Abstract: A system includes a first device comprising a first clock generating circuit and a transmitter circuit, and a plurality of second devices, each comprising a respective receiver circuit and a respective second clock generating circuit. The first clock generating circuit may be configured to generate a first clock signal, which may provide internal clocking for the first device. The transmitter circuit may be configured to generate a synchronization signal in response to the first clock signal and wirelessly transmit a broadcast signal communicating only the synchronization signal. The respective receiver circuit may be configured to receive the broadcast signal and present a recovered synchronization signal to the respective second clock generating circuit.

Abstract: A system includes a first device comprising a first clock generating circuit and a transmitter circuit, and a plurality of second devices, each comprising a respective receiver circuit and a respective second clock generating circuit. The first clock generating circuit may be configured to generate a first clock signal, which may provide internal clocking for the first device. The transmitter circuit may be configured to generate a synchronization signal in response to the first clock signal and wirelessly transmit a broadcast signal communicating only the synchronization signal. The respective receiver circuit may be configured to receive the broadcast signal and present a recovered synchronization signal to the respective second clock generating circuit.

Abstract: An apparatus includes a first independently clocked device and one or more second independently clocked devices. The first independently clocked device may comprise a clock generator. The clock generator may be configured to generate a clock signal. The first independently clocked device may be configured to wirelessly broadcast a synchronization signal based on the clock signal. The one or more second independently clocked devices may each comprise respective clock generators. The one or more second independently clocked devices may (a) be configured to receive the synchronization signal from the first independently clocked device and (b) synchronize the respective clock generators to the clock signal of the first independently clocked device in response to the synchronization signal.

Abstract: An apparatus includes a plurality of independently clocked devices and a low frequency beacon. Each of the plurality of independently clocked devices has a respective local clock generator. The low frequency beacon communicates a low frequency synchronization signal to each of the independently clocked devices. The respective local clock generators of the plurality of independently clocked devices are generally synchronized using the low frequency synchronization signal.

Abstract: An apparatus includes a plurality of independently clocked devices and a low frequency beacon. Each of the plurality of independently clocked devices has a respective local clock generator. The low frequency beacon communicates a low frequency synchronization signal to each of the independently clocked devices. The respective local clock generators of the plurality of independently clocked devices are generally synchronized using the low frequency synchronization signal.

Abstract: An apparatus includes a first independently clocked device and one or more second independently clocked devices. The first independently clocked device may comprise a clock generator. The clock generator may be configured to generate a clock signal. The first independently clocked device may be configured to wirelessly broadcast a synchronization signal based on the clock signal. The one or more second independently clocked devices may each comprise respective clock generators. The one or more second independently clocked devices may (a) be configured to receive the synchronization signal from the first independently clocked device and (b) synchronize the respective clock generators to the clock signal of the first independently clocked device in response to the synchronization signal.

Abstract: A clock generator having deskewed outputs signals wherein a transit time of each of a plurality of traces coupled to the clock generator outputs are determined and the longest trace is identified as the trace having the longest transit time. A time delay is then added to an output clock signal at each of the clock generator outputs that are not coupled to the longest trace. The addition of the time delay for each of the clock generator outputs is effective in automatically deskewing the clock generator outputs.

Abstract: An integrated circuit comprising, a resonator, a first clock circuit for generating a first clock signal having a first frequency in response to the resonator, a second clock circuit for generating a second clock signal having a second frequency in response to the resonator, wherein the second frequency of the second clock signal is determined by the programmable frequency divider and a clock mode control circuit coupled to the first clock circuit and the second clock circuit, the clock mode control circuit for gradually switching the resonator between the first oscillator circuit and the second oscillator circuit of the integrated circuit, using a shift register based state machine and utilizing the inertia of the resonator to smoothly transition between the two oscillators, to provide a dual mode clock output signal.

Abstract: Methods and apparatuses are described to convert analog signals to digital signals using a local charge averaging capacitor array (LCACA) in an analog-to-digital converter (ADC.) An apparatus includes a comparator. The comparator is configured with a first high input, a first low input, and is configure to receive a clock signal. A logic/latch block is configured to receive the clock signal and an output from the comparator. The logic/latch block is configured to output a control signal and a digital N-bit output signal. A local charge-averaging capacitor array (LCACA) is configured to receive the control signal and a reference voltage. An output of the LCACA is coupled to the first low input. The first LCACA is divided into a high sub-array and a low sub-array. The high sub-array is pre-charged to a high reference voltage and the low sub-array is pre-charged to a low reference voltage. The high reference voltage is greater than the low reference voltage.

Abstract: An integrated circuit to remove jitter from a clock signal includes an integrated circuit die. The integrated circuit die includes a signal comparator. The signal comparator is configured to determine a frequency difference between a jittery input clock signal and a correction signal. A digital low pass filter is coupled to receive and filter the frequency difference and to provide a filtered output signal. A free running crystal-less oscillator produces a reference signal. A fractional output divider is coupled to the free running crystal-less oscillator and the digital low pass filter. The fractional output divider utilizes the filtered output signal to establish a value to divide the reference signal by to obtain a clean output clock signal. The clean output clock signal is fed back to the signal comparator and is used as the correction signal.

Abstract: Methods and apparatuses are described to reduce phase noise in a low noise fractional reference-injection phase locked loop (FRIPLL). The FRIPLL includes a ring voltage controlled oscillator (VCO). An output of the ring VCO is input to a fractional interpolative frequency divider (FIFD). A signal comparison circuit receives a reference clock signal and a further delayed output of the FIFD. The signal comparison circuit produces a control voltage signal in response to a phase difference between the reference clock signal and the further delayed output of the FIFD. The control voltage signal is input to the ring VCO to control a ring VCO frequency. An oscillator control circuit has a first input and a second input. The first input is a first delayed output of the FIFD. The second input is the reference clock signal.

Abstract: A fractional N-frequency divider having a reduced fractional spurious output signal, which utilizes a multi-modulus frequency divider and an accumulator to generate a calibration-timing window that is used to calibrate two oscillator circuits and a phase compensation circuit. The calibrated phase compensation circuit is then used to mitigate the fractional spurs in the output signal of the fractional N-frequency divider. The fractional N-frequency divider may be implemented into a fractional N-frequency synthesizer.

Abstract: Integrated circuit devices include first and second periodic signal generators and a power down detection circuit. The first periodic signal generator is configured to generate at least a first periodic signal having a first frequency at an output thereof and the second periodic signal generator is configured to generate a second periodic signal having a second frequency less than the first frequency at an output thereof. The power down detection circuit is configured to selectively provide one or the other of the first and second periodic signals to an output terminal of the integrated circuit device, in response to monitoring a status of a signal received at an input terminal of the integrated circuit device. This received signal reflects a power down status of an external device that receives the selected one of the first and second periodic signals.

Abstract: A clock signal generator includes a phase-lock loop for generating an imaging clock signal having a frequency based on a reference clock signal. The imaging clock signal generator also includes a modulation circuit for determining a number of pixels in a horizontal line of an image to be generated based on the imaging clock signal. The modulation circuit generates a modulation signal based on the determined number of pixels and the clock signal generator spreads the frequency of the imaging clock signal across a frequency range based on the modulation signal. In this way, the clock signal generator reduces electromagnetic interference in the imaging clock signal. In further embodiments, the clock signal generator generates an adjustment signal for adjusting the frequency range based on the frequency of the reference clock signal and the frequency of the imaging clock signal.

Abstract: A clock circuit includes a phase-lock loop for generating an output clock signal based on a data signal and a harmonic frequency detector for detecting whether the frequency of the output clock signal is a harmonic frequency of a frequency of a reference clock signal. The harmonic frequency detector includes a counter for generating a first divided clock signal by dividing the frequency of the output clock signal by a first divisor. Additionally, the harmonic frequency detector includes a counter for generating a second divided clock signal by dividing the frequency of the reference clock signal by a second divisor. The harmonic frequency detector also includes a frequency comparator for generating an output indicating whether the frequency of the output clock signal is a harmonic frequency of the frequency of the reference clock signal based on the first divided clock signal and the second divided clock signal.

Abstract: The present invention provides for a voltage-controlled crystal oscillator (VCXO) which, other than the crystal itself, is full integrated. The VCXO has a pre-amplifier block, a gain stage, a first MOS transistor, a first capacitor, a second MOS transistor, and a one second capacitor. The pre-amplifier block receives an input tuning voltage and the gain stage is connected across the terminals of the oscillating crystal. The first MOS transistor and first capacitor are connected between one of the terminals of the oscillating crystal and a reference voltage. The second MOS transistor and the second capacitor are connected between the second crystal terminal and the reference voltage. The gates of both MOS transistors are connected to the output node of the pre-amplifier block. The first and second MOS transistors connect the first and second capacitors to the first and second terminals of the gain stage for a portion of the time responsive to the input tuning voltage.

Abstract: A voltage-controlled crystal oscillator circuit with an extended range is presented. The circuit has a crystal oscillator circuit, a phase-locked loop (PLL), and a look-up table. The crystal oscillator circuit generates a signal having a frequency f.sub.ref at its output node responsive to a voltage at its input terminal. The PLL has its input node connected to the crystal oscillator output node and generates a signal at the PLL output node having a frequency f.sub.o. A first divider circuit of the PLL divides the f.sub.ref frequency by a first variable integer M and a second PLL divider circuit divides the f.sub.o frequency by a second variable integer N. The look-up table, which has comparators connected to the input terminal, a counter connected to the comparators and a memory responsive to the counter and storing M and N values, varies M and N responsive to the input terminal voltage so that the voltage-controlled crystal oscillator circuit has an increased frequency range.