Patent classifications
H03L7/099
A FRACTIONAL-N FREQUENCY SYNTHESIZER BASED ON A CHARGE-SHARING LOCKING TECHNIQUE
The present disclosure relates to a phase-locked loop (PLL) based on a charge-sharing locking technique, capable of both fractional-N and integer-N operation. The PLL comprises a voltage pre-setting stage; an oscillator: a shared capacitive load; and a switching network configured for selectively connecting the voltage pre-setting stage to the shared capacitive load during a voltage pre-setting stage for applying an expectant voltage to the capacitive load. The switching network is being further configured for selectively connecting the capacitive load to the oscillator during a charge-sharing locking stage for correcting a phase error in response to a difference between the expected voltage of the capacitor and the voltage of the oscillator. Frequency-tracking and waveform-learning stages are also provided for maintaining PVT (process, voltage, temperature) robustness and for suppressing fractional-N spur, respectively.
A FRACTIONAL-N FREQUENCY SYNTHESIZER BASED ON A CHARGE-SHARING LOCKING TECHNIQUE
The present disclosure relates to a phase-locked loop (PLL) based on a charge-sharing locking technique, capable of both fractional-N and integer-N operation. The PLL comprises a voltage pre-setting stage; an oscillator: a shared capacitive load; and a switching network configured for selectively connecting the voltage pre-setting stage to the shared capacitive load during a voltage pre-setting stage for applying an expectant voltage to the capacitive load. The switching network is being further configured for selectively connecting the capacitive load to the oscillator during a charge-sharing locking stage for correcting a phase error in response to a difference between the expected voltage of the capacitor and the voltage of the oscillator. Frequency-tracking and waveform-learning stages are also provided for maintaining PVT (process, voltage, temperature) robustness and for suppressing fractional-N spur, respectively.
CONTROL ARRANGEMENT AND METHOD
A control arrangement is disclosed for providing a plurality of phase-coherent oscillating signals. It comprises a reference clock signal arrangement for providing a high-frequency reference clock signal and a plurality of modules each comprising a plurality of channels for providing the plurality of phase-coherent oscillating signals.
CONTROL ARRANGEMENT AND METHOD
A control arrangement is disclosed for providing a plurality of phase-coherent oscillating signals. It comprises a reference clock signal arrangement for providing a high-frequency reference clock signal and a plurality of modules each comprising a plurality of channels for providing the plurality of phase-coherent oscillating signals.
LOW-POWER FRACTIONAL-N PHASE-LOCKED LOOP CIRCUIT
Disclosed is a low-power fractional-N phase-locked loop circuit, which comprises a phase detector, a voltage-to-current converter, a loop filter, a voltage-controlled oscillator, a frequency divider and a digital logic processor; the phase detector, the voltage-to-current converter, the loop filter, the voltage-controlled oscillator and the frequency divider are connected in sequence; a reference signal is input from the phase detector, the phase detector detects the phases of the reference signal and a feedback signal with a quantization error output by the frequency divider, compensates a quantization phase error generated by fractional frequency division, and outputs a compensated phase detection result to the voltage-to-current converter; the quantization error generated by fractional frequency division is converted into a voltage domain through a digital domain or directly coupled to a phase error signal in the phase detector to complete the compensation of the quantization error.
PHASE LOCKED LOOP CIRCUIT WITH INCREASED ROBUSTNESS
A Phase Locked Loop PLL circuit and method therein for generating multiphase output signals are disclosed. The PLL circuit includes a digitally controlled oscillator, a sample circuit, an analog to digital converter and a digital processing unit. The digital processing unit comprises a phase estimator configured to estimate a phase of the multiphase output signals, a differentiator configured to calculate a phase difference between a current phase and a previous phase, and an accumulator configured to accumulate the phase differences generated by the differentiator. The PLL circuit further comprises a loop filter configured to receive an output from the accumulator and generate a control signal to the digitally controlled oscillator to adjust frequency of the digitally controlled oscillator generating the multiphase output signals.
METHODS AND APPARATUS OF CHARGE-SHARING LOCKING WITH DIGITAL CONTROLLED OSCILLATORS
An integrated circuit device includes a digitally controlled oscillator (DCO), two charge-sharing capacitors, two charge-sharing switches, two pre-charge switches, and two DACs. The DCO has a first inverter and a second inverter. A first charge-sharing capacitor has a first terminal coupled to an input terminal of the first inverter through a first charge-sharing switch. A first DAC has an output terminal coupled to the first terminal of the first charge-sharing capacitor through a first pre-charge switch. A second charge-sharing capacitor has a first terminal coupled to an input terminal or an output terminal of the second inverter through a second charge-sharing switch. A second DAC has an output terminal coupled to the first terminal of the second charge-sharing capacitor through a second pre-charge switch.
DETECTION, CORRECTION, AND COMPENSATION OF COUPLING EFFECTS OF MICROELECTROMECHANICAL SYSTEM (MEMS) AXES OF A TWO-DIMENSIONAL SCANNING STRUCTURE
An oscillator control system includes an oscillator structure configured to oscillate about first and second rotation axes according to a Lissajous pattern, wherein an oscillation about the second rotation axis imparts a cross-coupling error onto an oscillation about the first rotation axis, and wherein the cross-coupling error changes in accordance with a Lissajous position within the Lissajous pattern; and a driver circuit that includes a phase-locked loop (PLL) configured to regulate a driving signal that drives the oscillation about the first rotation axis. The PLL is configured to generate a PLL signal based on a phase error of the oscillation about the first rotation axis. The PLL includes a compensation circuit configured to receive the PLL signal and the Lissajous position within the Lissajous pattern, apply a compensation value to the PLL signal to generate a compensated PLL signal used for generating the driving signal based on the Lissajous position.
DETECTION, CORRECTION, AND COMPENSATION OF COUPLING EFFECTS OF MICROELECTROMECHANICAL SYSTEM (MEMS) AXES OF A TWO-DIMENSIONAL SCANNING STRUCTURE
An oscillator control system includes an oscillator structure configured to oscillate about first and second rotation axes according to a Lissajous pattern, wherein an oscillation about the second rotation axis imparts a cross-coupling error onto an oscillation about the first rotation axis, and wherein the cross-coupling error changes in accordance with a Lissajous position within the Lissajous pattern; and a driver circuit that includes a phase-locked loop (PLL) configured to regulate a driving signal that drives the oscillation about the first rotation axis. The PLL is configured to generate a PLL signal based on a phase error of the oscillation about the first rotation axis. The PLL includes a compensation circuit configured to receive the PLL signal and the Lissajous position within the Lissajous pattern, apply a compensation value to the PLL signal to generate a compensated PLL signal used for generating the driving signal based on the Lissajous position.
Phase lock loop circuit based signal generation in an optical measurement system
An exemplary system includes a PLL circuit and a precision timing circuit connected to the PLL circuit. The PLL circuit has a PLL feedback period defined by a reference clock and includes a voltage controlled oscillator configured to lock to the reference clock and having a plurality of stages configured to output a plurality of fine phase signals each having a different phase, and a feedback divider configured to be clocked by a single fine phase signal included in the plurality of fine phase signals and have a plurality of feedback divider states during the PLL feedback period. The precision timing circuit is configured to generate a timing pulse and set, based on a first combination of one of the fine phase signals and one of the feedback divider states, a temporal position of the timing pulse within the PLL feedback period.