Abstract:
A high-speed and low power divider includes a ring of four dynamic latches, an interlocking circuit, and four output inverters. Each latch has a first dynamic node M and a second dynamic node N. The interlocking circuit is coupled to the M nodes. Based on one or more of the M node signals received, the interlocking circuit selectively controls the logic values on one or more of the M modes such that over time, as the divider is clocked, only one of the signals on the N nodes is low at a given time. The output inverters generate inverted versions of the N node signals that are output from the divider as low phase noise 25% duty cycle output signals I, IB, Q and QB. In one specific example, each latch has eight transistors and no more than eight transistors. The divider recovers quickly and automatically from erroneous state disturbances.
Abstract:
Techniques for detecting and correcting phase discontinuity of a local oscillator (LO) signal are disclosed. In one design, a wireless device includes an LO generator and a phase detector. The LO generator generates an LO signal used for frequency conversion and is periodically powered on and off. The phase detector detects the phase of the LO signal when the LO generator is powered on. The detected phase of the LO signal is used to identify phase discontinuity of the LO signal. The wireless device may further include (i) a single-tone generator that generates a single-tone signal used to detect the phase of the LO signal, (ii) a downconverter that downconverts the single-tone signal with the LO signal and provides a downconverted signal used by the phase detector to detect the phase of LO signal, and (iii) phase corrector that corrects phase discontinuity of the LO signal in the analog domain or digital domain.
Abstract:
A high-speed and low power divider includes a ring of four dynamic latches, an interlocking circuit, and four output inverters. Each latch has a first dynamic node M and a second dynamic node N. The interlocking circuit is coupled to the M nodes. Based on one or more of the M node signals received, the interlocking circuit selectively controls the logic values on one or more of the M modes such that over time, as the divider is clocked, only one of the signals on the N nodes is low at a given time. The output inverters generate inverted versions of the N node signals that are output from the divider as low phase noise 25% duty cycle output signals I, IB, Q and QB. In one specific example, each latch has eight transistors and no more than eight transistors. The divider recovers quickly and automatically from erroneous state disturbances.
Abstract:
Techniques for detecting and correcting phase discontinuity of a local oscillator (LO) signal are disclosed. In one design, a wireless device includes an LO generator and a phase detector. The LO generator generates an LO signal used for frequency conversion and is periodically powered on and off. The phase detector detects the phase of the LO signal when the LO generator is powered on. The detected phase of the LO signal is used to identify phase discontinuity of the LO signal. The wireless device may further include (i) a single-tone generator that generates a single-tone signal used to detect the phase of the LO signal, (ii) a downconverter that downconverts the single-tone signal with the LO signal and provides a downconverted signal used by the phase detector to detect the phase of LO signal, and (iii) phase corrector that corrects phase discontinuity of the LO signal in the analog domain or digital domain.