Electronic device including PFC circuit and method for controlling PFC circuit

Abstract

An electronic device is disclosed. The present electronic device includes: a power factor correction (PFC) circuit; a rectifying circuit for rectifying an AC voltage to obtain an input voltage having a negative polarity and providing the input voltage to the PFC circuit; and a protection circuit for protecting the PFC circuit. The PFC circuit includes: a first diode; an inductor for storing energy on the basis of the input voltage provided by the rectifying circuit while a switching circuit is turned on and supplying energy while the switching circuit is turned off; and an output capacitor connected to the inductor through the first diode and providing an output voltage having a positive polarity by using the energy supplied by the inductor stored while the switching circuit is turned off. When the first diode is short-circuited, the PFC circuit is protected by a current path formed by the protection circuit while the switching circuit is turned on.

Description

Electronic device including PFC circuit and method for controlling PFC circuit

[0001] The present disclosure relates to a method for controlling a PFC circuit of an electronic device including a PFC circuit.

[0002] A variety of types of electronic devices are being developed, including low-profile electronic devices such as ultra-slim TVs.

[0003] Electronic devices may include a power circuit that supplies power to components of the electronic devices. The power circuit includes a power factor correction (PFC) circuit that satisfies power factor and harmonic regulation.

[0004] Accordingly, there is a need for PFC circuits suitable for low-profile electronic devices.

[0005] An electronic device according to an embodiment of the present disclosure may include a Power Factor Correction (PFC) circuit, a rectifier circuit for rectifying an AC voltage to obtain an input voltage having a negative polarity and providing the input voltage to the PFC circuit, and a protection circuit for protecting the PFC circuit. The PFC circuit may include a first diode, an inductor for storing energy based on an input voltage provided by the rectifier circuit while a switching circuit is turned on and supplying energy while the switching circuit is turned off, and an output capacitor connected to the inductor through the first diode and providing an output voltage having a positive polarity using energy provided by the inductor while the switching circuit is turned off. When the first diode is short-circuited, the PFC circuit may be protected by a current path formed by the protection circuit while the switching circuit is turned on.

[0006] The above protection circuit may include a second diode connected in parallel with the output capacitor.

[0007] The above rectifier circuit may include a diode bridge. The above PFC circuit may further include an input capacitor that receives the input voltage from the diode bridge.

[0008] A first terminal of the switching circuit may be connected to one terminal of the input capacitor. One terminal of the inductor may be connected to the other terminal of the input capacitor and the anode of the first diode. The other terminal of the inductor may be connected to one terminal of a resistor. One terminal of the output capacitor may be connected to the cathode of the first diode and the cathode of the second diode. The other terminal of the output capacitor may be connected to the other terminal of the resistor, the second terminal of the switching circuit, a ground voltage, and the anode of the second diode. The resistor may be used to detect a current flowing in the inductor.

[0009] The above PFC circuit can be driven in CrM (Critical conduction mode) based on the current flowing through the inductor. The current can be detected using the resistor.

[0010] A first terminal of the switching circuit may be connected to one terminal of the input capacitor. One terminal of the inductor may be connected to the other terminal of the input capacitor, the anode of the first diode, and one terminal of the first resistor. The other terminal of the first resistor may be connected to one terminal of a second resistor. One terminal of the output capacitor may be connected to the cathode of the first diode and the cathode of the second diode. The other terminal of the output capacitor may be connected to the other terminal of the inductor, the other terminal of the second resistor, the second terminal of the switching circuit, a ground voltage, and the anode of the second diode. The first and second resistors may be used to detect a current flowing in the inductor.

[0011] The above PFC circuit can be driven by CrM based on the current of the inductor sensed using the first resistor and the second resistor.

[0012] When the switching circuit is turned on while the first diode is short-circuited due to a fault, the voltage charged in the output capacitor by the input voltage can be discharged. When the voltage across both terminals of the output capacitor becomes 0 due to the discharge, the current path flowing through the second diode can be formed.

[0013] The electronic device may further include a fuse. The fuse may be blown by a current flowing through the current path, thereby stopping the operation of the PFC circuit.

[0014] The electronic device may further include a fuse. If the switching circuit is short-circuited due to a fault, the fuse may be blown by the current flowing through the switching circuit, thereby stopping the operation of the PFC circuit.

[0015] The electronic device may further include an electromagnetic interference (EMI) filter that filters a source AC voltage and provides the AC voltage to the rectifier circuit, and a DC / DC converter to which the output voltage is applied.

[0016] A method for controlling a PFC circuit of an electronic device, comprising a PFC circuit according to an embodiment of the present disclosure, a rectifier circuit for rectifying an AC voltage and applying an input voltage having a negative polarity to the PFC circuit, and a protection circuit for protecting the PFC circuit.

[0017] The method may include: a step of applying a gate signal to a gate terminal of a switching circuit of the PFC circuit to control the switching circuit from an on state to an off state; a step of detecting a current flowing in an inductor of the PFC circuit while the switching circuit is in an off state; a step of applying a gate signal to a gate terminal of the switching circuit of the PFC circuit based on the detected current to control the switching circuit from an off state to an on state; a step of storing energy based on an input voltage applied from the rectifier circuit while the switching circuit is in an on state; and a step of providing an output voltage having a positive polarity by using an output capacitor of the PFC circuit connected to the inductor through a first diode while the switching circuit is in an off state. When the first diode is short-circuited, the PFC circuit may be protected by a current path formed by the protection circuit while the switching circuit is turned on.

[0018] The above protection circuit may include a second diode connected in parallel with the output capacitor.

[0019] The above rectifier circuit may include a diode bridge. The method may further include a step of receiving the input voltage from the rectifier circuit to an input capacitor of the PFC circuit.

[0020] A first end of the switching circuit may be connected to one end of the input capacitor. One end of the inductor may be connected to the other end of the input capacitor and the anode of the first diode. The other end of the inductor may be connected to one end of a resistor. One end of the output capacitor may be connected to the cathode of the first diode and the cathode of the second diode. The other end of the output capacitor may be connected to the other end of the resistor, the second end of the switching circuit, a ground voltage, and the anode of the second diode. The method may further include a step of detecting a current flowing in the inductor using the resistor.

[0021] An electronic device according to an embodiment of the present disclosure may include a protection circuit including a Power Factor Correction (PFC) circuit, a first diode, an inductor that stores energy based on an input voltage while a switching circuit is turned on and provides energy while the switching circuit is turned off, and an output capacitor that is connected to the inductor through the first diode and provides an output voltage having a positive polarity using energy provided by the inductor while the switching circuit is turned off, and a PFC controller that controls the switching circuit to turn on and off based on a current flowing through the inductor.

[0022] The above PFC controller can control the switching circuit to turn on when the current flowing through the inductor is 0.

[0023] The above PFC controller can control the switching circuit to turn on and then turn off the switching circuit after a threshold time has elapsed.

[0024] The above and other aspects, features and advantages of specific embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings.

[0025] Figures 1a, 1b, and 1c are drawings for explaining an example of a PFC (power factor correction) circuit.

[0026] FIG. 2 is a block diagram illustrating the configuration of an electronic device according to an embodiment of the present disclosure.

[0027] FIG. 3 is a diagram for explaining a rectifier circuit, a PFC circuit, and a protection circuit according to an embodiment of the present disclosure.

[0028] FIGS. 4A and 4B are drawings for explaining the operation of a rectifier circuit, a PFC circuit, and a protection circuit according to an embodiment of the present disclosure.

[0029] FIGS. 5A, 5B and 5C are drawings for explaining an operation for protecting a PFC circuit according to an embodiment of the present disclosure.

[0030] FIG. 6 is a diagram for explaining a rectifier circuit, a PFC circuit, and a protection circuit according to an embodiment of the present disclosure.

[0031] FIGS. 7 and 8 are drawings for explaining examples of power circuits according to embodiments of the present disclosure.

[0032] FIG. 9 is a block diagram illustrating the configuration of an electronic device according to an embodiment of the present disclosure.

[0033] FIG. 10 is a drawing for explaining a method of providing power to a PFC controller according to an embodiment of the present disclosure.

[0034] FIG. 11 is a block diagram illustrating the configuration of an electronic device according to an embodiment of the present disclosure.

[0035] FIG. 12 is a drawing for explaining a method of providing power to a second gate driver according to an embodiment of the present disclosure.

[0036] FIGS. 13a, 13b, 14a, and 14b are drawings for explaining a rectifier circuit, a PFC circuit, and a protection circuit according to an embodiment of the present disclosure.

[0037] FIG. 15 is a flowchart for explaining a PFC circuit control method of an electronic device according to an embodiment of the present disclosure.

[0038] Hereinafter, embodiments will be described with reference to the attached drawings. The embodiments described in this specification are merely examples and are not limited thereto, and may be implemented in various other forms. Each embodiment provided in the description below does not exclude one or more features of other examples provided in this specification or other embodiments not provided in this specification but consistent with the present disclosure. Expressions such as “at least one of a, b, or c” can refer to “a,” “b,” “c,” “a and b,” “a and c,” “b and c,” “all of a, b, and c,” or variations thereof.

[0039] The terms used in this disclosure are selected from widely used, common terms, taking into account the functions of the disclosure. However, these terms may vary depending on the intentions of those skilled in the art, precedents, the emergence of new technologies, etc. Furthermore, in certain cases, terms may be arbitrarily selected by the applicant, in which case their meanings will be described in detail in the relevant description. Therefore, the terms used in this disclosure should not be defined simply as names, but rather based on the meanings of the terms and the overall content of the disclosure.

[0040] Singular expressions may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art described herein. Terms such as "first" or "firstly" and "secondly" or "secondly" as used herein may refer to a given element regardless of importance or order, and may be used to distinguish one element from another without limiting it.

[0041] When a part of the specification is said to "include" a component, this does not exclude other components, but rather implies the inclusion of other components, unless otherwise specifically stated. Furthermore, terms such as "part" and "module" used in the specification indicate a unit that processes at least one function or operation. A unit may be implemented in hardware.

[0042] The term "and / or" includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

[0043] The various elements and areas in the drawings are schematically drawn. Therefore, the embodiments are not limited by the relative sizes or spacing depicted in the attached drawings.

[0044] The present disclosure will be described below with reference to the attached drawings.

[0045] Figures 1a to 1c are drawings for explaining an example of a PFC (power factor correction) circuit.

[0046] Power supply circuits with output power exceeding 75 W must utilize a Power Factor Correction (PFC) circuit to meet power factor and high-frequency regulations (e.g., Total Harmonic Distortion (THD) regulations). For example, the PFC circuit may include a boost converter-based PFC circuit.

[0047] However, it is difficult to use a boost converter-based PFC circuit in electronic devices that require an ultra-slim (or slim) power circuit (e.g., ultra-slim TV).

[0048] Specifically, a boost converter is a step-up converter, with an output voltage higher than the input voltage. Therefore, the output capacitor of a boost converter must be an electrolytic capacitor with a high withstand voltage. However, capacitors with a high withstand voltage typically have a large diameter, making them unsuitable for ultra-slim power circuits. Furthermore, utilizing additional windings for ZCD (Zero Current Detection) can require the use of a large inductor.

[0049] To overcome these problems, step-down converters with low-voltage output capacitors can be used in PFC circuits. Step-down converters can generate output voltages lower than the input voltage. Step-down converters include buck converters, two-switch buck-boost converters, and single-ended primary-inductor converters (SEPIC converters).

[0050] Figure 1a is a diagram showing an example of a buck converter. The buck converter has the advantage of a simple structure and a small number of components, but if a switching circuit component (e.g., a switch circuit such as a MOSFET (Metal Oxide Semiconductor Field Effect transistor)) fails and is short-circuited, the input voltage may drop across the output capacitor (e.g., C bulk ) can be applied as is, which may cause the output capacitor to explode.

[0051] Figure 1b is a diagram showing an example of a two-switching buck-boost converter. The two-switching buck-boost converter has the advantage of being able to control the output voltage regardless of the size of the input voltage, as it is a converter that can both step up and step down. However, similar to a buck converter, if the switching circuit element is short-circuited due to a fault, the output capacitor (e.g., C bulk ) may cause explosion problems.

[0052] Figure 1c is a diagram showing an example of a SEPIC converter. Since the input and output of the SEPIC converter are separated by a capacitor (Cm), even if the switching circuit element is short-circuited, the output capacitor (e.g., C bulk ) can be protected. However, the SEPIC converter has a disadvantage in that it requires increased size and price of the converter because it has a topology that requires two inductors.

[0053] Additionally, each of the aforementioned step-down converters has the problem of large inductor size, similar to the boost converter, in that additional windings are required for ZCD.

[0054] FIG. 2 is a block diagram illustrating the configuration of an electronic device according to an embodiment of the present disclosure.

[0055] The electronic device (100) may include a power circuit for receiving an external power source (e.g., commercial power source) and supplying power to each component of the electronic device (100). The power circuit may include a PFC (Power Factor Correction) circuit based on a buck-boost converter.

[0056] For example, referring to FIG. 2, the electronic device (100) includes a rectifier circuit (110), a PFC circuit (120), and a protection circuit (130).

[0057] The rectifier circuit (110) receives an external voltage. The external voltage may be an AC voltage applied from an external power source. The rectifier circuit (110) can rectify the input AC voltage.

[0058] The PFC circuit (120) can improve the power factor. To this end, the PFC circuit (120) can include a buck-boost converter. The buck-boost converter can operate as a step-up converter or a step-down converter depending on the duty ratio of the switching circuit elements.

[0059] In the present disclosure, the duty ratio of the switching circuit elements may be set so that the buck-boost converter operates as a step-down converter. The PFC circuit (120) operates as a step-down converter and can generate an output voltage lower than the input voltage depending on the switching operation of the switching circuit elements.

[0060] Due to the circuit structure of the PFC circuit (120), the polarity of the output voltage of the PFC circuit (120) may be opposite to the polarity of the input voltage. Considering this, in the present disclosure, an input voltage having a negative polarity may be applied to the PFC circuit (120) using a rectifier circuit (110). For example, the rectifier circuit (110) may rectify an AC voltage and apply an input voltage having a negative polarity to the PFC circuit (120).

[0061] The PFC circuit (120) may include a switching circuit element, an inductor, a first diode, and an output capacitor.

[0062] The switching circuit element may be, for example, a MOSFET. The inductor may store energy based on an input voltage applied from the rectifier circuit (110) while the switching circuit element is turned on. An output capacitor may be connected to the inductor via a first diode. Then, the output capacitor may provide an output voltage having a positive polarity by utilizing the energy stored in the inductor while the switching circuit element is turned off.

[0063] The protection circuit (130) may be a circuit for protecting the PFC circuit (120). The protection circuit may be referred to as, for example, a short-circuit protection circuit, a short-circuit fault protection circuit, etc.

[0064] The protection provided by the PFC circuit (120) may be to protect other components of the PFC circuit (120) from failure when a component of the PFC circuit (120) is short-circuited due to a failure.

[0065] As described above, the inductor and the output capacitor may be connected through the first diode. Therefore, when the switching circuit element is turned on while the first diode is short-circuited due to a fault, the input voltage may be applied to the output capacitor. The input voltage has a negative polarity. Therefore, when the input voltage is applied to the output capacitor, a voltage of the opposite polarity is applied to the output capacitor, which may cause the output capacitor to be damaged or explode. In the present disclosure, the protection circuit (130) may form a current path according to the voltage across both terminals of the output capacitor when the switching circuit element is turned on while the first diode is short-circuited due to a fault. Accordingly, the protection circuit (130) may prevent a voltage of the opposite polarity from being applied to the output capacitor, thereby protecting the output capacitor.

[0066] Below, the structure and operation of the circuits are described in more detail.

[0067] FIG. 3 is a diagram for explaining a rectifier circuit, a PFC circuit, and a protection circuit according to an embodiment of the present disclosure.

[0068] Referring to FIG. 3, the rectifier circuit (110) may include a diode bridge including diodes (111, 112, 113, 114) connected in a bridge configuration. The diode bridge may be referred to as, for example, a bridge rectifier.

[0069] Diode (D B1 )(111) The anode of the diode (D B3 )(113) is connected to the anode of the diode (D B1 )(111) The cathode is a diode (D B2 )(112) can be connected to the anode.

[0070] Diode (D B2 )(112) The anode of the diode (D B1 )(111) is connected to the cathode of the diode (D B2 )(112) The cathode is a diode (D B2 )(114) can be connected to the cathode.

[0071] Diode (D B3 )(113) The anode of the diode (D B1 )(111) is connected to the anode of the diode (D B3 )(113) The cathode is a diode (D B4 )(114) can be connected to the anode.

[0072] Diode (D B4 )(114) The anode of the diode (D B3 )(113) is connected to the cathode of the diode (D B4 )(114) The cathode is a diode (D B2 )(112) can be connected to the cathode.

[0073] Also, diode (D B1 )(111) cathode and diode (D B2 )(112) is connected to an AC voltage source (10) (e.g., one end of the AC voltage source (10)), and the diode (D B3 )(113) cathode and diode (D B4 )(114) can be connected to an AC voltage source (10) (e.g., the other terminal of the AC voltage source (10)).

[0074] The PFC circuit (120) is an input capacitor (C in )(121), switching circuit element (Q1)(122), inductor (L B )(123), first diode (D1)(124), output capacitor (C bulk )(125) and resistance (R s )(126) may be included.

[0075] Input capacitor (C in )(121) can receive input voltage from diodes (111, 112, 113, 114) of the diode bridge. For example, input capacitor (C in )(121) One end of the diode (D B2 )(112) cathode and diode (D B4 )(114) is connected to the cathode, and the input capacitor (C in )(121) The other end is a diode (D B1 )(111) anode and diode (D B3 )(113) can be connected to the anode.

[0076] Also, the input capacitor (C in )(121) can be connected to the first terminal of the switching circuit element (Q1)(122). The first terminal of the switching circuit element (Q1)(122) can be a drain terminal. The input capacitor (C in )(121) The other end is an inductor (L B )(123) can be connected to the anode of the first diode (D1)(124). Inductor (L B)(123) The other end is resistance (R s )(126) can be connected to one end of the resistor (R s )(126) is an inductor (L B )(123) may be a resistor for detecting the current flowing through it.

[0077] Additionally, the output capacitor (C bulk )(125) is connected to the cathode of the first diode (D1)(124), and the output capacitor (C bulk )(125) The other end is resistance (R s )(126), the second terminal of the switching circuit element (Q1)(122) can be connected to the ground voltage (20). The second terminal of the switching circuit element (Q1)(122) can be a source terminal of the switching circuit element (Q1)(122).

[0078] The protection circuit (130) is a second diode (D f )(131) may be included. The second diode (D f )(131) is the output capacitor (C bulk )(125) can be connected in parallel. For example, the second diode (D f )(131) The cathode is the output capacitor (C bulk )(125) is connected to one end, and the second diode (D f )(131) The anode of the output capacitor (C bulk )(125) can be connected to the other end.

[0079] FIGS. 4A and 4B are drawings for explaining the operation of a rectifier circuit, a PFC circuit, and a protection circuit according to an embodiment of the present disclosure.

[0080] The rectifier circuit (110) can rectify the AC voltage provided from the AC voltage source (10) using the diodes (111, 112, 113, 114) of the diode bridge and apply the input voltage to the PFC circuit (120). For example, referring to FIG. 4A, when the switching circuit element (Q1) (122) is turned on, the negative input voltage (-V) is applied by the diodes (111, 112, 113, 114) of the diode bridge. in ) is the input capacitor (C in )(121) can be applied to the resistance (R s )(126) In that the resistance value is small, V in This inductor (L B )(123) can be applied. Accordingly, the inductor (L B )(123) current (i) LB ) is increased, and the inductor (L B )(123) Energy can be stored. This type of motion can be expressed as a build-up motion.

[0081] Referring to Fig. 4b, when the switching circuit element (Q1) (122) is turned off, the resistor (R s )(126) is small in size, so the negative output voltage (e.g. -V o ) is an inductor (L B )(123) can be applied. Accordingly, the inductor (L B )(123) current (i) LB ) is reduced, and the inductor (L B )(123) by the energy stored in the output capacitor (C bulk )(125) is charged and power can be supplied to the output side. This operation can be expressed as a powering operation.

[0082] In this way, the PFC circuit (120) can provide power to the output side according to the turn on / turn off of the switching circuit element.

[0083] In the present disclosure, the PFC circuit (120) can be implemented as a CrM (Critical conduction mode) PFC circuit. That is, the PFC circuit (120) can be controlled by the CrM method. The CrM method is implemented by the inductor L B Detect the current flowing through the inductor L B It may include a method of driving the PFC circuit (120) by turning on the switching circuit element whenever the current flowing through it reaches 0.

[0084] For example, the electronic device (100) may include a PFC controller and a gate driver. The PFC controller may include an integrated circuit (IC) chip. The PFC controller may control the gate driver to apply a gate signal to a gate terminal of the switching circuit element (Q1) (122) in a turn-on state to turn off the switching circuit element (Q1) (122).

[0085] When the switching circuit element (Q1) (122) is turned off, the inductor (L B )(123) can reduce the current flowing through the inductor (L B )(123) detects the current flowing through the inductor (L B )(123) becomes 0, a gate signal for turning on the switching circuit element (Q1)(122) can be applied to the gate terminal of the switching element (Q1)(122). Then, when a critical time has elapsed since the switching circuit element (Q1)(122) is turned on, the PFC controller can apply a gate signal for turning off the switching circuit element (Q1)(122) to the gate terminal of the switching circuit element (Q1)(122).

[0086] The PFC controller can drive the PFC circuit in CrM mode by repeatedly performing these operations.

[0087] The PFC circuit (120) illustrated in Fig. 3 includes a resistor (Rs )(126) is used to detect the inductor (L B )(123) can be driven in CrM mode based on the current of the inductor (L). That is, the PFC controller B )(123) is a resistor (R) connected in series s )(126) using the inductor (L B )(123) senses the current flowing through the inductor (L B )(123) can detect the point at which the current flowing through the inductor (L) becomes 0. And, the PFC controller B )(123) becomes 0, the switching circuit element (Q1)(122) can be turned on. That is, the PFC controller can turn on the resistor (R s )(126) can be used to perform ZCD. ZCD can mean detecting the point in time when the current flowing in the inductor of the converter becomes 0. Inductor L B The current passing through the node ZCD connected between (123) and the resistor (Rs) can be monitored for ZCD.

[0088] FIGS. 5A, 5B and 5C are drawings for explaining an operation for protecting a PFC circuit according to an embodiment of the present disclosure.

[0089] As described above, the PFC circuit (120) can operate as a step-down converter. In this case, if the active elements of the PFC circuit (120) (e.g., switching circuit element (Q1) (122), first diode (D1) (124)) are short-circuited due to a fault, the output capacitor (C bulk )(125) may cause an explosion problem. In the present disclosure, when the active element (specifically, the first diode (D1)(124)) is short-circuited, the output capacitor (C) is protected by using a protection circuit (130). bulk )(125) can be protected.

[0090] Referring to FIGS. 5A and 5B, the electronic device (100) may include a fuse (30). One end of the fuse (30) is connected to an AC voltage source (10) (e.g., the other end of the AC voltage source (10)), and the other end of the fuse (30) is connected to a diode (D B3 )(113) cathode and diode (D B4 )(114) can be connected to the anode. The embodiments are not limited thereto, and the fuse (30) can be connected to various locations. For example, one end of the fuse (30) is connected to an AC voltage source (10) (e.g., one end of the AC voltage source (10)), and the other end of the fuse (30) is connected to a diode (D B1 )(111) cathode and diode (D B2 )(112) can be connected to the anode. In this way, the fuse (30) can be placed at various locations on the current path through which the current output from the AC voltage source (10) flows or on the current path through which the current input to the AC voltage source (10) flows.

[0091] Figure 5a is a drawing for explaining a case where a switching circuit element (Q1) (122) is short-circuited due to a failure.

[0092] If the switching circuit element (Q1) (122) is short-circuited due to a failure, the fuse (30) may blow due to the current of the switching circuit element (Q1) (122), and the operation of the PFC circuit (120) may be stopped.

[0093] Referring to Fig. 5a, when the switching element (Q1) (122) is short-circuited due to a fault, the output capacitor (C bulk )(125) current is blocked by the first diode (D1)(124). Therefore, the inductor (L) is driven by the voltage on the input side. B )(123) increases, and the fuse (30) may be blown as the current increases. Accordingly, the operation of the PFC circuit (120) is stably stopped, and the components of the PFC circuit (120) can be protected.

[0094] FIG. 5b and FIG. 5c are drawings for explaining a case where the first diode (D1) (124) is short-circuited due to a failure.

[0095] Referring to Fig. 5b, when the switching circuit element (Q1) (122) is turned on while the first diode (D1) (124) is short-circuited due to a fault, the output capacitor (C) is turned on by the input voltage. bulk )(125) can be discharged. That is, the first diode (D1)(124) and the output capacitor (C) are charged by the input voltage. bulk )(125), current (① in Fig. 5b) flows, and the output capacitor (C) is driven by the current. bulk )(125) The charge stored in the can be discharged.

[0096] Accordingly, the output capacitor (C bulk )(125) Voltage at both ends (V) o ) may fall.

[0097] Referring to Fig. 5c, the output capacitor (C bulk )(125) becomes 0 (or the threshold voltage of the first diode (D1)(124)), the second diode (D f )(131), a current path is formed, and current (② of Fig. 5c) can flow through the current path. The current flowing through the current path increases, and the fuse (30) can be blown as the current increases. Accordingly, the operation of the PFC circuit (120) can be stably stopped, and the components of the PFC circuit (120) can be protected.

[0098] In this way, in the present disclosure, when the active element (specifically, the first diode (D1) (124)) is short-circuited due to a failure, the second diode (D f )(131) by the output capacitor (C bulk )(125) is prevented from applying negative voltage to the output capacitor (C bulk )(125) can prevent the phenomenon of explosion.

[0099] FIG. 6 is a drawing for explaining a rectifier circuit, a PFC circuit, and a protection circuit according to an embodiment.

[0100] Referring to FIG. 6, the rectifier circuit (110) may include a diode bridge including diodes (111, 112, 113, 114) connected in a bridge form. The bridge diode may include four diodes (111, 112, 113, 114).

[0101] Diode (D B1 )(111) The anode of the diode (D B3 )(113) is connected to the anode of the diode (D B1 )(111) The cathode is a diode (D B2 )(112) can be connected to the anode.

[0102] Diode (D B2 )(112) The anode of the diode (D B1 )(111) is connected to the cathode of the diode (D B2 )(112) The cathode is a diode (D B2 )(114) can be connected to the cathode.

[0103] Diode (D B3 )(113) The anode of the diode (D B1 )(111) is connected to the anode of the diode (D B3 )(113) The cathode is a diode (D B4 )(114) can be connected to the anode.

[0104] Diode (D B4 )(114) The anode of the diode (D B3 )(113) is connected to the cathode of the diode (D B4 )(114) The cathode is a diode (D B2 )(112) can be connected to the cathode.

[0105] Also, diode (D B1 )(111) cathode and diode (D B2)(112) is connected to an AC voltage source (10) (e.g., one end of the AC voltage source (10)), and the diode (D B3 )(113) cathode and diode (D B4 )(114) can be connected to an AC voltage source (10) (e.g., the other terminal of the AC voltage source (10)).

[0106] The PFC circuit (120) is an input capacitor (C in )(121), switching element (Q1)(122), inductor (L B )(123), first diode (D1)(124), output capacitor (C bulk )(125), first resistor (R s1 )(127) and the second resistor (R s2 )(128) may be included.

[0107] Input capacitor (C in )(121) can receive input voltage from diodes (111, 112, 113, 114) of the diode bridge. For example, input capacitor (C in )(121) One end of the diode (D B2 )(112) cathode and diode (D B4 )(114) is connected to the cathode, and the input capacitor (C in )(121) The other end is a diode (D B1 )(111) anode and diode (D B3 )(113) can be connected to the anode.

[0108] Also, the input capacitor (C in )(121) can be connected to the first terminal of the switching circuit element (Q1)(122). The first terminal of the switching circuit element (Q1)(122) can be a drain terminal. The input capacitor (C in )(121) The other end is an inductor (L B )(123), the anode of the first diode (D1)(124) and the first resistor (R s1 )(127) can be connected to one end.

[0109] First resistor (R) s1 )(127) and the second resistor (R s2 )(128) can be connected in series. For example, the first resistor (R s1 )(127) The other end is the second resistor (R s2 )(128) can be connected to one end.

[0110] Additionally, the output capacitor (C bulk )(125) is connected to the cathode of the first diode (D1)(124), and the output capacitor (C bulk )(125) The other end is an inductor (L B )(123), the other end, the second resistor (R s2 )(128), the second terminal of the switching circuit element (Q1)(122) can be connected to the ground voltage (20). The second terminal of the switching circuit element (Q1)(122) can be a source terminal of the switching circuit element (Q1)(122).

[0111] The protection circuit (130) is a second diode (D f )(131) may be included. The second diode (D f )(131) is the output capacitor (C bulk )(125) can be connected in parallel. For example, the second diode (D f )(131) The cathode is the output capacitor (C bulk )(125) is connected to one end, and the second diode (D f )(131) The anode of the output capacitor (C bulk )(125) can be connected to the other end.

[0112] Referring to FIGS. 3 and 6, the connection structures of other elements, except for the connection structure of the resistor, are substantially similar. Therefore, the contents described in FIGS. 4a, 4b, 5a, 5b, and 5c can also be applied to the circuit illustrated in FIG. 6.

[0113] Referring to Figure 3, the resistance (R s)(126) can be used for ZCD. Resistance (R s )(126) is an inductor (L B )(123) can be connected in series, and a node ZCD can be connected between them. Referring to Fig. 6, the first resistor (R) connected in series s1 )(127) and the second resistor (R s2 )(128) can be used for ZCD. In this regard, the node ZCD is a first resistor (R s1 )(127) and the second resistor (R s2 )(128) can be connected in series. The first resistor (R) connected in series s1 )(127) and the second resistor (R s2 )(128) is an inductor (L B )(123) can be connected in parallel.

[0114] The PFC circuit (120) illustrated in Fig. 6 includes a first resistor (R s1 )(127) and the second resistor (R s2 )(128) is used to detect the inductor (L B )(123) can be driven in CrM mode based on the current of the inductor (L). That is, the PFC controller B )(123) connected in parallel with the first resistor (R) s1 )(127) and the second resistor (R s2 )(128) using the inductor (L B )(123) detects the voltage at both ends of the inductor (L B )(123) senses the current flowing through the inductor (L B )(123) can detect the point at which the current flowing through the inductor (L) becomes 0. And, the PFC controller B )(123) becomes 0, the switching circuit element (Q1)(122) can be turned on. That is, the PFC controller can turn on the first resistor (R s1 )(127) and the second resistor (R s2 )(128) can be used to perform ZCD.

[0115] In this way, the present disclosure can perform ZCD operation by detecting the current or voltage of an inductor using a resistor without additional windings of the inductor for ZCD operation. Accordingly, an ultra-slim power supply can be provided using the PFC circuit (120).

[0116] In FIGS. 4A, 5A, 5B, and 5C, it is illustrated that a voltage of one polarity (e.g., a voltage of (+) polarity) of an AC voltage source is input to the rectifier circuit (110), but the embodiments are not limited thereto. That is, even when a voltage of another polarity (e.g., a voltage of (-) polarity) of an AC voltage source is input to the rectifier circuit (110), the above-described contents can be similarly applied.

[0117] FIG. 7 and FIG. 8 are drawings for explaining an example of a power circuit according to an embodiment of the present disclosure.

[0118] The electronic device (100) may include a power circuit (700) illustrated in FIG. 7 or a power circuit (800) illustrated in FIG. 8.

[0119] The power circuit (700) illustrated in FIG. 7 may include the rectifier circuit (110), PFC circuit (120), and protection circuit (130) described in FIG. 3. The description of the structure and operation of these circuits may be applied to the power circuit (700) illustrated in FIG. 7.

[0120] The power circuit (800) illustrated in FIG. 8 may include the rectifier circuit (110), PFC circuit (120), and protection circuit (130) described in FIG. 6. The description of the structure and operation of these circuits may be applied to the power circuit (800) illustrated in FIG. 8.

[0121] Referring to FIGS. 7 and 8, an EMI (electromagnetic interference) filter (140) can receive an AC voltage from an AC voltage source (10). In addition, the EMI filter (140) can remove noise from the AC voltage. The EMI filter (140) can include various elements such as a capacitor, an inductor, a reactor, etc. For example, the EMI filter (140) can discharge power for a spike through a resistor, discharge noise through a capacitor, or remove noise through an inductor. The embodiments are not limited thereto, and the EMI filter (140) can remove noise using various methods.

[0122] And, the EMI filter (140) can apply the AC voltage with noise removed (i.e., the filtered AC voltage) to the rectifier circuit (110). The rectifier circuit (110) receives the AC voltage with noise removed by the EMI filter (140), rectifies the AC voltage, and converts it into a negative input voltage (e.g., -V in ) can be applied to the PFC circuit (120).

[0123] The DC / DC converter (150) can step down or boost the input DC voltage and output a DC voltage having an operable voltage range of various configurations of the electronic device (100). For example, the output voltage of the PFC circuit (120) (e.g., V o ) can be applied to the DC / DC converter (150). The DC / DC converter (150) can convert the input voltage into a voltage suitable for each component of the electronic device (100) and output it. The output voltage of the DC / DC converter (150) can be applied to the output capacitor (160).

[0124] FIG. 9 is a block diagram illustrating the configuration of an electronic device according to an embodiment of the present disclosure.

[0125] Referring to FIG. 9, the electronic device (100) may include a rectifier circuit (110), a PFC circuit (120), a protection circuit (130), a gate driver (i.e., a gate driver circuit) (170), and a PFC controller (i.e., a PFC control circuit) (180). Among the configurations illustrated in FIG. 9, the rectifier circuit (110), the PFC circuit (120), and the protection circuit (130) may be applied to the previously described content, and therefore, a repeated description thereof will be omitted for the sake of brevity.

[0126] The gate driver (170) generates a gate signal for controlling the switching operation of the switching circuit element (Q1) (122) of the PFC circuit (120), and can apply the gate signal to the gate terminal of the switching circuit element (Q1) (122).

[0127] The PFC controller (180) can control the gate driver (170) to drive the PFC circuit (120) in the CrM manner.

[0128] For example, the PFC controller (180) can control the gate driver (170) to apply a gate signal to the gate terminal of the switching circuit element (Q1) (122) to turn on the switching circuit element (Q1) (122). The switching circuit element (Q1) (122) can be turned on when a gate signal is applied from the gate driver (170).

[0129] And, when a critical time has elapsed from the time when the switching circuit element (Q1) (122) is turned on, the PFC controller (180) can control the gate driver (170) to apply a gate signal to the gate terminal of the switching circuit element (Q1) (122) to turn off the switching circuit element (Q1) (122). The switching circuit element (Q1) (122) can be turned off when a gate signal is applied from the gate driver (170).

[0130] When the switching circuit element (Q1) (122) is turned off, the inductor (L B)(123) can be reduced. The PFC controller (180) is an inductor (L B )(123) using a resistor (126) connected in series with an inductor (L) B )(123) detects the current flowing through the inductor (L B )(123) using resistors (126, 127) connected in parallel to the inductor (L B )(123) detects the current flowing through the inductor (L B )(123) can detect whether the current flowing in has reached 0.

[0131] And, the PFC controller (180) is an inductor (L B )(123) is 0, the gate driver (170) can be controlled to apply a gate signal to the gate terminal of the switching circuit element (122)(Q1) to turn on the switching circuit element (Q1)(122).

[0132] Afterwards, the PFC controller (180) can control the gate driver (170) to apply a gate signal to the gate terminal of the switching circuit element (122) to turn off the switching circuit element (Q1) (122) when a critical time has elapsed from the time the switching circuit element (Q1) (122) is turned on. Then, the PFC controller (180) can control the gate driver (170) to apply a gate signal to turn off the switching circuit element (Q1) (122) to the gate terminal of the switching circuit element (122). B )(123) detects the current flowing through the inductor (L B )(123) is 0, a gate signal for turning on the switching circuit element (Q1)(122) can be applied to the gate terminal of the switching circuit element (122).

[0133] The PFC controller (180) can drive the PFC circuit in the CrM manner by repeatedly performing these operations.

[0134] FIG. 10 is a drawing for explaining a method of providing power to a PFC controller according to an embodiment of the present disclosure.

[0135] Referring to FIG. 10, in the present disclosure, a regulator (1010) is connected to an AC voltage source (10) through a rectifier circuit (1020), so that a power supply voltage (Vcc) for a PFC controller (180) can be generated through the regulator (1010).

[0136] Although a buck regulator is illustrated in FIG. 10, the embodiments are not limited thereto. The regulator may be implemented as, for example, a linear regulator.

[0137] In addition, although the circuit illustrated in FIG. 3 is illustrated as an example in FIG. 10, the embodiments are not limited thereto. As illustrated in FIG. 10, a circuit for generating power for a PFC controller (180) can be configured by connecting a rectifier circuit, a capacitor, a regulator, a diode, an inductor, etc. to the circuit illustrated in FIG. 6.

[0138] According to an embodiment, the first diode (D1) (124) may be replaced with a synchronous rectifier (SR). In this case, the electronic device (100) may further include a gate driver for controlling the switching operation of the synchronous rectifier. An embodiment in which the first diode (D1) (124) is replaced with a synchronous rectifier is described in more detail in FIG. 11.

[0139] FIG. 11 is a block diagram illustrating the configuration of an electronic device according to an embodiment of the present disclosure.

[0140] Referring to FIG. 11, the electronic device (100) may include a rectifier circuit (110), a PFC circuit (120), a protection circuit (130), a first gate driver (i.e., a first gate driver circuit) (170), a PFC controller (i.e., a PFC control circuit) (180), and a second gate driver (i.e., a second gate driver circuit) (190).

[0141] In Fig. 11, the first diode (D1) (124) in the PFC circuit (120) illustrated in Fig. 10 can be replaced with a synchronous rectifier. The synchronous rectifier can be implemented with a switching circuit element such as a MOSFET, for example.

[0142] For example, in the PFC circuit (120) shown in Fig. 3, the source terminal of the synchronous rectifier is connected to the input capacitor (C in )(121) and the other end of the inductor (L) B )(123) is connected to one end of the output capacitor (C bulk )(125) and the second diode (D f )(131) can be connected to the cathode.

[0143] For example, in the PFC circuit (120) shown in Fig. 6, the source terminal of the synchronous rectifier is connected to the input capacitor (C in )(121) other end, inductor (L B )(123) and the first resistor (R s1 )(127) is connected to one end of the output capacitor (C bulk )(125) and the second diode (D f )(131) can be connected to the cathode.

[0144] In Fig. 11, the gate driver (170) for controlling the switching element (Q1) (122) is described as the first gate driver (170), and the gate driver for controlling the synchronous rectifier is described as the second gate driver (190). Among the configurations illustrated in Fig. 11, the rectifier circuit (110), the PFC circuit (120), the protection circuit (130), the PFC controller (180), and the first gate driver (170) can be applied to the previously described content, and therefore, for the sake of brevity, a repeated description is omitted.

[0145] The second gate driver (190) can generate a gate signal for controlling the switching operation of the synchronous rectifier and apply the gate signal to the gate terminal of the synchronous rectifier.

[0146] The PFC controller (180) can control the second gate driver (190). For example, the PFC controller (180) can control the second gate driver (190) to apply a gate signal to the gate terminal of the synchronous rectifier for turning off the synchronous rectifier at the time when the switching circuit element (Q1) (122) is turned on. In addition, the PFC controller (180) can control the second gate driver (190) to apply a gate signal to the gate terminal of the synchronous rectifier for turning on the synchronous rectifier at the time when the switching circuit element (Q1) (122) is turned off.

[0147] Accordingly, the synchronous rectifier can be turned off during the time that the switching circuit element (Q1) (122) is turned on, and the synchronous rectifier can be turned on during the time that the switching circuit element (Q1) (122) is turned off. Accordingly, the synchronous rectifier can perform the same function as the diode (124).

[0148] FIG. 12 is a drawing for explaining a method of providing power to a second gate driver according to an embodiment of the present disclosure.

[0149] Referring to FIG. 12, when the diode (124) is replaced with a synchronous rectifier, the second gate driver (190) can be implemented as an isolated gate driver in that the source terminal of the synchronous rectifier (Q2) (1210) is separated from the ground and floats. In this case, as illustrated in FIG. 12, a circuit for supplying power to the second gate driver (190) can be provided.

[0150] Referring to Fig. 12, the other end of the input capacitor (121) (e.g., input voltage (V in) and the source terminal of the synchronous rectifier (Q2) (1210) are the same node, the power supply voltage (Vcc) generated by the regulator (1220) receiving the input voltage can be used as a power source for driving the second gate driver (190).

[0151] Although a buck regulator is illustrated in FIG. 12, the embodiments are not limited thereto. The regulator may be implemented as, for example, a linear regulator.

[0152] In addition, although the circuit illustrated in FIG. 3 is illustrated as an example in FIG. 12, the embodiments are not limited thereto. A circuit for generating power for the second gate driver (190) can be configured by connecting a regulator, a diode, an inductor, a capacitor, etc. to the circuit illustrated in FIG. 6 as in FIG. 12.

[0153] According to an embodiment, in the PFC circuit (120), a switching circuit element (Q1) (122) and a first diode (L B )(124) The connection structure can be changed in various ways.

[0154] For example, in the PFC circuit (120) illustrated in FIG. 3, the switching circuit element (Q1) (122) and the first diode (L B )(124) The connection structure can be changed as shown in Figs. 13a and 13b.

[0155] In addition, in the PFC circuit (120) illustrated in FIG. 6, the switching circuit element (Q1) (122) and the first diode (L B )(124) The connection structure can be changed as shown in Figs. 14a and 14b.

[0156] Referring to FIG. 13a, FIG. 13b, FIG. 14a, and FIG. 14b, the switching element (Q1) (122) and the first diode (L B )(124) can be placed on the same line, and accordingly, EMI characteristics can be improved.

[0157] The circuits illustrated in FIGS. 13a, 13b, 14a, and 14b operate substantially similarly to the circuits illustrated in FIGS. 3 and 6, and thus the above may also be applied to the circuits illustrated in FIGS. 13a, 13b, 14a, and 14b. In addition, in the circuits illustrated in FIGS. 13a, 13b, 14a, and 14b, the first diode (L B )(124) can be replaced with a synchronous rectifier. In addition, a power circuit can be configured by connecting an EMI filter (140), a DC / DC converter (150), and an output capacitor (160) to the circuits shown in FIGS. 13a, 13b, 14a, and 14b.

[0158] FIG. 15 is a flowchart for explaining a PFC circuit control method of an electronic device according to an embodiment of the present disclosure.

[0159] The electronic device includes a PFC circuit, a rectifier circuit for rectifying an alternating voltage and applying an input voltage having a negative polarity to the PFC circuit, and a protection circuit for protecting the PFC circuit.

[0160] In operation S1510, a gate signal is applied to the gate terminal of a switching circuit element of the PFC circuit so that the turned-on switching circuit element can be changed from an on state to an off state.

[0161] In operation S1520, the current flowing in the inductor of the PFC circuit is detected while the switching circuit element is turned off.

[0162] In operation S1530, a gate signal is applied to the gate terminal of the switching circuit element of the PFC circuit based on the detected current to turn on the turned-off switching circuit element.

[0163] The PFC circuit includes an inductor in which energy is stored based on an input voltage applied from the rectifier circuit while the switching circuit element is turned on, and an output capacitor connected to the inductor via a first diode and providing an output voltage having a positive polarity using the stored energy while the switching circuit element is turned off. In addition, when the first diode is short-circuited, the PFC circuit is protected by a current path formed by the protection circuit while the switching circuit element is turned on.

[0164] Additionally, the protection circuit may include a second diode connected in parallel with the output capacitor.

[0165] Additionally, the rectifier circuit may include a diode bridge. The PFC circuit may further include an input capacitor that receives the input voltage from the diode bridge.

[0166] For example, a first terminal of a switching circuit element may be connected to one terminal of the input capacitor. One terminal of an inductor may be connected to the other terminal of the input capacitor and the anode of the first diode. The other terminal of the inductor may be connected to one terminal of a resistor. In addition, one terminal of an output capacitor may be connected to the cathode of the first diode and the cathode of the second diode, and the other terminal of the output capacitor may be connected to the other terminal of the resistor, the second terminal of the switching circuit element, the ground voltage, and the anode of the second diode.

[0167] In this case, the resistor may be a resistor for detecting the current flowing through the inductor. Operation S1520 can detect the current of the inductor using the resistor.

[0168] For example, a first terminal of a switching circuit element may be connected to one terminal of an input capacitor. One terminal of an inductor may be connected to the other terminal of the input capacitor, the anode of a first diode, and one terminal of a first resistor. The other terminal of the first resistor may be connected to one terminal of a second resistor. In addition, one terminal of an output capacitor may be connected to a cathode of the first diode and a cathode of a second diode, and the other terminal of the output capacitor may be connected to the other terminal of the inductor, the other terminal of the second resistor, the second terminal of the switching element, a ground voltage, and the anode of the second diode.

[0169] In this case, the first and second resistors can be used to detect the current flowing in the inductor. Operation S1520 can detect the current in the inductor using the first and second resistors.

[0170] In addition, when the switching circuit element is turned on while the first diode is short-circuited due to a fault, the voltage charged in the output capacitor by the input voltage is discharged, and when the voltage at both ends of the output capacitor becomes 0 due to the discharge, a current path can be formed by the second diode.

[0171] Additionally, the rectifier circuit may further include a fuse. In this case, the fuse may be blown by current flowing through the current path, thereby stopping the operation of the PFC circuit.

[0172] Various embodiments may be implemented within a computer-readable recording medium, using hardware or a combination thereof. In some cases, the embodiments described herein may be implemented within the processor itself.

[0173] Computer instructions for performing processing operations of an electronic device according to various embodiments of the present disclosure described above may be stored in a non-transitory computer-readable medium.

[0174] A non-transitory computer-readable medium refers to a medium that permanently stores data and can be read by a device, rather than a medium that stores data for a short period of time, such as a register, cache, or memory. Specific examples of non-transitory computer-readable media include compact discs (CDs), digital video / versatile discs (DVDs), hard disks, Blu-ray discs, Universal Serial Bus (USB) storage devices, memory cards, and read-only memory (ROM).

[0175] While aspects of the embodiments have been particularly shown and described, it will be understood that various changes in form and detail may be made without departing from the spirit and scope of the following claims.

Claims

1. PFC (Power Factor Correction) circuit; A rectifier circuit that rectifies an AC voltage to obtain an input voltage having a negative polarity and provides the input voltage to the PFC circuit; and A protection circuit for protecting the above PFC circuit; The above PFC circuit, 1st diode; An inductor that stores energy based on an input voltage provided by the rectifier circuit while the switching circuit is turned on and supplies energy while the switching circuit is turned off; and An output capacitor connected to the inductor through the first diode and providing an output voltage having a positive polarity by utilizing energy provided by the inductor while the switching circuit is turned off; An electronic device in which the PFC circuit is protected by a current path formed by the protection circuit while the switching circuit is turned on when the first diode is short-circuited.

2. In paragraph 1, An electronic device wherein the protection circuit comprises a second diode connected in parallel with the output capacitor.

3. In paragraph 2, The above rectifier circuit includes a diode bridge, The above PFC circuit, An electronic device further comprising an input capacitor that receives the input voltage from the diode bridge.

4. In paragraph 3, The first stage of the above switching circuit is connected to one end of the input capacitor, One end of the above inductor is connected to the other end of the input capacitor and the anode of the first diode, The other end of the above inductor is connected to one end of the resistor, One end of the above output capacitor is connected to the cathode of the first diode and the cathode of the second diode, The other end of the output capacitor is connected to the other end of the resistor, the second end of the switching circuit, the ground voltage, and the anode of the second diode. The above resistor is an electronic device used to detect the current flowing in the inductor.

5. In paragraph 4, The above PFC circuit is driven in CrM (Critical conduction Mode) based on the current flowing through the inductor. An electronic device in which the above current is detected using the above resistance.

6. In paragraph 3, The first stage of the above switching circuit is connected to one end of the input capacitor, One end of the above inductor is connected to the other end of the input capacitor, the anode of the first diode, and one end of the first resistor, The other end of the first resistor is connected to one end of the second resistor, One end of the above output capacitor is connected to the cathode of the first diode and the cathode of the second diode, The other terminal of the output capacitor is connected to the other terminal of the inductor, the other terminal of the second resistor, the second terminal of the switching circuit, the ground voltage, and the anode of the second diode. The first and second resistors are an electronic device used to detect the current flowing in the inductor.

7. In paragraph 6, The above PFC circuit is an electronic device that drives CrM based on the current of the inductor detected using the first resistor and the second resistor.

8. In paragraph 2, When the switching circuit is turned on while the first diode is short-circuited due to a fault, the voltage charged in the output capacitor by the input voltage is discharged, An electronic device in which the current path flowing through the second diode is formed when the voltage across both terminals of the output capacitor becomes 0 due to the discharge.

9. In paragraph 8, Including fuse; An electronic device in which the fuse is blown by current flowing through the current path, thereby stopping the operation of the PFC circuit.

10. In paragraph 2, Including fuse; An electronic device in which, when the switching circuit is short-circuited due to a fault, the fuse is blown by the current flowing in the switching circuit, thereby stopping the operation of the PFC circuit.

11. In paragraph 1, An electromagnetic interference (EMI) filter that filters the source AC voltage and provides the AC voltage to the rectifier circuit; and An electronic device further comprising a DC / DC converter to which the above output voltage is applied.

12. A method for controlling a PFC circuit of an electronic device, comprising a PFC (Power Factor Correction) circuit, a rectifier circuit that rectifies an AC voltage and applies an input voltage with a negative polarity to the PFC circuit, and a protection circuit for protecting the PFC circuit. A step of controlling the switching circuit from an on state to an off state by applying a gate signal to a gate terminal of a switching circuit of the PFC circuit; A step of detecting a current flowing in an inductor of the PFC circuit while the switching circuit is in an off state; A step of controlling the switching circuit from an off state to an on state by applying a gate signal to a gate terminal of a switching circuit of the PFC circuit based on the detected current; A step of storing energy based on an input voltage applied from the rectifier circuit while the switching circuit is in an on state; and A step of providing an output voltage having a positive polarity by using an output capacitor of a PFC circuit connected to the inductor through a first diode while the switching circuit is in an off state: A control method in which the PFC circuit is protected by a current path formed by the protection circuit while the switching circuit is turned on when the first diode is short-circuited.

13. In paragraph 12, A control method wherein the protection circuit includes a second diode connected in parallel with the output capacitor.

14. In paragraph 13, The above rectifier circuit includes a diode bridge, The above method, A control method further comprising: a step of applying the input voltage from the rectifier circuit to the input capacitor of the PFC circuit.

15. In paragraph 14, The first stage of the above switching circuit is connected to one end of the input capacitor, One end of the above inductor is connected to the other end of the input capacitor and the anode of the first diode, The other end of the above inductor is connected to one end of the resistor, One end of the above output capacitor is connected to the cathode of the first diode and the cathode of the second diode, The other end of the output capacitor is connected to the other end of the resistor, the second end of the switching circuit, the ground voltage, and the anode of the second diode. A control method, wherein the method further comprises a step of detecting a current flowing in the inductor using the resistance.

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