Samsung Electro-mechanics Co., Ltd.

Solum Co., Ltd.

Bo Hyun Hwang

Seung Kon Kong

Jae Shin Lee

Jung Sun Kwon

Jung Hyun Kim

Joon Youp Sung

Dae Hoon Han

Jung Eui Park

Seo Hyung Kim

Ki Joong Kim

Jun Goo Won

Sung Hwan Park

Jin Soo Lee

Da Hye Park

Dae Hee No

Hyun Jun Kim

Byoung Own Min

Sang Wook Park

Byoung Woo Ryu

Sang Cheol Shin

Jeong In Cheon

Yoshiyuki Tonami

Min Young Ahn

Yun Jin Jang

A bias circuit of an amplifying device including amplifying circuits and a bypass circuit responding to a first control signal, includes a first bias circuit, a second bias circuit, and a compensating circuit. The first bias circuit is configured to supply a first base bias voltage to a first amplifying circuit of the amplifying circuits in response to a second control signal. The second bias circuit is configured to supply a second base bias voltage to a second amplifying circuit of the amplifying circuits in response to a third control signal. The compensating circuit is connected to either one or both of the first bias circuit and the second bias circuit, and configured to vary an impedance in response to a fourth control signal, and compensate for either one or both of the first base bias voltage and the second base bias voltage based on the varied impedance.

Bias circuit and amplifying device with bias compensation function

A power amplifier circuit includes a bias circuit and an amplifier circuit. The bias circuit includes a first bias circuit to receive a reference voltage and an operation voltage and generate a first bias signal, a bias supply circuit to transmit the base bias signal to a base of a power amplifier, based on the first bias signal input from the first bias circuit, a switching control circuit to transmit a switching signal after a preset delay time based on a driving start signal, and a switching circuit connected between an output node of the first bias circuit and a ground, to operate in an ON state after the delay time in response to the switching signal to form a current path between the output node of the first bias circuit and the ground.

Bias circuit and power amplifier circuit

Disclosed herein is a converter including a switching unit, an energy storage unit for storing energy from a direct current (DC) input voltage and then generating an output voltage according to a switching operation of the switching unit, and a switching controller for controlling the switching unit to selectively execute a first operation mode for turning on the switching unit at a fixed frequency or a second operation mode for turning on the switching unit when a voltage between one end and the other end of the switching unit reaches a zero point of a resonance waveform, wherein the switching controller includes an operation mode selection unit for selectively executing the first operation mode or the second operation mode according to whether the voltage between one end and the other end of the switching unit resonates.

Converter

There is provided a multi-output power supply capable of maintaining power balancing between multiple output powers by fixing a switching duty until a voltage level reaches a predetermined voltage level during an initial stage of a soft-start operation, the multi-output power supply including a power supply unit switching an input power and outputting a plurality of powers having levels determined according to the switching, and a controller controlling a soft switching operation of the power supply unit during an initial operation and fixing a switching duty of the power supply unit to a preset switching duty according to a result of a comparison between a preset reference voltage level and an operating voltage determining whether the soft switching operation is performed or not during the soft switching operation.

Multi-output power supply

There is provided a multi-output power supply apparatus capable of maintaining multiple output voltages in a balanced state by limiting a variable range of a switching duty according to a load state. The multi-output power supply apparatus includes: a power supply unit switching input power to output a plurality of voltages whose power levels are determined according to the switching operation; and a controller detecting power states of at least some of the plurality of voltages from the power supply unit, and limiting a range of a switching duty of the power supply unit to a pre-set range when the detected power states correspond to a pre-set limited power state.

Multi-output power supply apparatus enhancing a power imbalance between multiple outputs

There is provided a light emitting diode power supply apparatus capable of limiting a rise in a voltage level of a power supplied to a light emitting diode even in the case in which driving of the light emitting diode is stopped for a long period of time. The light emitting diode power supply apparatus includes: a power supply unit supplying a driving power set under a control to a light emitting diode; and a controlling unit selecting one of a detection voltage obtained by detecting a current flowing to the light emitting diode and a voltage provided according to an operation state of the light emitting diode to control a power supply operation of the power supply unit.

Light emitting diode power supply apparatus

There is provided a light emitting diode driver capable of improving power efficiency by using a resistor having a low power consumption rating while controlling an LED channel so that it has constant brightness stably. The light emitting diode driver includes: a power supplying unit converting an input voltage into a predetermined driving voltage so as to supply the driving voltage to an LED channel; and a driving unit amplifying a detection voltage detected based on a current from the LED channel by a predetermined gain and controlling the current flowing through the LED channel so that the amplified detection voltage has a level equal to that of a predetermined reference voltage.

Light emitting diode driver

There is provided a light emitting diode driving apparatus capable of uniformly maintaining current balance between light emitting diode channels. The light emitting diode driving apparatus includes: a DC to DC converting unit converting the direct current power into settable driving power; a detecting unit detecting voltage drops generated in each of a plurality of light emitting diode channels each having a plurality of light emitting diodes; a converting unit converting an analog value into a digital value; and a driving unit differentially setting duty cycles of switching signals according to the digital values from the converting unit to drive the plurality of light emitting diode channels.

Light emitting diode driving apparatus

There is provided a light emitting diode driving apparatus, including: a power supplying unit converting input power into driving power according to a control and supplying the converted driving power to a light emitting diode channel; a driving unit controlling current flowing in the light emitting diode channel according to a pulse width modulation (PWM) dimming signal from the outside; and a controlling unit comparing a reference level set by a duty of the PWM dimming signal with a detection voltage level of the light emitting diode channel and controlling a power converting operation of the power supplying unit according to the comparison result.

Disclosed herein is a light emitting diode (LED) driving device for driving a multi-channel LED element or an LED array for each channel, the LED driving device including: a constant current driver driving currents flowing in each channel; and a minimum voltage selector receiving voltage levels of each channel and selecting a minimum voltage level to thereby feedback the selected minimum voltage level to the constant current driver, wherein matching characteristics of currents flowing in each channel is improved and a size of an integrated circuit (IC) chip is also reduced as compared to a case according to the related art, thereby making it possible to reduce a production cost and satisfy the trend of miniaturization of the chip, while solving a performance deterioration problem due to deterioration of the matching of the currents between the channels.

LED driving device

Disclosed herein is a light emitting diode (LED) driving device for driving a multi-channel LED element or an LED array for each channel, the LED driving device including: a constant current driver driving currents flowing in each channel; a first switching unit selectively feeding-back voltage levels of each channel; and a switching controller controlling the turn on/off of the first switching unit, wherein matching characteristics of currents flowing in each channel is improved and a size of an integrated circuit (IC) chip is also reduced as compared to a case according to the related art, thereby making it possible to reduce a production cost and satisfy the trend of miniaturization of the chip, while solving a performance deterioration problem due to degradation of the matching of the currents between the channels.

Disclosed herein is a device for controlling current of an LED including a constant current generator, a current mirror, and a current amplifier, the device controlling current of an LED, comprising: a selector outputting an L signal or an H signal according to an input control signal; and a current changing unit formed by connecting at least one switching unit in parallel, the switching unit including a transistor and a switch connected to the transistor in series. The device for controlling current of an LED adjusts current supplied to the current amplifier using a SEL input without an effect of a noise, thereby making it possible to change the current of the LED without separately changing a resistor.

Device for controlling current of LED

There is provided a digital PWM generator according to a first exemplary embodiment of the present invention including: an A/D converter dividing a predetermined reference voltage into a plurality of sections corresponding to a predetermined first set value, searching a section to which the magnitude of an input voltage Vin corresponds, among the plurality of sections, and converting a value corresponding to the searched section into a digital signal; a frequency selector providing a counting number by counting a predetermined high-speed counting clock during a one-cycle section of a predetermined reference clock; and a PWM signal generator converting the digital signal from the A/D converter into a ratio value corresponding to a ratio for the reference voltage and generating a PWM signal having a controlled duty ratio of the reference clock by using the ratio value and the counting number from the frequency selector.

Digital PWM generator and apparatus for driving light emitting device

The device for generating three mode signals includes: a voltage setting block including an input terminal receiving three input signals of driving voltage, open, and ground and setting three voltages according to the three input signals; and an output block including two output terminals and a second node B receiving the three voltages from the voltage setting block, and outputting three combined signals by comparing an input voltage with a reference voltage, whereby only a small number of resistors and amplifiers generates three mode signals to further reduce the chip size than the related art and the external power source is not required to solve the problems of the related art due to noise.

Device and method for generating three mode signal

An apparatus for driving a light emitting device (LED) is provided. The apparatus for driving the LED includes a first driving control element, a first current detection unit, a first effective value detection unit, a first reference signal generation unit, and a first comparison unit. The first driving control element controls a current flowing through a first LED channel, in response to a first pulse-width modulated control signal. The first current detection unit detects the current flowing through the first LED channel. The first effective value detection unit detects an effective value of the current detected by the first current detection unit. The first reference signal generation unit generates a preset reference signal having a sawtooth waveform. The first comparison unit compares the reference signal from the first reference signal generation unit with the effective value from the first effective value detection unit.

Growing community of inventors

Gyunggi-do, South Korea

Bo Hyun Hwang