Medison Co., Ltd.

Lg Semicon Co., Ltd.

Ki Jeon

Chang Sun Kim

Moo Ho Bae

Song Bai Park

The present invention relates to a variable gain amplifier. The variable gain amplifier in an ultrasound includes an attenuator. The attenuator includes resistor strings each having a plurality of resistors connected in series to each other and a gain control unit. The gain control unit has tap inputs taken from a plurality of junctions between a first resistor string receiving a first input signal and a second resistor string receiving a second input signal. The gain control unit is configured to provide an attenuated differential input signal based on the tap inputs. The variable gain amplifier includes an amplifying unit having a feedback amplifying section configured to amplify the attenuated differential input signal to output a first amplified signal and a clipping amplifying section configured to amplify the first amplified signal to output a second amplified signal that falls within a predetermined voltage range.

Variable gain amplifier

The present invention relates to a variable gain amplifier. The variable gain amplifier includes an input unit including first and second input nodes and an output node, the input unit being configured to receive first and second input signals. The variable gain amplifier further includes a first clipping unit operable to clip a voltage level at the output node to be equal to or lower than a level of a first reference voltage and a second clipping unit operable to clip a voltage level at the output node to be equal to or greater than a level of a second reference voltage, wherein the second reference voltage is lower than the first reference voltage. A predetermined level of a voltage is outputted through an output unit included in the variable gain amplifier based on the clipped voltage level.

Wideband variable gain amplifier with clipping function

A read circuit for a disc player or the like is provided that can achieve a high-speed data recovery, which can be varied by increasing only a clock speed. The read circuit can include a control signal generating unit receiving a radio frequency signal detected from a disc and outputting first and second control signals to an external circuit and outputting first and second output signals. A level compensating unit receives the first output signal from the control signal generating unit and feeds back a level compensation control signal to the control signal generating unit. A gain compensating unit receives the second output signal from the control signal generating unit to feed back a gain compensation control signal to the control signal generating unit to compensate a gain of the control signal generating unit. A timing control unit receives the second output signal from the control signal generating unit and feeds back a timing control signal to the control signal generating unit.

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Seoul, South Korea

Ki Jeon