Fairchild Korea Semiconductor Ltd.

Maps, Inc.

Jong-Tae Hwang

Dong-Hwan Kim

Joon Rhee

Hyun-Ick Shin

Sang-O Jeon

Dae-Ho Kim

Moon-Sang Jung

Jin-sung Kim

Yun-kee Lee

Ik-Gyoo Song

Jin-Ho Choi

Sung-Min Park

Gye-Hyun Cho

Chang-ki Jeon

Sung-lyong Kim

Jong-jib Kim

Sung-Yun Park

Ki-Woong Jin

Han-seung Lee

Yun-Kee Lee

Min-Ho Jung

Dong-Su Lee

Jong-Hoon Lee

Jin-Sung Kim

A dual band wireless power reception unit is disclosed. The wireless power reception unit according to one embodiment comprises: a first resonator; a second resonator connected to the first resonator in parallel; a single rectifier having, as an input, a node in which outputs of the first resonator and the second resonator are connected to each other in parallel; at least one switch having a first output, a second output, and an input, wherein the second output is connected to the ground; at least one capacitor connected to the second resonator in parallel, and of which one terminal is connected to the first output of the switch and the other terminal is connected to the rectifier input; and a frequency sensor sensing an input frequency from the rectifier input, and of which an output is connected to the input of the switch.

Dual band wireless power reception unit

A magnetic resonance wireless power transmission device capable of adjusting resonance frequency is disclosed. A wireless power transmission device according to an embodiment of the present invention comprises: a power amplifier for amplifying a wireless power signal using a driving frequency signal; a resonator for configuring a resonance tank and wirelessly transmitting, through magnetic resonance, the wireless power signal output from the power amplifier using a resonance frequency of the resonance tank; and a resonance control unit for controlling a duty ratio using a frequency applied to the resonator or a frequency signal generated by the resonator and adjusting the resonance frequency of the resonator.

Magnetic resonance wireless power transmission device capable of adjusting resonance frequency

An active diode having an improved transistor turn-off control method is disclosed. The active diode comprises: a comparator for comparing voltages of both ends of a parasitic diode of a transistor; and a gate driver for controlling a gate terminal of the transistor according to the comparison result of the comparator, and estimates a turn-on time of the transistor and uses the same to control the gate terminal of the transistor.

Active diode having improved transistor turn-off control method

An active diode driver for operating a switch of an active rectifier using an active diode is provided. The active diode driver may first control a soft turn-on of the switch and secondly control a hard turn-on of the switch, thereby making it possible for the switch to be softly turned-on.

Active diode driver

An active diode that features improved control of transistor turn-off is provided. Such an active diode may include a comparator to compare voltages between opposite ends of a parasitic diode, and a gate driver to control a gate terminal of the transistor according to the comparison result of the comparator. Furthermore, the active diode may further include an off-timing controller to control the transistor to be turned off at a point in time when voltages of the opposite ends of the parasitic diode turn positive. Thus, the active diode may be turned off when required.

A gate driver driving a switching device is disclosed. The gate driver includes a capacitor which is coupled to the input of the switching device. The gate drive power consumption is reduced by this additional capacitor.

Gate driver for isolated input switching device

The present invention relates to a power factor correction circuit and a method of driving the power factor correction circuit. The power factor correction circuit according to the present invention includes a power transfer element configured to receive an input voltage, an input current corresponding to the input voltage flowing through the power transfer element, and a switch connected to the power transfer element and configured to control an output voltage generated by the current flowing through the power transfer element. The power factor correction circuit is configured to detect a zero voltage edge timing of the input voltage by detecting the input voltage, generate a reference clock signal having a frequency that varies according to the detected edge timing, generate a reference signal using the reference clock signal, generate an error amplification signal based on a difference between the output voltage and a predetermined error reference signal, generate the amplification reference signal by multiplying the reference signal by the error amplification signal, and control a switching operation of the switch using the amplification reference signal and a detection signal corresponding to a current flowing through the switch.

Power factor correction circuit and method of driving the same

Disclosed are a switch controller, a switch control method, and a converter based thereon. The switch controller generates an input sensing voltage corresponding to the input voltage of the converter, and compares the input sensing voltage with a predetermined first reference value. The switch controller generates a zero cross detection signal with a first level or a second level depending upon the comparison result, and generates a reference clock signal varying in frequency in accordance with one cycle of the zero cross detection signal. The switch controller generates digital signals by using the reference clock signal and the zero cross detection signal. The digital signals synchronize with the zero cross detection signal, and increase in accordance with the reference clock signal during a half of one cycle of the zero cross detection signal, while decreasing in accordance with the reference clock signal during the other half cycle of the zero cross detection signal. The switch controller generates a reference signal with a voltage level corresponding to the digital signal.

Switch controller, switch control method, and converter using the same

In one embodiment, a power integrated circuit device is provided. The power integrated circuit device includes a high-side power switch having a high voltage transistor and a low voltage transistor. The high voltage transistor has a gate, a source, and a drain, and is capable of withstanding a high voltage applied to its drain. The low voltage transistor has a gate, a source, and a drain, wherein the drain of the low voltage transistor is connected to the source of the high voltage transistor and the source of the low voltage transistor is connected to the gate of the high voltage transistor, and wherein a control signal is applied to the gate of the low voltage transistor from the power integrated circuit device. The high-side power switch is turned on when a predetermined voltage is applied to the source of the low voltage transistor, a voltage higher than the predetermined voltage is applied to the drain of the high voltage transistor, and a voltage level of the control signal becomes higher than the predetermined voltage by a threshold voltage of the low voltage transistor.

Power integrated circuit device having embedded high-side power switch

In one embodiment, a power switch driving circuit is provided for a fluorescent lamp ballast. The circuit includes a first power switch driven by a first driver. A controller has a first output terminal for outputting a control signal for controlling the first driver. The first driver includes a first capacitor having a first terminal electrically connected to a control electrode of the first power switch and a second terminal electrically connected to the first output terminal.

Lamp ballast circuit

A resonant inverter includes a first driver and a second driver for driving a first and second switching devices, respectively, a dead time generator for generating a first drive signal and a second drive signal respectively, a current-controlled oscillator for supplying, to the dead time generator, an output clock having a frequency determined based on a first current input to the current-controlled oscillator, and a current mirror for supplying the first current to the current-controlled oscillator in an amount proportional to a second current flowing through an external resistor. The current mirror includes a track/hold circuit, to supply the second current in an amount equal to an amount of the second current supplied before a variation in the amount of the second current, during a transition of an output signal between the first and second switching devices.

Resonant inverter exhibiting depressed duty variation

A temperature-independent current source is provided, which includes a current source generating a current that is proportional to the temperature and a current source generating a current that is inversely proportional to the temperature. Values of the circuit elements are selected so that the currents of the current sources add up to a substantially temperature-independent current. Related current sources utilize dual-base Darlington bipolar transistors to generate a temperature-independent current.

Temperature-independent current source circuit

A high voltage gate driver circuit according to an embodiment of the present invention controls an operational range of an output signal of a level shifter to be appropriate for an operational range of a reshaper through a VIV converter. Even though the voltage range of the signal which is input from the high voltage gate driver circuit to the level shifter is different from the operational range of the reshaper, the input signal can always be recognized exactly regardless of the VTH voltage of the reshaper by controlling the operational range of the signal through the VIV converter. In addition, incorrect operation of the circuit can be prevented by erasing a common mode noise which is input with the input signal.

Gate driver circuit

An RC oscillator integrated circuit includes: an active current mirror connected to an external resistor, for receiving a current signal corresponding to a voltage signal applied to the external resistor, performing 1/N-times division of the received current signal according to an input clock signal, and generating a 1/N-times current signal; an oscillation circuit for generating an output voltage corresponding to a charging- or discharging-operation of a capacitor via a current path formed by the active current mirror; a feedback switching circuit for controlling a charging- or discharging-path of the capacitor by a feedback of an output signal Vo of the oscillation circuit; and a divider for generating not only a first clock signal capable of driving the active current mirror according to the output signal of the oscillation circuit, but also a second output clock signal having a compensated mismatch of the active current mirror.

RC oscillator integrated circuit including capacitor

A ballast integrated circuit (IC) for driving a first switching element and a second switching element includes: a variable gain amplifier (VGA) connected to a first input terminal connected to a resistor, for generating an output current signal according to a resistance value of the resistor and a gain control signal; a preheating/ignition controller connected to a second input terminal connected to a capacitor, for generating an output current signal and an output voltage signal acting as the gain control signal according to a voltage of the second input terminal; an active zero-voltage controller for generating a hard-switching current signal and an active zero-voltage switching current signal, such that it adjusts the voltage of the second input terminal according to switching states of the first switching element and the second switching element; an oscillator for generating an oscillation signal upon receiving the output current signal from the variable gain amplifier (VGA); and a dead-time controller for receiving the voltage signal of the second input terminal and an output signal of the oscillator, adjusting a dead time using the received signals, and at the same time generating driving signals of the first and second switching elements.

Growing community of inventors

Seoul, South Korea

Jong-Tae Hwang