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6937106 Built-in jitter measurement circuit for voltage controlled oscillator and phase locked loop  
A built-in jitter measurement circuit for a VCO (voltage-controlled oscillator) and a PLL (phase-locked loop) is disclosed. The circuit includes a divider for dividing frequency of a signal, a time...
6930559 Oscillation state discrimination circuit and oscillation control circuit adapted to oscillation circuit  
An oscillation control circuit comprising a PLL circuit and a phase-locked state discrimination circuit is adapted to an oscillation circuit that performs oscillation to produce an oscillation...
6930560 High-speed and high-precision phase locked loop  
A phase lock loop includes a charge pump, a voltage controlled oscillator (VCO), and a phase frequency detector. The phase frequency detector has a dynamic logic structure. The phase frequency...
6927635 Lock detectors having a narrow sensitivity range  
Lock detectors are provided that have a narrow sensitivity range.
6927642 Duty cycle correction method for frequency synthesis  
A duty cycle correction method converts a pair of differential analog signals from an oscillator into an output pulse signal with 50% of duty cycle. The pulse signal has the same frequency as that...
6924705 Inject synchronous narrowband reproducible phase locked looped  
The invention discloses an injection synchronization narrowband regenerative phase-locked loop (ISNRPLL) circuit. The circuit includes a synchronous oscillation loop composed by the connecting of...
6924704 Charge pump for phase-locked loop  
When both the sourcing command and the sinking command to the phase comparator are high, the charge pump phase detector creates a high impedance output dead period, which is undesirable. The dead...
6919769 Method and apparatus for fast lock acquisition in self-biased phase locked loops  
A self-biased phase locked loop (PLL) circuit includes a charge pump to generate a control voltage, a controlled oscillator coupled to the charge pump to generate the output signal based at least...
6914489 Voltage-controlled oscillator presetting circuit  
A circuit comprises a frequency synthesizing circuit with a voltage-controlled oscillator whose frequency is preset to a preset value. The voltage-controlled oscillator generates an oscillating...
6911868 Phase-locked loop frequency synthesizer using automatic loop control and method of operation  
In a phase-locked loop (PLL) frequency synthesizer, a first frequency divider divides an output signal from a voltage-controlled oscillator by a first divider value. A second frequency divider...
6909329 Adaptive loop bandwidth circuit for a PLL  
A phase-locked loop (PLL) employs a phase detector (PD) generating an up/down signal based on the phase error between a data signal and a clock signal input to the phase detector. The PD senses...
6903615 Digitally-controlled oscillator with switched-capacitor frequency selection  
A digitally-controlled oscillator (DCO) ( 60 ), such as may be used in clock generator or clock recovery circuitry in an integrated circuit, is disclosed. The disclosed DCO ( 60 ) is a single-stage...
6901339 Eye diagram analyzer correctly samples low dv/dt voltages  
A sampling transition-detector sets two latches to different values when an input signal comparator referenced to the selected voltage transitions during a sample interval: at the beginning one...
6894571 Phase locked loop circuit with selectable variable frequency dividers  
A PLL circuit comprises a reference signal generating unit for generating reference signals of different phases, variable frequency dividers for dividing the frequency of the output signal of a...
6891441 Edge synchronized phase-locked loop circuit  
A phase-locked loop circuit for synchronizing an edge of an output signal with an edge of an input signal. The circuit detects an edge of an input clock signal, and a corresponding edge on an...
6888902 Digital variable frequency oscillator  
Disclosed is a digital variable oscillator which has: a cycle change detector for detecting the change of cycle between two input data; a decoder for outputting a predetermined signal in relation...
6888412 Phase locked loop circuit for reducing electromagnetic interference and control method thereof  
For a phase-locked loop, disclosed is a method (and corresponding apparatus) for reducing electromagnetic interference caused by a clock signal produced by a voltage controlled oscillator, the...
6885254 Calibration device and method for generating a clock in an integrated circuit  
To generate an accurate frequency standard in an integrated circuit, it is proposed to activate a reference oscillator at certain time intervals and to calibrate the local oscillator. For this...
6882231 Adjustable frequency oscillator with programmable calibrating circuit and related system and method  
An adjustable frequency oscillator circuit includes: an odd number of inverters connected so as to form a loop; a plurality of capacitive elements each connected to an output terminal of a...
6882229 Divide-by-X.5 circuit with frequency doubler and differential oscillator  
A divide by X.5 circuit can be implemented as a divided by 1.5 circuit. A phase-locked loop (PLL) has a quadrature voltage-controlled oscillator (VCO) that generates four phases offset at 0, 90,...
6876240 Wide range multi-phase delay-locked loop  
A delay locked loop apparatus includes a first delay element to receive a reference signal, to delay the reference signal by a delay time, and to output a first delayed signal. A second delay...
6873213 Fractional N frequency synthesizer  
A frequency synthesizer ( 100 ) that may have reduced spurious noise caused by a voltage controlled oscillator (VCO) ( 4 ) output sneaking into an input side of a phase comparison circuit ( 1 ) has...
6864715 Windowing circuit for aligning data and clock signals  
Described are circuits and methods for aligning data and clock signals. Circuits in accordance with some embodiments separate incoming data into three differently timed data signals: an early...
6859109 Double-data rate phase-locked-loop with phase aligners to reduce clock skew  
A phase-locked loop (PLL) has an analog divider in the feedback path that receives either the in-phase or quadrature-phase pair of outputs from a voltage-controlled oscillator (VCO) while the other...
6859107 Frequency comparator with hysteresis between locked and unlocked conditions  
A frequency comparator apparatus used with a reference clock, a voltage controlled oscillator circuit and a phase locked loop circuit includes a reference loop circuit wherein the reference loop...
6859106 PLL circuit and phase difference detecting circuit that can reduce phase pull-in time and adjust a skew at a higher precision  
A PLL circuit for comparing with a phase comparator 1 a phase between an input signal and one of multiphase pulse signals CK 0 DIV to CKNDIV used as a channel clock generated by an output of a...
6859108 Current biased phase locked loop  
A phase locked loop (PLL) circuit adjusts a voltage controlled differential oscillator to generate an output frequency signal that is a selected multiple of an input reference signal. An oscillator...
6856202 Phase/frequency detector and phase lock loop circuit  
The present invention relates to cycle slip detectors for phase and frequency detectors (PFD) and to lock detectors for phase lock loop (PLL) circuits. The present invention provides a cycle slip...
6856205 VCO with automatic calibration  
Voltage-controlled oscillator with apparatus for automatic calibration. The voltage-controlled oscillator includes switches connecting associated coarse-tuning capacitors to an LC resonant tank of...
6856207 Jitter-less phase detector in a clock recovery circuit  
A jitter-less phase detector in a clock recovery circuit is disclosed. A first control signal generating circuit generates a first control signal by inverting and delaying input data signals...
6853252 Phase-lock loop having programmable bandwidth  
A phase-locked loop having a programmable loop bandwidth is provided. A PLL comprises an oscillator operable to receive an error-correction signal and to generate an oscillator signal having a...
6853255 AFC circuit compensating an error in oscillation frequency  
An AFC circuit compensates for an error of the oscillation frequency of a detecting oscillator based on a detection signal from a detector circuit. The detector circuit generates the detection...
6844785 Phase-lock loop for preventing frequency drift and jitter and method thereof  
A phase-lock loop for preventing frequency drift and jitter problems is disclosed. A phase comparator compares an input signal and a feedback signal, and outputs a control voltage according to...
6842078 Ring oscillator with variable loading  
A ring oscillator circuit device is achieved. The device comprises an odd number of inverting stages. Each inverting stage has an input terminal and an output terminal. The inverter stages are...
6838945 Data resynchronization circuit  
An apparatus comprising three sampling circuits to sample incoming data and a quarter clock. A clock generation unit is included to generate at least three sampling clocks from a local clock. Each...
6833764 Apparatus and method for synthesizing a frequency using vernier dividers  
A PLL frequency synthesizer tunable in small step sizes that comprises: 1) a first PLL circuit comprising: i) a first feedforward frequency divider that receives an F(in) frequency and generates an...
6831523 Auto-detection between referenceless and reference clock mode of operation  
An internal frequency reference, such as a VCO used in a PLL, having a free-running frequency fairly well controlled within a predictable range, is used to determine which of two possible modes of...
6825728 Method and device for generating frequency adjustment parameters for a voltage controlled oscillator  
A method for generating parameters for adjusting the frequency of a VCO. A desired carrier frequency may be based off the output of the VCO. The method determines parameters that are operable to...
6825729 Frequency synthesizer with sigma-delta modulation  
A frequency synthesizer, especially for mobile radio base stations, transforms a digital input signal having a first frequency rapidly into a digital output signal having a second frequency....
6822519 Synthesizer structures and alignment methods that facilitate quadrature demodulation  
Synthesizer structures and alignment methods are provided that facilitate quadrature demodulation. The structures are realized with phase-locked loops that include half-rate frequency dividers to...
6816019 Automatically calibrated phase locked loop system and associated methods  
A method for automatically calibrating a phase locked loop (PLL) system includes estimating a frequency value of an input signal applied to the system. Based on the estimated frequency value, a...
6816018 System and method for partitioning a system timing reference among multiple circuit boards  
In a phase-locked loop, multiple input clock references can each connect to a different interface card. Each interface card can include a phase comparator portion of a phase-locked loop. The phase...
6809600 Dual loop phase lock loops using dual voltage supply regulators  
Dual loop phase lock loops having a high loop bandwidth with low power consumption are described. Each loop is provided with a voltage supply regulator circuit which regulates the voltage of a...
6809601 Phase detector for a delay locked loop and delay locked loop with the phase detector  
A phase detector for a delay locked loop with a delay unit that delays a periodic clock signal by a settable delay, has a first input for the periodic clock signal, a second input for the delayed...
6809598 Hybrid of predictive and closed-loop phase-domain digital PLL architecture  
A phase-domain digital PLL loop is implemented using a hybrid of predictive and closed-loop architecture that allows direct DCO oscillator transmit modulation in the GFSK modulation scheme of...
6806782 Frequency synthesizer circuit  
The frequency synthesizer circuit includes a phase-locked loop (PLL) circuit, a voltage controlled oscillator (VCO), a low pass filter (LPF), an input terminal for providing serial data provided...
6803826 Delay-locked loop circuit and method using a ring oscillator and counter-based delay  
A delay-locked loop includes a ring oscillator that generates a plurality of tap clock signals, with one tap clock signal being designated an oscillator clock signal. Each tap clock signal has a...
6803834 Sigma-delta modulated discrete time oscillator  
A sigma-delta modulated discrete time oscillator. The sigma-delta modulated discrete time oscillator comprises a synchronous counter and a sigma-delta modulator. The sigma-delta modulator operating...
6803827 Frequency acquisition system  
A frequency acquisition system for a tunable oscillator is provided that generally includes a frequency-locked loop circuit including a detector system, responsive to the frequency of an output...
6801094 Phase comparator  
A phase comparator is disclosed that can provide a phase comparison result at high speed that essentially does not vary according a power source voltage, ambient temperature and/or manufacturing...
Matches 201 - 250 out of 1561 < 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 >