Semiconductor Components Industries, LLC

Fairchild Korea Semiconductor Ltd.

Seunguk Yang

Taesung Kim

Hyun-Chul Eom

Gye-Hyun Cho

Youngbae Park

Moonsik Song

Inki Park

Hyunchul Eum

Ilyong Jung

Minwoo Lee

Young-Bae Park

Byunghak Ahn

Jae-yong Lee

Hak-Hee Lee

Moonho Choi

Eung-Woo Lee

Chan Son

Eungwoo Lee

Wonseok Lim

Jinkyum Kim

A power supply device includes a power switch that is switched according to a gate voltage. A sense resistor receives a switch current that flows through the power switch to develop a sense voltage. A peak of a primary-side current is detected from the sense voltage. The gate driver has a pair of switches for generating the gate voltage in accordance with a control signal. When a low-side switch of the gate driver is turned on according to the control signal, the gate voltage of the power switch decreases as a sink current flows from the gate of the power switch via the transistor.

Coupling structure of gate driver in power supply device

A light emitting diode (LED) control circuit includes an inductor current sense circuit with a high-side diode string, a low-side diode string, and a sense resistor in series with and between the high-side and low side diode strings. The LED control circuit receives an input voltage on an end that connects to the high-side diode string. An end of the low-side diode string is connected to a switch through an inductor. A sense voltage developed on the sense resistor by an inductor current is sensed by a controller integrated circuit (IC). A pin of the controller IC that receives the sense voltage can have a breakdown voltage specification that is lower than the input voltage.

Light emitting diode control circuit with wide range input voltage

A signal calculator includes a capacitor and a variable current source. The variable current source charges the capacitor and generates a current corresponding to a predetermined voltage during a first period. A first voltage is generated using a voltage of the capacitor charged during an enable period of a first signal in the first period, and a second voltage is generated using a voltage of the capacitor charged during the first period. The variable current source further generates a current corresponding to the second voltage during a second period. A second signal is generated according to a result of comparing the first voltage with the voltage of the capacitor during the second period, and a fourth voltage is generated by generating and sampling a third voltage which is increased according to a first current during an enable period of the second signal in the second period.

Signal calculator

Examples of a signal calculator include a voltage multiplier and a time divider. The voltage multiplier copies time information corresponding to a first voltage and generates a third voltage using a second current corresponding to a second voltage during a first period corresponding to the copied time information. The time divider generates an output according to a result of comparing a voltage generated by a first current on the basis of a voltage corresponding to a first time with a second voltage corresponding to a second time.

An electronic device includes a first circuit having a first ground that receives first and second control signals. A third control signal is produced by a second circuit. The second circuit uses a second ground, and the first ground floats with respect to the second ground. The first circuit determines a value corresponding to a value of a third control signal using a difference between a value of the first control signal and a value of the second control signal, the value of a third control signal being a value relative to the second ground. The first circuit controls a value of an output signal of the first circuit according to the value corresponding to the value of a third control signal.

Signal communication for circuit with floating ground

A lighting circuit includes a light emitting diode (LED), a transistor that controls a current through the LED, and a lighting controller integrated circuit (IC) that controls the transistor to vary a brightness of the LED. The controller IC has a dimming pin that receives a dimming signal. The controller IC generates a low reference threshold and a high reference threshold that follow the dimming signal. The lighting controller IC controls the transistor by hysteretic control by comparing a sense signal indicative of the current through the LED to the low reference threshold and the high reference threshold.

Lighting circuit with internal reference thresholds for hybrid dimming

A light emitting diode (LED) driving circuit disclosed herein controls a switching operation of a power switch connected to an LED string and includes a reference voltage generator configured to generate a frequency modulation reference voltage according to a dimming signal that controls brightness of the LED string, and a switching controller configured to control a switching frequency of the power switch to be constant when a level of the dimming signal is higher than that of the frequency modulation reference voltage, and control the switching frequency of the power switch based on the dimming signal when a level of the dimming signal is lower than that of the frequency modulation reference voltage.

LED driving circuit, LED device comprising the same, and driving method of LED

A lighting circuit includes a light emitting diode (LED), a transistor that controls a current through the LED, and a controller integrated circuit (IC) that controls the transistor to vary a brightness of the LED. The controller IC has a dimming pin that receives a hybrid dimming signal from a dimming input circuit. The dimming input circuit receives pulse width modulation (PWM) dimming signals and generates the hybrid dimming signal as a PWM dimming signal, an analog dimming signal, or both depending on the received PWM dimming signals.

Hybrid dimming for lighting circuits

An LED control circuit controls a switching operation of a switch by hysteretic control. The LED control circuit includes a controller integrated circuit (IC) that senses a current sense voltage from a current sense resistor that is on a low-side of the switch. The LED control circuit senses the current sense voltage during on-time of the switch to determine when to turn off the switch. During off-time of the switch, the controller IC determines when to turn on the switch by comparing a sawtooth voltage to a turn-on threshold that is generated from the on-time of the switch.

Light emitting diode control circuit with hysteretic control and low-side output current sensing

The present invention relates to a dimmer and an input current regulator provided in a power supply. The input current regulator includes: a bleeding circuit generating a bleeding current from an input current passed through the dimmer; a sensing circuit sensing the input current, and controlling the bleeding circuit according to a sense voltage corresponding to the input current; and a biasing circuit generating a power voltage for operation of the input current regulator during operation of the power supply. The input current includes a bleeding current and a power current supplied to the power supply.

Input current regulator, driving method thereof, and disable circuit thereof

The present invention relates to a switch control circuit, a power factor corrector including the same, and a driving method thereof. According to an exemplary embodiment of the present invention, a turn-on time of a power switch is controlled according to a zero crossing voltage to sense a voltage of both terminals of the power switch, and a turn-off time of the power switch is controlled according to a feedback voltage corresponding to the output voltage. At this time, the switching frequency of the power switch is sensed by the zero crossing voltage and the switching frequency is restricted by a predetermined threshold frequency.

Switch control circuit, power factor corrector including the same, and driving method of the power factor corrector

The present invention relates to a dimming angle sensing circuit and a driving method thereof. A dimming angle sensing circuit according to an exemplary embodiment of the present invention uses a zener diode. The dimming angle sensing circuit generates a comparison voltage according to a comparison result of a line voltage and a zener voltage. The line voltage is generated from rectification of an AC input passed through a dimmer. The dimming angle sensing circuit generates a sense voltage corresponding to a dimming angle of the dimmer by low-pass filtering the comparison voltage.

Dimming angle sensing circuit and driving method thereof

An exemplary embodiment of the present invention relates to an active damper and a driving method thereof. An AC input passed through a dimmer is transmitted to an active damper through a rectification circuit. The active damper includes a damper resistor connected to the rectification circuit, a damper switch connected to the damper resistor in parallel, and a delay circuit delaying a turn-on time of the damper switch by a predetermined initial period from a turn-on time of the dimmer.

Growing community of inventors

Anyang, South Korea

Seunguk Yang