Abstract: One embodiment describes a Josephson transmission line (JTL) system. The system includes a plurality of JTL stages that are arranged in series. The system also includes a clock transformer comprising a primary inductor configured to propagate an AC clock signal and a secondary inductor arranged in a series loop with at least two of the plurality of JTL stages. The clock transformer can be configured to propagate a single flux quantum (SFQ) pulse to set a respective one of the plurality of JTL stages in response to a first phase of the AC clock signal and to reset the respective one of the plurality of JTL stages in response to a second phase of the AC clock signal that is opposite the first phase.

Abstract: A processing method and electronic apparatus for a digital signal are provided. The method includes: detecting the quality of a first eye in an eye diagram of the digital signal; equalizing the digital signal; detecting the quality of a second eye in the eye diagram of the equalized digital signal; determining whether the quality of the second eye superior to the quality of the first eye by a predetermined threshold; and if so, outputting the digital signal, or else again equalizing and performing subsequent steps on the auto-compensated digital signal. The above solution is capable of effectively improving the quality of eyes in the eye diagram of the digital signal.

Abstract: Some embodiments include apparatuses and methods of using the apparatuses. One of the apparatuses includes a data path to receive data information based on timing of a data capture clock signal, a clock path including a delay circuit to apply a time delay to an input clock signal and generate a delayed clock signal, a clock tree circuit to provide the data capture clock signal and a first feedback clock signal based on the delayed clock signal, a circuitry including latches to sample the input clock signal based on timing of the feedback clock signal and provide sampled information, and a controller to control the delay circuit based on the sampled information in order to cause the data capture clock signal to be out of phase with the input clock signal by one-fourth of a period of the input clock signal.

Abstract: An optical receiver adapted to convert a received optical signal into a phase change of a timing signal to generate a first modified timing signal and to generate a data signal by comparing the first modified timing signal with a reference signal.

Abstract: Apparatus for managing power in a data storage device, such as a solid state drive (SSD). In some embodiments, an energy management circuit supplies electrical power to a non-volatile memory (NVM). The energy management circuit has cascaded first and second E-Fuse switch circuits each with an input terminal and an output terminal. The second E-Fuse switch circuit receives input power from the first E-Fuse switch circuit used as a rail voltage for the device. The second E-Fuse switch circuit is configured to monitor the rail voltage, deactivate the first E-Fuse switch circuit responsive to the rail voltage falling below a predetermined threshold, and supply backup power to the device from a backup power source.

Abstract: System and methods for a clock system disciplined to an external reference. In one embodiment, the clock includes a flywheel oscillator controlled by the external reference and a free running holdover oscillator. The holdover oscillator provides increased accuracy during periods of holdover when the external reference is not available. In a further embodiment, the flywheel oscillator is additionally controlled by a phase-locked loop with the holdover oscillator frequency as input, and a control switch for switching the flywheel oscillator to analog control if the phase-locked loop exhibits a fault.

Abstract: Apparatus and methods for phase synchronization of phase-locked loops (PLLs) are provided. In certain configurations, an RF communication system includes a PLL that generates one or more output clock signals and a phase synchronization circuit that synchronizes a phase of the PLL. The phase synchronization circuit includes a sampling circuit that generates samples by sampling the one or more output clock signals based on timing of a reference clock signal. Additionally, the phase synchronization circuit includes a phase difference calculation circuit that generates a phase difference signal based on the samples and a tracking digital phase signal representing the phase of the PLL. The phase synchronization circuit further includes a phase adjustment control circuit that provides a phase adjustment to the PLL based on the phase difference signal so as to synchronize the PLL.

Abstract: Apparatus for clock synchronization comprising a first phase locked loop (405) and a second phase locked loop (400). The first phase locked loop (405) is configured to receive a reference signal (Fcrystal) having a reference frequency, and operable to produce an output signal (Fout) having an output frequency that is a multiple of the reference frequency. The first phase locked loop (405) comprises a frequency divider (428) that controls the multiple in response to a control signal. The second phase locked loop (400) is configured to determine a phase error between the output signal (Fout) and an input signal (Fantenna), and to provide the control signal to the first phase locked loop (405). The second phase locked loop (400) comprises phase adjustment means (450), operable to adjust a phase difference between the input and output signal by varying the control signal for a duration.

Abstract: A system and method for correcting for phase errors, in a phase locked loop, resulting from spread spectrum clocking involving a reference clock signal having a frequency modulation. A correction generation circuit generates an offset signal, that when injected after the charge pump of the phase locked loop, causes the voltage controlled oscillator to produce a signal with substantially the same frequency modulation, thereby reducing the phase error. The correction generation circuit may include a timing estimation circuit for estimating the times at which transitions (between positive-sloping and negative-sloping portions of the triangle wave) occur, and an amplitude estimation circuit for estimating the amplitude of the offset signal that results in a reduction in the phase error.

Abstract: A circuit for compensating quantized noise in fractional-N frequency synthesizer, comprising a PLL circuit that locks a phase compensated signal to a phase of a reference phase, wherein the phase lock loop circuit comprises a frequency divider and a phase frequency detector; a sigma-delta modulation and phase difference calculator coupled to the frequency divider generating an accumulated phase error by accumulating all previous differences between an input of the frequency divider and an output of the frequency divider within a period; a digital controlled delay line coupled to both the frequency divider and the SDM and Phase Difference calculator and generates the phase compensated signal by multiplying the accumulated phase error with a delay control word; and the phase frequency detector further generates a phase error by comparing the phase compensated signal with the reference clock.

Abstract: Disclosed herein is an apparatus that includes a clock circuit configured to receive first and second clock signals and perform a phase control operation in which a phase relationship between the first and second clock signals is controlled, the clock circuit configured to initiate the phase control operation each time a first control signal is asserted, the clock circuit including a comparator circuit that is configured to produce a second control signal indicative of a phase difference between the first and second clock signals, and a timing generator configured to assert the first control signal cyclically, the timing generator configured to respond to the second control signal to control a cycle of producing the first control signal.

Abstract: Embodiments are directed to a system for synchronizing switching events. The system includes a controller, a clock generator communicatively coupled to the controller and a delay chain communicatively coupled to the controller. The delay chain is configured to perform a plurality of delay chain switching events in response to an input to the delay chain. The controller is configured to initiate a synchronization phase that includes enabling the clock generator to provide as an input to the delay chain a clock generator output at a synchronization frequency, wherein the clock generator output passing through the delay chain synchronizes the plurality of delay chain switching events to occur at the synchronization frequency resulting in a frequency of an output of the delay chain being synchronized to the synchronization frequency of the clock generator output.

Abstract: An extremely high frequency (EHF) protocol converter may include a transducer, an EHF communication circuit, a protocol conversion circuit, and a circuit port. The transducer may be configured to convert between an electromagnetic EHF data signal and an electrical EHF signal. The EHF communication circuit may be configured to convert between a baseband data signal and the electrical EHF signal. The protocol conversion circuit may be adapted to convert between the baseband data signal having data formatted according to a first data protocol associated with a first external device and a second baseband data signal having data formatted according to a second data protocol associated with a second external device. The second data protocol may be different from the first data protocol. The circuit port may conduct the second baseband data signal to the second external device.

Abstract: Provided are a time correction method and a time correction apparatus for a slave clock device. The method is applied to a slave clock device, wherein the method includes: acquiring background traffic information, in a running process, of the slave clock device; acquiring a deviation correction value according to the background traffic information and a fitted function reflecting delay on an asymmetric link; and correcting a synchronization time, which is output from the slave clock device, in real time according to the deviation correction value. With the above technical solution, the technical problem in related art that there is no technical solution for effectively eliminating a dynamic delay change of an asymmetric link due to a background traffic change is solved, thereby greatly reducing the impact of the traffic change on the asymmetric link delay.

Abstract: An example phase-locked loop (PLL) includes a digital filter, an oscillator, and a time-to-digital converter (TDC). The digital filter is configured to sample at a discrete time that is responsive to a reference clock signal received at the digital filter. The oscillator is coupled to the digital filter and configured to generate an output signal of the PLL. The TDC is coupled to the oscillator to determine a phase difference between the output signal and the reference clock signal. The TDC also provides a time signal to the digital filter that is based on the phase difference and is representative of an instantaneous rate of operation of the PLL. The digital filter is further configured to adjust a response characteristic of the digital filter according to the time signal.

Abstract: A phase detection circuit includes a sampling signal generation circuit configured to generate a plurality of sampling signals in response to a plurality of phase change clocks having different phases and data; a charging voltage generation circuit configured to compare the plurality of sampling signals, and change a voltage level of one charging voltage between a first charging voltage and a second charging voltage; and a comparison circuit configured to compare voltage levels of the first and second charging voltages, and generate a result signal.

Abstract: A phase detector including a first latch and a control circuit is provided. The first latch generates a first output signal and a second output signal in response to a phase difference between a first input signal and a second input signal. Each of the first and second output signals includes first phase information and second phase information of the phase difference. The control circuit generates a phase indicating signal in response to the first phase information of the phase difference. The phase indicating signal indicates a relative position between the first input signal and the second input signal.

Abstract: A phase interpolator is provided with a plurality of slices. Each slice includes a first switch for mixing a first clock signal into an interpolated output signal and a second switch for mixing a second clock signal into the interpolated output signal. In response to a high-resolution signal, at least one of the slices may switch on both the first switch and the second switch.

Abstract: Systems and methods involving phase-locked-loop (PLL) circuitry are disclosed. In one illustrative implementation, a PLL circuit device may comprise voltage controlled oscillator (VCO) circuitry having a bias signal that sets a frequency range, circuitry that shifts the VCO circuitry to operate in one of the frequency ranges, and other circuitry to compare/calibrate signals and/or set the bias current. According to further implementations, as a function of operation of the circuitry, an operating frequency range of the VCO circuitry may be shifted to a different operating frequency range, and closed-loop, continuous frequency range, auto-calibration or other features may be provided.

Abstract: A delay circuit includes a delay line configured to output an output signal by imposing a delay value on an input signal. The delay circuit further includes an arithmetic unit configured to calculate a control code for the delay value based on delay codes. The delay circuit further includes a delay locked loop (DLL) configured to generate the delay codes based on a clock signal. The delay circuit further includes a controller configured to suspend operation of the DLL when the clock signal operates at a first frequency, to set the DLL to operate based on a second frequency when the DLL is suspended, and to resume operation of the DLL when the clock signal operates at the second frequency without the need to relock the DLL.

Abstract: A hybrid analog/digital control approach for a digitally controlled oscillator augments a digital control path with an analog control path that acts to center the digital control path control signal within its range. The digital control path controls a first group of varactors within an oscillator tank circuit using a digital filter and a delta sigma modulator, which generates a dithered control signal for at least one of the first group of varactors. The analog control path controls a second group of varactors in the tank circuit but actively tunes only one varactor at a time. The analog control path performs relatively low bandwidth centering of the digital control signal resulting in negligible impact on PLL bandwidth, stability, and noise performance. Instead, the digital control path dominates in setting the PLL dynamic and noise behavior, and has reduced range requirements due to the centering action.

Abstract: A clock data recovery apparatus includes an oscillator, a phase detector and an oscillator control circuit. The oscillator generates an original clock signal. The phase detector includes a first sampling circuit, a frequency dividing circuit, a second sampling circuit and a selecting circuit. The first sampling circuit samples a data signal using the original clock signal to generate a first set of sample results. The frequency dividing circuit divides the original clock signal to generate a frequency divided clock signal. The second sampling circuit performs sampling using the frequency divided clock signal to generate a second set of sample results. The selecting circuit selectively outputs one of the first and second sets of sample results as a final set of sample results. The oscillator control circuit controls the oscillator according to the final set of sample results.

Abstract: A multichannel receiver includes multiple receiver modules, each having: a voltage-controlled oscillator that generates a clock signal with a controllable frequency; a phase interpolator that applies a controllable phase shift to the clock signal to provide a sampling signal; a sampling element that produces a digital receive signal by sampling an analog receive signal in accordance with the sampling signal; a timing error estimator that operates on the digital receive signal to provide timing error estimates; a phase control filter that derives, from the timing error estimates, a phase control signal supplied to the phase interpolator, wherein the phase control signal minimizes a phase error between the sampling signal and the analog receive signal; and a frequency control filter that derives, from the timing error estimates, a frequency control signal for controlling the clock signal frequency, wherein the frequency control signal minimizes a frequency offset between the clock signal and the analog receive

Abstract: A technique for reducing noise in an output clock signal of a feedback control system (e.g., a PLL or FLL) samples rising edge errors and falling edge errors between a reference clock signal and a feedback clock signal. The technique applies edge alignment correction to reduce or eliminate edge alignment errors between the reference clock signal and the feedback clock signal. A PLL generates an output clock signal based on a control signal generated using an error signal generated based on a rising edge difference between a rising edge of an input clock signal and a corresponding edge of an edge alignment corrected feedback clock signal and based on a falling edge difference between a falling edge of the input clock signal and a corresponding edge of the edge alignment corrected feedback clock signal. The edge alignment corrected feedback clock signal is partially based on the output clock signal.

Abstract: A Continuous Time Linear Equalizer (CTLE) and a method of operating a CTLE in a receiver for a Pulse Amplitude Modulation (PAM) signal are disclosed. The method includes initiating equalization using an initial equalization setting that is optimized to meet a first objective and responsive to a determination, shifting to a final equalization setting that is optimized to meet a second objective.

Abstract: In one implementation an output signal of an oscillator is varied to be within a desired frequency band with respect to a reference signal, the output signal having a plurality of phases. The implementation may include comparing the output signal with the reference signal, counting falling edges about each phase of the number of phases in a predetermined time period and summing to define a count output; comparing the count output with a product of the number of phases of the output signal and the factor to define a comparison, generating a control signal based upon the comparison, and inputting the control signal to the oscillator to alter the output signal thereof.

Abstract: A design method for a phase-locked loop comprises: a controlled-frequency oscillator; a phase comparator, to determine a phase difference between an output signal of the controlled-frequency oscillator and a reference signal; a corrector to receive as input a signal representative of the phase difference and to generate at its output a first correction signal; at least one second corrector, to receive as input a signal representative of or affected by a phase noise of the reference signal or of the output signal of the controlled-frequency oscillator and to generate at its output a second correction signal; and a circuit for generating a slaving signal for the controlled-frequency oscillator on the basis of the first and second correction signals; the method using the H-infinity method. Method for fabricating such a loop comprising a design step implementing this method. Phase-locked loop thus obtained.

Abstract: In some example embodiments, there may be provided an apparatus. The apparatus may include a delay line including a plurality of cells; and tuning circuitry coupled to the delay line and configured to generate a first output and a second output to tune the delay of the delay line, wherein the first output tunes in aggregate the plurality of cells of the delay line, and wherein the second output tunes each of the plurality of cells separately. Related methods, systems, and articles of manufacture are also disclosed.

Abstract: A method and device for dynamically updating a phase interpolator circuit module using a phase update circuit module. The method can include interpolating a set of input clock phases based on a phase interpolator code input and sequentially updating the rising edge generator and falling edge generator starting from a synchronizer update signal. The dynamic sequential update involves disabling a rising edge ramp signal while updating a rising edge interpolator and generating old clock out falling edge according to an old phase interpolator code input, disabling a falling edge ramp signal while updating a falling edge interpolator, enabling the rising edge ramp signal and generating a new clock out rising edge according to a new phase interpolator code input, and enabling the falling edge ramp signal and generating a new clock out falling edge according to the new phase interpolator code input.

Abstract: A method and apparatus and computer program product for calibrating a Phase Lock Loop (PLL) that reduces a PLL lock time for subsequent calibrations to thereby improve an overall system time and latency. The system and method for calibrating obviates effect of Process, Voltage and Temperature to achieve a faster PLL lock.

Abstract: The present disclosure includes methods and systems for channel skewing. One or more methods for channel skewing includes providing a number of groups of data signals to a memory component, each of the number of groups corresponding to a respective channel, and adjusting a phase of a group of data signals corresponding to at least one of the number of channels such that the group of data signals are skewed with respect to a group of data signals corresponding to at least one of the other respective channels.

Abstract: Provided is a method for driving a SERDES circuit, which may reduce waste of a space of the SERDES circuit. The circuit driving method includes generating a common clock signal from a common phase locked loop (PLL) supplying a clock signal to a serializer/deserializer (SERDES) circuit, distributing the common clock signal to an eye opening monitor and a data transmission lane in the SERDES circuit, and driving the eye opening monitor and the data transmission lane using the common clock signal.

Abstract: A circuit according to an example includes a digital-to-time converter and a signal processing circuit coupled to the digital-to-time converter and configured to generate a processed signal derived from a signal provided to the signal processing circuit, the processed signal including a predetermined phase relation with respect to the signal provided to the signal processing circuit, wherein the circuit is configured to receive a reference signal and to generate an output signal based on the received reference signal. The a measurement circuit is configured to measure a delay between the output signal and the reference signal, wherein the output of the digital-to-time converter is coupled to a memory configured to store calibration data of the digital-to-time converter based on the measured delay.

Abstract: A sensor, a time alignment apparatus, a time processing method, and a time alignment method are provided. The sensor begins to sense at least one sensed data at a first local time instant. The sensor transmits a response message at a second local time instant. The response message carries the at least one sensed data, the first local time instant, and the second local time instant. The time alignment apparatus receives the response message at a first global time instant. The time alignment apparatus calculates a second global time instant that the at least one sensed data being sensed according to a required transmission time between the time alignment apparatus and the sensing apparatus, a clock skew rate between the time alignment apparatus and the sensing apparatus, the first global time instant, the first local time instant, and the second local time instant.

Abstract: In accordance with an embodiment, an actuator control circuit includes a driver circuit connected to a ringing characteristic determination circuit. A signal generator that is configured to generate an output signal having first period that has first and second portions where the first portion longer than the second portion is connected to the ringing characteristic determination circuit. Another embodiment includes a method for controlling an actuator by determining a resonant frequency and a ringing amplitude of an actuator signal; generating a control signal in response to the resonant frequency and the ringing amplitude of the actuator signal; and causing the actuator to move in response to the second drive signal.

Abstract: A frequency synthesizer includes circuitry configured to generate two or more feedback clocks based on the oscillation signals output from a voltage-controlled oscillator. The circuitry also modulates the feedback clocks based on fractional offsets from a reference clock frequency for input into two or more phase and frequency detectors. Multiple charge pump circuits receive inputs from these phase and frequency detectors. The current from these charge pumps is summed and input to a low pass filter. The output of the filter represents an average of the time difference between the reference clock and the multiple feedback clocks.

Abstract: A circuit for providing a plurality of clock signals of differing frequencies includes: a phase locked loop section including a first voltage controller oscillator, connected to receive a reference clock value and generate therefrom a first voltage level, wherein the first voltage controller oscillator receives the first voltage level and generates therefrom a first clock signal; and one or more second voltage controller oscillators, each connected to receive the first voltage level, a corresponding trim value and a corresponding control voltage and derive therefrom a corresponding second clock signal.

Abstract: Apparatuses and methods for controlling timing circuit locking and/or latency during a change in clock frequency (e.g. gear down mode) are described herein. An example apparatus may include a timing circuit. The timing circuit may be configured to provide a clock signal to the forward path, adjust a rate of the clock signal responsive to receipt of a command to adjust the rate of the clock signal, select a feedback clock signal responsive to a loop delay of the timing circuit, and provide a control signal to an adjustable delay circuit of the forward path circuit. Another example apparatus may include a forward path configured to delay a signal based at least in part on a loop delay and a latency value, and a latency control circuit configured to provide an adjusted latency value as the latency value responsive to receipt of a command, wherein the forward path is configured to operate at least in part at an adjusted clock rate responsive to receipt of the command.

Abstract: An apparatus is disclosed in which a clock signal may propagate through a delay circuit. The delay circuit may include a first and a second delay stage, in which each delay stage may be programmable for one of two delay times, depending on a value of a respective control signal to each delay stage. The delay circuit may also include circuitry which may change the value of the respective control signal from a first value to a second value. The circuitry may change the value of the respective control signal responsive to a determination that an output of the first stage and an output of the second stage are equal.

Abstract: Apparatus and methods for frequency lock enhancement of phase-locked loops (PLLs) are provided. In one aspect, a PLL can include a VCO having a tuning voltage input and a frequency tuning circuit configured to set a frequency band setting of the VCO. The frequency tuning circuit can include a voltage monitor configured to compare the voltage level of the tuning voltage input to one or more tuning voltage threshold levels, a control circuit configured to control at least a frequency band setting and a bias current setting of the VCO, and an amplitude detection circuit configured to compare an amplitude of an oscillation signal of the VCO to one or more amplitude threshold levels.

Abstract: An integrated circuit comprises a dual port modulator and a voltage controlled oscillator (VCO). The dual port modulator has a first input for receiving a transmitter modulation signal, a first output for providing a fractional portion of a high port modulation signal, a second output for providing a integer portion of the high port modulation signal, and a third output for providing a low port modulation signal. The VCO is coupled to the dual port modulator and has a first input for receiving the fractional portion of the high port modulation signal, a second input for receiving the integer portion of the high port modulation signal, a third input for receiving a tuning signal based on the low port modulation signal, and a first output for outputting an RF signal. The dual port modulator provides a signed single bit signal for generating the fractional portion of the high port modulation signal.

Abstract: Technologies are generally described for quadrature-based injection-locking of ring oscillators. In some examples, an external signal may be injected into a ring oscillator. Phase signals may be measured from within the ring oscillator and used to determine a mean quadrature error (MQE) that characterizes the difference in frequency between the external signal and the ring oscillator's natural frequency. A control signal may then be generated from the MQE and used to adjust the ring oscillator natural frequency to reduce the difference between the ring oscillator natural frequency and the external signal.

Abstract: A multichannel input device with automatic number-of-channels detection includes an automatic channel and bit depth detector, a digital audio interface (DAI), an analog device, and a digital-to-analog converter (DAC) coupling the DAI to the analog device. The automatic number-of-channels and bit depth detector has a BCLK input, a LRCLK input, a number of channels NCHAN output, and a bit depth B output. The DAI has a data DIN input, the BCLK input, the LRCLK input, an NCHAN input and a B input and has an output including data associated with an assigned channel.

Abstract: A phase error detection unit measures a phase error between an external synchronization signal and a spectacles control signal that is fed back, more specifically, a discrepancy between vertical synchronization timing and shutter opening/closing timing, that is, jitter. A timing correction unit corrects the shutter opening/closing timing, using the measured jitter. Specifically, a parameter indicating the corrected shutter opening/closing timing is written to a storage unit. The storage unit stores a parameter used to generate the spectacles control signal, for example, the parameter indicating the shutter opening/closing timing. A signal generation unit generates the spectacles control signal, using the parameter stored in the storage unit. A frequency divider divides the frequency of the spectacles control signal by n.

Abstract: The present application discloses a method, a device, and a system for reporting a signal quality measurement result, relates to the field of communications, and implements reporting of an adjacent-frequency signal quality measurement result by a terminal. Embodiments of the present application disclose a method for reporting a signal quality measurement result, including: receiving adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a reporting threshold corresponding to the adjacent-frequency signal quality reporting amount from a radio network node; according to the adjacent frequency information, performing measurement to obtain an adjacent-frequency signal quality measurement result; and reporting the adjacent-frequency signal quality measurement result in a preset bit string format to the radio network node. The embodiments of the present application are mainly used for redirection, handover, and cell change operations of a terminal.

Abstract: A frequency tracking loop receives a result from a phase detector that detects an advance and a retard of a phase between input data and an extracted clock signal, and conducts a control to reduce a frequency deviation between the input data and the extracted clock signal. A phase interpolator adjusts a phase of the clock signal subjected to spread-spectrum frequency modulation on the basis result of the frequency deviation in the frequency tracking loop, and outputs the extracted clock signal. In the frequency tracking loop, the frequency deviation between the data signal and the clock signal is corrected to offset a variation of the frequency of the clock signal, on the basis of the frequency modulation information related to the clock signal subjected to the spread-spectrum frequency modulation which is input to the phase interpolator. The frequency of the clock signal seemingly follows the frequency of the data signal.

Abstract: A hybrid numeric-analog clock synchronizer, for establishing a clock or carrier locked to a timing reference. The clock may include a framing component. The reference may have a low update rate. The synchronizer achieves high jitter rejection, low phase noise and wide frequency range. It can be integrated on chip. It may comprise a numeric time-locked loop (TLL) with an analog phase-locked loop (PLL). Moreover a high-performance number-controlled oscillator (NCO), for creating an event clock from a master clock according to a period control signal. It processes edge times rather than period values, allowing direct control of the spectrum and peak amplitude of the justification jitter. Moreover a combined clock-and-frame asynchrony detector, for measuring the phase or time offset between composite signals. It responds e.g. to event clocks and frame syncs, enabling frame locking with loop bandwidths greater than the frame rate.

Abstract: A charge pump circuit includes a constant current circuit configured to have one terminal connected with a power source node; a first node configured to input or output a current; a second node configured to be set to have a potential difference with the first node being less than or equal to a predetermined value; a first transistor configured to have one terminal connected with the first node; a second transistor configured to have one terminal connected with the second node, and to operate inverse to an operation of the first transistor; and a third transistor configured to be connected between a connection node, to which another terminal of the first transistor and another terminal of the second transistor are connected, and another terminal of the constant current circuit. The third transistor has a gate connected with a constant voltage source, and functions as a constant current source.

Abstract: Disclosed are an apparatus for lock detection suitable for a fractional-N frequency synthesizer and a method thereof. The lock detector for use in the fractional-N frequency synthesizer includes a delay unit delaying an N-divider output frequency clock based on an output value of a fraction ratio modulator, a lock detection unit outputting a lock detection signal by comparing a reference frequency clock with the N-divider output frequency clock delayed by the delay unit, a counter counting the number of lock detection signals received from the lock detection unit, and a controller issuing a command to output a lock identification signal based on the number of lock detection signals counted by the counter.

Abstract: Some embodiments regard a circuit comprising: a first circuit configured to lock a frequency of an output clock to a frequency of a reference clock; a second circuit configured to align an input signal to a phase clock of the output clock; a third circuit configured to use a first set of phase clocks of the output clock and a second set of phase clocks of the output clock to improve alignment of the input signal to the phase clock of the output clock; and a lock detection circuit configured to turn on the first circuit when the frequency of the output clock is not locked to the frequency of the reference clock; and to turn off the first circuit and to turn on the second circuit and the third circuit when the frequency of the output clock is locked to the frequency of the reference clock.