Integrant Technologies Inc.

Minsu Jeong

Seyeob Kim

Bo-Eun Kim

Bonkee Kim

Junghwan Lee

Jinkyu Lim

Rajath Kedilaya

A tuning circuit of a filter is disclosed to correct a cut-off frequency of the filter. The tuning circuit comprises a current generation unit which includes a first transistor and a resistor, and a capacitor compensation unit which includes a second transistor and a capacitor unit.

Tuning circuit

Provided is a frequency control loop circuit changing division ratios of a frequency synthesizer to oscillate frequencies in a broadband with high precision. The circuit comprises a clock oscillator, a frequency synthesizer, and a demodulator.

Automatic frequency control loop circuit

The present invention relates to a filter and, more particularly, to a tuning circuit of a filter for correcting a cut-off frequency of the filter. The tuning circuit comprises a current generation unit having a first transistor and a variable resistor unit, and a capacitance correction unit having a second transistor, a capacitor unit, an up-down counter and a selection unit for selecting a control path of the up-down counter for varying the resistance or capacitance.

Disclosed herein is a circuit for generating reference current. The circuit for generating reference current comprises a current providing unit for generate a PTAT current, mirroring the PTAT current to generate an analogous PTAT current and generate an analogous BGR current, a current ratio control unit for generating an analogous BGR current in a first ratio, a PTAT current in a second ratio, and a current corresponding to the difference between the analogous PTAT current in the second ratio and the analogous BGR current in the first ratio, and a current increasing/decreasing unit for generating a BGR current in the first ratio.

Circuit for generating reference current

The present invention is to provide a charge pump circuit for improving switching speed and compensating mismatch between a source and a sink currents flowing to output terminal. A charge pump circuit according to the first embodiment of the present invention comprises a first and second switching elements, a discharging and charging elements, a biasing unit, a first and second compensating unit, a charge pumping unit, a current mirror unit, a control unit, and a biasing unit. The compensating circuit removes the deterioration owing to the parasitic capacitance, and the control circuit controls the charge that is flowed or emitted from the parasitic capacitance. A charge pump circuit according to the second embodiment of the present invention comprises a charge pumping unit, a current mirror unit, a control unit a biasing unit. The charge pump circuit decects the mismatch between the output currents via the control unit, and compensates the mismatch by the biasing unit.

Charge pump circuit for compensating mismatch of output currents

The present invention relates to a circuit for varying bandwidth of transconductance-capacitor filter by controlling transconductance of a transconductance circuit, and a digital tuning circuit of transconductor-capacitor filter. A transconductor of an embodiment of the present invention comprises a first and second amplifying devices; a resistor; a first and second bias current sources; and transconductance varying circuit. A tuning circuit of another embodiment of the invention relates to a digital tuning circuit comprising a transconductor that outputs current proportional to input voltage and a varying capacitance that is connected with output node of transconductor and between grounds and varies its capacitance depending upon the level of control signal. The digital tuning circuit further comprises a transconductor, a comparator, a counter, a varying capacitor, means for maintaining the output voltage of the transconductor as substantial zero for first period, and means for inputting input voltage to the transconductor for second period and means for inputting the output voltage of the transconductor to input node of the comparator.

Transconductance varying circuit of transconductor circuit, varying bandwidth filter circuit using the same and digital tuning circuit of transconductor-capacitor filter

A signal processing apparatus for correcting DC offset in a communication system is provided. The signal processing apparatus comprises: a low noise amplifier (LNA) ; a mixer for mixing the output from said LNA with local oscillation signal LO; a first offset correction amplifier for amplifying output signal from said mixer and for eliminating DC offset in the output signal in accordance with first control signal Vc ; a second offset correction amplifier for amplifying output signal from said first offset correction amplifier and for eliminating DC offset in the output signal in accordance with second control signal Vc ; a variable gain amplifier for amplifying output from said second offset correction amplifier wherein gain is controlled such that power level of output be maintained to a desired value; offset calibration mean for calibrating DC offset in output from said variable gain amplifier ; and offset correction mean for outputting the first and second control signals Vc and Vc in accordance with the output from said offset calibration mean , to eliminate DC offset in the output from said variable gain amplifier

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Gyeonggi-do, South Korea

Minsu Jeong