Abstract: The present invention provides a filtering circuit comprising a poly phase filter and a quadrature phase detector. The poly phase filter comprises a first path, a second path, a third path and a fourth path. The first path is configured to receive a first input signal to generate a first clock signal. The second path comprising a first adjustable delay circuit is configured to receive the first input signal to generate a second clock signal. The third path comprising a second adjustable delay circuit is configured to receive a second input signal to generate a third clock signal. The fourth path is configured to receive the second input signal to generate a fourth clock signal. The quadrature phase detector is configured to detect phases of these clock signals to generate control signals to control the first adjustable delay circuit and the second adjustable delay circuit.

Abstract: The electrical circuit of power supply includes a series of discharge gaps, storage capacitors, and charging resistors. The work of multispark reactor based on the parallel breakdown of discharge gaps in the mode of self-breakdown. Simultaneous triggering of all gaps is achieved using self-breakdown on the rising edge of voltage, particularly when using the power frequency AC voltage.

Abstract: In one embodiment, a system for generating an oscillating signal includes a transconductance amplifier comprising a single-ended output and a differential input. The system also includes only one feedback loop coupled to the transconductance amplifier. The feedback loop includes a low pass filter configured to receive the output of the transconductance amplifier. Also, the feedback loop includes a high pass filter configured to receive the output of the first low pass filter and output a signal to only one terminal of the differential input of the transconductance amplifier.

Abstract: Techniques for mitigating VCO pulling are described. In an aspect, VCO pulling may be mitigated by (i) injecting an oscillator signal, which is a version of a VCO signal from a VCO, into a transmitter and (ii) using coupling paths from the transmitter to the VCO to re-circulate the oscillator signal back to the VCO. In one design, an apparatus includes a VCO and a coupling circuit. The VCO generates a VCO signal at N times a desired output frequency. The coupling circuit receives an oscillator signal generated based on the VCO signal and injects the oscillator signal into a transmitter to mitigate pulling of the frequency of the VCO due to undesired coupling from the transmitter to the VCO. The apparatus may include a phase adjustment circuit that adjusts the phase of the oscillator signal and/or an amplitude adjustment circuit that adjusts the amplitude of the oscillator signal.

Abstract: A time constant automatic adjusting circuit comprises: a filter circuit varying a phase of an clock signal to be input so as to output the clock signal; a phase comparison circuit comparing a phase of an output signal of the filter circuit with the phase of the clock signal, and outputting a predetermined voltage when the phase of the output signal and the phase of the clock signal are the same; at least three comparators comparing the output voltage with a plurality of different voltages; an up-down counter counting a number of output bits of either one of the at least three different voltages in accordance with an output result of the comparators; and a control circuit varying the time constant of the filter circuit in accordance with the number of output bits counted by the up-down counter.

Abstract: A method of generating an output signal from an input signal includes a step of generating a set of n signals, n being an integer greater than or equal to 3, by generating a signal for each integer i such that 0?i?(n?1), each signal within the set having the same frequency and approximately equal amplitude and a phase equal to (360/n)i degrees. The method also includes a step of inputting each of the set of n signals to a gate terminal of a corresponding one of a set of n transistors. Each of the transistors has a source terminal electrically connected to a common voltage drain and each of the transistors has a drain terminal electrically connected to a coupling. The coupling is electrically connected to a common voltage source. The output signal at the coupling has a frequency equal to the frequency of the input signal multiplied by n.

Abstract: Nth-order voltage- and current-mode arbitrary phase shift oscillator structures are synthesized using n operational trans-conductance amplifiers (OTAs) or second-generation current controlled conveyors (CCCIIs) and n grounded capacitors. Linking up the I/O characteristics of the OTA and the CCCII and the reactance of grounded capacitor, the step of synthesis is first based on the algebraic analysis to oscillatory characteristic equations, resulting in a quadrature oscillator structure. Secondly, instead of the quadrature characteristic, to control each output signal with one another by a desired phase difference > or <90°, selectively superposing any of two fundamental OTA/CCCII-C sub-circuitries benefits the transformation of quadrature to arbitrary-phase-shift characteristic for the sinusoidal oscillator structure. Furthermore, several compensation schemes are presented for reducing the output parameter deviation due to the non-ideal effects.

Abstract: A time constant automatic adjusting circuit comprises: a filter circuit varying a phase of an clock signal to be input so as to output the clock signal; a phase comparison circuit comparing a phase of an output signal of the filter circuit with the phase of the clock signal, and outputting a predetermined voltage when the phase of the output signal and the phase of the clock signal are the same; at least three comparators comparing the output voltage with a plurality of different voltages; an up-down counter counting a number of output bits of either one of the at least three different voltages in accordance with an output result of the comparators; and a control circuit varying the time constant of the filter circuit in accordance with the number of output bits counted by the up-down counter.

Abstract: A quadrature signal generator capable of phase-tuning with respect to all of four generated quadrature signals. The quadrature signal generator includes four phase tuning units each having two input terminals, one receiving a differential signal, the other being grounded, and changing a phase of the differential signal to thereby generate quadrature signals. Accordingly, it is possible to tune phases of all the four generated quadrature signals. It is also possible to prevent the amplitude of quadrature signals from being deviated from a reference value.

Abstract: An oscillator that provides a quadrature output and has a cross-coupled configuration is disclosed. The oscillator generates an output signal having a frequency. Two phase shift circuits, or stages, are activated by a control signal to provide phase shifts within the oscillator. Each phase shift circuit includes poles to provide the phase shift. A pole includes a varactor to tune, adjust or vary the phase shift accordingly.

Abstract: A frequency adjustment circuit that maintains a target frequency even when frequency adjustment data of zapping circuit is changed by an external noise is offered. The frequency adjustment circuit includes a reset signal generation circuit, a frequency adjustment data latch circuit that latches and retains the frequency adjustment data ZP1 and ZP2 generated by a first zapping circuit and a second zapping circuit based on a latch clock ZCLK and a latch clock generation circuit that generates the latch clock ZCLK. The reset signal generation circuit generates a periodic reset signal ZRES that is synchronized with a rise of an enable signal EN generated from an interface circuit. The latch clock generation circuit generates the latch clock ZCLK that is synchronized with a fall of the enable signal EN.

Abstract: Methods, apparatuses, and systems are presented for performing channel equalization involving receiving a signal from a channel associated with inter-s interference (ISI), providing the received signal to an inductor, capacitor, resistance (LCR) network comprising a plurality of inductors and a plurality of capacitors, generating in the LCR network a first plurality of intermediate signals representing voltages associated with capacitors in the LCR network and a second plurality of intermediate signals representing currents associated with inductors in the LCR network, wherein the first plurality and second plurality of intermediate signals correspond to application of linearly independent impulse responses to the received signal, applying a corresponding one of a plurality of multiplier factors to each of the first plurality and second plurality of intermediate signals, and generating from the LCR network a resulting signal corresponding to an equalized version of the received signal.

Abstract: An oscillator that provides a quadrature output and has a cross-coupled configuration is disclosed. The oscillator generates an output signal having a frequency. Two phase shift circuits, or stages, are activated by a control signal to provide phase shifts within the oscillator. Each phase shift circuit includes poles to provide the phase shift. A pole includes a varactor to tune, adjust or vary the phase shift accordingly.

Abstract: An integrated oscillator that may be used as a time clock includes circuitry that oscillates about an RC time constant, which RC time constant is adjustable to provide a desired frequency of oscillation. More specifically, the oscillator includes a capacitor array that has a plurality of capacitors coupled in parallel wherein each capacitor may be selectively included into the RC time constant or selectively excluded there from. Rather than setting the capacitance values to a desired capacitance value, a system for adjusting the time constant includes circuitry for measuring an output frequency and for comparing that to a certified frequency source wherein the time constant is adjusted by adding or removing capacitors from the capacitor array until the frequency of the internal clock matches an expected frequency.

Abstract: A quadrature signal generator includes a polyphase filter where four resistive elements and four variable capacitive elements are connected alternately in series to form a loop; and a phase corrector that variably controls the capacitance of the variable capacitive elements.

Abstract: An integrated oscillator that may be used as a time clock includes circuitry that oscillates about an RC time constant, which RC time constant is adjustable to provide a desired frequency of oscillation. More specifically, the oscillator includes a capacitor array that has a plurality of capacitors coupled in parallel wherein each capacitor may be selectively included into the RC time constant or selectively excluded there from. Rather than setting the capacitance values to a desired capacitance value, a system for adjusting the time constant includes circuitry for measuring an output frequency and for comparing that to a certified frequency source wherein the time constant is adjusted by adding or removing capacitors from the capacitor array until the frequency of the internal clock matches an expected frequency.

Abstract: A resistor-capacitor oscillator for receiving a current source, comprising a first switch path and a second switch path that are symmetric and connected in parallel. The first switch path comprises a signal output terminal and a first voltage output terminal. The second switch path comprises a complementary signal output terminal and the second voltage output terminal. One of these two voltage output terminals is selected randomly and input to both the first comparator and the second comparator simultaneously. The first comparator further receives a {fraction (1/2 )} VBG voltage, and the second comparator further receives 2VBG voltage. The first comparator outputs to a PMOS transistor, and the second comparator outputs to an NMOS transistor. The PMOS transistor is in series with the NMOS transistor, and is jointly coupled in between the system power supply and the ground voltage. Moreover, a latch and an inverter are serially coupled to the location of the serial junction node of these two transistors.

Abstract: An integrated circuit configuration for producing a clock signal includes an integrated inverter connected between an input terminal and an output terminal. A crystal is externally connected to the oscillator circuit. A feedback path of the inverter contains a phase-shifting element which effects a phase shift through 180.degree., so that conditions for oscillation continue to be provided if the crystal breaks.

Abstract: A phase-locked-loop circuit includes an oscillator having switched capacitors that are selectively coupled to a positive feedback path of the oscillator in a coarse frequency error correction mode of operation. When the frequency error is small, the circuit operates in a fine error correction mode without varying the selection of the switched reactive elements.

Abstract: This invention relates to oscillators employing a primary feedback network and a high pass filter feedback network. The feedback networks are connected between the input and output of a of a high signal gain amplifier system. The primary feedback network provides positive feedback to cause oscillation to occur and also determines the nominal frequency of oscillation. The high pass filter feedback network provides a negative feedback signal that controls the rise and fall time of the amplifier system's output signal. By varying the output signal's rise and fall time the frequency of oscillation is also changed. The high signal gain amplifier system operates with one or more amplifier stages in the non-linear region to produce a significantly distorted sine wave or pulse output signal.

Abstract: This invention deals with significant innovations on multiphase signal oscillators including quadrature oscillators for the use in frequency shifters, or sequential gating devices for special multichannel sound effects, or three-phase power sources or other electronic apparatus.

Abstract: A resonant circuit is provided with a number of phase shift circuits connected in series. A control circuit is connected in series with the phase shift circuits for controlling the direct current flowing through the circuits. One of the phase shift circuits is constructed of a pair of transistors interconnected by a capacitor. The emitter resistance of the transistors is determined by the direct currents flowing therethrough from the control circuit, whereupon the frequency of oscillation or resonance of the resonant circuit is dependant upon the emitter resistance.