Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery using a positive electrode containing the positive electrode active material. More particularly, the present invention relates to a positive electrode active material that is able to solve a problem of increased resistance according to an increase in Ni content by forming a charge transport channel in a lithium composite oxide and a lithium secondary battery using a positive electrode containing the positive electrode active material.

Abstract: A server according to an embodiment includes a processor configured to receive a friend add request for a target account from a user terminal accessed with a user account; based on one of the user account and the target account being a protected account, transmit an approval request for the friend add request to a protector account connected to the protected account; and based on receiving a reply to the approval request from the protector terminal, add the target account to a friend list of the user account.

Abstract: A wireless power transmitter includes an amplifier configured to amplify a power; a transmitter configured to resonate the power amplified by the amplifier; and a reference signal provider configured to provide a reference signal to the amplifier and change a frequency of the reference signal.

Abstract: A rectifier includes: a rectifying circuit configured to rectify alternating current (AC) power into direct current (DC) power through a switching operation; a driver configured to apply a switching signal to the rectifying circuit; and a signal modulator configured to select a parameter from among parameters of the switching signal based on a frequency of the switching signal, and adjust the selected parameter.

Abstract: A gate driving circuit may include: a bias unit receiving an input signal having preset high and low signal levels, including a first N-MOSFET turned on in the case in which the input signal has the high level and a first P-MOSFET turned on in the case in which the input signal has the low level, and supplying bias powers by the turning-on of the first N-MOSFET and the first P-MOSFET; and an amplifying unit including a second N-MOSFET turned on by receiving the bias power supplied from the first N-MOSFET in the case in which the input signal has the high level and a second P-MOSFET turned on by receiving the bias power supplied from the first P-MOSFET turned on in the case in which the input signal has the low level and providing a gate signal depending on the turning-on of the second N-MOSFET and the second P-MOSFET.

Abstract: Disclosed herein are a start-up circuit capable of reducing a leakage current to reduce power consumption, and a power device using the same. The start-up circuit includes: a bias unit connected between a first power source and a second power source and allowing a first current to flow from the first power source to the second power source according to a predetermined voltage; a first start unit connected to the bias unit and driving a second current to apply the predetermined voltage to the bias unit, and stopping driving the second current when a voltage received from the second power source reaches a first voltage; and a second start unit connected to the bias unit and driving a third current, the predetermined voltage being applied to the bias unit by the third current, and stopping driving the third current upon receiving a stop signal.

Abstract: A wireless power transmitter includes an amplifier configured to amplify a power; a transmitter configured to resonate the power amplified by the amplifier; and a reference signal provider configured to provide a reference signal to the amplifier and change a frequency of the reference signal.

Abstract: A rectifier includes: a rectifying circuit configured to rectify alternating current (AC) power into direct current (DC) power through a switching operation; a driver configured to apply a switching signal to the rectifying circuit; and a signal modulator configured to select a parameter from among parameters of the switching signal based on a frequency of the switching signal, and adjust the selected parameter.

Abstract: There are provided a phase shift circuit and a power factor correction circuit including the same. The phase shift circuit includes a switching circuit unit charging power in or discharging power from a capacitor through a plurality of switching devices and comparing a voltage of the capacitor with a predetermined reference voltage, and a clock generating unit generating a reference clock signal based on an output of the switching circuit unit, wherein the switching circuit unit turns the plurality of switching devices on or off, based on currents from inductors respectively included in a main circuit and a sub-circuit of a power factor correction circuit to determine a polarity of the voltage of the capacitor.

Abstract: A phase shift circuit may include a ramp generation unit charging or discharging a capacitor connected to a switch device to generate a ramp signal, a reference signal generation unit generating a predetermined reference signal from the ramp signal, and a comparison unit comparing the ramp signal with the reference signal to generate a clock signal, wherein at least one of the reference signal generation unit and the comparison unit changes a negative or positive value of offset components included in the reference signal or the ramp signal within every operating period of the switch device.

Abstract: There is provided a power factor correction circuit including: a power conversion circuit unit controlling an inductor current according to a switching signal applied to a main switch to convert an external input voltage into an output voltage having a predetermined range; an imbalance detection circuit outputting an imbalance state signal when the external input voltage is in an unbalanced state by using the inductor current; and a soft start circuit unit performing soft starting by adjusting the switching signal when the imbalance state signal is output by the imbalance detection circuit unit.

Abstract: Disclosed herein are a start-up circuit capable of reducing a leakage current to reduce power consumption, and a power device using the same. The start-up circuit includes: a bias unit connected between a first power source and a second power source and allowing a first current to flow from the first power source to the second power source according to a predetermined voltage; a first start unit connected to the bias unit and driving a second current to apply the predetermined voltage to the bias unit, and stopping driving the second current when a voltage received from the second power source reaches a first voltage; and a second start unit connected to the bias unit and driving a third current, the predetermined voltage being applied to the bias unit by the third current, and stopping driving the third current upon receiving a stop signal.

Abstract: A gate driver comprises a level shifter outputting first and second signals; an output switch unit causing a first current flow in an output terminal by a voltage of the first signal in a first section of the driver to charge the output terminal, causing a second current flow by a voltage of the second signal in a second section, and discharging the output terminal depending on the second current. A current sensing unit causes a sensing current flow depending on the voltage of the second signal in the second section and outputting a preset voltage depending on the flow of the sensing current. A feedback unit causes the voltage of the second signal to attain at least a preset level in the second section depending on the preset voltage.

Abstract: There are provided a power supply device switching power input to a primary side to supply the power to a predetermined load connected to a secondary side electrically insulated from the primary side and a control circuit thereof. The control circuit generates a predetermined PWM signal to apply the PWM signal to a dimming switch connected to an end of the load and controls a switching frequency of the primary side, based on a control voltage generated according to a feedback signal according to the power supplied to the load and the PWM signal, and the control voltage maintains a constant difference between a minimum voltage level and a maximum voltage level regardless of a duty of the PWM signal.

Abstract: There is provided an illumination driving apparatus for a light emitting diode, the apparatus including: a light emitting unit including M number of light emitting diodes (LEDs) connected in series and driven by an output voltage rectified in a rectifying unit; an LED switch unit including N number of LED switches connected in parallel with at least N number of the M LEDs, respectively, and connected in series; an LED switch control signal generating unit comparing the output voltage of the rectifying unit with each of the first to Nth preset reference voltages to generate N number of LED switch control signals controlling the LED switch unit; and an LED switch controlling unit transferring the N number of LED switch control signals to the LED switch unit.

Abstract: A gate driving circuit may include: a bias unit receiving an input signal having preset high and low signal levels, including a first N-MOSFET turned on in the case in which the input signal has the high level and a first P-MOSFET turned on in the case in which the input signal has the low level, and supplying bias powers by the turning-on of the first N-MOSFET and the first P-MOSFET; and an amplifying unit including a second N-MOSFET turned on by receiving the bias power supplied from the first N-MOSFET in the case in which the input signal has the high level and a second P-MOSFET turned on by receiving the bias power supplied from the first P-MOSFET turned on in the case in which the input signal has the low level and providing a gate signal depending on the turning-on of the second N-MOSFET and the second P-MOSFET.

Abstract: The present invention relates to a PFC control circuit, an active PFC circuit, and a PFC control method. According to an embodiment of the present invention, a PFC control circuit including: an inductor current sensing unit for sensing an inductor current of a PFC circuit; an output voltage feedback unit for outputting a feedback output signal; a sensing and feedback signal application unit for outputting a sensing voltage signal during switching duty on of the PFC circuit and adding the feedback output signal to the sensing voltage signal to output the added signal during switching duty off of the PFC circuit; and a PFC control unit for generating a comparison signal and generating a duty control signal from the comparison signal and a first reference signal to make variations due to an internal offset be removed or reduced is provided.

Abstract: A logic device may include a first functional block, the first functional block including, a first storage block, a second storage block, and a first function controller. In a first operation time period, the first function controller may be configured to receive a first configuration selection signal and a first configuration command signal that instructs a first function be configured, select the first storage block as a configured storage block in the first operation time period based on the first configuration selection signal, and configure the first function in the first storage block based on the first configuration command signal.

Abstract: There are provided a power supply apparatus switching a power input to a primary side to supply the power to a predetermined load connected to a secondary side electrically insulated from the primary side and a control circuit thereof, the control circuit generating a predetermined PWM signal to apply the generated PWM signal to a dimming switch connected to an end of the load and controlling a switching frequency of the primary side based on a control voltage generated according to a feedback signal depending on the power supplied to the load and the PWM signal, wherein a voltage variation amount of the control voltage may be constantly maintained regardless of a duty of the PWM signal.

Abstract: There are provided a power supply device switching power input to a primary side to supply the power to a predetermined load connected to a secondary side electrically insulated from the primary side and a control circuit thereof. The control circuit generates a predetermined PWM signal to apply the PWM signal to a dimming switch connected to an end of the load and controls a switching frequency of the primary side, based on a control voltage generated according to a feedback signal according to the power supplied to the load and the PWM signal, and the control voltage maintains a constant difference between a minimum voltage level and a maximum voltage level regardless of a duty of the PWM signal.