| Patent application number | Description | Published |
|---|
| 20080246545 | DIGITAL PHASE AND FREQUENCY DETECTOR - Disclosed are a digital phase-frequency detector and a method of operating a digital phase-frequency detector. The detector includes an input circuit, an output circuit and a reset circuit. In use, the input circuit receives first and second input signals during a plurality of cycles, and during a given one of the cycles, generates a first intermediate signal or a second intermediate signal depending on which of the first and second input signals was received first during that given one of said cycles. The output circuit receives these intermediate signals, and outputs, during said one cycle, a first output signal or a second output signal depending on which one of intermediate signals was received by the output circuit during said one cycle. The reset circuit applies a reset signal to the input circuit under defined conditions to begin a new one of said plurality of cycles. | 10-09-2008 |
| 20090195275 | TECHNIQUE FOR EFFICIENTLY MANAGING BOTH SHORT-TERM AND LONG-TERM FREQUENCY ADJUSTMENTS OF AN ELECTRONIC CIRCUIT CLOCK SIGNAL - A control system for generating an electronic circuit clock signal that can optimize operating frequency margins by responding to short term effects by quickly varying the clock frequency and long term effects by finding an optimal frequency point. A sensor indicates frequency margins associated with safe use of the clock signal, and these frequency margins are input into a frequency compensator and used to determine whether the system is operating within acceptable margins, or alternatively to modify the operating clock frequency on a short-term basis in order to achieve acceptable operating margins. The requests for frequency adjustment by the frequency compensator are provided to a frequency filter, which combines such request with a maintained/accumulated history of previous short-term frequency requests that have previously been made in order to determine whether an update needs to be made to the target frequency to provide long-term frequency control. | 08-06-2009 |
| 20090195278 | METHOD AND CIRCUIT FOR CONTROLLING CLOCK FREQUENCY OF AN ELECTRONIC CIRCUIT WITH NOISE MITIGATION - A technique to mitigate noise spikes in an electronic circuit device such as an integrated circuit. The clock frequency of a clock signal used by the electronic circuit is controlled such that instantaneously large changes to the clock frequency are avoided by use of a frequency filter that is capable of generating frequency ramps having a linear slope which is used as a feedback signal in a digital phase-locked loop clock circuit in lieu of a discrete, stair-stepped feedback control signal. | 08-06-2009 |
| 20090252215 | SAMPLED CURRENT-INTEGRATING DECISION FEEDBACK EQUALIZER AND METHOD - A decision feedback equalizer (DFE) and method including a branch coupled to an input and including a sample-and-hold element configured to receive and sample a received input signal from the input and a current-integrating summer. The current-integrating summer is coupled to an output of the sample-and-hold element. The summer is configured to receive and sum currents representing at least one previous decision and an input sample. The at least one previous decision and the input sample are integrated onto a node, wherein the input sample is held constant during an integration period, thereby mitigating the effects of input transitions on an output of the summer. | 10-08-2009 |
| 20100013531 | PHASE-LOCKED LOOP CIRCUITS AND METHODS IMPLEMENTING PULSEWIDTH MODULATION FOR FINE TUNING CONTROL OF DIGITALLY CONTROLLED OSCILLATORS - PLL (phase locked loop) circuits and methods are provided in which PWM (pulse width modulation) techniques are to achieve continuous fine tuning control of DCO (digitally controlled oscillator) circuits. In general, pulse width modulation techniques are applied to further modulate dithered control signals that are used to enhance the frequency tuning resolution of the DCO such that the dithered control signals are applied to the fractional tracking control port of the DCO for a selected fraction of a full clock signal based pulse width modulation applied. | 01-21-2010 |
| 20100013532 | PHASE-LOCKED LOOP CIRCUITS AND METHODS IMPLEMENTING MULTIPLEXER CIRCUIT FOR FINE TUNING CONTROL OF DIGITALLY CONTROLLED OSCILLATORS - Circuits and methods are provided in which fine tuning control of a DCO (digitally controlled oscillator) circuit in a digital PLL circuit is realized by dither controlling a multiplexer circuit under digital control to selectively output one of a plurality of analog control voltages with varied voltage levels that are input to a fractional frequency control port of the DCO to drive tuning elements of the DCO at fractional frequency resolution and achieve continuous fine tuning of the DCO under analog control. | 01-21-2010 |
| 20100017690 | METHOD AND APPARATUS FOR LOW LATENCY PROPORTIONAL PATH IN A DIGITALLY CONTROLLED SYSTEM - A digitally controlled circuit and method includes an error input coupled to a proportional path. The proportional path includes a selector which directly receives the error input as a select signal. The selector receives a proportional control weight from a location other than the proportional path wherein the proportional control weight is input to a digitally controlled oscillator (DCO). | 01-21-2010 |
| 20100188158 | OPTIMAL DITHERING OF A DIGITALLY CONTROLLED OSCILLATOR WITH CLOCK DITHERING FOR GAIN AND BANDWIDTH CONTROL - A digital phase locked loop (DPLL) and method include an adjustable delay line configured to receive a reference clock as an input and to output a dithered reference clock signal. A phase and frequency detector (PFD) is configured to compare the dithered reference clock signal with a feedback clock signal to determine phase and frequency differences between the dithered reference clock signal and the feedback clock signal. A digitally controlled oscillator (DCO) is configured to receive early or late determinations from the PFD to adjust an output in accordance therewith, wherein the dithered reference clock signal distributes jitter response to enhance overall operation of the DPLL. | 07-29-2010 |
| 20110063003 | PHASE AND FREQUENCY DETECTOR WITH OUTPUT PROPORTIONAL TO FREQUENCY DIFFERENCE - Phase and frequency detectors and techniques are disclosed. For example, apparatus comprises a first circuit for receiving first and second clock signals and for generating at least one signal indicative of a phase difference between the first and second clock signals. The apparatus also comprises a second circuit for receiving the at least one signal generated by the first circuit and, in response to the at least one received signal, generating at least one output signal, wherein a frequency associated with the at least one output signal is proportional to a frequency difference between the first and second clock signals. | 03-17-2011 |
