Power supply device for changing response speed of power factor correction circuit, and electronic device including same

Abstract

An electronic circuit is disclosed. The electronic circuit may comprise: a power factor correction (PFC) circuit configured to generate a power signal on the basis of a power factor of an alternating current signal; a feedback circuit including a variable capacitor for generating a feedback voltage on the basis of a voltage of the power signal generated by the PFC circuit; and a control circuit for controlling the voltage of the PFC circuit on the basis of the feedback voltage generated through the variable capacitor. The feedback circuit may be configured to change the capacitance of the variable capacitor to a first capacitance in response to the voltage being less than a reference voltage. The feedback circuit may be configured to change the capacitance of the variable capacitor to a second capacitance greater than the first capacitance in response to the voltage being greater than or equal to the reference voltage.

Description

A power supply that changes the response speed of a power factor correction circuit, and an electronic device including the same

[0001] The following descriptions relate to a power supply that changes the response speed of a power factor correction (PFC) circuit, and an electronic device including the same.

[0002] An electronic device may receive a power signal from an infrastructure for providing power, referred to as a power distribution system. Upon receiving the power signal, the electronic device may execute various functions based on the design of the electronic device based on the power signal. Such an electronic device may include a power factor correction (PFC) circuit to satisfy power factor regulation and harmonic regulation while supplying stable power to hardware components.

[0003] An electronic circuit is disclosed. The electronic circuit may include a power factor correction (PFC) circuit configured to generate a power signal based on the power factor of an alternating current signal, a feedback circuit including a variable capacitor for generating a feedback voltage based on the voltage of the power signal generated by the PFC circuit, and a control circuit for controlling the voltage of the PFC circuit based on the feedback voltage generated through the variable capacitor. The feedback circuit may be configured to change the capacitance of the variable capacitor to a first capacitance in response to the voltage being less than a reference voltage. The feedback circuit may be configured to change the capacitance of the variable capacitor to a second capacitance greater than the first capacitance in response to the voltage being greater than or equal to the reference voltage.

[0004] An electronic device is disclosed. The electronic device may include at least one electronic component and a power circuit (170) configured to transmit a DC signal to the at least one electronic component. The power circuit (170) may include a rectifier circuit configured to rectify an AC signal, a PFC circuit configured to generate a power signal based on the power factor of the rectified AC signal, a capacitor in which the power signal generated through the PFC circuit is charged, a DC-DC converter circuit configured to generate a DC signal using the power signal charged in the capacitor, a feedback circuit including a variable capacitor for generating a feedback voltage based on the voltage of the power signal generated by the PFC circuit, and a control circuit for controlling the voltage of the PFC circuit based on the feedback voltage generated through the variable capacitor. The feedback circuit may be configured to change the capacitance of the variable capacitor to a first capacitance in response to the voltage being less than a reference voltage. The above feedback circuit may be configured to change the capacitance of the variable capacitor to a second capacitance greater than the first capacitance in response to the voltage being greater than the reference voltage.

[0005] A method is disclosed. The method may be performed by a power circuit (170). The method may include an operation of comparing a voltage of a power signal generated by a PFC circuit configured to generate a power signal based on the power factor of an AC signal with a reference voltage. The method may include an operation of determining the capacitance of a variable capacitor for generating a feedback voltage based on the result of the comparison between the voltage and the reference voltage. The method may include an operation of controlling the voltage of the PFC circuit based on the feedback voltage generated through the variable capacitor having the determined capacitance.

[0006] FIG. 1 illustrates an electronic device according to one embodiment.

[0007] FIG. 2 illustrates an exemplary power circuit included in an electronic device according to one embodiment.

[0008] FIG. 3 illustrates a feedback circuit included in a power circuit according to one embodiment.

[0009] Figure 4 is a timing diagram showing the control state of the response speed of the control circuit according to the output of the power factor improvement circuit.

[0010] FIG. 5 is a flowchart showing the operation of a power circuit according to one embodiment.

[0011] FIG. 6 illustrates a feedback circuit included in a power circuit according to one embodiment.

[0012] Figure 7 is a timing diagram showing the control state of the response speed of the control circuit according to the output of the power factor improvement circuit.

[0013] FIG. 8 is a flowchart showing the operation of a power circuit according to one embodiment.

[0014] The various embodiments of this document and the terms used therein are not intended to limit the technology described in this document to specific embodiments and should be understood to include various modifications, equivalents, and / or substitutions of such embodiments. In connection with the description of the drawings, similar reference numerals may be used for similar components. A singular expression may include a plural expression unless the context clearly indicates otherwise. In this document, expressions such as “A or B,” “at least one of A and / or B,” “A, B or C,” or “at least one of A, B and / or C” may include all possible combinations of items listed together. Expressions such as “first,” “second,” “first,” or “second” may modify the components, regardless of order or importance, and are used only to distinguish one component from another and do not limit the components. Where it is stated that a certain (e.g., first) component is “(functionally or telecommunicationally) connected” or “connected” to another (e.g., second) component, said certain component may be directly connected to said other component or connected through another component (e.g., third component).

[0015] As used in this document, the term “module” includes a unit composed of hardware and may be used interchangeably with terms such as, for example, component, and / or circuit. A module may be a component formed as a whole, or a minimum unit or part thereof that performs one or more functions. For example, a module may be composed of an application-specific integrated circuit (ASIC).

[0016] FIG. 1 illustrates an electronic device according to one embodiment.

[0017] In FIG. 1, the electronic device (101) may be an electronic device capable of displaying images. For example, the electronic device (101) may be a TV (television), a monitor, a computer, a smartphone, a tablet PC (personal computer), a portable media player, a wearable device, a video wall, or an electronic picture frame. The electronic device (101) may be a display device. For convenience of explanation, the following description assumes that the electronic device (101) is a TV, but the embodiment is not limited thereto.

[0018] The electronic device (101) may be configured to operate by power provided from the power system (110) (e.g., alternating current (AC) power signal, and / or alternating current signal). The power system (110) (or power distribution system) may be described as infrastructure built to provide power. The electronic device (101) may include a plug (120) (or port, power cord) configured to be connected to a power outlet (or outlet, socket, receptacle) located at one end of the power system (110). The plug (120) may be connected to a component of the electronic device (101) for power conversion (e.g., power conversion from an alternating current signal to a direct current (DC) signal (or direct current power signal)) (e.g., an AC-DC adapter (or power adapter) and / or a power circuit (170) described later with reference to FIG. 1).

[0019] While the plug (120) is electrically connected to the power system (110), the electronic device (101) can perform a function to output video, sound, or a combination thereof (e.g., multimedia content) based on the power of the power system (110). When the electronic device (101) receives information representing video and / or sound, the electronic device (101) can perform the function using said information. The information representing video and / or sound may be stored in the electronic device (101) or received from an external electronic device (e.g., a set-top box (STB)) (130) connected to the electronic device (101). The electronic device (101) may include an antenna configured to receive said information wirelessly or may be electrically connected to said antenna.

[0020] While receiving power from the power system (110) through the plug (120), the electronic device (101) may be operated according to any one of a normal mode (or active mode, enabled mode) and a standby mode (or inactive mode, disabled mode, hibernate mode, sleep mode). The normal mode may be described as a mode that consumes power exceeding the power consumption of the standby mode (e.g., standby power) to output video. The modes of the electronic device (101) are not limited to the normal mode and the standby mode. In this disclosure, the term “mode” may be used interchangeably with the term “state.” In the standby mode, the output of video and sound by the electronic device (101) may be substantially stopped or minimized. In standby mode, the electronic device (101) may output a message (e.g., “Press the power button”) guiding input to switch to normal mode. The message may be output through the display and / or speaker of the electronic device (101). In normal mode, the electronic device (101) may output video (e.g., video different from the message) and / or sound. The electronic device (101) may switch between standby mode and normal mode, or toggle based on user input.

[0021] The electronic device (101) may include hardware for receiving user input for controlling the electronic device (101) (e.g., user input for switching between standby mode and normal mode). For example, the electronic device (101) may include a switch (or button) that is at least partially visible through the housing of the electronic device (101). For example, the electronic device (101) may include a touch sensor (e.g., a pressure-sensitive touch sensor and / or a capacitive touch sensor) for detecting touch input on at least a portion of the housing. User input may include a direct action by the user on the electronic device (101) (e.g., pressing the switch and / or button, or touching one side of the housing). Embodiments are not limited thereto, and user input may be identified by an audio signal representing the user's speech received through a microphone. The embodiments are not limited thereto, and user input may include indirect actions of the user related to the electronic device (101) based on the remote controller (140).

[0022] Referring to FIG. 1, the electronic device (101) may be configured to receive a wireless signal (or optical signal) from a remote controller (140) based on infrared (IR). Embodiments are not limited thereto, and the remote controller (140) may be configured to transmit a wireless signal based on Bluetooth, BLE (Bluetooth low energy), NFC (near-field communication), UWB (ultra-wideband), WiFi (wireless fidelity), WiFi-direct, and / or other wireless short-range communication protocols. For example, the electronic device (101) may be configured to receive a wireless signal based on the illustrated wireless short-range communication protocols. In both standby mode and normal mode, the electronic device (101) may be configured to receive a wireless signal from the remote controller (140).

[0023] FIG. 1 includes an exploded perspective view illustrating electronic components included in an electronic device (101). The electronic device (101) may include a housing (150), a display panel (160), a power circuit (170), and a main circuitry (180). The housing (150) may include a rear cover (or back cover, back cover) of the electronic device (101). The housing (150) may include an object for supporting the electronic device (101) (e.g., support legs and / or VESA (video electronics standards association) mount holes). One side of the electronic device (101) where the housing (150) is visible may be described as the rear side (e.g., rear side) of the electronic device (101).

[0024] The other side of the electronic device (101), opposite to one side of the electronic device (101) where the housing (150) is visible, may be described as the front side (e.g., front side) of the electronic device (101). The display panel (160) may be visible from the front side of the electronic device (101). The display panel (160) may include a liquid crystal display (LCD), a plasma display panel (PDP), and a plurality of LEDs. The LEDs of the display panel (160) may include organic LEDs (OLED). In one embodiment, the display panel (160) may include electronic paper. If the display panel (160) has a flat shape, the display panel (160) may be referred to as a flat panel display (FPD). If the display panel (160) has a curved shape, the display panel (160) may be referred to as a curved display. If the display panel (160) has a deformable shape, the display panel (160) may be referred to as a bendable display, a flexible display, and / or a rollable display.

[0025] The main circuit (180) may be configured to execute the functions of the electronic device (101) described above (e.g., a function for outputting video, sound, or a combination thereof, a turn-on function, a turn-off function, a function for adjusting volume, a function for changing channels, and / or a function for controlling the execution of a software application (e.g., an OTT (over the top) application) installed on the electronic device (101). For example, the main circuit (180) may control the display panel (160) using information received from an external electronic device (130) (or an antenna of the electronic device (101)) to output audio, images, video, or any combination thereof that appears according to said information. For example, the main circuit (180) may be configured to control the display panel (160). The power circuit (170) may be configured to provide power to the main circuit (180). The power circuit (170) may be configured to convert an alternating current signal received from the power system (110) into a direct current signal for driving the main circuit (180). For example, the power circuit (170) may be configured to transmit a direct current signal to the main circuit (180).

[0026] For driving an electronic device (101), the amount of electrical energy provided from a power system (110) to an electronic device (101) may be referred to as apparent power. Apparent power may be a combination of active power (or consumed power) and reactive power. In the case where the power system (110) supplies electrical energy to electronic devices having the same active power, if the reactive powers of said electronic devices are different, the apparent power provided by the power system (110) to said electronic devices may be different. For example, the higher the reactive power, the higher the apparent power may be. Power factor (PF) refers to the ratio between active power and apparent power. To reduce the load on the power system (110), it may be (legally) required that the electronic device (101) have a power factor higher than a critical power factor.

[0027] According to one embodiment, an electronic device (101) and / or a power circuit (170) may be configured to receive an alternating current signal from a power system (110) while satisfying conditions related to power factor (e.g., legal regulations). The legal regulations may be set such that an electronic device (101) consuming 75 W or more of power has a power factor greater than a critical power factor. In accordance with the legal regulations, the electronic device (101) may include a power circuit (170) (e.g., a switching mode power supply (SMPS)) that is controlled to have a power factor greater than the critical power factor. To receive an alternating current signal at a power factor higher than the critical power factor, the power circuit (170) of the electronic device (101) may include a power factor improvement circuit.

[0028] Hereinafter, with reference to FIG. 2, a power circuit (170) of an electronic device (101) including a power factor improvement circuit is described.

[0029] FIG. 2 illustrates an exemplary power circuit included in an electronic device according to one embodiment.

[0030] Referring to FIG. 2, a power circuit (170) included in an electronic device (e.g., the electronic device (101) of FIG. 1) can be electrically connected to a power system (110). The electrical connection between the power system (110) and the power circuit (170) can be established based on the plug (120) of FIG. 1.

[0031] Through an electrical connection, the power circuit (170) can receive an alternating current signal. The alternating current signal may be a power signal having a voltage that changes over time. In one embodiment, the voltage of the alternating current signal may change along a sinusoidal wave having a specified frequency (e.g., 50 Hz and / or 60 Hz) and a specified amplitude (e.g., 220 V and / or 110 V). The power circuit (170) can output a direct current signal having a constant voltage from the alternating current signal. The direct current signal output from the power circuit (170) may be described as a power signal having a constant voltage (within a specified error range) in the time domain.

[0032] Referring to FIG. 2, the power circuit (170) may include an electromagnetic interference (EMI) filter (210), a rectifier circuit (220), a power factor correction (PFC) circuit (240), a DC-DC conversion circuit (250), a control circuit (270), a feedback circuit (280), or any combination thereof. The power circuit (170) may further include circuits not shown in FIG. 2. For example, the power circuit (170) may further include circuits such as a lightning protection circuit, a varistor, and / or a surge arrester. At least some of the circuits shown in FIG. 2 may be omitted depending on the implementation.

[0033] The EMI filter (210) of the power circuit (170) may be configured to remove or reduce noise in an AC signal provided from the power system (110). The noise may include voltage ripples caused by other frequency components different from the main frequency component (e.g., 50 Hz and / or 60 Hz) of the AC signal. The EMI filter (210) may be connected to a rectifier circuit (220). For example, an AC signal having noise reduced by the EMI filter (210) may be transmitted to the rectifier circuit (220). For example, the EMI filter (210) may include a line filter.

[0034] The rectifier circuit (220) of the power circuit (170) can rectify an AC signal of the power system (110) (or an AC signal transmitted from the EMI filter (210)) and output the rectified AC signal. The rectifier circuit (220) can be configured to rectify the AC signal when it receives the AC signal. To rectify the AC signal, the rectifier circuit (220) may include a plurality of diodes. For example, the rectifier circuit (220) may include a bridge diode circuit connected to perform full-wave rectification of the AC signal. Referring to FIG. 2, the EMI filter (210) may be connected to nodes (A, B) between pairs of diodes included in the rectifier circuit (220). For example, the rectifier circuit (220) may be configured to perform half-wave rectification of the AC signal. The embodiments are not limited thereto, and the rectifier circuit (220) may include a non-bridge type rectifier circuit.

[0035] The PFC circuit (240) of the power circuit (170) can adjust the power factor of an AC signal input to the power circuit (170) (e.g., an AC signal transmitted from a power system (110) to an EMI filter (210). Since the voltage of the AC signal is defined as a sine wave, the PFC circuit (240) can be configured to adjust the magnitude of the current of the AC signal in order to adjust the power factor. The PFC circuit (240) can be configured to improve the power factor (or have a power factor exceeding a critical power factor). The PFC circuit (240) can adjust the power factor by synchronizing the phases of the voltage and current of the AC signal. For example, if the magnitude (or envelope) of the current of the AC signal has a sine wave that has the phase and / or frequency of the voltage of the AC signal, the power factor can be increased or improved.

[0036] The PFC circuit (240) may be configured to change the phase of the current of an alternating current signal. The PFC circuit (240) may be configured to control the charging of a capacitor (243) based on an alternating current signal rectified by a rectifier circuit (220). The capacitor (243) may be configured to store relatively large electrical energy. In terms of storing relatively large electrical energy, the capacitor (243) may be referred to as a supercapacitor and / or a bulk capacitor. The capacitor (243) may include an electrolytic capacitor, a film capacitor, and / or a multilayer ceramic capacitor (MLCC).

[0037] The power circuit (170) may include a DC-DC conversion circuit (250) configured to generate a DC signal for driving at least one electronic component included in the electronic device using power (or electrical energy) charged in the capacitor (243). The DC-DC conversion circuit (250) may transmit a DC signal having a voltage required by the hardware component to each of the hardware components of the electronic device (101). The DC-DC conversion circuit (250) may include at least one of an isolated DC-DC conversion circuit, a flyback conversion circuit, or a forward conversion circuit. For example, the power circuit (170) may be configured to transmit a DC signal to at least one electronic component of the electronic device.

[0038] The DC-DC conversion circuit (250) can output a DC signal to a different other end (e.g., node (260-1)) and one end (e.g., node (240-2)) connected to the PFC circuit (240). The DC-DC conversion circuit (250) may include a capacitor (260) comprising one end connected to node (260-1) and the other end grounded (e.g., node (260-2)). Node (260-1) of the DC-DC conversion circuit (250) may be connected to an electronic component. The DC-DC conversion circuit (250) can output a DC signal to the electronic component through node (260-1), having a voltage required for driving the electronic component. When the power consumption of the electronic component increases, the capacitor (243) may discharge more quickly because the electrical energy of the capacitor (243) is discharged to drive the electronic component. Discharging the capacitor (243) can reduce the voltage at both ends of the capacitor (243) (e.g., the voltage at node (240-2)). For example, as the power consumption of the electronic component increases, the capacitor (243) discharges quickly, so the potential difference between the two ends of the inductor (230) (e.g., nodes (220-1, 240-1)) can increase.

[0039] According to one embodiment, the power circuit (170) may include an inductor (230) between the rectifier circuit (220) and the PFC circuit (240). In this document, the inductor (230) is described as being connected to the PFC circuit (240), but the embodiment is not limited thereto, and the inductor (230) may be (integrally) included in the PFC circuit (240) as shown in FIG. 2.

[0040] In one embodiment, one end of the inductor (230) is connected to one end of the rectifier circuit (220) (e.g., node (220-1)), and the other end of the inductor (230) can be connected to one end of the PFC circuit (240) (e.g., node (240-1)).

[0041] In one embodiment, one end of the capacitor (225) is connected to a node (220-1), and the other end of the capacitor (225) may be connected to another end of the rectifier circuit (220) (e.g., node (220-2)). In one embodiment, the capacitor (225) may be charged at least temporarily based on an alternating current signal rectified by the rectifier circuit (220). In one embodiment, the electrical energy charged in the capacitor (225) may be used to induce current in the inductor (230).

[0042] In one embodiment, the PFC circuit (240) may be based on a critical conduction mode (CrM). In one embodiment, the PFC circuit (240) may include a switch (e.g., transistor (241)) and a diode (242) for controlling the flow of current induced in the inductor (230). In one embodiment, one end of the PFC circuit (240) (e.g., node (240-1) connected to the other end of the inductor (230)) may be connected to the anode of the diode (242) and the drain of the transistor (241). For example, the transistor (241) may be configured to control the electrical connection between the anode and the ground node by being connected to the anode of the diode (242). The cathode of the diode (242) may be connected to one end of the capacitor (243) (e.g., node (240-2)). A diode (242) can be placed in the power circuit (170) so that the electrical energy of the capacitor (243) is not transmitted to the inductor (230) and / or rectifier circuit (220).

[0043] In one embodiment, the source of the transistor (241) may be connected to a ground node. Although not illustrated, the gate of the transistor (241) may be connected to a control circuit (270) of the PFC circuit (240). The control circuit (270) may measure the current induced in the inductor (230). The control circuit (270) may be configured to control the transistor (241). Using the measured current, the control circuit (270) may control the transistor (241). The control circuit (270) may apply a voltage to the gate of the transistor (241) to activate the transistor (241) at least temporarily (e.g., establish an electrical connection between the drain and the source).

[0044] For example, the control circuit (270) of the CrM-based PFC circuit (240) can activate the transistor (241) when the magnitude of the current induced in the inductor (230) corresponds to a specified magnitude (e.g., 0 A). By the activated transistor (241), an electrical connection can be established between the anode of the diode (242) (e.g., node (240-1)) and the ground node. By the activated transistor (241), the potential difference between the two ends of the inductor (230) (e.g., nodes (220-1, 240-1)) can be increased to the potential difference between the capacitor (225) (or nodes (220-1, 220-2)) corresponding to the two ends of the rectifier circuit (220). According to the characteristic equation of the inductor, such as mathematical equation 1, the increased potential difference can induce current in the inductor (230).

[0045]

[0046] Referring to Equation 1, v represents the magnitude of the voltage applied to the inductor (230), i represents the magnitude of the current induced in the inductor (230), and L represents the inductance of the inductor (230). The larger the inductance (L), the higher the rate of change of the magnitude of the current This can be reduced.

[0047] A control circuit (270) based on CrM can activate the transistor (241) for a time interval of a specified length (or a fixed length). In response to the expiration of the time interval, the control circuit (270) can deactivate the transistor (241) (e.g., disconnect the electrical connection between the drain and the source). For example, based on the expiration of the time interval, the control circuit (270) can control the transistor (241) to disconnect the electrical connection between the anode and the ground node of the diode (242). The current induced in the inductor (230) by the deactivated transistor (241) can be transmitted to the capacitor (243) through the diode (242). The magnitude of the current in the inductor (230) has a continuous characteristic. The magnitude of the current in the inductor (230) induced during the time interval may not immediately decrease to zero after the time interval due to the continuous characteristic. For example, the capacitor (243) can receive the current of the inductor (230) induced during the time interval. For example, the capacitor (243) can receive the electrical energy accumulated in the inductor (230) during the time interval due to the current induced in the inductor (230).

[0048] While receiving the current induced in the inductor (230), the capacitor (243) can be charged by said current. When the capacitor (243) is charged, the voltage at both ends of the capacitor (243) (e.g., the voltage at node (240-2)) can be increased. Because the capacitor (243) receives electrical energy from the inductor (230), the magnitude of the current induced in the inductor (230) can be (gradually) (continuously) decreased while the capacitor (243) is being charged. A PFC circuit (240) configured to charge the capacitor (243) based on the connection of the inductor (230), transistor (241), and diode (242) can be referred to as a boost converter.

[0049] The feedback circuit (280) can provide feedback to the control circuit (270) based on the voltage of the current charged in the capacitor (243) (or the voltage of the power signal generated by the PFC circuit (240)). In one embodiment, the control circuit (270) can control the PFC circuit (240) (or the transistor (241) of the PFC circuit (240)) based on the feedback from the feedback circuit (280).

[0050] However, when the voltage of the power signal input to the PFC circuit (240) is low or / or the load is high during a transient state (e.g., a state of being connected or disconnected between the power system (110) and the power circuit (170), or a state of voltage switching of the power system (110)), if the response of the control circuit (270) is delayed (or, if the response is slow), the voltage of the power signal generated by the PFC circuit (240) may be low. Accordingly, a method may be required to quickly restore the voltage of the power signal generated by the PFC circuit (240) during a transient state where the voltage of the power signal is low or / or the load is high.

[0051] Hereinafter, with reference to FIGS. 3 and FIGS. 4, a configuration of a power circuit (170) for rapidly recovering the voltage of a power signal generated by a PFC circuit (240) can be described.

[0052] FIG. 3 illustrates a feedback circuit included in a power circuit (170) according to one embodiment. FIG. 4 is a timing diagram showing the control state of the response speed of a control circuit according to the output of a power factor improvement circuit.

[0053] Referring to FIG. 3, the feedback circuit (280) may include a variable capacitor (310), a comparison circuit (350), a voltage divider (360), or any combination thereof.

[0054] In one embodiment, one end of the voltage divider (360) is connected to one end of the PFC circuit (240) (e.g., node (240-2)), and the other end of the voltage divider (360) may be connected to a ground node. In one embodiment, the voltage divider (360) may divide the voltage of the PFC circuit (240) according to a specified ratio (or, the ratio of resistances between serially connected resistors). In one embodiment, the voltage divider (360) may divide the voltage of the power signal of the PFC circuit (240) for charging the capacitor (243) according to the ratio between the resistance between node (240-2) and node (365) (e.g., 8 mega ohms) and the resistance between node (365) and the ground node (e.g., 255.1 kilo ohms).

[0055] In one embodiment, the comparison circuit (350) may include an amplifier (351) (or a comparator) and a voltage divider (355).

[0056] In one embodiment, the comparison circuit (350) (or the output terminal of the amplifier (351)) may be connected to a variable capacitor (310). In one embodiment, the comparison circuit (350) (or the first input terminal of the amplifier (351)) may be connected to a voltage divider (360). In one embodiment, the comparison circuit (350) (or the second input terminal of the amplifier (351)) may receive the voltage of the power supply (Vcc) distributed at a predetermined ratio through the voltage divider (355). For example, the voltage divider (355) can distribute the voltage of the power supply (Vcc) according to the ratio between the resistance (e.g., 155 kiloohms) between the power supply (Vcc) and the comparison circuit (350) (or the second input terminal of the amplifier (351)) and the resistance (e.g., 20 kiloohms) between the comparison circuit (350) (or the second input terminal of the amplifier (351)) and the ground node.

[0057] In one embodiment, the comparison circuit (350) can control the on or off of the switching circuit (340) based on the voltage of the power signal of the PFC circuit (240) for charging the capacitor (243). In one embodiment, the comparison circuit (350) can control the on or off of the switching circuit (340) based on the voltage of the PFC circuit (240) distributed at a ratio specified by the voltage divider (360).

[0058] For example, the comparison circuit (350) can generate a control signal to set the capacitance of the variable capacitor (310) to a first capacitance (e.g., 100 nanofarads) in response to the voltage of the PFC circuit (240) being less than the reference voltage (Vth) (e.g., 300 volts). For example, the comparison circuit (350) can generate a control signal to turn off the switching circuit (340) of the variable capacitor (310) in response to the voltage of the PFC circuit (240) being less than the reference voltage (Vth).

[0059] For example, the comparison circuit (350) can generate a control signal to set the capacitance of the variable capacitor (310) to a second capacitance (e.g., 570 nanofarads) higher than the first capacitance in response to the voltage of the PFC circuit (240) being greater than the reference voltage (Vth). For example, the comparison circuit (350) can generate a control signal to turn on the switching circuit (340) of the variable capacitor (310) in response to the voltage of the PFC circuit (240) being greater than the reference voltage (Vth).

[0060] For example, referring to FIG. 4, during a time interval (time interval before t1) when the voltage (410) of the PFC circuit (240) is less than the reference voltage (e.g., 300 volts (V)), the control signal (420) generated by the comparison circuit (350) may have a value for turning off the switching circuit (340) of the variable capacitor (310). For example, during a time interval (time interval from t1 to t2) when the voltage (410) of the PFC circuit (240) is greater than or equal to the reference voltage (e.g., 300 volts (V)), the control signal (420) generated by the comparison circuit (350) may have a value for turning on the switching circuit (340) of the variable capacitor (310). For example, during a time interval (time interval from t2 to t3) when the voltage (410) of the PFC circuit (240) is less than the reference voltage (e.g., 300 volts (V)), the control signal (420) generated by the comparison circuit (350) may have a value for turning off the switching circuit (340) of the variable capacitor (310). For example, during a time interval (time interval from t3 to t4) when the voltage (410) of the PFC circuit (240) is greater than or equal to the reference voltage (e.g., 300 volts (V)), the control signal (420) generated by the comparison circuit (350) may have a value for turning on the switching circuit (340) of the variable capacitor (310). For example, during a time interval (time interval after t4) when the voltage (410) of the PFC circuit (240) is less than the reference voltage (e.g., 300 volts (V)), the control signal (420) generated by the comparison circuit (350) may have a value for turning off the switching circuit (340) of the variable capacitor (310).

[0061] In one embodiment, the variable capacitor (310) can generate a feedback voltage based on the voltage of the power signal generated by the PFC circuit (240). For example, referring to FIG. 3, the variable capacitor (310) can provide the feedback voltage to the control circuit (270) through a compensation node (311). In one embodiment, the compensation node (311) may be referred to as a compensation pin of the control circuit (270).

[0062] In one embodiment, the variable capacitor (310) may include a first capacitor (320), a second capacitor (330), and a switching circuit (340).

[0063] In one embodiment, one end of the first capacitor (320) is connected to one end of the control circuit (270) (e.g., compensation node (311)), and the other end of the first capacitor (320) can be connected to the ground node (315).

[0064] In one embodiment, one end of the second capacitor (330) is connected to one end of the control circuit (270) (e.g., compensation node (311)) and one end of the first capacitor (320), and the other end of the second capacitor (330) may be connected to one end of the switching circuit (340).

[0065] In one embodiment, the switching circuit (340) may include a switch (341), a first register (343), and a second register (345).

[0066] In one embodiment, the switch (341) may include a transistor (e.g., a MOSFET (metal-oxide-semiconductor field effect transistor), a MISFET (metal-insulator-semiconductor FET), and / or a BJT (bipolar junction transistor)).

[0067] In one embodiment, the drain of the switch (341) may be connected to the first register (343). In one embodiment, the gate of the switch (341) may be connected to the comparison circuit (350). In one embodiment, the gate of the switch (341) may be connected to one end of the second register (345). In one embodiment, the source of the switch (341) may be connected to the ground node (315). In one embodiment, the source of the switch (341) may be connected to the other end of the first capacitor (320). In one embodiment, the source of the switch (341) may be connected to the other end of the second register (345). In one embodiment, the first register (343) may have 12 kiloohms, and the second register (345) may have 100 kiloohms.

[0068] In one embodiment, one end of the switching circuit (340) (or one end of the first register (343)) may be connected to the other end of the second capacitor (330). In one embodiment, the other end of the switching circuit (340) (or the source of the switch (341) or the other end of the second register (345)) may be connected to the other end of the first capacitor (320) and the ground node (315).

[0069] In one embodiment, the switching circuit (340) may be turned on or off in response to a control signal of the comparison circuit (350). For example, the switch (341) of the switching circuit (340) may be turned on or off in response to a control signal of the comparison circuit (350) input to the gate of the switch (341).

[0070] In one embodiment, as the switch (341) (or switching circuit (340)) is turned on, the second capacitor (330) may be electrically connected to the ground node (315) through the first resistor (343). For example, as the switch (341) (or switching circuit (340)) is turned on, the second capacitor (330) may be electrically connected to the ground node (315) through the first resistor (343). For example, as the switch (341) (or switching circuit (340)) is turned off, the second capacitor (330) may be electrically disconnected from the ground node (315). For example, as the switch (341) (or switching circuit (340)) is turned off, the second capacitor (330) may be electrically disconnected from the ground node (315).

[0071] In one embodiment, as the switch (341) (or switching circuit (340)) is turned on or off in response to a control signal of the comparison circuit (350), the capacitance of the variable capacitor (310) (or the capacitance between the compensation node (311) and the ground node (315)) may be changed. For example, when the switch (341) (or switching circuit (340)) is turned off, the capacitance of the variable capacitor (310) (or the capacitance between the compensation node (311) and the ground node (315)) may correspond to the first capacitance of the first capacitor (320). For example, when the switch (341) (or the switching circuit (340)) is turned on, the capacitance of the variable capacitor (310) (or the capacitance between the compensation node (311) and the ground node (315)) may be greater than the capacitance of the first capacitor (320). For example, when the switch (341) is turned on, the capacitance of the variable capacitor (310) may correspond to the second capacitance, which is the sum of the first capacitance of the first capacitor (320) and the capacitance of the second capacitor (330).

[0072] For example, referring to FIG. 4, the variable capacitor (310) may have a first capacitance by turning off the switching circuit (340) during a time interval (time interval before t1) in which the control signal (420) has a value for turning off the switching circuit (340). For example, the variable capacitor (310) may have a second capacitance by turning on the switching circuit (340) during a time interval (time interval from t1 to t2) in which the control signal (420) has a value for turning on the switching circuit (340). For example, the variable capacitor (310) may have a first capacitance by turning off the switching circuit (340) during a time interval (time interval from t2 to t3) in which the control signal (420) has a value for turning off the switching circuit (340). For example, during a time interval (time interval from t3 to t4) in which the control signal (420) has a value for turning on the switching circuit (340), the switching circuit (340) is turned on, so that the variable capacitor (310) can have a second capacitance. For example, during a time interval (time interval after t4) in which the control signal (420) has a value for turning off the switching circuit (340), the switching circuit (340) is turned off, so that the variable capacitor (310) can have a first capacitance.

[0073] In one embodiment, when the capacitance of the variable capacitor (310) has a first capacitance, the voltage generated through the variable capacitor (310) (or the voltage difference between the compensation node (311) and the ground node (315)) can change relatively quickly depending on the change in the PFC circuit (240). For example, when the voltage of the power signal of the PFC circuit (240) decreases, the compensation voltage of the compensation node (311) generated through the variable capacitor (310) having a low capacitance rises quickly, and accordingly, the control circuit (270) can quickly turn off the transistor (241) to increase the voltage of the PFC circuit (240). That is, as the compensation voltage rises quickly through the variable capacitor (310) having a low capacitance, the response speed of the control circuit (270) for controlling the transistor (241) can be increased.

[0074] In one embodiment, when the capacitance of the variable capacitor (310) has a second capacitance, the voltage generated through the variable capacitor (310) (or the voltage difference between the compensation node (311) and the ground node (315)) may change relatively slowly depending on the change in the PFC circuit (240).

[0075] FIG. 5 is a flowchart showing the operation of a power circuit according to one embodiment.

[0076] FIG. 5 can be explained with reference to FIGS. 1 to 4.

[0077] In one embodiment, in operation 510, the power circuit (170) (e.g., the power circuit (170) of FIG. 2) can identify the voltage of the power signal generated by the PFC circuit (e.g., the PFC circuit (240) of FIG. 2). For example, the power circuit (170) can identify the voltage of the power signal of the PFC circuit (240) through the feedback circuit (280).

[0078] In one embodiment, in operation 520, the power circuit (170) can determine whether the voltage is less than the reference voltage (Vth). For example, the power circuit (170) can determine whether the voltage of the power signal of the PFC circuit (240) is less than the reference voltage (Vth). For example, the power circuit (170) can determine whether the voltage of the power signal of the PFC circuit (240) is less than the reference voltage (Vth) through the feedback circuit (280).

[0079] In response to the determination that the voltage is less than the reference voltage (Vth) in operation 520, the power circuit (170) may perform operation 530. In response to the determination that the voltage is greater than or equal to the reference voltage (Vth) in operation 520, the power circuit (170) may perform operation 540.

[0080] In one embodiment, in operation 530, the power circuit (170) can change the response speed of the control circuit (270) to a first speed. In one embodiment, the power circuit (170) can change the response speed of the control circuit (270) to a first speed by increasing the rate of change of the feedback voltage provided to the control circuit (270).

[0081] For example, the power circuit (170) can change the capacitance of the variable capacitor (310) that inputs a voltage signal to the compensation node (311) of the control circuit (270) to a relatively low capacitance. For example, the power circuit (170) can increase the rate of change of the feedback voltage provided to the control circuit (270) by changing the capacitance of the variable capacitor (310) in the feedback circuit (280) to a relatively low capacitance.

[0082] In one embodiment, in operation 540, the power circuit (170) can change the response speed of the control circuit (270) to a second speed. In one embodiment, the power circuit (170) can change the response speed of the control circuit (270) to a second speed by reducing the rate of change of the feedback voltage provided to the control circuit (270). For example, the second speed may be lower than the first speed.

[0083] For example, the power circuit (170) can change the capacitance of the variable capacitor (310) that inputs a voltage signal to the compensation node (311) of the control circuit (270) to a relatively high capacitance. For example, the power circuit (170) can reduce the rate of change of the feedback voltage provided to the control circuit (270) by changing the capacitance of the variable capacitor (310) in the feedback circuit (280) to a relatively high capacitance.

[0084] FIG. 6 illustrates a feedback circuit included in a power circuit according to one embodiment. FIG. 7 is a timing diagram showing the control state of the response speed of a control circuit according to the output of a power factor improvement circuit.

[0085] FIGS. 6 and FIGS. 7 may be described with reference to FIGS. 1 through 5. In the description of FIG. 6, descriptions that overlap with the feedback circuit (280) described in FIG. 3 may not be repeated.

[0086] Referring to FIG. 6, the feedback circuit (280) may include a feedback circuit portion (601) for voltage control of the control circuit (270) and a feedback circuit portion (605) for current control of the control circuit (270). For example, the feedback circuit portion (601) may include a variable capacitor (310), a comparison circuit (350), a voltage divider (360), or any combination thereof. For example, the feedback circuit portion (605) may include a sensing resistor (610), an RC filter (620), a variable resistor (630), a comparison circuit (640), or any combination thereof. In one embodiment, the sensing resistor (610) may be located between the rectifier circuit (220) and the ground node.

[0087] In one embodiment, the comparison circuit (640) may include an amplifier (or comparator) and a voltage divider.

[0088] In one embodiment, the comparison circuit (640) (or the output terminal of the amplifier) ​​may be connected to a variable resistor (630). In one embodiment, the comparison circuit (640) (or the first input terminal of the amplifier) ​​may be connected to a voltage divider (360). In one embodiment, the comparison circuit (640) (or the second input terminal of the amplifier) ​​may receive the voltage of the comparison circuit (350) distributed at a predetermined ratio through another voltage divider.

[0089] In one embodiment, the comparison circuit (640) can control the resistance of the variable resistor (630) (or the on or off of the switch within the variable resistor (630)) based on the voltage of the power signal of the PFC circuit (240) for charging the capacitor (243).

[0090] For example, the comparison circuit (640) can generate a control signal to set the resistance of the variable resistor (630) to a first resistance in response to the voltage of the PFC circuit (240) being less than another reference voltage (Vth2) (e.g., 360 volts) and greater than or equal to the reference voltage (Vth1) (e.g., 300 volts). For example, the comparison circuit (640) can generate a control signal to turn on the switch of the variable resistor (630) in response to the voltage of the PFC circuit (240) being less than another reference voltage (Vth2) (e.g., 360 volts) and greater than or equal to the reference voltage (Vth1) (e.g., 300 volts).

[0091] For example, the comparison circuit (640) may generate a control signal to set the resistance of the variable resistor (630) to a second resistance in response to the voltage of the PFC circuit (240) being greater than or equal to another reference voltage (Vth2) (e.g., 360 volts) or less than the reference voltage (Vth1) (e.g., 300 volts). For example, the comparison circuit (640) may generate a control signal to turn off the switch of the variable resistor (630) in response to the voltage of the PFC circuit (240) being greater than or equal to another reference voltage (Vth2) (e.g., 360 volts) or less than the reference voltage (Vth1) (e.g., 300 volts). For example, the first resistance may be smaller than the second resistance.

[0092] For example, referring to FIG. 7, during a time interval (time interval before t1, time interval from t2 to t3, time interval after t4) when the voltage (710) of the PFC circuit (240) is less than the reference voltage (Vth1) (e.g., 300 volts (V)), the control signal (720) generated by the comparison circuit (350) may have a value for turning off the switching circuit (340) of the variable capacitor (310). For example, during a time interval (time interval from t1 to t2, time interval from t3 to t4) when the voltage (410) of the PFC circuit (240) is greater than or equal to the reference voltage (e.g., 300 volts (V)), the control signal (720) generated by the comparison circuit (350) may have a value for turning on the switching circuit (340) of the variable capacitor (310).

[0093] For example, referring to FIG. 7, during a time interval (time interval from t1 to t5, time interval from t6 to t2, time interval from t3 to t7, time interval from t8 to t4) in which the voltage (710) of the PFC circuit (240) is less than another reference voltage (Vth2) (e.g., 360 volts) and greater than or equal to the reference voltage (Vth1) (e.g., 300 volts), the control signal (730) generated by the comparison circuit (640) may have a value for turning on the switch of the variable resistor (630). For example, during a time interval when the voltage (710) of the PFC circuit (240) is greater than or equal to another reference voltage (Vth2) (e.g., 360 volts) or less than or equal to the reference voltage (Vth1) (e.g., 300 volts), the control signal (730) generated by the comparison circuit (640) may have a value for turning off the switch of the variable resistor (630).

[0094] In one embodiment, the variable resistor (630) can generate a different feedback voltage based on the voltage of the power signal generated by the PFC circuit (240). For example, referring to FIG. 6, the variable resistor (630) can provide a different feedback voltage to the control circuit (270) through the CS node (635). In one embodiment, the CS node (635) may be referred to as the CS pin of the control circuit (270).

[0095] In one embodiment, when the resistance of the variable resistor (630) has a first resistance (or when the switch of the variable resistor (630) is turned on), the control circuit (270) may not limit the current (or peak current) of the power signal of the PFC circuit (240). In one embodiment, when the resistance of the variable resistor (630) has a first resistance (or when the switch of the variable resistor (630) is turned on), the control circuit (270) may turn off the transistor (241) of the PFC circuit (240).

[0096] In one embodiment, when the resistance of the variable resistor (630) has a second resistance (or when the switch of the variable resistor (630) is turned off), the control circuit (270) can limit the current (or peak current) of the power signal of the PFC circuit (240). In one embodiment, when the resistance of the variable resistor (630) has a second resistance (or when the switch of the variable resistor (630) is turned off), the control circuit (270) can turn on the transistor (241) of the PFC circuit (240).

[0097] In one embodiment, when the voltage of the power signal of the PFC circuit (240) is greater than another reference voltage (Vth2) (e.g., 360 volts) (or when the switching circuit (340) of the variable capacitor (310) is turned on and the switch of the variable resistor (630) is turned off), the control circuit (270) can maintain the response speed of the PFC circuit (240) at a low state and limit the current of the PFC circuit (240).

[0098] In one embodiment, when the voltage of the power signal of the PFC circuit (240) is less than another reference voltage (Vth2) (e.g., 360 volts) and greater than or equal to the reference voltage (Vth1) (e.g., 300 volts) (or when the switching circuit (340) of the variable capacitor (310) is turned on and the switch of the variable resistor (630) is turned on), the control circuit (270) may keep the response speed of the PFC circuit (240) low and may not limit the current of the PFC circuit (240).

[0099] In one embodiment, when the voltage of the power signal of the PFC circuit (240) is less than the reference voltage (Vth1) (e.g., 300 volts) (or when the switching circuit (340) of the variable capacitor (310) is turned off and the switch of the variable resistor (630) is turned off), the control circuit (270) can maintain the response speed of the PFC circuit (240) in a high state and limit the current of the PFC circuit (240).

[0100] FIG. 8 is a flowchart showing the operation of a power circuit according to one embodiment.

[0101] FIG. 8 can be explained with reference to FIGS. 1 to 7.

[0102] Referring to FIG. 8, in operation 810, the power circuit (170) can identify the voltage of the power signal generated by the PFC circuit (240).

[0103] In operation 820, the power circuit (170) can determine whether the voltage is less than the reference voltage (Vth1) (e.g., 300 volts). For example, the power circuit (170) can determine whether the voltage is less than the reference voltage (Vth1) (e.g., 300 volts) through the feedback circuit (280).

[0104] In one embodiment, based on the determination that the voltage is less than a reference voltage (Vth1) (e.g., 300 volts), the power circuit (170) may perform operation 830. In one embodiment, based on the determination that the voltage is greater than or equal to a reference voltage (Vth1) (e.g., 300 volts), the power circuit (170) may perform operation 850.

[0105] In operation 830, the power circuit (170) can change the response speed to a first speed. For example, the power circuit (170) can change the response speed of the control circuit (270) and / or the PFC circuit (240) to a first speed. For example, the power circuit (170) can change the response speed of the control circuit (270) and / or the PFC circuit (240) to a first speed by changing the capacitance of the variable capacitor (310) of the feedback circuit (280) to a first capacitance. For example, the power circuit (170) can change the response speed of the control circuit (270) and / or the PFC circuit (240) to a first speed by turning off the switch (341) of the variable capacitor (310) of the feedback circuit (280).

[0106] In operation 840, the power circuit (170) can limit the peak current. For example, the power circuit (170) can limit the peak current of the power signal of the PFC circuit (240) through the control circuit (270). For example, in response to the voltage being less than the reference voltage (Vth1) (e.g., 300 volts), the power circuit (170) can limit the peak current of the power signal of the PFC circuit (240). For example, the control circuit (270) of the power circuit (170) can limit the peak current of the PFC circuit (240) in response to the resistance of the variable resistor (630) of the feedback circuit (280) changing to a second resistance. For example, the control circuit (270) of the power circuit (170) can limit the peak current of the PFC circuit (240) in response to the switch of the variable resistor (630) of the feedback circuit (280) being turned off.

[0107] In operation 850, the power circuit (170) can change the response speed to a second speed. For example, the power circuit (170) can change the response speed of the control circuit (270) and / or the PFC circuit (240) to a second speed. For example, the power circuit (170) can change the response speed of the control circuit (270) and / or the PFC circuit (240) to a second speed by changing the capacitance of the variable capacitor (310) of the feedback circuit (280) to a second capacitance. For example, the power circuit (170) can change the response speed of the control circuit (270) and / or the PFC circuit (240) to a second speed by turning on the switch (341) of the variable capacitor (310) of the feedback circuit (280).

[0108] In operation 860, the power circuit (170) can determine whether the voltage is less than another reference voltage (Vth2) (e.g., 360 volts). For example, the power circuit (170) can determine whether the voltage is less than another reference voltage (Vth2) (e.g., 360 volts) through the feedback circuit (280). For example, when the voltage is determined to be greater than or equal to the reference voltage (Vth1) (e.g., 300 volts), the power circuit (170) can determine whether the voltage is less than another reference voltage (Vth2) (e.g., 360 volts) through the feedback circuit (280).

[0109] In one embodiment, based on the determination that the voltage is less than another reference voltage (Vth2) (e.g., 360 volts), the power circuit (170) may perform operation 870. In one embodiment, based on the determination that the voltage is greater than or equal to another reference voltage (Vth2) (e.g., 360 volts), the power circuit (170) may perform operation 840.

[0110] In operation 870, the power circuit (170) may stop limiting the peak current. For example, the power circuit (170) may stop limiting the peak current of the power signal of the PFC circuit (240) through the control circuit (270). For example, in response to the voltage being less than another reference voltage (Vth2) (e.g., 360 volts), the power circuit (170) may stop limiting the peak current of the power signal of the PFC circuit (240). For example, while the voltage is determined to be greater than or equal to the reference voltage (Vth1) (e.g., 300 volts), the power circuit (170) may stop limiting the peak current of the power signal of the PFC circuit (240) in response to the voltage being less than another reference voltage (Vth2) (e.g., 360 volts). For example, the control circuit (270) of the power circuit (170) can stop limiting the peak current of the PFC circuit (240) in response to the resistance of the variable resistor (630) of the feedback circuit (280) changing to the first resistance. For example, the control circuit (270) of the power circuit (170) can stop limiting the peak current of the PFC circuit (240) in response to the switch of the variable resistor (630) of the feedback circuit (280) turning on.

[0111] The technical problems to be solved in this disclosure are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which this disclosure pertains.

[0112] As described above, the power circuit (170) may include a power factor correction (PFC) circuit (240) configured to generate a power signal based on the power factor of an AC signal, a feedback circuit (280) including a variable capacitor (310) for generating a feedback voltage based on the voltage of the power signal generated by the PFC circuit (240), and a control circuit (270) for controlling the voltage of the PFC circuit (240) based on the feedback voltage generated through the variable capacitor (310). The feedback circuit (280) may be configured to change the capacitance of the variable capacitor (310) to a first capacitance in response to the voltage being less than a reference voltage. The feedback circuit (280) may be configured to change the capacitance of the variable capacitor (310) to a second capacitance greater than the first capacitance in response to the voltage being greater than or equal to the reference voltage.

[0113] The variable capacitor (310) may include a first capacitor (320), a second capacitor (330), and a switching circuit (340). One end of the first capacitor (320) may be electrically connected to the control circuit (270). The other end of the first capacitor (320) may be electrically connected to ground. One end of the second capacitor (330) may be electrically connected to the control circuit (270). The other end of the second capacitor (330) may be electrically connected to one end of the switching circuit (340). The other end of the switching circuit (340) may be electrically connected to ground.

[0114] The feedback circuit (280) may be configured to turn off the switching circuit (340) in response to the voltage being less than the reference voltage. The feedback circuit (280) may be configured to turn on the switching circuit (340) in response to the voltage being greater than or equal to the reference voltage.

[0115] The switching circuit (340) may include a first resistor (343), a second resistor (345), and a switch (341). One end of the first resistor (343) may be electrically connected to the other end of the second capacitor (330). The other end of the first resistor (343) may be electrically connected to one end of the switch (341). The other end of the switch (341) may be electrically connected to the ground and one end of the second resistor (345), respectively. An electrode for controlling the on or off of the switch (341) may be electrically connected to the other end of the second resistor (345).

[0116] The capacitance of the first capacitor (320) may be smaller than the capacitance of the second capacitor.

[0117] The feedback circuit (280) may include a first comparison circuit (350) and a second comparison circuit (640). The first comparison circuit (350) may be configured to generate a signal indicating the result of a comparison between the voltage and the reference voltage. The second comparison circuit (640) may be configured to generate another signal based on the signal, which causes the control circuit (270) to control the current of the power signal of the PFC circuit (240).

[0118] The power circuit (170) may include a voltage divider (360) that distributes the voltage at a specified ratio. The first comparison circuit (350) and the second comparison circuit (640) may be configured to receive the voltage distributed at the specified ratio as an input.

[0119] The control circuit (270) above may be configured to receive the feedback voltage through a compensation pin.

[0120] The feedback circuit (280) may include a variable resistor (630) configured to generate a different feedback voltage based on the voltage of the PFC circuit (240). The control circuit (270) may be configured to control the current of the power signal of the PFC circuit (240) based on the different feedback voltage generated through the variable resistor (630).

[0121] The feedback circuit (280) may be configured to generate a signal that causes the control circuit (270) to control the current in response to the voltage being less than the reference voltage. The feedback circuit (280) may be configured to stop generating the signal that causes the control circuit (270) to control the current in response to the voltage being greater than the reference voltage and less than another reference voltage that is higher than the reference voltage. The feedback circuit (280) may be configured to generate the signal that causes the control circuit (270) to control the current in response to the voltage being greater than the other reference voltage.

[0122] The power circuit (170) may include a rectifier circuit (220) configured to rectify an AC signal and input the rectified AC signal to the PFC circuit (240), a capacitor (243) in which the power signal generated through the PFC circuit (240) is charged, and a DC-DC conversion circuit (250) configured to generate a DC signal using the power signal charged in the capacitor (243).

[0123] As described above, the electronic device (101) may include at least one electronic component and a power circuit (170) configured to transmit a DC signal to said at least one electronic component. The power circuit (170) may include a rectifier circuit (220) configured to rectify an AC signal, a power factor correction (PFC) circuit (240) configured to generate a power signal based on the power factor of said rectified AC signal, a capacitor (243) in which the power signal generated through said PFC circuit (240) is charged, a DC-DC conversion circuit (250) configured to generate a DC signal using the power signal charged in said capacitor, a feedback circuit (280) including a variable capacitor (310) for generating a feedback voltage based on the voltage of said power signal generated by said PFC circuit (240), and a control circuit (270) for controlling said voltage of said PFC circuit (240) based on said feedback voltage generated through said variable capacitor (310). The feedback circuit (280) may be configured to change the capacitance of the variable capacitor (310) to a first capacitance in response to the voltage being less than the reference voltage. The feedback circuit (280) may be configured to change the capacitance of the variable capacitor (310) to a second capacitance greater than the first capacitance in response to the voltage being greater than the reference voltage.

[0124] The variable capacitor (310) may include a first capacitor (320), a second capacitor (330), and a switching circuit (340). One end of the first capacitor (320) may be electrically connected to the control circuit (270). The other end of the first capacitor (320) may be electrically connected to ground. One end of the second capacitor (330) may be electrically connected to the control circuit (270). The other end of the second capacitor (330) may be electrically connected to one end of the switching circuit (340). The other end of the switching circuit (340) may be electrically connected to ground.

[0125] The feedback circuit (280) may be configured to turn off the switching circuit (340) in response to the voltage being less than the reference voltage. The feedback circuit (280) may be configured to turn on the switching circuit (340) in response to the voltage being greater than or equal to the reference voltage.

[0126] The switching circuit (340) may include a first resistor (343), a second resistor (345), and a switch (341). One end of the first resistor (343) may be electrically connected to the other end of the second capacitor (330). The other end of the first resistor (343) may be electrically connected to one end of the switch (341). The other end of the switch (341) may be electrically connected to the ground and one end of the second resistor (345), respectively. An electrode for controlling the on or off of the switch (341) may be electrically connected to the other end of the second resistor (345).

[0127] The feedback circuit (280) may include a first comparison circuit (350) and a second comparison circuit (640). The first comparison circuit (350) may be configured to generate a signal indicating the result of a comparison between the voltage and the reference voltage. The second comparison circuit (640) may be configured to generate another signal based on the signal, which causes the control circuit (270) to control the current of the power signal of the PFC circuit (240).

[0128] The power circuit (170) may include a voltage divider (360) that distributes the voltage at a specified ratio. The first comparison circuit (350) and the second comparison circuit (640) may be configured to receive the voltage distributed at the specified ratio as an input.

[0129] The feedback circuit (280) may include a variable resistor (630) configured to generate a different feedback voltage based on the voltage of the PFC circuit (240). The control circuit (270) may be configured to control the current of the power signal of the PFC circuit (240) based on the different feedback voltage generated through the variable resistor (630).

[0130] The feedback circuit (280) may be configured to generate a signal that causes the control circuit (270) to control the current in response to the voltage being less than the reference voltage. The feedback circuit (280) may be configured to stop generating the signal that causes the control circuit (270) to control the current in response to the voltage being greater than the reference voltage and less than another reference voltage that is higher than the reference voltage. The feedback circuit (280) may be configured to generate the signal that causes the control circuit (270) to control the current in response to the voltage being greater than the other reference voltage.

[0131] The method described above may be performed by a power circuit (170). The method may include an operation in which a power factor correction (PFC) circuit (240), configured to generate a power signal, compares the voltage of a power signal generated based on the power factor of an AC signal with a reference voltage. The method may include an operation in which the capacitance of a variable capacitor (310) for generating a feedback voltage is determined based on the result of the comparison between the voltage and the reference voltage. The method may include an operation in which the voltage of the PFC circuit (240) is controlled based on the feedback voltage generated through the variable capacitor (310) having the determined capacitance.

[0132] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs.

[0133] The device described above may be implemented as a hardware component, a software component, and / or a combination of a hardware component and a software component. For example, the device and components described in the embodiments may be implemented using one or more general-purpose or special-purpose computers, such as a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing unit may execute an operating system (OS) and one or more software applications executed on said operating system. Additionally, the processing unit may access, store, manipulate, process, and generate data in response to the execution of the software. For ease of understanding, the processing unit may be described as being used as a single unit, but those skilled in the art will understand that the processing unit may include multiple processing elements and / or multiple types of processing elements. For example, the processing unit may include multiple processors or one processor and one controller. In addition, other processing configurations, such as parallel processors, are also possible.

[0134] Software may include computer programs, code, instructions, or a combination of one or more of these, and may configure a processing unit to operate as desired or instruct the processing unit independently or collectively. Software and / or data may be embodied in any type of machine, component, physical device, computer storage medium, or device so as to be interpreted by the processing unit or to provide instructions or data to the processing unit. Software may be distributed over networked computer systems and may be stored or executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media.

[0135] The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. In this case, the medium may continuously store a program executable by a computer, or temporarily store it for execution or download. Additionally, the medium may be various recording or storage means in the form of a single or several hardware combined, and may not be limited to a medium directly connected to a computer system but may exist distributed over a network. Examples of media may include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical recording media such as CD-ROMs and DVDs; magneto-optical media such as floptical disks; and media configured to store program instructions, including ROM, RAM, and flash memory. Additionally, other examples of media may include recording or storage media managed by app stores that distribute applications or sites and servers that supply or distribute various other software.

[0136] Although the embodiments have been described above with reference to limited examples and drawings, those skilled in the art can make various modifications and variations from the description above. For example, suitable results can be achieved even if the described techniques are performed in a different order than described, and / or the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents.

[0137] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below.

Claims

1. In the power circuit (170), A PFC (power factor correction) circuit (240) configured to generate a power signal based on the power factor of an AC signal, A feedback circuit (280) including a variable capacitor (310) for generating a feedback voltage based on the voltage of the power signal generated by the PFC circuit (240), and It includes a control circuit (270) for controlling the voltage of the PFC circuit (240) based on the feedback voltage generated through the variable capacitor (310), and The above feedback circuit (280) is, In response to the above voltage being less than the reference voltage, the capacitance of the variable capacitor (310) is changed to the first capacitance, and In response to the voltage being greater than or equal to the reference voltage, the capacitance of the variable capacitor (310) is configured to be changed to a second capacitance greater than the first capacitance. Power circuit.

2. In Claim 1, The variable capacitor (310) includes a first capacitor (320), a second capacitor (330), and a switching circuit (340). One end of the first capacitor (320) is electrically connected to the control circuit (270), and The other end of the first capacitor (320) is electrically connected to ground, and One end of the second capacitor (330) is electrically connected to the control circuit (270), and The other end of the second capacitor (330) is electrically connected to one end of the switching circuit (340), and The other end of the switching circuit (340) is configured to be electrically connected to the ground. Power circuit.

3. In Claim 2, The above feedback circuit (280) is, In response to the above voltage being less than the above reference voltage, the switching circuit (340) is turned off, and Configured to turn on the switching circuit (340) in response to the above voltage being greater than or equal to the above reference voltage, Power circuit.

4. In Claim 2, The switching circuit (340) includes a first register (343), a second register (345), and a switch (341). One end of the first resistor (343) is electrically connected to the other end of the second capacitor (330), and The other end of the first register (343) is electrically connected to one end of the switch (341), and The other end of the switch (341) is electrically connected to one end of the ground and the second resistor (345), respectively, and An electrode for controlling the on or off of the above switch (341) is configured to be electrically connected to the other end of the second register (345). Power circuit.

5. In Claim 2, The capacitance of the first capacitor (320) is smaller than the capacitance of the second capacitor. Power circuit.

6. In any one of claims 1 to 5, The above feedback circuit (280) includes a first comparison circuit (350) and a second comparison circuit (640), and The first comparison circuit (350) is configured to generate a signal indicating the result of comparison between the voltage and the reference voltage, and The second comparison circuit (640) is configured to generate another signal based on the signal, which causes the control circuit (270) to control the current of the power signal of the PFC circuit (240). Power circuit.

7. In Claim 6, It includes a voltage divider (360) that distributes the above voltage at a specified ratio, and The first comparison circuit (350) and the second comparison circuit (640) are configured to receive the voltage distributed at the specified ratio as an input. Power circuit.

8. In any one of claims 1 to 7, The above control circuit (270) is configured to receive the feedback voltage through a compensation pin, Power circuit.

9. In any one of claims 1 to 8, The feedback circuit (280) includes a variable resistor configured to generate a different feedback voltage based on the voltage of the PFC circuit (240), and The control circuit (270) is configured to control the current of the power signal of the PFC circuit (240) based on the other feedback voltage generated through a variable resistor. Power circuit.

10. In Claim 9, The above feedback circuit (280) is, In response to the voltage being less than the reference voltage, the control circuit (270) generates a signal to control the current, and In response to the voltage being greater than or equal to the reference voltage and less than another reference voltage that is higher than the reference voltage, the generation of the signal that causes the control circuit (270) to control the current is stopped, and In response to the voltage being greater than or equal to the other reference voltage, the control circuit (270) is configured to generate the signal that causes the current to be controlled. Power circuit.

11. In any one of claims 1 to 10, A rectifier circuit (220) configured to rectify an AC signal and input the rectified AC signal to the PFC circuit (240); A capacitor (243) in which the power signal generated through the above PFC circuit (240) is charged, and A DC-DC conversion circuit (250) configured to generate a DC signal using the power signal charged in the capacitor (243), Power circuit.

12. In the electronic device (101), At least one electronic component; and It includes a power circuit (170) configured to transmit a DC signal to at least one electronic component, and The above power circuit (170) is: A rectifier circuit (220) configured to rectify an alternating current signal; A PFC (power factor correction) circuit (240) configured to generate a power signal based on the power factor of the rectified AC signal, A capacitor (243) that charges the power signal generated through the above PFC circuit (240), A DC-DC conversion circuit (250) configured to generate a DC signal using the power signal charged in the capacitor, A feedback circuit (280) including a variable capacitor (310) for generating a feedback voltage based on the voltage of the power signal generated by the PFC circuit (240), and It includes a control circuit (270) for controlling the voltage of the PFC circuit (240) based on the feedback voltage generated through the variable capacitor (310), and The above feedback circuit (280) is, In response to the above voltage being less than the reference voltage, the capacitance of the variable capacitor (310) is changed to the first capacitance, and In response to the voltage being greater than or equal to the reference voltage, the capacitance of the variable capacitor (310) is configured to be changed to a second capacitance greater than the first capacitance. Electronic device.

13. In Claim 12, The variable capacitor (310) includes a first capacitor (320), a second capacitor (330), and a switching circuit (340). One end of the first capacitor (320) is electrically connected to the control circuit (270), and The other end of the first capacitor (320) is electrically connected to ground, and One end of the second capacitor (330) is electrically connected to the control circuit (270), and The other end of the second capacitor (330) is electrically connected to one end of the switching circuit (340), and The other end of the switching circuit (340) is configured to be electrically connected to the ground. Electronic device.

14. In Claim 13, The above feedback circuit (280) is, In response to the above voltage being less than the above reference voltage, the switching circuit (340) is turned off, and Configured to turn on the switching circuit (340) in response to the above voltage being greater than or equal to the above reference voltage, Electronic device.

15. In Claim 13, The switching circuit (340) includes a first register (343), a second register (345), and a switch (341). One end of the first resistor (343) is electrically connected to the other end of the second capacitor (330), and The other end of the first register (343) is electrically connected to one end of the switch (341), and The other end of the switch (341) is electrically connected to one end of the ground and the second resistor (345), respectively, and An electrode for controlling the on or off of the above switch (341) is configured to be electrically connected to the other end of the second register (345). Electronic device.

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