A detector includes a frequency multiplier and a transceiving node. The frequency multiplier includes a first terminal, a second terminal and an output terminal. The first terminal is used to receive a first injection signal having a first frequency. The output terminal is used to output an output signal. The second terminal is used to receive a second injection signal having a second frequency. The frequency multiplier is used to output the output signal at a frequency substantially equal to a multiple of the first frequency by injection locking and pull the output signal to the second frequency by injection pulling. The transceiving node is coupled to the output terminal and the second terminal of the frequency multiplier. The transceiving node is used to transmit the output signal, and receive a received signal having a third frequency. The received signal is used to update the second injection signal.

A dynamic rotary traveling wave oscillator circuit includes plurality of multi-output spot-advancing blocks (MOSABs) forming a main-loop and a plurality of multi-input spot-advancing blocks (MISABs) forming a sub-loop. Depending on a desired division ratio, a connection connects blocks on the MOSABs and MISABs to create the desired division ratio.

A circuit device is configured to switching between a first mode in which phase noise of an output clock signal is low and a second mode in which power consumption is small, and includes an oscillation circuit configured to generate an oscillation signal, an output circuit configured to output the output clock signal, a temperature sensor configured to output a temperature detection signal, a temperature compensation circuit configured to perform temperature compensation on an oscillation frequency based on the temperature detection signal, and a control circuit. The control circuit performs control such that a power supply voltage supplied to the oscillation circuit in the first mode is higher than a power supply voltage supplied to the oscillation circuit in the second mode. In addition, the control circuit performs control such that at least one of a reference voltage supplied to the temperature compensation circuit and a reference current supplied to the temperature sensor does not change between the first mode and the second mode.

A low power mode control module for a crystal oscillator which performs the following steps: detecting whether an oscillation output signal of the crystal oscillator is output stably; when the oscillation output signal of the crystal oscillator is output stably, comparing at least one of an oscillation input signal and the oscillation output signal with an amplitude control signal to determine whether to adjust the amplitude control signal; when the amplitude control signal does not need to be adjusted, generating an upper bound reference voltage and a lower bound reference voltage associated with the amplitude control signal; and according to whether the oscillation output signal exceeds a reference voltage range of the upper reference voltage and the lower reference voltage, generating a low power mode control output signal associated with a crystal oscillator enable signal for enabling the crystal oscillator.

Systems and methods of low power docking of sleep mode radios are disclosed herein. In an example embodiment, a crystal oscillator is purposefully mistuned to achieve lower power consumption, and then synchronized using a high frequency crystal oscillator. In an alternative embodiment, the input offset voltages of the comparator in an RC oscillator are cancelled, which allows low power operation and high accuracy performance when tuned to the high frequency crystal. A lower power comparator may be used with higher input offset voltages but still achieve higher accuracy. The RC circuit is switched back and forth on opposite phases of the output, cancelling the offset voltage on the inputs of the comparator.

Provided are a constant voltage circuit configured to, when a power supply voltage is low, detect a leakage current to output a stable voltage at a power supply voltage level, and a crystal oscillation circuit using the constant voltage circuit. The constant voltage circuit includes a leakage current detection circuit including a PMOS transistor for monitoring a leakage current, which has a gate and a source being grounded. When a leakage current is detected, even with a constant voltage power supply, a voltage sufficient for turning on an output transistor of the constant voltage circuit can be applied to a gate of the output transistor.

Systems and methods of low power clocking of sleep mode radios are disclosed herein. In an example embodiment, a crystal oscillator is purposefully mistuned to achieve lower power consumption, and then synchronized using a high frequency crystal oscillator. In an alternative embodiment, the input offset voltages of the comparator in an RC oscillator are cancelled, which allows low power operation and high accuracy performance when tuned to the high frequency crystal. A lower power comparator may be used with higher input offset voltages but still achieve higher accuracy. The RC circuit is switched back and forth on opposite phases of the output, cancelling the offset voltage on the inputs of the comparator.

Certain aspects of the present disclosure generally relate to voltage-controlled oscillators (VCOs) using a lowered or an adjustable negative transconductance (g.sub.m) compared to conventional VCOs. This g.sub.m degeneration technique suppresses the noise injected into an inductor-capacitor (LC) tank of the VCO, thereby providing lower signal-to-noise ratio (SNR) for a given VCO voltage swing, lower power consumption, and decreased phase noise. One example VCO generally includes a resonant tank circuit, an active negative transconductance circuit connected with the resonant tank circuit, and a bias current circuit for sourcing or sinking a bias current through the resonant tank circuit and the active negative transconductance circuit to generate an oscillating signal. The active negative transconductance circuit includes cross-coupled transistors and an impedance connected between the cross-coupled transistors and a reference voltage.

Systems and methods of low power docking of sleep mode radios are disclosed herein. In an example embodiment, a crystal oscillator is purposefully mistuned to achieve lower power consumption, and then synchronized using a high frequency crystal oscillator. In an alternative embodiment, the input offset voltages of the comparator in an RC oscillator are cancelled, which allows low power operation and high accuracy performance when tuned to the high frequency crystal. A lower power comparator may be used with higher input offset voltages but still achieve higher accuracy. The RC circuit is switched back and forth on opposite phases of the output, cancelling the offset voltage on the inputs of the comparator.

A low power crystal oscillator circuit having a high power part and a low power part. Oscillation is initialized using the high power part. Once the crystal is under stable oscillation, the circuit switches to the low power part and continue operation for a long duration.