A semiconductor device includes an internal clock generation circuit configured to generate an internal clock; a plurality of unit circuits configured to have a first unit circuit and a second unit circuit operating while being synchronized with an internal clock; a plurality of transfer circuits including a first transfer circuit configured to provide a first transfer path having a first delay time, and a second transfer circuit configured to provide a second transfer path having a second delay time different from the first delay time; and a delay compensation circuit configured to compare a first clock input to the first unit circuit through the first transfer path with a second clock input to the second unit circuit through the second transfer path, and to adjust the second delay time so that the adjusted second delay time matches the first delay time.

Changes in a clock signal, such as phase changes or resets, may propagate glitches, such as shortened clock cycles that may cause undesired effects in subsequent circuitry, to circuitry reliant upon the clock signal. Glitches in the clock signal may not allow a circuit component to finish operating before the shortened next clock cycle arrives, which may cause an unknown or error state in the circuit component. As such, clock change circuitry may reduce or eliminate glitches by holding the clock signal in a particular state (e.g., logically low) while the change occurs, and release the clock signal afterwards, effectively skipping or overall reducing potentially glitched clock cycles.

One embodiment of a duty-cycle corrector phase shift (DCCPS) circuit includes a voltage-controlled delay line circuit, a duty-cycle correct circuit, an error amplifier circuit, and DC sampler circuits. Another embodiment of a duty-cycle corrector phase shift circuit includes a digital-controlled delay line circuit, a duty-cycle correct circuit, DC sampler circuits, a comparator circuit, a counter circuit, a control circuit, and a lock detector circuit. In some instances, the DCCPS circuit provides a clock signal with a duty-cycle of approximately fifty percent (50%) and a given phase shift between an input clock signal and the output clock signal.

A clock data recovery circuit includes a phase detector, a first signal processing path, a second signal processing path, an oscillator circuit and a phase control circuit. The phase detector samples input data signal according to first clock signals to generate an up control signal and a down control signal. The first signal processing path includes at least one first signal processing device generating a phase control signal according to the up control signal and the down control signal. The second signal processing path includes at least one second signal processing device generating a frequency control signal according to the up control signal and the down control signal. The oscillator circuit generates second clock signals according to the frequency control signal. The phase control circuit controls phases of the second clock signals according to the phase control signal to generate the first clock signals.

An initialization circuit of a delay locked loop (DLL) includes a sense circuit and a control circuit. The sense circuit receives an enable signal, a reference clock signal, and various delayed reference clock signals, and outputs another enable signal. The control circuit receives the two enable signals and outputs and provides a control signal to a loop filter of the DLL to control a delay value associated with the DLL. The control signal is provided to the loop filter such that the delay value associated with the DLL equals a predetermined delay value for a predetermined time duration. Further, after a lapse of the predetermined time duration, the delay value associated with the DLL increases until a difference between a time period of the reference clock signal and the delay value equals a threshold value.

An oscillator drive circuit and a trim circuit are implemented inside an integrated circuit of a sensor. The drive circuit provides an oscillating drive signal at a resonant frequency to drive a movable mass of the sensor. The drive circuit includes a phase shift circuit having an input for receiving a first signal indicative of an oscillation of the movable mass and having an output. The phase shift circuit adds a phase shift component to the first signal and produces a second signal shifted in phase by the phase shift component. The trim circuit includes a first comparator for receiving the first signal, a second comparator for receiving the second signal, and a processing element. The processing element determines a phase lag between the first and second signals and produces trim code for use by the phase shift circuit, the trim code being configured to adjust the phase shift component.

An electronic device is disclosed. The electronic device comprises a first clock configured to operate at a frequency. First circuitry of the electronic device is configured to synchronize with the first clock. Second circuitry is configured to determine a second clock based on the first clock. The second clock is configured to operate at the frequency of the first clock, and is further configured to operate with a phase shift with respect to the first clock. Third circuitry is configured to synchronize with the second clock.

An optoelectronic oscillator (OEO) including a drift compensation circuit is provided. The OEO includes a set of optical domain components communicatively coupled with a set of RF domain components. The RF domain components include a mode selection filter, a phase locked loop (PLL) and a drift compensation circuit communicatively coupled between the mode selection filter and the PLL. The mode selection filter provides a mode selection result to the drift compensation circuit. The drift compensation circuit phase modulates the mode selection result in a vector based coordinate system to maintain a drift compensated mode selection result within a locking bandwidth of the PLL, and to minimize phase shifting from accumulating phase drift. The PLL detects a phase difference between the drift compensated mode selection result and a reference signal, for use in maintaining the PLL in a phase lock with the reference signal, in particular over wide operational temperature ranges.

The present invention provides a clock signal generation circuit including a global PLL and a plurality of local PLLs. In the operation of the clock signal generation circuit, the global PLL is configured to receives a reference clock signal to generate a synchronization clock signal, and the plurality of local PLLs receive the synchronization clock signal to generate a plurality of clock signals, respectively, and the plurality of clock signals are used to generate a plurality of output clock signals.

Systems and methods for integrating injection-locked oscillators into transceiver arrays are disclosed. In one aspect, there is provided an injection-locked oscillator (ILO) distribution system including a master clock generator configured to generate a master clock signal. The ILO distribution system also includes an ILO distribution circuit including an ILO and configured to receive the master clock signal. The ILO is configured to generate a reference clock signal based on the master clock signal. The ILO distribution circuit is further configured to generate an output signal indicative of an operating frequency of the ILO. The ILO distribution system further includes an injection-locked detector (ILD) configured to receive the master clock signal and the output signal. The ILD is further configured to determine whether the ILO is in a locked state or in an unlocked state based on the master clock signal and the output signal.