Abstract: An interleaved ring oscillator includes a first ring oscillator having n stages, and a second ring oscillator having n stages, wherein each stage includes a nth first gated inverter in the first ring oscillator and a nth second gated inverter in the second ring oscillator, such that output from the nth first gated inverter enables the nth second gated inverter, and output from the nth second gated inverter enables the nth first gated inverter.

Abstract: A multi-stage clock generation circuit is disclosed. The circuit includes first and second ring oscillators. The ring oscillators include a corresponding plurality of delay elements coupled in series, with a plurality of shunt circuits in parallel with corresponding inverters. The shunt circuits include respective interpolation nodes, which are resistively coupled to input and output nodes of their corresponding inverters. The interpolation nodes of the first ring oscillator are coupled to delay element input and output nodes of the second ring oscillator. Similarly, the interpolation nodes of the second ring oscillator are coupled to delay element input and output nodes of the first ring oscillator.

Abstract: Methods and systems are described for generating multiple phases of a local clock at a controllable variable frequency, using loop-connected strings of active circuit elements. A specific embodiment incorporates a loop of four active circuit elements, each element providing true and complement outputs that are cross-coupled to maintain a fixed phase relationship, and feed-forward connections at each loop node to facilitate high frequency operation. A particular physical layout is described that maximizes operating frequency and minimizes clock pertubations caused by unbalanced or asymmetric signal paths and parasitic node capacitances.

Abstract: A time-to-digital conversion circuit includes; an oscillator circuit that outputs a plurality of phase signals different from each other, a counter that counts a number of edges of at least one phase signal among the plurality of phase signals and outputs a count signal, a phase sampling circuit that samples the value of each of the plurality of phase signals at a stop time point and outputs a stop phase signal, a start phase signal generating circuit that outputs a start phase signal, and an output circuit that, based on the count signal, the stop phase signal, and the start phase signal, generates an output signal, the output signal being a digital signal indicating a time period from a start time point to a stop time point.

Abstract: The techniques of this disclosure may digitally generate a driver signal with a period (or frequency) at a finer resolution than can be achieved by simply counting clock cycles of a system clock. The driver signal may be configured to trigger based on single output clock signal that may be phase-shifted relative to the master system clock. A clock phase shift circuit may increment the phase shift of the output clock signal to any fraction relative to the master system clock. A driver signal generated based on the phase-shifted output clock may achieve the high resolution in frequency desirable when controlling some pulse-width modulated circuits, such as an LLC converter.

Abstract: An integrated circuit includes at least two identical, synchronous and independent oscillator circuits that are coupled one to one in parallel with each other at homologous oscillating nodes of the respective oscillator circuits. The coupling in parallel is made using at least one coupling track that is configured so as to not introduce any phase shift or to introduce a very small phase shift.

Abstract: Embodiments of the invention provide advances in liquid-crystal technology for use as tunable phase-delay lines. The amount of phase delay through the liquid crystal is adaptively tuned, in order to coherently combine two signals, regardless of their phase differences. By adaptively adjusting the phase delays in the two signal paths, maximum coherent power combining is ensured. This ability to coherently combine the power of two signals regardless of their initial phase differences can greatly simplify, for example, antenna-diversity techniques used in MIMO applications as well as other applications.

Abstract: A voltage-controlled delay line including a clipper configured to produce a clipped input voltage from an input voltage, an oscillator configured to produce a strobe pulse train that is initiated by the clipped input voltage, and a divider module configured to divide the strobe pulse train and produce an output voltage from the divided strobe pulse train.

Abstract: Methods and systems for a multi-core multi-mode voltage-controlled-oscillator (VCO) may comprise generating a plurality of oscillating signals utilizing a plurality of voltage controlled oscillators (VCOs) arranged symmetrically on an integrated circuit, where interconnects for the VCOs may be arranged in quiet zones at locations equidistant from each pair of the plurality of VCOs. An interconnection ring may be centered within the arranged VCOs that comprises at least two conductive lines that couple to output terminals of each of said plurality of VCOs. The plurality of VCOs may receive control signals from interconnects coupled to at least one conductive line in the interconnection ring. The plurality of VCOs may receive control signals from a conductive line in said interconnection ring. A positive terminal of a first VCO of a pair of adjacent VCOs of the plurality of VCOs may be coupled to a same conductive line of the interconnection ring as a negative terminal of a second of the pair of adjacent VCOs.

Abstract: Described herein is a self-biased oscillator. The self-biased oscillator comprises a first differentiator with adjustable resistance or capacitance, the first differentiator having an output node and an input node; and a second differentiator with adjustable resistance or capacitance, the second differentiator having an input node coupled to the output node of the first differentiator, and having an output node coupled to the input node of the first differentiator.

Abstract: Apparatus and methods for phase linearization and interpolation in rotary traveling wave oscillators (RTWOs) are provided. In certain configurations, an RTWO system includes a first elongated RTWO and a second elongated RTWO that are phase-locked to one another with a non-zero phase shift. The first and second elongated RTWOs each include two elongated sections of differential transmission line of high phase linearity. For example, such long and straight sections of the differential transmission lines can have uniform capacitance loading and avoid non-uniformities in length and/or thickness associated with poor phase linearity. The RTWO system further includes tap circuitry that receives clock signal phases from the elongated sections of the RTWOs. In certain implementations, the tap circuitry includes one or more interpolation circuits that interpolate received clock signal phases to increase the number of available phases. The RTWO system can include a large number of taps of high phase linearity.

Abstract: The invention relates to an input circuit arrangement (11), which is designed for operation either in a first or a second operating mode (A, B) and comprises a connection (13) for supplying a connection signal (SWI) and a detection circuit (14). The detection circuit (14) is coupled on the input side to the connection (13) and is designed to put the input circuit arrangement (11) into an operating mode from a group comprising the first and second operating modes (A, B) depending on the steepness of a change of the connection signal (SWI).

Abstract: A method, an apparatus, and a computer program product are provided. The apparatus generates LO signals. The apparatus includes a LO generator module and an injection signal generator module coupled together. The LO generator module has a plurality of LO outputs and a plurality of injection signal inputs. The LO module is configured to generate the LO signals on the LO outputs based on injection signals received on the injection signal inputs. The injection signal generator module has a plurality of LO inputs and a plurality of injection signal outputs. The LO inputs are coupled to the LO outputs. The injection signal outputs are coupled to the injection signal inputs. The injection signal generator module is configured to generate injection signals on the injection signal outputs based on the LO signals received on the LO inputs and based on a received VCO signal.

Abstract: One embodiment of the present invention features a poly-phase local oscillator generator combining frequency dividers and direct-injection-locked phase correctors. The poly-phase local oscillator generator comprises a plurality of phase correctors configured to relax frequency and tuning range of a reference local oscillator (LO), and a plurality of frequency dividers, coupled to the phase correctors, configured to offer different frequency segments. The phase correctors are expandable, so that phase accuracy can be optimized by cascading more of themselves.

Abstract: Embodiments provide a multi-phase voltage controlled oscillator (VCO) that produces a plurality of output signals having a common frequency and different phases. In one embodiment, the VCO may include a passive conductive structure having a first ring and a plurality of taps spaced around the first ring. The VCO may further include a capacitive load coupled to the passive conductive structure, one or more feedback structures coupled between a pair of opposing taps of the plurality of taps, and one or more current injection devices coupled between a pair of adjacent taps of the plurality of taps.

Abstract: A memristor-based emulator including a memristor circuit for use in digital modulation that includes a first current feedback operational amplifier (CFOA) having multiple terminals in communication with a capacitor Cd and in further communication with a resistor Ri. A second CFOA having multiple terminals is in communication with the first CFOA and is adapted to be in further communication with a voltage vM to provide an input current iM for integration by a capacitor Ci. A nonlinear resistor is in communication with the second CFOA. A third CFOA having multiple terminals is in communication with the nonlinear resistor and is in further communication with the first CFOA and a resistor Rd. The third CFOA and the resistor Rd act as an inverting amplifier associated with the nonlinear resistor to increase a current gain to increase a difference between ON and OFF values of a resistance of a realized memristor.

Abstract: A slew rate enhancing system includes a first input configured to receive a first complementary signal of a differential pair and a second input configured to receive a second complementary signal of the differential pair. The slew rate enhancing system further includes a first switch configured to selectively connect the first input to an output in response to a voltage of the second input being greater than a first predetermined voltage. The slew rate enhancing system further includes a second switch configured to selectively connect the first input to the output in response to the voltage of the second input being less than a second predetermined voltage.

Abstract: An oscillator and a method of fabricating the oscillator are described. The oscillator includes a resonator with a plurality of transmission lines. An oscillation frequency of the oscillator is independent of at least one dimension of the plurality of transmission lines. The oscillator also includes a negative resistance circuit coupled to the resonator that cancels internal loss resistance of the resonator.

Abstract: The oscillation method uses an oscillation circuit in which a plurality of MOSFETs are annularly connected. The method comprises the steps of: forming GND of the circuit, which is separated from GND of a driving electric source of the MOSFETs, in a part of a first connection line which connects the MOSFET with the adjacent MOSFET; connecting a probe with a second connection line which connects another MOSFET with the adjacent MOSFET, an odd number of the MOSFETs being connected between the GND and the second connection line; and generating an oscillation waveform between the probe and the GND.

Abstract: A gated voltage-controlled oscillator receives a gating signal and outputs an oscillating signal having a frequency corresponding to the gating signal. The gated voltage-controlled oscillator includes a delay unit, having a first terminal and a second terminal, and a multiplexer, having a first input terminal, a second input terminal, a select terminal and an output terminal. The first input terminal and the select terminal are coupled to the gating signal. The second input terminal is coupled to the first terminal of the delay unit. The output terminal outputs the oscillating signal and is coupled to the second terminal of the delay unit. The delay unit delays the oscillating signal and outputs the delayed oscillating signal into the second input terminal. The multiplexer outputs a signal of the first input terminal or the second input terminal according to the gating signal.

Abstract: A voltage-controlled oscillator is disclosed. The voltage-controlled oscillator includes an inverter circuit configured to output an oscillation signal. The first inverter circuit includes a complementary transistor pair and a transistor string. The complementary transistor pair includes a first switch transistor and a second switch transistor. The second switch transistor is connected to the first switch transistor, in which a first terminal of the second switch transistor is connected to a second terminal of the first switch transistor. The first delaying unit includes at least one delaying transistor. A first terminal of the at least one delaying transistor is connected to a control terminal of the second switch transistor. A second terminal of the at least one delaying transistor is connected to a control terminal of the first switch transistor. A control terminal of the at least one delaying transistor is configured to receive a voltage control signal.

Abstract: An apparatus comprising a frequency divider comprising a first latch and a second latch coupled to the first latch in a toggle-flop configuration, and an output circuit comprising a first p-channel transistor, wherein the gate of the first p-channel transistor is configured to receive a clock signal, a first n-channel transistor, wherein the gate of the first n-channel transistor is coupled to the first latch, a second n-channel transistor connected in series with the first p-channel transistor and the first n-channel transistor and wherein the gate of the second n-channel transistor is configured to receive the clock signal, a second p-channel transistor, wherein the gate of the second p-channel transistor is configured to receive the clock signal, and a third n-channel transistor in series with the second p-channel transistor and the second n-channel transistor, wherein the output circuit is configured to generate a pair of in-phase reference signals.

Abstract: A conversion circuit (20) for converting a complex analog input signal having an in-phase, I, component and a quadrature-phase, Q, component resulting from frequency down conversion of a radio-frequency, RF, signal (XRF) to a frequency band covering 0 Hz into a digital representation is disclosed. It comprises a channel-selection filter unit (40) arranged to filter the complex analog input signal, thereby generating a channel-filtered I and Q components, and one or more processing units (53, 53a-b). Each processing unit comprises four mixers (60-75) for generating a first and a second frequency-translated I component and a first and a second channel-filtered Q component based on two LO signals with equal LO frequency and a 90° mutual phase shift. Furthermore, each processing unit comprises a combiner unit (85, 120) for generating a first, a second, a third, and a fourth combined signal proportional to sums and differences between said frequency translated I and Q components.

Abstract: Embodiments provide a multi-phase voltage controlled oscillator (VCO) that produces a plurality of out-put signals having a common frequency and different phases. In one embodiment, the VCO may include a passive conductive structure having a first ring and a plurality of taps spaced around the first ring. The VCO may further include a capacitive load coupled to the passive conductive structure, one or more feedback structures coupled between a pair of opposing taps of the plurality of taps, and one or more current injection devices coupled between a pair of adjacent taps of the plurality of taps.

Abstract: A gated voltage controlled oscillator has four identically structured delay cells, each of the delay cells having the same output load by connecting to the same number of inputs of other ones of the delay cells. Optionally a four phase sampling clock selects from the delay cell output and samples, at a four phase sampler, an input signal. Optionally an edge detector synchronizes the phase of the gated voltage controlled oscillator to coincide with NRZ bits. Optionally a variable sampling rate selects different phases from the delay cells to selectively sample NRZ bits at a lower rate. Optionally, a pulse width modulation (PWM) mode synchronizes a phase of the sampling clock to sample PWM symbols and recover encoded bits.

Abstract: An exemplary calibration apparatus for calibrating timing mismatch of an edge rotator operating on multiple phases of an oscillator includes a capturing block arranged to capture phase error samples, and a calibrating block arranged to adjust timing of said edge rotator according to said phase error samples. An exemplary calibration method for calibrating timing mismatch of an edge rotator operating on multiple phases of an oscillator includes the following steps: capturing phase error samples, and adjusting timing of said edge rotator according to said phase error samples.

Abstract: Coupled multi-inductors and their applications. An apparatus includes several circuit stages. Each circuit stage includes an inductive element that overlaps with the inductive elements of its adjacent circuit stages, forming a loop of coupled circuit stages. The apparatus may be, for example, a multi-phase oscillator with multiple oscillators that are magnetically coupled to each other for generating oscillation signals at different phases. The apparatus may also be, for example, a phase interpolator for combining input signals.

Abstract: A voltage control oscillator includes: first and second field effect transistors, a drain of one of which is connected to a gate of the other and a drain of the other of which is connected to a gate of the one; third and fourth field effect transistors, a drain of one of which is connected to a gate of the other and a drain of the other of which is connected to a gate of the one; a first inductor connected between the drain of the first field effect transistor and the drain of the second field effect transistor; a second inductor connected between the drain of the third field effect transistor and the drain of the fourth field effect transistor; a third inductor magnetically coupled to the first inductor; a fourth inductor magnetically coupled to the second inductor; a first capacitor; and a second capacitor.

Abstract: A stochastic beating time-to-digital converter (TDC) can include triggered ring oscillator (TRO) and a stochastic TDC (sTDC). The TRO, when triggered by a reference signal edge, can generate a periodic TRO signal with a TRO period that is a selected ratio of a voltage-controlled oscillator (VCO) period. The TRO period can be greater than or less than the VCO period by the specified ratio. The sTDC with an event triggered memory can include an sTDC component with a plurality of groups of latches. Each group of latches can be configured to sample and store a VCO state at an edge of a TRO signal. The sTDC component can trigger a capture of a select number of VCO states of the group of latches when one latch in the group of latches transitions to a different digital state referred to as a transition edge.

Abstract: A phase-shift keying (PSK) demodulator and a smart card including the same are disclosed. The PSK demodulator includes a delay circuit and a sampling circuit. The delay circuit generates a plurality of clock signals by delaying the input signal. The sampling circuit samples the input signal in response to the clock signals, and generates output data.

Abstract: A voltage-controlled oscillator (VCO) module including a first VCO unit, a second VCO unit, and a matching circuit is provided. The first VCO unit includes a first terminal and a second terminal and generates a first oscillator signal. The second VCO unit is coupled to the first VCO unit and generates a second oscillator signal. The matching circuit is coupled between the first VCO unit and second VCO unit. The matching circuit includes a plurality of inductor modules respectively coupled between the first terminal of the first VCO unit and the second VCO unit, between the first terminal and the second terminal of the first VCO unit, and between the second terminal of the first VCO unit and the second VCO unit. Furthermore, a method for generating oscillator signals is also provided.

Abstract: A local timing circuit receives a reference timing signal and generates a multi-phase timing signal for output to a digital signal processing circuit.

Abstract: The present invention relates to a circuit arrangement (300) for generating non-overlapping and immune-to-1/f-noise signals as has been described. A break-before-make (BBM) circuit ensures that the differential I/Q signals (LO—0, LO—90, LO—180, LO—270), driving the transistors (M11, M12, M21, M22) of mixers (16A, 16B) in an RF receiver (200), are non-over-lapping for having at any time only one of these transistors turned on. The duty cycle of each driving signal is measured, and the difference (?) in the duty cycle corresponding to two subsequent LO phases is determined through a respective differential amplifier (38A-38D). Each differential amplifier is configured to have a current output (LT—0, LT—90, LT—180, LT—270), which is then fed back to the input of the input buffer (30A-30D) corresponding to the first LO phase in order to adjust its logic threshold (LT) level and make the difference (?) equal to zero.

Abstract: In one embodiment, one or more circuits convert an n-bit control code of a phase interpolator to a coupling control signal of k-bit wide. The one or more circuits couple one or more output signals of the phase interpolator to a reference clock of the phase interpolator based on the coupling control signal.

Abstract: The invention relates to a digital signal generator for providing one or more phases of a local oscillator signal for use in digital to analogue converters and harmonic rejection mixers. Embodiments disclosed include a local oscillator signal generator (200) for a mixer of a radiofrequency receiver, the signal generator (200) comprising a bit sequence generator (201) having a plurality of parallel output lines (203), a digital signal generator (202) having a serial output line (204) and a plurality of input lines connected to respective output lines (203) of the bit sequence generator (201) and a clock signal input line (205), wherein the digital signal generator (202) is configured to provide an output bit sequence on the serial output line (204) at a rate given by a clock signal provided on the clock signal input line (205) and a sequence given by a sequence of bits from the bit sequence generator (201) on the plurality of input lines (203).

Abstract: A signal generator for generating an output signal with a frequency that is a multiple of a frequency of a reference signal, the signal generator including an oscillator configured to generate the output signal in dependence on the reference signal and a control signal and a control circuit configured to generate the control signal to comprise a series of pulses in which one or more of the pulses is offset in phase relative to the reference signal, the control circuit thereby being capable of controlling the frequency and/or phase of the output signal.

Abstract: A method for generating an oscillator signal uses a multiphase oscillator having a plurality of input stages and a reference stage. Each input stage produces an input stage voltage that represents a phase for the oscillator. The input stage voltages produced by each of the input stages are compared to a reference voltage produced by the reference stage. An input stage having a maximum input stage voltage is selected and an output of the selected input stage having the maximum input stage voltage is changed. A current need of the oscillator is detected with a negative feedback loop coupled to the reference stage. An appropriate supply current is provided to each input stage with the negative feedback loop.

Abstract: An oscillation signal generator includes a quadrature voltage-controlled oscillator (QVCO), a phase corrector and a frequency adjusting circuit. The QVCO provides multiple oscillation signals having difference phases. The phase corrector selects one of the oscillation signals as a first oscillation signal and outputs the first oscillation signal from a first output terminal, and selects one of the oscillation signals as a second oscillation signal and outputs the second oscillation signal from a second output terminal. A phase difference between the first and second oscillation signals satisfies a predetermined relationship. The frequency adjusting circuit is coupled to the phase corrector, and generates a quadrature signal and an in-phase signal according to the oscillation signals. The frequency of the oscillation signals is a non-integral multiple of the frequencies of the quadrature and in-phase signals.

Abstract: A wideband phase modulator comprises a multiphase generator, a phase selector, and a phase adjuster. The wideband phase modulator is configured to receive an N-bit digital phase-modulating signal comprising a timed sequence of N-bit phase-modulating words, where N is a positive integer representing the bit resolution of the N-bit digital phase-modulating signal. The multiphase generator generates a plurality of coarse carrier phases, all having the same carrier frequency but each offset in phase relative to the other. The M most significant bits of the N-bit phase-modulating words are used to form M-bit phase select words that control the output phase of the phase selector. The phase adjuster performs a precision rotation operation, whereby a selected coarse carrier phase is adjusted so that the phase of the resulting final precision phase-modulated signal more closely aligns with a desired precision phase.

Abstract: An object is to provide a method for preventing the occurrence of variations in time resolution by providing a calibration process to a TDC at the time of start up and further preventing the increase in circuit scale by reducing the redundancy of delay elements. A calibration of a multiphase oscillator TDC and a vernier TDC is carried out at the time of power-on. In the calibration, a timing input to be input to the vernier TDC is selected from output signals of DCCO based on a reference clock. Also, data is defined as an output signal which is adjacent to the output signal of DCCO mentioned above and proceeds in phase, and the delay therebetween is derived. By repeating it to all of the output signals, the one cycle of the output signal of DCCO is derived.

Abstract: An adjustable-frequency oscillator, is formed by two looped systems, functioning at the same frequency but the signals are phase shifted by 90°. Each looped system includes a phase shift device, an active element providing the gain and a resonator having a fixed phase-frequency characteristic. As the phase shift in each loop is imperatively a whole multiple of 2?, the phase shift added in each loop by the phase shift device entails that each resonator introduces a complementary phase shift to comply with the oscillation criterion. This complementary phase shift is produced at a frequency defined by the resonator, this then defining the frequency of oscillation. The frequency is adjusted by two phase shift stages, which carry out the analogue multiplication of the signals coming from the two looped systems by control voltages and the summing of these products.

Abstract: A quadrature VCO includes a first oscillator unit and a second oscillator unit. Each of the first and second oscillator unit is composed of a DC bias source, a complementary cross-coupled pair, an LC resonator unit, a frequency-doubling sub-harmonic coupler unit, and a ground terminal. When the LC resonator units of the first and second oscillator units are operated, four signals of different phases can be outputted via the output terminals. In this way, the output phase difference of the two oscillator units can keep 180 degrees and allow the two oscillator units to mutually inject signals to generate quadrature output signals.

Abstract: A voltage controlled oscillator includes a resonant circuit including one or more transformers and a plurality of variable capacitor circuits connected in parallel to the one or more transformers and generating a plurality of oscillation signals having multiple phases, and a negative resistance circuit including a plurality of transistors cross-coupled via the one or more transformers and generating negative resistance for maintaining the oscillation of the resonant circuit.

Abstract: The present invention is directed to an oscillator circuit comprising an oscillator input for providing an input signal, a first integrator circuit comprising a first integrator capacitor and a first integrator output, a comparator, a discharge circuit for discharging said first integrator capacitor once per cycle of said oscillator circuit, and an oscillator output for providing an output signal, wherein said oscillator circuit further comprises a second integrator circuit comprising a second integrator capacitor and a second integrator output, and wherein said oscillator circuit is arranged for allowing said input signal to be subsequently integrated by said first and second integrator circuit in an alternating manner, and for providing said integrated output signal of said first and second integrator circuit subsequently to said comparator in said alternating manner.

Abstract: Electronic circuitry comprising operational circuits of active switching type requiring timing signals, and conductive means for distributing said timing signals to the operational circuits, wherein the timing signal distribution means includes a signal path that has different phases of a drive signal are supplied via active means at different positions about the signal path where that path exhibits endless electro-magnetic continuity without signal phase inversion or has interconnections with another signal path having different substantially unidirectional signal flow where there is no endless electromagnetic continuity between those signal paths and generally has non-linear associated circuit means where the signal path is of a transmission line nature.

Abstract: Multiple multi-stage delay circuits each have n (n is an integer) output terminals. The multi-stage delay circuits each apply delay times to a corresponding input signal, and output, via n output terminals, n delayed signals to which different delay times have been applied. Multiple inverters invert the respective input signals. The multiple multi-stage delay circuits and multiple inverters are alternately connected in the form of a ring.

Abstract: A signal generator provides a plurality of oscillating signals, whereby each oscillating signal has a different peak voltage and has a predictable and consistent phase relationship with the other oscillating signals. The signal generator includes a plurality of stacked oscillators arranged between two reference voltages, such that each oscillator in the stack generates an oscillating signal having a different peak voltage. Each oscillator stage in a designated oscillator includes a transistor that is connected to a transistor of a corresponding stage in another oscillator. This arrangement of the oscillators provides for charge transfer between the corresponding stages to provide for similar voltage swings in each oscillating signal, as well as to provide for predictable phase relationship between the oscillating signals.

Abstract: An oscillator architecture and a method for powering up/down the oscillator architecture are described. In one embodiment, an oscillator architecture includes a reference generator configured to generate reference signals and an in-phase/quadrature (IQ) oscillator configured to generate oscillation signals based on the reference signals. The reference generator includes a distributed start-up circuitry that includes multiple start-up circuits. The IQ oscillator includes at least one turbo comparator having a low power functional mode and a turbo functional mode. Other embodiments are also described.

Abstract: Embodiments of a device and circuit implementing a digitally controlled oscillator with reduced analog components. In an example, the digitally controlled oscillator can include a phase accumulator controlled by a stall circuit to selective stall the phase accumulator. In some examples, the digitally controlled oscillator can include a phase select circuit to select multiple phases of a phase select circuit based on the output of the phase accumulator. In some examples, these selected phases can then be used by a phase interpolator to generate a synthetic clock signal.

Abstract: According to embodiments of the present invention, a quadrature voltage controlled oscillator is provided.