Abstract: Active circuits with isolation switches are described. In one design, an apparatus includes first and second amplifiers coupled in parallel. Each amplifier receives an input signal and provides an output signal. Each amplifier has a switch that isolates the amplifier when the amplifier is turned off. The first and second amplifiers may be high and low gain amplifiers or two low noise amplifiers (LNAs). The first and second amplifiers may be for different communication systems, different frequency bands, and/or different gain ranges. In general, any number of amplifiers may be coupled in parallel, and each amplifier may have a switch to isolate that amplifier when turned off. A switch for an amplifier may be a shunt switch coupled between an internal node of the amplifier and ground. The shunt switch may be closed when the amplifier is turned off and may be opened when the amplifier is turned on.

Abstract: A high resolution time detecting apparatus using interpolation and a time detecting method using the same are provided. The time detecting apparatus includes a delayer which generates delayed signals by sequentially delaying a reference signal using a plurality of delay elements, a latch unit which outputs latch signals using the delayed signals, and an interpolation unit which outputs interpolated signals using input and output signals of the delay elements. As a result, a high resolution TDC using an interpolation and a time detecting method using the same provide improved performance of digital PLL, high resolution digital signal output at a low power consumption, and controlled circuit size.

Abstract: The present invention relates to a differential amplifier and a mixer for improving the linearity. The differential amplifier circuit according to this present invention, includes first and second load stages each having a predetermined voltage value, a main differential amplifier unit having a first differential stage that forms a differential pair in such a way as to amplify a difference between a first input voltage and a second input voltage, and a constant current source, which has a predetermined current driving capability and is connected serially between a power source voltage terminal and a ground terminal, and a auxiliary differential amplifier unit having a second differential stage that forms a differential pair in such a way as to amplify a difference between a third input voltage and a fourth input voltage connected between the first load stage and a second load stage, and the ground, respectively.

Abstract: The present invention relates to improved linearity of an active circuit, and more particularly, to an active circuit having improved linearity using a main circuit unit and an assistant circuit unit. According to the present invention, the common gate circuit includes a main circuit unit consisting of a common gate circuit having a drain terminal through which an input signal is output as an output signal, an assistant circuit unit having a common gate circuit in order to assist the linearity of the main circuit unit, a biasing unit for biasing the main circuit unit and the assistant circuit unit, respectively, and load stages connected to output stages of the main circuit unit and the assistant circuit unit, wherein the output stages of the main circuit unit and the assistant circuit unit are coupled to each other.

Abstract: A digitally controlled oscillator (DCO) includes a current generator which generates an electric current having a magnitude corresponding to an input signal, and a digitally controlled oscillating unit which generates an oscillating frequency based on an inductance which varies according to the magnitude of the electric current generated by the current generator.

Abstract: The present invention relates to a filter, and more particularly, to a tracking filter for selecting a channel of a wideband frequency. The tracking filter for selecting a channel of a wideband frequency, which is for increasing the selectivity of a wideband frequency, includes: a first tracking portion for filtering and amplifying a specific frequency band while converting a low input impedance of the input terminal of the tracking filter into a high impedance; a second tracking portion for maintaining the high impedance of the first tracking portion, and for filtering and amplifying the specific frequency band while increasing the selectivity Q of a frequency outputted from the first tracking portion; and a third tracking portion for filtering the specific band wherein has low input impedance and high output impedance.

Abstract: The present invention relates to improved linearity of an active circuit, and more particularly, to an active circuit having improved linearity using a main circuit unit and an assistant circuit unit. According to the present invention, the common gate circuit includes a main circuit unit consisting of a common gate circuit having a drain terminal through which an input signal is output as an output signal, an assistant circuit unit having a common gate circuit in order to assist the linearity of the main circuit unit, a biasing unit for biasing the main circuit unit and the assistant circuit unit, respectively, and load stages connected to output stages of the main circuit unit and the assistant circuit unit, wherein the output stages of the main circuit unit and the assistant circuit unit are coupled to each other.

Abstract: A high resolution time detecting apparatus using interpolation and a time detecting method using the same are provided. The time detecting apparatus includes a delayer which generates delayed signals by sequentially delaying a reference signal using a plurality of delay elements, a latch unit which outputs latch signals using the delayed signals, and an interpolation unit which outputs interpolated signals using input and output signals of the delay elements. As a result, a high resolution TDC using an interpolation and a time detecting method using the same provide improved performance of digital PLL, high resolution digital signal output at a low power consumption, and controlled circuit size.

Abstract: A plasma display device, which gradually increases the current to the panel capacitors is disclosed. The display uses an inductor to reduce the current spike which would otherwise occur and create large electromagnetic interference.

Abstract: A digital frequency detector and a digital phase locked loop (PLL) are provided. The digital frequency detector includes a first conversion unit which outputs a first frequency as first frequency information of a digital type using a first ring oscillator that operates in a high-level period of the first frequency, a second conversion unit which outputs a second frequency as second frequency information of a digital type using a second ring oscillator that operates in a high-level period of the second frequency, and an operation unit which outputs a digital frequency for the first frequency by calculating a ratio of the first frequency information to the second frequency information.

Abstract: A plasma display device and a method of driving the same, capable of reducing or preventing the deterioration of components such as a switching device, due to an overcurrent. In a reset period, in order to cause the voltage of a scan electrode to ramp down from a first voltage to a second voltage, a panel driver includes a falling ramp switch that repeats turn-on/turn-off operations, alternately coupling and de-coupling a low-level power supply to the scan electrode, resulting in a gradually falling ramp waveform. A switch controller generates a switching pulse to control the falling ramp switch. Each turn-on time of the switching pulse for the initial falling ramp waveform following a power-on of the plasma display device is controlled to be shorter than each turn-on time of the switching pulse for other falling ramp waveform.

Abstract: The present invention relates to improved linearity of an active circuit, and more particularly, to an active circuit having improved linearity using a main circuit unit and an assistant circuit unit. According to the present invention, the common gate circuit includes a main circuit unit consisting of a common gate circuit having a drain terminal through which an input signal is output as an output signal, an assistant circuit unit having a common gate circuit in order to assist the linearity of the main circuit unit, a biasing unit for biasing the main circuit unit and the assistant circuit unit, respectively, and load stages connected to output stages of the main circuit unit and the assistant circuit unit, wherein the output stages of the main circuit unit and the assistant circuit unit are coupled to each other.

Abstract: The present invention relates to improved linearity of an active circuit, and more particularly, to an active circuit having improved linearity using a main circuit unit and an assistant circuit unit. According to the present invention, the common gate circuit includes a main circuit unit consisting of a common gate circuit having a drain terminal through which an input signal is output as an output signal, an assistant circuit unit having a common gate circuit in order to assist the linearity of the main circuit unit, a biasing unit for biasing the main circuit unit and the assistant circuit unit, respectively, and load stages connected to output stages of the main circuit unit and the assistant circuit unit, wherein the output stages of the main circuit unit and the assistant circuit unit are coupled to each other.

Abstract: In a plasma display device and a driving apparatus thereof, a scan electrode driver for applying a driving voltage to a scan electrode has a diode including a cathode coupled to a sustain voltage supplying power and an anode coupled to a switch for applying a reset rising waveform to the scan electrode. In the scan electrode driver, when a switch for applying a reset rising waveform is turned on, the voltage at the scan electrode is gradually increased by a voltage that is less than the sustain voltage due to the breakdown voltage of the diode. Therefore, the number of power sources is reduced simplifying the circuit configuration and reducing the plasma display device production cost.

Abstract: A plasma display device, and a driving apparatus thereof, is provided, which includes: a plasma display panel for displaying an image, the plasma display panel including a plurality of discharge cells and a plurality of electrodes corresponding to the discharge cells; and an electrode driver for applying a driving voltage to the plurality of electrodes, wherein the electrode driver includes: a first switch coupled between the plurality of electrodes and a first power supply for supplying a sustain voltage to the plurality of electrodes in a sustain period, a second switch having a first terminal and a second terminal, the first terminal coupled to the first power supply, the second switch for gradually increasing a voltage of the second terminal to the sustain voltage.

Abstract: Active circuits with isolation switches are described. In one design, an apparatus includes first and second amplifiers coupled in parallel. Each amplifier receives an input signal and provides an output signal. Each amplifier has a switch that isolates the amplifier when the amplifier is turned off. The first and second amplifiers may be high and low gain amplifiers or two low noise amplifiers (LNAs). The first and second amplifiers may be for different communication systems, different frequency bands, and/or different gain ranges. In general, any number of amplifiers may be coupled in parallel, and each amplifier may have a switch to isolate that amplifier when turned off. A switch for an amplifier may be a shunt switch coupled between an internal node of the amplifier and ground. The shunt switch may be closed when the amplifier is turned off and may be opened when the amplifier is turned on.

Abstract: This disclosure is directed to a frequency-selective low noise amplifier (LNA) with wide-band impedance and noise matching. The LNAS may include a closed loop circuit that supports wideband input matching. For example, the closed loop circuit may be configure to impedance match an input signal and provide a low noise figure. In addition, the LNA may include an open loop circuit that amplifies the input signal and provides a high output impedance. The open loop circuit may further include a selectivity filter that filters out frequencies outside a desired frequency band. The LNA may drive a tunable band-pass filter via the open loop circuit.

Abstract: An amplifier with integrated filter (e.g., an LNA) is described. In one design, the amplifier may include a gain stage, a filter stage, and a buffer stage. The gain stage may provide signal amplification for an input signal. The filter stage may provide filtering for the input signal. The buffer stage may buffer a filtered signal from the filter stage. The amplifier may further include a second filter stage and a second buffer stage. The second filter stage may provide additional filtering for the input signal. The second buffer stage may buffer a second filtered signal from the second filter stage. All of the stages may be stacked and coupled between a supply voltage and circuit ground. The filter stage(s) may implement an elliptical lowpass filter. Each filter stage may include an inductor and a capacitor coupled in parallel and forming a resonator tank to attenuate interfering signals.

Abstract: A linearity-improved differential amplification circuit is provided, A linearity-improved differential amplification circuit comprises a main differential amplification unit differentially amplifying a first and a second input signals, a main bias unit biasing the main differential amplification unit, a first current source coupled in series between a power supply voltage terminal and the main bias unit and an auxiliary differential amplification unit differentially amplifying the first and the second input signal and coupled to the main differential amplification unit.

Abstract: Disclosed is a high linearity programmable gain amplifier using a switch, including an attenuating portion for controlling a gain of a signal and an amplifying portion having a first amplifying part and a second amplifying part, for amplifying an input signal and outputting a signal amplified, wherein the first amplifying part has a first amplifier for amplifying an input signal and a first switch for activating the first amplifier and the second amplifying part has a second amplifier for amplifying an input signal and a second switch for activating the second amplifier.