Abstract: A method and apparatus of generating precision phase skews is disclosed. In some embodiments, a phase skew generator includes: a charge pump having a first mode of operation and a second mode of operation, wherein the first mode of operation provides a first current path during a first time period, and the second mode of operation provides a second current path during a second time period following the first time period; a sample and hold circuit, coupled to a capacitor, and configured to sample a voltage level of the capacitor at predetermined times and provide an output voltage during a third time period following the second time period; and a voltage controlled delay line, coupled to the sample and hold circuit, and having M delay line stages each configured to output a signal having a phase skew offset with respect to preceding or succeeding signal.

Abstract: Systems, methods, and circuits for determining a duty cycle of a periodic input signal are provided. A delay element is configured to delay the periodic input signal based on a digital control word. A digital circuit is configured to generate a first digital control word used to delay the periodic input signal a first amount of time corresponding to a period of the periodic input signal, generate a second digital control word used to delay the periodic input signal a second amount of time corresponding to a portion of the periodic input signal having a logic-level high value, and generate a third digital control word used to delay the periodic input signal a third amount of time corresponding to a portion of the periodic input signal having a logic-level low value. A controller is configured to determine the duty cycle based on the first, second, and third digital control words.

Abstract: A controlling circuit for ring oscillator is provided. A first transistor and a second transistor of a first conductive type are coupled in series and between a node and a first power source. A third transistor and a fourth transistor of a second conductive type are coupled in parallel and between the node and a second power source. The node is coupled to an input of a delay chain of the ring oscillator. The second and third transistors are coupled in series. Gates of the second and third transistors are configured to receive an output signal of the delay chain. When the first transistor is turned off and the fourth transistor is turned on, the node is pulled to a first logic level from a second logic level in order to align a phase of a waveform of the ring oscillator.

Abstract: Systems and methods are provided for a phase locked loop. A phase/frequency detector is configured to receive a reference signal and a feedback signal. A charge pump is configured to receive outputs from the phase/frequency detector and to generate pulses. An oscillator is configured to generate an output waveform based on the charge pump pulses. A realignment path is configured to generate a clock realignment signal that is provided to the oscillator based on the outputs from the phase/frequency detector.

Abstract: An electrical system is provided. The electrical system comprises a first phase lock circuit embedded within a first chip for receiving a first periodic signal having a first frequency. The electrical system comprises a first buffering circuit embedded within the first chip for receiving a second periodic signal having the first frequency, wherein the first buffering circuit is configured to provide a third periodic signal having the first frequency to an output terminal of the first chip.

Abstract: Systems and methods are provided for a cascade phase locked loop. A first phase locked loop receives a reference clock signal having a first frequency and generates a high frequency clock signal that is phase aligned with the reference clock signal. A first divider divides the high frequency clock signal to generate a middle frequency clock signal, and a second divider divides the middle frequency clock signal to generate a low frequency reference clock signal. A second phase locked loop receives the low frequency reference clock signal and generates an output signal, compares the output signal to the low frequency reference clock signal to generate a frequency increasing (UP) signal that indicates a phase difference between the output signal and the low frequency reference clock signal.

Abstract: Systems and methods are provided for a cascade phase locked loop. A first phase locked loop receives a reference clock signal having a first frequency and generates a high frequency clock signal that is phase aligned with the reference clock signal. A first divider divides the high frequency clock signal to generate a middle frequency clock signal, and a second divider divides the middle frequency clock signal to generate a low frequency reference clock signal. A second phase locked loop receives the low frequency reference clock signal and generates an output signal, compares the output signal to the low frequency reference clock signal to generate a frequency increasing (UP) signal that indicates a phase difference between the output signal and the low frequency reference clock signal.

Abstract: Digital delay lock circuits and methods for operating digital delay lock circuits are provided. A phase detector is configured to receive first and second clock signals and generate a digital signal indicating a relationship between a phase of the first clock signal and a phase of the second clock signal. A phase accumulator circuit is configured to receive the digital signal and generate a phase signal based on values of the digital signal over multiple clock cycles. A decoder is configured to receive the phase signal and generate a digital control word based on the phase signal. A delay element is configured to receive the digital control word. The delay element is further configured to change the relationship between the phase of the first clock signal and the phase of the second clock signal by modifying the phase of the second clock signal according to the digital control word.

Abstract: An apparatus and method for providing a phase noise built-in self test (BIST) circuit are disclosed herein. In some embodiments, a method and apparatus for forming a multi-stage noise shaping (MASH) type high-order delta sigma (??) time-to-digital converter (TDC) are disclosed. In some embodiments, an apparatus includes a plurality of first-order ?? TDCs formed in an integrated circuit (IC) chip, wherein each of the first-order ?? TDCs are connected to one another in a MASH type configuration to provide the MASH type high-order ?? TDC, wherein the MASH type high-order ?? TDC is configured to measure the phase noise of a device under text (DUT).

Abstract: A system, a method and a built-in phase noise measurement apparatus are introduced. The built-in phase noise measurement apparatus includes a first DLL and a TDC, in which the first DLL circuit controls a delay of a first signal to generate a second signal based on a control code, tune the control code until a phase of the second signal is aligned to a phase of a reference clock signal, and record a value of the control code when the phase of the second signal is aligned to the phase of the reference clock signal. The DLL circuit controls the delay of the first signal based on the value of the control code after the phase of the second signal is aligned to the phase of the reference clock signal. The TDC determines the phase noise of the first signal based on the reference clock signal and the second signal.

Abstract: An automatic gain adjustor for a hybrid oscillator can be employed to overcome the frequency limitations of hybrid phase lock loops (PLLs). For example, an automatic gain adjustor for a hybrid oscillator can include a hybrid oscillator that is configured to receive a course tuning signal and a gain adjustment signal and generate an output signal with any frequency within the specified frequency range of the hybrid PLL. The automatic gain adjustor for a hybrid PLL may further include a fine tuning array that receives one or more fine tuning selection signals and generates a gain adjustment signal that is received by the hybrid oscillator. The fine tuning array generates a gain adjustment signal to adjust the gain of the hybrid oscillator according to an operating frequency range of the hybrid oscillator.

Abstract: A tuning array selection circuit, together with a decoder and a voltage controlled oscillator (VCO), can be employed to overcome some disadvantages of previous methods of phase locked loops. For example, a VCO can include a coarse tuning array and a fine tuning array. A coarse tuning array can be used to tune a VCO to generate a signal within a wide frequency range. A fine tuning array can be used to tune a VCO to generate a signal within a narrow frequency range. In one embodiment, the narrow frequency range is within the wide frequency range. The tuning array selection circuit can coordinate selection of appropriate fine tuning devices and narrow tuning devices to reduce transition jitter and the risk of fail locking of phase locked loops.

Abstract: Systems and methods are provided for a phase locked loop. A phase/frequency detector is configured to receive a reference signal and a feedback signal. A charge pump is configured to receive outputs from the phase/frequency detector and to generate pulses. An oscillator is configured to generate an output waveform based on the charge pump pulses. A realignment path is configured to generate a clock realignment signal that is provided to the oscillator based on the outputs from the phase/frequency detector.

Abstract: Systems, methods, and devices are provided for a circuit for generating a pulse output having a controllable pulse width. Systems and methods may include a delay line having a plurality of stages. A delay per stage calculation circuit is configured to determine a per-stage delay of the delay line using a first clock input. A pulse generation circuit is configured to generate the pulse output using the delay line based on the per-stage delay using a second clock input, the second clock input having a lower frequency than the first clock input.

Abstract: Systems, methods, and devices are provided for a circuit for generating a pulse output having a controllable pulse width. Systems and methods may include a delay line having a plurality of stages. A delay per stage calculation circuit is configured to determine a per-stage delay of the delay line using a first clock input. A pulse generation circuit is configured to generate the pulse output using the delay line based on the per-stage delay using a second clock input, the second clock input having a lower frequency than the first clock input.

Abstract: Systems, devices, and methods are described herein for aligning a phase of a ring oscillator and removing jitter. An oscillator includes a resistor bank array, an operational amplifier, a first and second transistor, and a realignment circuit. The resistor bank array has a plurality of resistors configured to generate a first signal. The operational amplifier is coupled to a PLL circuit and is configured to compare a voltage of the PLL circuit with a voltage of the resistor bank array. The first transistor is coupled between the operational amplifier and a ring oscillator. The first transistor is configured to generate a second signal to control a frequency of the ring oscillator during a realignment state. The realignment circuit is coupled to the first transistor and the ring oscillator. The realignment circuit is configured to generate a realignment signal to align the ring oscillator with a first clock signal.

Abstract: Digital delay lock circuits and methods for operating digital delay lock circuits are provided. A phase detector is configured to receive first and second clock signals and generate a digital signal indicating a relationship between a phase of the first clock signal and a phase of the second clock signal. A phase accumulator circuit is configured to receive the digital signal and generate a phase signal based on values of the digital signal over multiple clock cycles. A decoder is configured to receive the phase signal and generate a digital control word based on the phase signal. A delay element is configured to receive the digital control word. The delay element is further configured to change the relationship between the phase of the first clock signal and the phase of the second clock signal by modifying the phase of the second clock signal according to the digital control word.

Abstract: A counter signal counting at a frequency of a clock signal is generated. Among a plurality of different numeric ranges corresponding to a plurality of different thresholds, a threshold corresponding to a numeric range containing a frequency ratio is selected. In response to the counter signal reaching the selected threshold, a logic level of an output signal is switched.

Abstract: A device includes a phase detector circuit, a charge pump circuit, a sample and hold circuit, a comparator, and a controller. The phase detector circuit detects a clock skew between a reference signal and an input signal. The charge pump circuit translates the clock skew into a voltage. A sample and hold circuit samples the voltage, at a first time, and maintain the sampled voltage until a second time. The comparator (i) detects a loop gain associated with the input signal based on the sampled voltage and the voltage at the second time and (ii) outputs a loop gain signal for adjustment of the input signal. The controller is coupled to the phase detector, the comparator, and the sample and hold circuit. The controller generates a plurality of control signals for automatically controlling operation of the phase detector, the comparator, and the sample and hold circuit.

Abstract: A semiconductor structure including first finfet cells and second finfet cells. Each of the first finfet cells has an analog fin boundary according to analog circuit design rules, and each of the second finfet cells has a digital fin boundary according to digital circuit design rules. The semiconductor structure further includes first circuits formed with the first finfet cells, second circuits formed with the second finfet cells, and third circuits formed with one or more of the first finfet cells and one or more of the second finfet cells.