Abstract: A power voltage required to operate the switch control device is generated by using full-wave current rectification voltage generated by rectifying an AC input. A zero cross-point is detected when a full-wave rectification voltage is zero voltage by using the power voltage. A reference signal synchronized to the full-wave rectification voltage is generated by using the detected zero cross-point. A switching operation of a power switch is controlled by comparing a reference signal with current that flows on the power switch.

Abstract: The present invention relates to a clock signal generating circuit and a power supply including the same. The present invention includes: a counter for counting one period of an input clock signal by using a reference clock signal, and generating a count signal; and a clock signal generator for receiving the count signal and the reference clock signal, dividing the count signal to generate a quotient and a remainder, setting the quotient as a reference period of an output clock signal, and distributing and disposing the remainder to the output clock signal with a plurality of periods occurring for one period of the input clock signal.

Abstract: The power supply device includes a power switch including one terminal to which an input voltage is transferred; an inductor including one terminal connected to another terminal of the power switch; a diode connected between a ground and a floating ground; a sensing resistor connected between the floating ground and the one terminal of the inductor. A switch controller compares a modulation sensing voltage depending on a sensing voltage generated from the sensing resistor with a high peak reference and a low peak reference when a LED string is connected between an inductor and the ground. The switch controller controls a switching operation of a power switch according to the comparison result. The high peak reference and the low peak reference are references for controlling an upper limit and a lower limit of an LED current flowing through the LED string, respectively.

Abstract: The present invention related to a switch control circuit, a coupled inductor boost converter including the same, and a driving method thereof. The coupled inductor boost converter includes a first inductor connected between an input voltage and a first node, a second inductor connected between the first node and a second node, and a power switch connected between the first node and a ground, and a switch control circuit. The switch control circuit receives a voltage of the second node and turn on the power switch by using the voltage of the second node at a time when a voltage of the first node becomes a zero voltage.

Abstract: The present invention relates to an error voltage generation circuit, a switch control circuit, and a power factor corrector. The error voltage generation circuit generates an error voltage using an error input voltage corresponding to an output voltage of a power factor corrector and a soft start voltage. The error voltage generation circuit samples an error input voltage at an AC input supply time point of the power factor corrector and holes a sampling voltage according to the sampled error input voltage during a soft start period. The error voltage generation circuit generates a soft start voltage increasing from a start voltage corresponding to the sampling voltage. The switch control circuit controls a duty of a power switch of the power factor corrector using the error voltage.

Abstract: The present invention relates to a clock signal generating circuit and a power supply including the same. The present invention includes: a counter for counting one period of an input clock signal by using a reference clock signal, and generating a count signal; and a clock signal generator for receiving the count signal and the reference clock signal, dividing the count signal to generate a quotient and a remainder, setting the quotient as a reference period of an output clock signal, and distributing and disposing the remainder to the output clock signal with a plurality of periods occurring for one period of the input clock signal.

Abstract: Embodiments of the present invention relate to a switch control circuit, a switch control method, and a power supply device using the same. Embodiments generate a reference signal according to a full-wave rectification voltage and control a switching operation of a power switch according to a comparing result of a sense voltage corresponding to a current flowing to the power switch and the reference voltage. Embodiments determine whether a line is opened between a first output terminal and a second output terminal of the power supply device using the sense voltage. When the line is opened, Embodiments turn off the protection switch.

Abstract: A power supply has a TRIAC dimmer, and an AC-DC converter connected to the TRIAC dimmer. The AC-DC converter has a power switch, a bleed switch, and a controller. The controller turns off the bleed switch in a first time duration and turns on the bleed switch in a second time duration. Magnitude of a current of the power switch in the first time duration is larger than magnitude of a current of the power switch in the second time duration. Magnitude of a current of the bleed switch in a third time duration within the second time duration is smaller than magnitude of a current of the bleed switch in a fourth time duration within the second time duration.

Abstract: The present invention relates to a switch control circuit, a switch control method, and a converter using the same. An input voltage of a converter is provided to an inductor, and an output voltage is generated by an inductor current caused by the input voltage. A switch control circuit for controlling a switching operation of a power switch connected to the inductor to control the inductor current senses a drain current flowing to the power switch while the power switch is turned on, and controls a slope of a sawtooth wave signal for determining a turn-off time of the power switch according to the sensed drain current.

Abstract: The present invention relates to a switch control circuit, a switch control method, and a converter using the same. An input voltage rectified from an AC input in a converter is transmitted to an inductor, and output power is generated from an inductor current by the input voltage. The converter includes a power switch connected to the inductor to control the inductor current and a sense resistor having a first end connected to a ground and a second end connected to the AC input. At a time point that a sense voltage generated in the sense voltage reaches the peak point and then decreased to an on-reference voltage, the power switch is turned on. The on-reference voltage is a sense voltage at a resonance start time point between a parasite capacitor of the power switch and the inductor.

Abstract: Provided are a switch control device and a switch control method. The present invention generates power voltage required to operate the switch control device by using full-wave current rectification voltage generated by rectifying an AC input and detects a zero cross-point when a full-wave rectification voltage is zero voltage by using power voltage. The present invention generates a reference signal synchronized to the full-wave rectification voltage by using the detected zero cross-point and controls a switching operation of a power switch by comparing a reference signal with current which flows on the power switch.

Abstract: Provided are a switch control device, a switch control method, and a power supply device. The present invention generates power voltage required to operate the switch control device by using full-wave current rectification voltage generated by rectifying an AC input and detects a zero cross-point when a full-wave rectification voltage is zero voltage by using the edge of power voltage. The present invention generates a reference signal synchronized to the full-wave rectification voltage by using the detected zero cross-point and controls a switching operation of a power switch by comparing a reference signal with current which flows on the power switch.

Abstract: Provided are a method and an apparatus for deciding a channel quality indicator (CQI) in a wireless communication system. The method includes randomly generating CQI values encoded into genotypes to form an initial genetic group; evaluating fitnesses using the CQI values and a measured block error rate (BLER), and if the CQI value indicating the highest fitness is not within a range of the BLER, selecting a specific gene of genes of the initial genetic group to perform crossover and mutation operations; and repeating the crossover and mutation operations to allow a new genetic group generated by the crossover and mutation operations to be within the range of the BLER.

Abstract: Disclosed is a system and a method for setting an internal time corresponding to a standard time at a current location in a mobile station of an asynchronous scheme. The mobile station of the asynchronous scheme uses a Simple Network Time Protocol (SNTP), which is an application of a Network Time Protocol (NTP), allowing the mobile station to easily update internal time information using a synchronized time. The SNTP can provide a time value which can be used to accurately reset an internal time of the mobile station of the asynchronous scheme. By using the SNTP, the mobile station of the asynchronous scheme can obtain exact time information as in a CDMA network and update the mobile station's internal time with the time corresponding to an area in which a standard time is changed.

Abstract: Provided are a method and an apparatus for deciding a channel quality indicator (CQI) in a wireless communication system. The method includes randomly generating CQI values encoded into genotypes to form an initial genetic group; evaluating fitnesses using the CQI values and a measured block error rate (BLER), and if the CQI value indicating the highest fitness is not within a range of the BLER, selecting a specific gene of genes of the initial genetic group to perform crossover and mutation operations; and repeating the crossover and mutation operations to allow a new genetic group generated by the crossover and mutation operations to be within the range of the BLER.

Abstract: Disclosed is a system and a method for setting an internal time corresponding to a standard time at a current location in a mobile station of an asynchronous scheme. The mobile station of the asynchronous scheme uses a Simple Network Time Protocol (SNTP), which is an application of a Network Time Protocol (NTP), allowing the mobile station to easily update internal time information using a synchronized time. The SNTP can provide a time value which can be used to accurately reset an internal time of the mobile station of the asynchronous scheme. By using the SNTP, the mobile station of the asynchronous scheme can obtain exact time information as in a CDMA network and update the mobile station's internal time with the time corresponding to an area in which a standard time is changed.