Abstract:
A fast frequency hopping implementation in a phase lock loop (PLL) circuit achieves a PLL lock to a new frequency in a very short period of time. In one instant, frequency allocation at a transceiver is changed. In response, a local oscillator frequency hops to a new center frequency based on the changed frequency allocation. The hopping to the new center frequency is based on two-point modulation of a phase locked loop.
Abstract:
Certain aspects of the present disclosure provide methods and apparatus for implementing a fully differential charge pump circuit that eliminates a source of noise and power consumption by using a low-noise switched-capacitor common-mode feedback (CMFB) circuit, rather than a continuous-time amplifier-based CMFB circuit. The fully differential charge pump circuit presented in this disclosure includes the switched-capacitor CMFB (SC-CMFB) unit connected to differential output nodes of the charge pump and provides a feedback signal to the charge pump to control a common-mode voltage of the differential signals based on a reference common-mode voltage. In certain aspects, a replica phase-frequency detector (PFD), a frequency divider, and a non-overlapping clock generator provides control signals for the SCCMFB circuit.
Abstract:
Described herein is apparatus and system for a digitally controlled oscillator (DCO). The apparatus comprises a voltage regulator to provide an adjustable power supply; and a DCO to generate an output clock signal, the DCO including one or more delay elements, each delay element operable to change its propagation delay via the adjustable power supply, wherein each delay element comprising an inverter with adjustable drive strength, wherein the inverter is powered by the adjustable power supply. The apparatus further comprises a digital controller to generate a first signal for instructing the voltage regulator to adjust a voltage level of the adjustable power supply.
Abstract:
The disclosed clock-data recovery architecture includes out-of-lock (including false lock) detection. A clock-data recovery (CDR) circuit (100) for out-of-lock (including false lock) detection includes a phase/frequency detector (PFD) (101) for clock recovery and a data retimer (111) for recovering/retiming data. A received data signal is input to phase/frequency detector (101), which generates a recovered clock, and to retimer (111) which recovers and retimes data based on the recovered clock. Out-of-lock detection is accomplished by sampling retimed/recovered data with positive and negative edges of the received data. In example embodiments, an out-of-lock condition is determined either by detecting the occurrence of, or counting, missed edges corresponding to the failure of received data sampling to detect corresponding positive/negative edges of the retimed/recovered data.
Abstract:
An analog phase-locked loop, PLL, (100, 200) is disclosed, comprising a voltage controlled oscillator (102, 202); a frequency divider (104, 204) having its input connected to an output of the VCO; a first phase detector (106, 206) arranged to detect a phase difference between an output signal of the frequency divider and a reference frequency signal and provide an output signal based on the phase difference, wherein the detectable phase difference is within one cycle of the reference frequency; a first charge pump (108, 208) connected to an output of the first phase detector and arranged to output a charge per detected phase error based on the output of the first phase detector; and an analog loop filter (110, 210) connected to the first charge pump and arranged to provide a voltage, based on the output of the first charge pump, to the VCO. The PLL further comprises a second phase detector (112, 212, 300, 400, 500) arranged to detect a number of cycles in phase difference between the output signal of the frequency divider and the reference frequency signal and provide an output signal based on the number of cycles in phase difference; and a second charge pump (114, 214, 600, 700) connected to an output of the second phase detector and arranged to provide a charge per detected phase error, based on the output of the second phase detector, to the loop filter. A radio circuit, a communication device and a communication node are also disclosed.
Abstract:
A clock and data recovery device receives a serial data stream and produces recovered clock and data signals. The clock and data recovery device operates over a range of frequencies and without use an external reference clock. A first loop supplies a first clock signal to a second loop. The second loop modifies the first clock signal to produce the recovered clock signal and uses the recover clock signal to produce the recovered data signal. The first loop changes the frequency of the first clock signal based on frequency comparison and data transition density metrics.
Abstract:
A phase locked loop (10) comprising: a tuneable oscillator (12); a mixer-based phase sensitive detector (18) to receive input signals from the tuneable oscillator (12) and a reference signal (20); a cycle slip detector (26) to receive input signals from the tuneable oscillator (12) and the reference signal (20), the cycle slip detector (26) being configured to generate an output signal when two consecutive pulses are present in one of its input signals without an intervening pulse in the other of its input signals; coarse tune signal means (32, 34) to receive the output signal generated by the cycle slip detector; and adding means (24) for adding a signal output by the coarse signal means (32, 34) to a signal output by the phase sensitive detector (18) to control the frequency of the tuneable oscillator (12).
Abstract:
A device is provided having a local oscillator (LO) configured to generate a first signal having timing information, frequency information, phase information or combinations thereof. The device also includes a prioritizer comprising at least two inputs, each input configured to receive a respective second signal having timing information, frequency information, phase information or combinations thereof. The prioritizer is configured to determine an accuracy of at least one second signal of the at least two second signals in relation to a second signal assigned to be a most accurate of the at least two second signals. The prioritizer is also configured to order the at least two second signals from most accurate to least accurate. The LO is disciplined to correct an offset error of the LO relative to a most accurate second signal that is available to the device, based on the order of the at least two second signals.