voltage is adjusted and follows the input voltage. When the input voltage of PFC 130 is low, the PFC output voltage can be is set to low, and when the input voltage of the PFC 130 is high, a high output voltage can be maintained in the same manner as the existing PFC In the low AC input voltage area, because the output voltage Since the switching frequency of the PFC operation can be lowered, the loss in the transistor 131 can be reduced. At the same time, when generating the same output power, since the current increases as much as the voltage drops, the capacitor is reduced compared to the prior art implementation. In addition, the loss of the transistor 131 can be reduced, but there may be a limitation that the inductor 132 may be designed to be the same as the inductor of the embodiment of the related art.

[0045] Figure 2 and Figure 3 is a block diagram illustrating an example configuration of an electronic device 100 according to one or more embodiments of the present disclosure.

[0046] The electronic device 100 may include a power circuit for receiving external power and supplying power to each component of the electronic device 100. However, the embodiment is not limited thereto, and the electronic device 100 may be a device for receiving external power and supplying power to an external device, or any device capable of supplying power.

[0047] like Figure 2 As shown, the electronic device 100 may include an EMI filter 110 , a bridge diode 120 , and a PFC 130 .

[0048] The EMI filter 110 may filter and suppress noise included in the external power using a capacitor, an inductor, a reactor, etc.

[0049] For example, the EMI filter 110 may use a resistor to discharge power corresponding to a spike such as a voltage spike or a current spike, a capacitor to absorb or discharge noise, or an inductor to suppress noise.

[0050] The bridge diode 120 may be connected to the output terminal of the EMI filter 110 and output AC power as DC power by using four diodes. For example, the bridge diode 120 may be a circuit for full-wave rectifying AC power and may also be referred to as a bridge rectifier.

[0051] The PFC 130 may be connected to the output terminal of the bridge diode 120 and may include a PFC integrated circuit (IC). Here, the PFC IC 170 may control the PFC 130 so that the current flowing in the inductor 132 included in the PFC 130 may be maintained less than or equal to a preset or predetermined current value. For example, the predetermined current value may be less than the value of the current flowing in the inductor 132 in response to the peak voltage applied to the PFC 130.

[0052] For example, the PFC IC 170 may control the PFC 130 to maintain a current flowing in the inductor 132 included in the PFC 130 below a predetermined current value by controlling the transistor 131 included in the PFC 130 according to the current flowing in the inductor.

[0053] For example, the electronic device 100 may further include a sensing resistor 160 disposed or connected between the bridge diode 120 and the PFC 130. In an embodiment, the PFC IC 170 may turn off the transistor 131 based on the increase in the current flowing in the inductor 132 and the voltage of the sensing resistor 160 reaching a predetermined voltage value corresponding to a predetermined current value. In an embodiment, the PFC IC 170 may turn on the transistor 131 based on the decrease in the current flowing in the inductor 132 and the voltage determined based on the sensing resistor reaching zero. When the transistor 131 is turned off, the current flowing in the inductor 132 may decrease, and when the transistor 131 is turned on, the current flowing in the inductor 132 may increase. Through this operation, the current flowing in the inductor 132 may maintain a triangular waveform between 0 and a predetermined current value.

[0054] like Figure 3 As shown, the DC / DC converter 310 may be connected to the output terminal of the PFC 130, and the electronic device may further include a feedback circuit configured to detect the output voltage of the PFC 130 and change the voltage of the sensing resistor 160 based on the output voltage of the PFC 130 decreasing below the voltage of the allowable input range of the DC / DC converter 310. The voltage applied to the sensing resistor 160 may be a voltage obtained by resistor / capacitor (RC) filtering and voltage division of the voltage of the sensing resistor 160. Figure 7 and Figure 8 Describe the example in detail.

[0055] For example, when the load increases, the output voltage of the PFC 130 may decrease, and based on the output voltage of the PFC gradually decreasing to be less than or equal to the allowable range of the DC / DC converter 310, the feedback circuit may gradually decrease the voltage of the sensing resistor 160, and the PFC IC 170 may increase the on-time of the transistor 131 as the voltage of the sensing resistor 160 decreases.

[0056] The feedback circuit may include a sensing circuit configured to output a value that gradually changes from a first value to a second value as the output voltage of the PFC 130 decreases, and a variable voltage circuit configured to change the voltage of the sensing resistor 160 based on the value output from the sensing circuit. For example, the sensing circuit may output a value of 0 when the output voltage of the PFC 130 is within the allowable input range of the DC / DC converter 310 by sensing the output voltage of the PFC 130, and may gradually change to a value of 1 as the output voltage of the PFC 130 gradually decreases beyond the allowable input range of the DC / DC converter 310. The variable voltage circuit may gradually decrease the voltage of the sensing resistor 160 based on the value output from the sensing circuit. When the voltage of the sensing resistor 160 reaches a threshold value, the PFC IC 170 may turn off the transistor 131. Here, as the voltage of the sensing resistor 160 decreases, the time until the transistor 131 is turned off may be delayed. For example, as the voltage of the sensing resistor 160 decreases, the PFCIC 170 may further maintain the on-time of the transistor 131. When the transistor 131 is further turned on, the current flowing in the inductor 132 may further increase, and thus, the substantially predetermined current value may increase.

[0057] As another example, the PFC IC 170 may change the on-time of the gate of the transistor 131 included in the PFC 130 to a preset method to control the PFC 130 so that the current flowing in the inductor 132 maintains a preset current value or less. For example, the on-time of the gate of the transistor 131 that allows the current flowing in the inductor 132 to maintain a triangular waveform between 0 and a predetermined current value may be obtained in advance. The PFC IC 170 may control the transistor 131 based on the obtained on-time so that the current flowing in the inductor 132 maintains equal to or less than the predetermined current value.

[0058] Based on the current flowing in the inductor 132 reaching a predetermined current value during a portion of the plurality of time intervals in which the gate of the transistor 131 included in the PFC 130 is turned on, the PFC IC 170 may maintain the output voltage of the PFC 130 at a predetermined voltage by increasing the turn-on time of the gate of the transistor 131 included in the PFC 130 during the remaining time intervals among the plurality of time intervals. The output voltage of the PFC 130 may gradually decrease based on the turn-on time of the gate reaching the turn-on limit time. Through this operation, the current flowing in the inductor 132 may be a triangular waveform, or the entire profile of the plurality of triangular waveforms may be changed to a rectangular waveform. Referring to FIG. 1 below, Figure 4 Describe the example in detail.

[0059] The PFC 130 may further include an inductor 132 having one end connected to the output terminal of the bridge diode 120, a transistor 131 having a drain connected to the other end and a source grounded, a diode 133 having an anode connected to the other end of the inductor 132, and a capacitor 134 having one end connected to the cathode of the diode and the other end of the capacitor grounded.

[0060] As described above, the electronic device 100 can improve the efficiency of the transistor 131 included in the PFC 130 and reduce heat generation by maintaining the current flowing in the inductor 132 included in the PFC 130 below a preset current value. In addition, the electronic device 100 can reduce the size of the inductor 132 by reducing the peak value of the current flowing in the inductor included in the PFC 130, and thus the miniaturization of the PFC 130 or the electronic device 100 can be achieved.

[0061] For example, when the magnetic flux is saturated, the inductor 132 may not function as an inductor. Therefore, the saturation magnetic flux (Φsat) should be appropriately designed according to the power specification. The inductance (L) can be represented by the number of turns (N) wound around the magnet, the current (I), and the magnetic flux (Φ), and can be expressed according to Equation 1:

[0062] LI = NΦ Equation 1

[0063] Here, Φ=BA, where B represents magnetic flux density and A represents cross-sectional area, and therefore the following Equation 2 may hold:

[0064] LI = NBA Equation 2

[0065] Since the inductor saturation current Isat may be proportional to the cross-sectional area A, if the peak current of the inductor 131 is reduced, the cross-sectional area of ​​the inductor 131 may be reduced to reduce the overall volume of the inductor 131 .

[0066] In the electronic device 11 including the boost follower 150, the boost follower 150 can sense the input voltage and change the output voltage of the PFC 130, and thus there may be a loss of standby power and a change in the output voltage of the PFC 130 compared to the embodiment of the prior art. Therefore, in the electronic device 100 not including the boost follower 150, the input voltage is not sensed, so that the standby power is not affected like the boost follower 150, and the peak current of the inductor 131 included in the PFC 130 may not increase according to the change of the output voltage of the PFC 130, and thus The ripple current flowing in the AC input voltage may not increase. In addition, when the AC input voltage changes from 90VAC to 264VAC, unlike the implementation of the prior art, the peak value can be significantly reduced, and thus the present embodiment may not burden the device. In some countries using low AC input voltages, there may only be regulations on power factor (PF) and no regulations on harmonics, so there may be no restrictions on the use of the embodiment.

[0067] The following will refer to Figures 3 to 7 An example of the operation of the electronic device 100 is described in more detail. For ease of description, reference will be made to Figures 3 to 7 Describes a single embodiment. However, Figures 3 to 7 The various embodiments of the present invention may be performed in a combined state.

[0068] Figure 3 is a diagram showing a circuit structure of an electronic device 100 according to one or more embodiments of the present disclosure.

[0069] The electronic device 100 may include an EMI filter 110, a bridge diode 120, and a PFC 130. In addition, the electronic device 100 may further include a DC / DC converter 310 connected to an output terminal of the PFC. The electronic device 100 may further include a feedback circuit 320, which may be or may include an adaptive constant PV control.

[0070] According to the embodiment, as mentioned above Figure 2 As described above, the current flowing in the inductor included in the PFC 130 can be set to be lower than that of the embodiment of the related art, so that the entire profile of the current flowing in the inductor can be changed from a sine wave to a square wave. In addition, by reducing the output voltage of the PFC 130, the efficiency of the PFC 130 can be improved. Even if the output voltage of the PFC 130 decreases as the load increases, the output voltage of the PFC 130 can be maintained within the input allowable range of the DC / DC converter 310 through the feedback circuit 320.

[0071] Figure 4 a is a diagram showing an example operation of a prior art electronic device according to one or more embodiments of the present disclosure, and Figure 4 b is a diagram illustrating an example operation of the electronic device 100 according to one or more embodiments of the present disclosure.

[0072] Since the input voltage can be relatively small in the low AC input voltage region, a relatively large current can be used compared to a high AC input voltage when the load is the same. Figure 4 As shown in FIG. 1 , the current flowing in the inductor included in the prior art PFC may follow the waveform of the input voltage, and the profile of the current flowing in the inductor included in the prior art PFC may be as shown in FIG. Figure 4 The form of the sine wave shown in the upper part of a.

[0073] The current flowing in the inductor 132 included in the PFC 130 according to the embodiment may be maintained at a predetermined current value or less, and thus may be as follows. Figure 4 b. By this operation, the current flowing in the inductor 132 included in the PFC 130 can have a smaller peak value, and the currents on both sides can be increased (for example, as shown in FIG. Figure 4 b), so that the output voltage of the PFC 130 can be maintained at a predetermined voltage. That is, when the current flowing in the inductor 132 reaches a preset current value during a part of the plurality of time intervals in which the gate of the transistor 131 included in the PFC 130 is turned on, the PFC IC 170 can increase the turn-on time of the gate of the transistor 131 included in the PFC 130 during the remaining time intervals among the plurality of time intervals to maintain the output voltage of the PFC 130 at the preset voltage.

[0074] Since the current flowing in the inductor 132 increases with a slope proportional to the input voltage, the predetermined current value can be quickly reached in the period when the input voltage is high. Figure 4 As shown in the lower part of b, time can be shorter than the part with low input voltage. When the part with low input voltage (not square wave) When the current flowing in the PFC 130 is at its maximum value, the current flowing in the PFC 130 may be changed into a rectangular waveform, such as Figure 4 As shown in the upper part of b.

[0075] When the peak voltage is applied to Figure 4 In a prior art PFC, the peak value of the current flowing in the inductor can be determined, and Figure 4 The predetermined current value in b may be smaller.

[0076] This operation may reduce an RMS value of a current flowing through a transistor 131 included in the PFC 130 , thereby improving efficiency of the transistor 131 , and reduce a peak value of a current flowing in an inductor included in the PFC 130 , thereby ensuring a DC bias to reduce a size of the inductor 132 .

[0077] Figure 5 and Figure 6 is a diagram illustrating operating waveforms according to one or more embodiments of the present disclosure.

[0078] Figure 5 The middle part shows the Figure 4 The same square wave as the upper part of b, Figure 5 The left side portion of is an enlarged view of the waveform of the current flowing in the inductor 132 in the portion where the input voltage is high, and Figure 5 The right side portion of is an enlarged view of the waveform of the current flowing in the inductor 132 in a portion where the input voltage is low.

[0079] Figure 5 The left side of the diagram shows the peak power ring portion operating at approximately 131 kilohertz (kHz) and due to the higher frequency The amplitude can be very small .

[0080] Figure 5 The right side of shows operation at about 40kHz as an overcompensation period, and because Very small, so Can be very large, so the frequency can be lower.

[0081] Figure 6 a shows an example operating waveform of a prior art PFC. Figure 6 b shows example operating waveforms of the PFC 130 according to an embodiment.

[0082] from Figure 6 a and Figure 6 As can be seen in FIG. 1b, the output voltage of the PFC 130 according to the embodiment can be lower than that of the implementation of the prior art, and the switching frequency can be reduced in most parts, thereby improving the efficiency.

[0083] Figure 7 is a diagram illustrating a feedback operation according to one or more embodiments of the present disclosure.

[0084] When the current flowing in the inductor included in the PFC 130 is a square wave and the load increases, the output voltage of the PFC 130 may decrease. When the output voltage of the PFC 130 decreases, the loss of the transistor 131 included in the PFC 130 may be reduced. For example, when the output voltage of the PFC 130 decreases, the characteristics of the PFC 130 may be improved, but the characteristics of the DC / DC converter 310 connected to the PFC 130 may be deteriorated, and when the output voltage of the PFC 130 decreases below the allowable input range of the DC / DC converter, the DC / DC converter may not operate. In order to prevent this, a feedback circuit (e.g., feedback circuit 320) may be added. First, for ease of description, a configuration in which there is no feedback circuit will be described.

[0085] The PFC IC 170 may include a CS pin, and when there is no feedback circuit, the node between the resistor 721 and the capacitor 722 may be connected to the CS pin in the RC filter 720 connected to the sense resistor 160 disposed between the bridge diode 120 and the PFC 130. Here, the voltage sensed by the CS pin may be referred to as the voltage of the sense resistor 160.

[0086] When the current flowing in the inductor included in the PFC 130 increases, the absolute value of the voltage of the sensing resistor 160 may also increase, and when the current flowing in the inductor included in the PFC 130 decreases, the absolute value of the voltage based on the sensing resistor 160 may also decrease. When the voltage of the sensing resistor 160 sensed by the CS pin is 0, the PFC IC 170 may turn on the transistor 131 included in the PFC 130. In addition, when the voltage of the sensing resistor 160 reaches a threshold voltage, the PFC IC 170 may turn off the transistor 131 included in the PFC 130. When the transistor 131 is turned on, the voltage of the sensing resistor 160 may increase, and when the transistor 131 is turned off, the voltage of the sensing resistor 160 may decrease. Through this operation, the PFCIC 170 may maintain the current flowing in the inductor 132 included in the PFC 130 below a preset current value.

[0087] If the load does not change significantly without the feedback circuit, the PFC 130 may operate normally. However, if the load increases, the output voltage of the PFC 130 may gradually decrease. In this case, the PFC IC 170 may sense the output voltage of the PFC 130 and increase the on-time of the gate of the transistor 131 included in the PFC 130 during a partial period of time to maintain the output voltage of the PFC 130.

[0088] However, the turn-on time of the gate of the transistor 131 included in the PFC 130 may have a turn-on limit time, and when the load further increases, the output voltage of the PFC 130 may gradually decrease.

[0089] In this case, if the output voltage of the PFC 130 decreases below the voltage of the allowable input range of the DC / DC converter 310, the feedback circuit 320 may change the voltage of the sensing resistor 160. For example, the feedback circuit 320 may include: a sensing circuit 710 for gradually changing the output value from a first value to a second value as the output voltage frequency of the PFC 130 decreases; and a variable voltage circuit 730 for changing the voltage of the sensing resistor 160 based on the value output from the sensing circuit 710. In an embodiment, the variable voltage circuit 730 may include an amplifier, a capacitor C, and resistors R, R4, R5, R6, and R7.

[0090] For example, the sensing circuit 710 may output a value gradually increasing from 0 to 1 when the output voltage of the PFC 130 decreases, and the variable voltage circuit 730 may be connected to the RC filter 720 to distribute the voltage. The R2 resistor of the variable voltage circuit 730 may be much larger than the R1 and R3 resistors, and when the sensing circuit 710 outputs 0, the transistor 731 connected in series to the R3 resistor may be turned on, so that most of the node voltage between the resistor 721 and the capacitor 722 of the RC filter 720 may be applied to the R2 resistor. When the sensing circuit 710 outputs a value gradually increasing from 0 to 1, the transistor 731 connected in series to the R3 resistor may be turned on, so that the R2 resistor and the R3 resistor may be in a parallel connection state, and only a portion of the node voltage between the resistor and the capacitor of the RC filter 720 may be applied to the R2 resistor. Therefore, when the sensing circuit 710 outputs a value gradually increasing from 0 to 1, the voltage applied to the R2 resistor may be gradually reduced.

[0091] Because the voltage applied to the R2 resistor (e.g., the voltage of the sense resistor 160) is reduced, the PFC IC 170 may increase the on-time of the transistor 131 included in the PFC 130. For example, the PFC IC 170 may maintain the on-time of the transistor 131 included in the PFC 130 until the voltage applied to the R2 resistor reaches the threshold voltage, and as the voltage applied to the R2 resistor is reduced, the on-time of the transistor 131 included in the PFC 130 may be increased. Therefore, the current flowing in the inductor 132 included in the PFC 130 may be further increased, and thus, an effect that the predetermined current value may be significantly increased may be produced. In addition, as the current flowing in the inductor 131 included in the PFC 130 is further increased, the output voltage of the PFC 130 may also be increased to be maintained within the allowable input range of the DC / DC converter.

[0092] Figure 8 is a flowchart illustrating a control method of an electronic device according to one or more embodiments of the present disclosure.

[0093] First, in operation S810, a current flowing in an inductor included in the PFC 130 is sensed by the PFC IC 170 included in the PFC 130. Next, in operation S820, the PFC IC 170 may control the PFC 130 so that a current flowing in the inductor 132 included in the PFC 130 may be maintained below or equal to a predetermined current value, which may be less than a current flowing in the inductor 132 in response to a peak voltage applied to the PFC 130.

[0094] The controlling in operation S820 may include controlling the PFC 130 to maintain the current flowing in the inductor included in the PFC 130 below a preset current value by controlling the transistor 131 included in the PFC 130 according to the current flowing in the inductor.

[0095] Control S820 may include turning off transistor 131 based on an increase in the current flowing in the inductor and based on the voltage of the sensing resistor 160 reaching a predetermined voltage value corresponding to the predetermined current value, and turning on transistor 131 based on a decrease in the current flowing in the inductor and the voltage of the sensing resistor 160 reaching zero.

[0096] The method may further include detecting an output voltage of the PFC, and when the output voltage of the PFC decreases below a voltage of an input allowable range of the DC / DC converter 310 , changing a voltage of the sensing resistor 160 .

[0097] The change in operation S820 may include gradually reducing the voltage based on the sensing resistor 160 based on the output voltage of the PFC 130 gradually decreasing to be less than or equal to the allowable input range of the DC / DC converter 310, and the control in operation S820 may include increasing the on-time of the transistor 131 as the voltage based on the sensing resistor 160 decreases.

[0098] The changing may include: gradually changing the output value from the first value to the second value as the output voltage of the PFC decreases; and changing the voltage of the sensing resistor 160 based on the output value output from the sensing circuit 710 .

[0099] The controlling in operation S820 may include controlling the PFC by changing the on-time of the gate of the transistor 131 included in the PFC to a predetermined method so that the current flowing in the inductor is maintained less than or equal to a preset current value.

[0100] The controlling in operation S820 may include maintaining the output voltage of the PFC at a preset voltage by increasing a turn-on time of the gate of the transistor 131 included in the PFC 130 during a remaining time interval among the plurality of time intervals, based on the current flowing in the inductor reaching a preset current value during a partial time interval of the plurality of time intervals in which the gate of the transistor 131 included in the PFC is turned on.

[0101] The output voltage of the PFC 130 may gradually decrease based on the on-time of the gate reaching the on-limit time.

[0102] The PFC 130 may further include an inductor 132; a transistor 131 having a drain connected to the other end and a source grounded; a diode 133 having an anode connected to the other end of the inductor 132; and a capacitor 134 having one end connected to a cathode of the diode 133 and the other end of the capacitor grounded.

[0103] According to various embodiments of the present disclosure, the electronic device 100 may maintain a current flowing in the inductor 132 included in the PFC 130 below a predetermined current value to improve efficiency of the transistor 131 included in the PFC 130 and reduce heat generation.

[0104] The electronic device 100 can reduce the size of the inductor 132 by lowering the peak value of the current flowing in the inductor included in the PFC 130 , thereby allowing the size of the PFC 130 or the electronic device 100 to be reduced.

[0105] The above-described embodiments may be implemented as software including instructions stored in a machine-readable storage medium that can be read by a machine (e.g., a computer). The device may include an electronic device (e.g., electronic device A) according to the disclosed embodiment as a device that calls the stored instructions from the storage medium and can operate according to the called instructions. When the instructions are executed by the processor, the processor may use other components to directly perform the functions corresponding to the instructions, or these functions may be executed under the control of the processor. The instructions may include code generated or executed by a compiler or interpreter. The machine-readable storage medium may be set in the form of a non-transitory storage medium. "Non-transitory" means that the storage medium does not include a signal and is tangible, but does not distinguish whether the data is stored semi-permanently or temporarily in the storage medium.

[0106] According to one or more embodiments, the above method may be provided as part of a computer program product. The computer program product may be traded between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., a compact disk read-only memory (CD-ROM)), or through an application store (e.g., PlayStore). TM ) Online distribution. In the case of online distribution, at least a portion of the computer program product (e.g., a downloadable application) may be at least temporarily stored or temporarily generated on a storage medium such as a manufacturer's server, an application store's server, or a memory in a relay server.

[0107] The above-described embodiments can be implemented in a recordable medium that can be read by a computer or a computer-like device using software, hardware, or a combination of software and hardware. In some cases, the example embodiments described herein can be implemented by a processor itself. According to software implementation, example embodiments such as the processes and functions described herein can be implemented with separate software modules. Each software module can perform one or more functions and operations described herein.

[0108] According to the above-mentioned embodiments, computer instructions for executing processing operations of the devices according to the above-mentioned various embodiments may be stored in a non-transitory computer-readable medium. The computer instructions stored in the non-transitory computer-readable medium, when executed by a processor of a specific device, may cause the specific device to perform processing operations on the devices according to the above-mentioned various embodiments. A non-transitory computer-readable medium is not a medium that stores data for a short time, such as a register, a cache, or a memory, but may refer to a medium that stores data semi-permanently and can be read by a machine. Specific examples of non-transitory computer-readable media may include CDs, DVDs, hard disk drives, Blu-ray discs, USBs, memory cards, and ROMs.

[0109] Each element (e.g., module or program) according to an embodiment may be composed of a single entity or multiple entities, and some of the above-mentioned sub-elements may be omitted, or different sub-elements may also be included in various exemplary embodiments. Alternatively or additionally, some elements (e.g., modules or programs) may be integrated into one entity to perform the same or similar functions performed by each corresponding element before integration. According to various exemplary embodiments, the operations performed by a module, program, or other element may be performed sequentially, in parallel, repeatedly, or in an heuristic manner, or may be performed in a different order, at least some operations may be omitted, or different operations may be added.

[0110] Although exemplary embodiments have been shown and described, the present disclosure is not limited to the specific embodiments described above. 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 true spirit and full scope of the present disclosure (including the appended claims and their equivalents).

Claims

1. An electronic device, comprising: Electromagnetic interference EMI filter; A bridge diode connected to the output terminal of the EMI filter; as well as A power factor correction PFC is connected to the output terminal of the bridge diode and includes a PFC integrated circuit IC, wherein the PFC IC is configured to: control an inductor current flowing in an inductor included in the PFC so that the inductor current remains less than or equal to a predetermined current value, and The predetermined current value is smaller than a current value of a current flowing in the inductor based on a peak voltage applied to the PFC.

2. The electronic device according to claim 1, wherein: The PFC IC is further configured to control the inductor current by controlling a transistor included in the PFC according to the inductor current.

3. The electronic device according to claim 2, further comprising: A sense resistor, connected between the bridge diode and the PFC, Wherein, the PFC IC is further configured as: turning off the transistor based on the inductor current increasing and the voltage of the sense resistor reaching a predetermined voltage value corresponding to the predetermined current value; and Based on the inductor current decreasing and the voltage of the sense resistor reaching zero, the transistor is turned on.

4. The electronic device according to claim 3, further comprising: a DC to DC converter connected to the output terminal of the PFC; as well as A feedback circuit is configured to detect an output voltage of the PFC and change a voltage of the sense resistor based on the output voltage of the PFC decreasing below an allowable input range of the DC / DC converter.

5. The electronic device according to claim 4, wherein: The feedback circuit is further configured to: based on the output voltage of the PFC decreasing to be less than or equal to the allowable input range, decrease the voltage of the sensing resistor, and The PFC IC is further configured to increase the on-time of the transistor as the voltage of the sensing resistor decreases.

6. The electronic device according to claim 4, wherein: The feedback circuit comprises: a sensing circuit configured to: output an output value, and change the output value from a first output value to a second output value based on a decrease in an output voltage of the PFC; and The variable voltage circuit is configured to change a voltage of the sense resistor based on the output value.

7. The electronic device according to claim 1, wherein: The PFC IC is further configured to control the PFC by changing a conduction time of a gate of a transistor included in the PFC so that the inductor current is maintained less than or equal to the predetermined current value.

8. The electronic device according to claim 1, wherein: The PFC IC is also configured to: Based on the inductor current reaching the predetermined current value during a first time interval among a plurality of time intervals in which a gate of a transistor included in the PFC is turned on, an output voltage of the PFC is maintained at a predetermined voltage by increasing a turn-on time of the gate of the transistor included in the PFC during a second time interval among the plurality of time intervals.

9. The electronic device according to claim 8, wherein: Based on the on-time of the gate reaching the on-limit time, the output voltage of the PFC is reduced.

10. The electronic device according to claim 1, wherein: The PFC also includes transistors, diodes and capacitors. wherein the first end of the inductor is connected to the output terminal of the bridge diode, wherein the drain of the transistor is connected to the second end of the inductor, and the source of the transistor is grounded; wherein an anode of the diode is connected to the second end of the inductor; and The first end of the capacitor is connected to the cathode of the diode, and the second end of the capacitor is grounded.

11. A method for controlling an electronic device, the method comprising: sensing an inductor current flowing in an inductor included in the power factor correction PFC of the electronic device through a PFC integrated circuit IC included in the PFC; as well as controlling the inductor current by the PFC IC so that the inductor current remains less than or equal to a predetermined current value, The predetermined current value is smaller than a current value of a current flowing in the inductor based on a peak voltage applied to the PFC.

12. The method according to claim 11, wherein: Controlling the inductor current includes controlling a transistor included in the PFC according to a current flowing in the inductor.

13. The method according to claim 12, wherein: Controlling the transistor comprises: turning off the transistor based on the inductor current increasing and the voltage of the sense resistor reaching a predetermined voltage value corresponding to the predetermined current value; and Based on the inductor current decreasing and the voltage of the sense resistor reaching zero, the transistor is turned on.

14. The method according to claim 13, further comprising: Detecting an output voltage of the PFC; as well as Based on the output voltage of the PFC decreasing below an allowable input range of a DC to DC (Direct Current) converter, the voltage of the sense resistor is changed.

15. The method according to claim 14, wherein: The changing includes: based on the output voltage of the PFC decreasing to be less than or equal to the allowable input range, decreasing the voltage of the sensing resistor, and The controlling includes: increasing the on-time of the transistor as the voltage of the sensing resistor decreases.

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