Abstract: Systems and methods for providing a clock signal are provided. A frequency multiplier circuit is provided that can include a plurality of serially connected delay elements that are configured to generate a plurality of delay tap signals from an input signal. The frequency multiplier circuit can also include a phase detector configured to receive a first selected delay tap signal and the input signal. The phase detector can detect a phase shift between the first selected delay tap signal and the input signal, and can generate a phase detection signal indicative of a value of the phase shift. The frequency multiplier circuit can also include a digital logic gate configured to receive the input signal and a second selected delay tap signal. The digital logic gate can be further configured to generate an output signal responsive to the second selected delay tap signal and the input signal. The frequency multiplier circuit can also include a controller coupled to the phase detector and coupled to an output gate.

Abstract: Methods and apparatuses for retiming of multirate system for clock period minimization with a polynomial time without sub-optimality. In an embodiment, a normalized factor vector for the nodes of multirate graph is introduced, allowing the formulation of the multirate graph retiming constraints to a form similar to a single rate graph. In an aspect, the retiming constraints are formulated to allowed the usage of linear programming methodology instead of integer linear programming, thus significantly reducing the complexity of the solving algorithm. The present methodology also uses multirate constraints, avoiding unfolding to single rate equivalent, thus avoiding graph size increase. In a preferred embodiment, the parameters of the multirate system are normalized to the normalized factor vector, providing efficient algorithm in term of computational time and memory usage, without any sub-optimality.

Abstract: A semiconductor apparatus includes a signal source 7 that outputs a signal of predetermined frequency, a frequency divider 15 that receives the output signal of the signal source and is capable of switching the output signal to two or more frequency division ratios, a delta-sigma modulator 16 that controls the frequency division ratio of the frequency divider, and a bandpass filter 17 that receives an output of the frequency divider. The frequency of the input signal of the frequency divider is divided by the frequency division ratio controlled by the delta-sigma modulator, and quantization noise appearing in the output of the frequency divider generated by the delta-sigma modulator is attenuated with the bandpass filter. The semiconductor apparatus easily can convert a signal output by a single signal source to a signal of predetermined frequency and supply a plurality of signals of predetermined frequency using a simple configuration with reduced chip size.

Abstract: A master stage 101 comprises a differential circuit composed of transistors 1 and 2, a differential circuit composed of transistors 3 and 4, a differential circuit composed of transistors 5 and 6, a load circuit 7 (a first load circuit), a load circuit 8 (a second load circuit), and a current source transistor 9. The load circuit 7 (the first load circuit) is composed of an inductor 7A (a first inductor), an inductor 7B (a fifth inductor), and a capacity 7C (a first capacity). The inductor 7B and capacity 7C cooperates together in forming a parallel resonance circuit (a first LC parallel resonance circuit), while the parallel resonance circuit is connected in series to the inductor 7A.

Abstract: Systems and methods for providing a clock signal are provided. A frequency multiplier circuit is provided that can include a plurality of serially connected delay elements that are configured to generate a plurality of delay tap signals from an input signal. The frequency multiplier circuit can also include a phase detector configured to receive a first selected delay tap signal and the input signal. The phase detector can detect a phase shift between the first selected delay tap signal and the input signal, and can generate a phase detection signal indicative of a value of the phase shift. The frequency multiplier circuit can also include a digital logic gate configured to receive the input signal and a second selected delay tap signal. The digital logic gate can be further configured to generate an output signal responsive to the second selected delay tap signal and the input signal. The frequency multiplier circuit can also include a controller coupled to the phase detector and coupled to an output gate.

Abstract: Systems and methods for providing a clock signal are provided. A frequency multiplier circuit is provided that can include a plurality of serially connected delay elements that are configured to generate a plurality of delay tap signals from an input signal. The frequency multiplier circuit can also include a phase detector configured to receive a first selected delay tap signal and the input signal. The phase detector can detect a phase shift between the first selected delay tap signal and the input signal, and can generate a phase detection signal indicative of a value of the phase shift. The frequency multiplier circuit can also include a digital logic gate configured to receive the input signal and a second selected delay tap signal. The digital logic gate can be further configured to generate an output signal responsive to the second selected delay tap signal and the input signal. The frequency multiplier circuit can also include a controller coupled to the phase detector and coupled to an output gate.

Abstract: The present disclosure is directed to a unit phase mixer in combination with an input buffer. The unit phase mixer has a pull-up path for pulling an output terminal up to a first voltage. The pull-up path has a first transistor responsive to a first enable signal and a series connected second transistor responsive to a first clock signal. The unit phase mixer has a pull-down path for pulling the output terminal down to a second voltage. The pull-down path has a third transistor responsive to a second clock signal and a series connected fourth transistor responsive to a second enable signal. The input buffer skews the first and second clock signals by different amounts to enable a break-before-make method of operation so that the first voltage is not connected to the second voltage. The unit phase mixer can be used as a building block in more complex mixers which may include the ability to weight the input clocks as well as providing feed-forward paths for certain of the signals.

Abstract: A phase locked loop (PLL) is provided. In one implementation, the PLL includes a multiphase voltage controlled oscillator (VCO) operable to generate an output signal containing one or more phase signals, a programmable divider operable to divide a frequency of the output signal of the multiphase VCO to produce a divided frequency output signal, and a fractional divider to fractionally divide an input phase signal. The fractional divider can include an integer divider operable to receive the input phase signal and divide the input phase signal in accordance with an integer divisor to produce a divided signal as an input to the multiphase VCO, and a phase interpolator operable to select a phase signal from among the one or more phase signals output by the multiphase VCO, to produce an interpolated output signal having a desired frequency resolution.

Abstract: A frequency synthesizer includes first and second frequency dividers for receiving and frequency-dividing a signal generated by a voltage-controlled oscillator, a frequency mixer for mixing output signals of the first and second frequency dividers, and a third frequency divider for receiving and frequency-dividing a signal having one frequency of two frequencies that are output by the frequency mixer. The first, second third and frequency dividers and the frequency mixer are provided in a feedback loop within a PLL circuit between the voltage-controlled oscillator and the phase comparator. The phase comparator has a first input terminal to which a signal to which a signal that is output by the third frequency divider is input and a second input terminal to which a reference clock signal that is output by a reference signal generator is input. A loop filter supplies the voltage-controlled oscillator with a voltage that is based upon result of the phase comparison by a phase comparator.

Abstract: Phase-coherent differential structures contain a phase-coherent transformer having two pairs of phase-coherent coupled differential inductors.

Abstract: Mixer topologies that have sufficiently high IIP2 and sufficiently low quadrature error to make zero IF receivers possible without special calibration techniques. This simplifies the receiver, avoids circuit startup delay and provides more stable performance over time and temperature. The methodology to achieve this performance in preferred embodiments consists of as many as three elements: (a) a high power local oscillator buffer circuit capable of driving low impedance loads coupled to the bases of the bipolar mixer transistors, (b) an optimized bias block for the mixer core and (c) incorporating two or more electronically programmable quad sections and selecting the best quad for use. Other types of transistors may also be used.

Abstract: An electronic circuit exhibiting synchronization with an external synchronization signal, the electronic circuit comprising: an input connection arranged to receive a synchronization input signal; a triangular waveform oscillator operatively associated with the synchronization signal input connection and responsive to a condition of the received synchronization input signal to initiate a triangular waveform; and a pulse train generator operatively associated with the triangular waveform oscillator, the pulse train generator arranged to generate a plurality of pulse trains having a fixed non-zero phase relationship between them and a frequency responsive to the condition of the synchronization input signal.

Abstract: A multifunction RF circuit on a single semiconductor chip. The multifunction RF circuit includes a power amplifier circuit, a mixer circuit forming an integral part of the power amplifier circuit and a low-pass filter circuit. The power amplifier circuit may include two amplifier circuits.

Abstract: A frequency multiplier is disclosed. A plurality of voltage regulators each regulate levels of voltages at first and second common nodes in response to a corresponding one of input signals from a voltage-controlled delay line. An input buffer charges the first node or discharges the second node in response to a feedback signal. An output buffer regulates a level of a voltage at an output node and outputs a frequency-multiplied clock signal and the feedback signal corresponding to the voltage level of the output node. A discharge circuit discharges the first node before a rising edge of each of the input signals from the voltage-controlled delay line is inputted. A charge circuit charges the second node before the rising edge of each of the input signals from the voltage-controlled delay line is inputted.

Abstract: A frequency divider including at least one frequency divider cell having an adjustable circuit configuration which may be selected adaptively according to properties of an oscillator signal to be frequency-divided in the frequency divider. Accordingly, the circuit configuration of the frequency divider may be changed on the fly during the operation.

Abstract: The present invention relates to an apparatus for frequency conversion, comprising: an analog-to-digital (A/D) converter, receiving and sampling an input signal according to a sampling frequency for producing a first digital signal, and the sampling frequency and the frequency of the input signal having a correspondence; a sign conversion circuit, used for receiving the first digital signal, and performing a sign conversion on the first digital signal and producing a second digital signal; a first switching module, used for selecting one of the first digital signal and the second digital signal as an output signal according to the sampling frequency; a filter, coupled to the first switching module, used for filtering the output signal from the first switching module, and producing a filter signal; and a second switching module, coupled to the filter, used for outputting the filter signal to a first output path or a second output path alternately according to the sampling frequency.

Abstract: Systems and methods for design and operation of signal generator circuitry with output frequencies greater than the oscillator frequency. Accordingly, in a first method embodiment, a method of producing an output periodic electronic signal comprises accessing four signals having a quadrature phase relationship. First and second pairs of these signals having a one half cycle phase relationship are averaged to produce two signals having an improved duty cycle and a one-quarter cycle phase relationship. The first and second averaged periodic electronic signals are combined in an exclusive OR circuit to produce the output periodic electronic signal at twice the oscillator frequency. Advantageously, the periodic signal may comprise a desirable duty cycle of 50 percent.

Abstract: A frequency multiplier is provided that includes a switching component having a plurality of differential pairs of transistors. The frequency multiplier further includes a gain stage. A common mode feedback generated by the switching component is also provided to the gain stage.

Abstract: A signal processor includes a reference clock generator configured to generate a reference clock as a synchronization reference for a signal processing. A counter is configured to count the reference clock. A frequency controller is configured to sample a count value of the counter by utilizing an input clock, to compare an increment value increased from the last sampled value with an expected value, and to control a frequency of the reference clock in accordance with a comparison result.

Abstract: A clock multiplier includes a phase-frequency detector, a voltage-current converter, a duty ratio control circuit, a plurality of variable delay cells and an edge combiner. The phase-frequency detector generates control signals. The voltage-current converter converts the control signals to generate first and second current control voltages. The duty ratio control circuit modifies the duty ratio of an input clock signal based on the first and second current control voltages. Each of the variable delay cells generates a triangular wave voltage based on the modified input signal, generates a square wave voltage based on the triangular wave voltage to generate a delay signal. The edge combiner generates a plurality of multiplied clocks based on the delay signals from the variable delay cells.

Abstract: A frequency multiplier circuit comprising a delay line receiving at one end thereof a reference clock for generating clock tap outputs from respective ones of a plurality of period matched delay elements; a clock combining circuit responsive to pairs of tap outputs for generating a rising and falling edge of an output clock pulse from respective ones of the pairs whereby the output clock period is less than the input clock period.

Abstract: A device for modifying an input signal having an input signal frequency and a duty cycle is disclosed. The device determines two separate counts for each of the high and low pulses of the input signal. One of the two counts for each of the high and low pulses is divided. The divided count is then compared with the undivided count. Based on this comparison, an output module outputs an output signal that has the same duty cycle as the input signal but at a frequency that is a multiple of the input signal frequency.

Abstract: A phase locked loop (PLL) based frequency translator provides a divider augmented with a sigma delta modulator (SDM) in a reference path. The PLL is configured as an all digital PLL and includes a bang-bang phase frequency detector, digital loop filter, and digitally-controlled oscillator. The frequency translator is located in either the reference clock path for division or the PLL feedback loop path for multiplication. The SDM produces a predictable noise characteristic set with known stochastic properties which can be used to smooth any discontinuity in the bang-bang phase frequency detector. The predictable noise of the SDM will produce a dithering delay that eliminates any hard discontinuities. This allows for a bang-bang phase frequency detector based digital PLL.

Abstract: Systems and methods for design and operation of signal generator circuitry with output frequencies greater than the oscillator frequency. Accordingly, in a first method embodiment, a method of producing an output periodic electronic signal comprises accessing four signals having a quadrature phase relationship. First and second pairs of these signals having a one half cycle phase relationship are averaged to produce two signals having an improved duty cycle and a one-quarter cycle phase relationship. The first and second averaged periodic electronic signals are combined in an exclusive OR circuit to produce the output periodic electronic signal at twice the oscillator frequency. Advantageously, the periodic signal may comprise a desirable duty cycle of 50 percent.

Abstract: A semiconductor integrated circuit is provided in which the timing margin for fetching data is prevented from being reduced even in the case where the duty ratio of a clock signal is different from 50%. The semiconductor integrated circuit includes: a clock input terminal for receiving a clock signal; a data input terminal for receiving a data signal; internal clock generating circuits for generating an internal clock signal which is switched at an intermediate timing between the i-th (i: an integer of 1 or larger) switch timing and the (i+1)th switch timing of the clock signal; and a latch circuit for latching the data signal synchronously with the internal clock signal. An internal clock signal which is switched at an intermediate timing between the i-th switch timing and the (i+1)th switch timing of the clock signal is generated, and the data signal is fetched synchronously with the internal clock signal.

Abstract: A phase comparison of timing signals is made by combinational circuitry which receives the timing signals and a window signal, the window signal identifying edges of the timing signals to be compared. The comparison may result in a charge pumped output which can be fed back to control the phase of one of the timing signals. The phase comparator and charge pump circuit can be included in a multiplier circuitry in which the phase of an input signal is directly compared to the phase of an edge of the multiplied signal.

Abstract: A clock multiplier for multiplying an input clock by N includes a phase/frequency detector, a clock selector, and a voltage-controlled delay line. The phase/frequency detector generates a first control signal and a second control signal according to a frequency/phase difference between the input clock and a count signal indicating a signal that is generated by delaying the input clock N times. The clock selector selects one of the input clock and a feedback clock based on the input clock and the count signal. The voltage-controlled delay line adjusts a delay time of the selected signal according to a control voltage that is generated based on the first control signal and the second control signal, and outputs the feedback clock based on the adjusted signal. The clock multiplier operates without accumulating a frequency/phase difference between the input clock and the output clock when the multiplying ratio is increased.

Abstract: An input unit receives input of a clock signal having a voltage that varies continuously. A supply unit supplies a constant reference voltage. A selector outputs a clock signal having voltage that is changed alternately each time the voltage of the clock signal input from the input unit shifts across the reference voltage supplied from the supply unit. A calculating circuit outputs the exclusive-OR of the clock signal input from the input unit and a clock signal output from the selector.

Abstract: A reference clock signal generation circuit for generating a reference clock signal for a charge-pump operation which raises or lowers a voltage includes a clock signal generation circuit which generates a reference clock signal having one of first to nth (n is an integer of two or more) frequencies, a wait time setting register in which a value corresponding to a wait time is set, and a frequency setting register in which a value corresponding to one of the first to nth frequencies is set. The clock signal generation circuit generates the reference clock signal having a predetermined frequency in a start period from start of the charge-pump operation to completion of the wait time, and generates the reference clock signal having a frequency corresponding to the value set in the frequency setting register in an operation period after the start period.

Abstract: A circuit is provided for multiplying a frequency by a cascade formed of a transadmittance having a transfer characteristic and a transimpedance having a transfer characteristic. The transadmittance includes two terminals for a signal of a first frequency and the transimpedance includes two terminals for a signal of a second frequency. A transfer characteristic of the transimpedance is steeper than a transfer characteristic of the transadmittance, and a modulation region of the transadmittance is larger than a modulation region of the transimpedance.

Abstract: A clock circuit includes a waveform generator, a comparison module, and a clock signal module. The waveform generator is coupled to generate a waveform based on a reference oscillation. The comparison module is coupled to compare the waveform with a plurality of references to produce a plurality of waveform comparisons. The clock signal module is coupled to generate a clock signal from the plurality of waveform comparisons.

Abstract: A frequency doubler circuit includes first and second arrangements of switches connected to the positive and negative inputs of a comparator, respectively, and arranged in such a way that first and third voltages during the first phase of a reference clock signal and second and fourth voltages during a second phase opposite to the first phase are applied to the positive and negative inputs, where the first and second voltages and the third and fourth voltages are shifted with respect to each other at a half-period of the reference clock signal and the ratio between slopes of the voltages is fixed with respect to a selected current.

Abstract: An on-chip clock multiplier for outputting a fast clock that is approximately a predetermined multiple n of a slow clock. The multiplier utilizing a high-speed oscillator to generate a high-frequency base signal. A lower frequency signal is generated using the high-frequency base signal as a function of the output of a rollover counter that counts from a seed value to a terminal value. A saturation counter is used to determine whether no more than n pulses of the lower frequency signal occur within a single cycle of the slow clock. If not, the lower frequency signal is iteratively slowed by changing the seed value until no more than n pulses of the lower frequency signal occur within a single cycle of the slow clock. When this iteration is done, the fast clock having a frequency that is approximately n times the frequency of the slow clock is output.

Abstract: A frequency multiplier is disclosed. A plurality of voltage regulators each regulate levels of voltages at first and second common nodes in response to a corresponding one of input signals from a voltage-controlled delay line. An input buffer charges the first node or discharges the second node in response to a feedback signal. An output buffer regulates a level of a voltage at an output node and outputs a frequency-multiplied clock signal and the feedback signal corresponding to the voltage level of the output node. A discharge circuit discharges the first node before a rising edge of each of the input signals from the voltage-controlled delay line is inputted. A charge circuit charges the second node before the rising edge of each of the input signals from the voltage-controlled delay line is inputted.

Abstract: It is intended to provide a frequency multiplier capable of switching as appropriate among frequency signals having frequencies obtained by multiplying prescribed multiplication numbers with low current consumption and a simple circuit configuration in effectively utilizing frequencies in radio communication equipment. The base terminals of an input differential pair are biased by respective voltage sources, and an input frequency signal is input to one of the base terminals. The differential output terminals are connected to the base terminals of next-stage buffer circuit transistors, and their emitter terminals are connected to respective diodes. A full-wave-rectified signal, which is obtained at the connecting point of the cathode terminals of the diodes, is input to a comparison differential pair, which produces an output frequency signal by comparing the full-wave-rectified signal with a reference voltage.

Abstract: A system and method for programmable in-situ launch and capture clock generation is provided. The system provides an efficient and improved manner for delay and signal transition fault testing in electronic circuits. The system comprises i) an in-situ delay clock generator for generating one or more clocks; ii) a pulse Programmable Selection Generator (PSG) which can be either a pulse PSG and/or an expanded pulse PSG for generating the sequence in which the clocks are to be selected, the clocks being selected with a delay; and iii) a multiplexer for selecting the plurality of clocks, based on the generated sequence, the selected clocks being used for generating the launch and capture clocks.

Abstract: A multiplier circuit includes a bias circuit which outputs a reference voltage and a bias signal, a first delay circuit which inputs an input signal and outputs a first delayed signal according to the reference voltage and the bias signal, a second delay circuit which inputs an inversed input signal and outputs a second delay signal according to the reference voltage and the bias signal, and an OR circuit which outputs an OR logic result generated responsive to the first and second delayed signals.

Abstract: This invention relates to devices, a chip, a method and a computer-readable medium for controlling operation of a delay-locked loop. A delay-locked loop unit is adapted to trigger generation of first-type edges of a target signal. A main control unit is adapted to control operation of the delay-locked loop unit in a way that the delay-locked loop unit is turned on before generation of each first-type edge of the target signal and turned off after generation of each first-type edge.

Abstract: A double conversion RF tuner includes an up-conversion unit and a down-conversion unit. The up-conversion unit up converts a received radio frequency (RF) signal corresponding to a first frequency band to a first intermediate frequency (IF) signal and up-converts the received RF signal corresponding to a second frequency band higher than the first frequency band to a second IF frequency. The down conversion unit down converts one of the first and second IF signals outputted from the up-conversion unit to a final IF signal.

Abstract: A rational number frequency multiplier circuit and a method for generating rational number multiple frequency are disclosed. The circuit receives a plurality of input signals having the same frequency and different phase, and outputs at least one multiple frequency signal. The rational number frequency multiplier circuit includes a frequency divider module, for receiving and dividing the input signals to output frequency-divided signals having the same frequency and different phase; a first phase synthesis module and a second phase synthesis module for receiving and synthesizing the frequency-divided and input signals respectively into a plurality of first pulse period signals and second pulse period signals; and an adder for receiving and combining the first pulse period signals and the second pulse period signals into the multiple frequency signal according to the desired multiplication of the frequency.

Abstract: A clock multiplier includes a phase-frequency detector, a voltage-current converter, a duty ratio control circuit, a plurality of variable delay cells and an edge combiner. The phase-frequency detector generates control signals. The voltage-current converter converts the control signals to generate first and second current control voltages. The duty ratio control circuit modifies the duty ratio of an input clock signal based on the first and second current control voltages. Each of the variable delay cells generates a triangular wave voltage based on the modified input signal, generates a square wave voltage based on the triangular wave voltage to generate a delay signal. The edge combiner generates a plurality of multiplied clocks based on the delay signals from the variable delay cells.

Abstract: When a signal of a double frequency is generated from the original signal, conventionally a 90-degree phase-shift circuit is necessary to suppress an output of a DC component and efficiently obtain a double wave. According to the present invention, an equal RF signal is inputted to input terminals and an output is matched with a frequency as high as that of the original frequency in a Gillbert cell double-balanced mixer, so that a doubled output is obtained with no DC offset. According to the circuit configuration of the present invention, it is possible to provide a circuit readily performing integration and to efficiently output only a double frequency merely by inputting a simple differential signal without the need for the original signal which has been phase controlled. Further, a DC short circuit in the resonance circuit makes it possible to eliminate a DC offset voltage in an output.

Abstract: In a circuit arrangement for generation of a reference signal with an oscillation generator, a phase-controlled filter and a frequency multiplier are arranged downstream from the oscillation generator. The frequency multiplier is connected with an output for emission of the reference signal.

Abstract: A frequency multiplier circuit comprising a delay line receiving at one end thereof a reference clock for generating clock tap outputs from respective ones of a plurality of period matched delay elements; a clock combining circuit responsive to pairs of tap outputs for generating a rising and falling edge of an output clock pulse from respective ones of the pairs whereby the output clock period is less than the input clock period.

Abstract: A jitter calculator engine that includes a core effects module, an input/output (I/O) module, and a phase lock loop (PLL) module is provided. The core effects module estimates core jitter caused by noise effects impacting a core clock network. The I/O module estimates I/O input pin switching effects on a clock network input signal. In one embodiment, the I/O module identifies a relative frequency of switching by I/O pins in the circuit design. The PLL module estimates an effect of a PLL on a signal delivered to the PLL from an I/O pin. The PLL module accounts for I/O input pin switching effects and core jitter. The jitter calculator engine may be in communication with a database and the different designs evaluated may be stored in the database so that the database becomes a repository for the different designs and may provide useful information for future designs.

Abstract: Systems and methods for providing a clock signal are provided. A frequency multiplier circuit is provided that can include a plurality of serially connected delay elements that are configured to generate a plurality of delay tap signals from an input signal. The frequency multiplier circuit can also include a phase detector configured to receive a first selected delay tap signal and the input signal. The phase detector can detect a phase shift between the first selected delay tap signal and the input signal, and can generate a phase detection signal indicative of a value of the phase shift. The frequency multiplier circuit can also include a digital logic gate configured to receive the input signal and a second selected delay tap signal. The digital logic gate can be further configured to generate an output signal responsive to the second selected delay tap signal and the input signal. The frequency multiplier circuit can also include a controller coupled to the phase detector and coupled to an output gate.

Abstract: Disclosed is a frequency converter including: a passive type analog multiplier configured to output a multiplication result in a current; a buffer outputting a buffering current by buffering the current of the multiplication result; and a current-voltage converter current-voltage converting the buffering current. Alternately, disclosed is a frequency converter including: a passive type analog multiplier configured to output a multiplication result in a current; a buffer outputting a buffering current by buffering the current of the multiplication result; and an integrator integrating the buffering current to output a voltage.

Abstract: A phase locked loop (PLL) is provided. In one implementation, the PLL includes a feedback loop having a frequency multiplier and an integer divider to generate a divided signal. The PLL includes a re-sampling circuit operable to re-sample one or more digital pulses of the divided signal using one or more phase signals if a multiplication factor of the frequency multiplier does not divide evenly into the integer divisor.

Abstract: A device is provided for multiplying the pulse frequency of a pulse train signal. The device includes input means for the signal and means for accessing the signal at points with a predetermined phase difference between them. The device additionally comprises means at a first level for combining accessed signal pairs, with one and the same phase distance within all the combined pairs, the output from each first level combining means being a pulse train. The device additionally comprises combining means at a second level for combining the pulse trains from the first level, and the combining means at the first level are such that the pulses in their output pulse trains have rise flanks which always coincide with the rise flank of the first signal in the combined accessed signal pairs, and fall flanks which always coincide with the fall flanks of the second signal in said pair.

Abstract: A digital clock frequency multiplier (100) for increasing an input frequency of an input clock signal includes a generator (102) that receives the input clock signal and a high frequency digital signal. The generator (102) divides a count (Nhf) of a number of cycles of the high frequency digital signal in one period of the input clock signal by a predetermined multiplication factor (MF) for generating an output clock signal. The output clock signal has a predetermined output frequency.