An electronic device comprises a first feedback circuit operatively connected to an amplitude detector and a first control input of an oscillator. The first feedback circuit is configured to control an amplitude of an output of the oscillator by continuously applying a first control signal to the first control input in response to an amplitude detected by the amplitude detector. The electronic device further comprises a second feedback circuit operatively connected to the amplitude detector and a second control input of the oscillator. The second feedback circuit is configured to modify one or more amplitude regulating parameters of the oscillator by providing a second control signal in response to the amplitude being beyond an upper or lower amplitude threshold, and refrain from modifying the one or more amplitude regulating parameters when the amplitude is within the upper and lower amplitude thresholds.

In examples, an electronic device comprises an oscillator circuit configured to provide an output signal and a controller coupled to the oscillator circuit. The controller is configured to receive first and second target rates; dynamically adjust a frequency accuracy of the output signal based on the first target rate; and dynamically adjust an amplitude of the output signal based on the second target rate.

Circuits and processes for locking a voltage-controlled oscillator (VCO) at a high frequency signal are described. A circuit may include an adjustable current converter (ACC), coupled at an input terminal to a power source, operable to output a control signal (VC) at an output terminal. A first switch may be coupled to the ACC and to the VCO. The VCO, when in an “ON” state, receives the control signal and outputs a high frequency signal (VHF). A digital filter may be coupled to the VCO and operable to receive the VHF. Based on the VHF, the digital filter generates a data signal having a data value. The circuit may also include a digital-to-analog converter (DAC) operable to receive the data signal and, based on the data value, output an adjustment signal to the ACC. The ACC may adjust the control signal based on the adjustment signal received from the DAC.

A trigger, includes: a first voltage input terminal; a bias voltage input terminal; a first bias transistor having a scaling of N to a first component of an external device; a comparator transistor having a scaling of N to a second component of the external device; a first switch transistor and a second switch transistor; a shunt transistor having a control terminal connected to the first voltage input terminal, a second terminal connected to the second terminal of the second switch transistor, and a first terminal connected to the first terminal of the comparator transistor. The shunt transistor has an enlarging scale of M to the comparator transistor. A voltage output terminal is respectively connected to the second terminal of the first switch transistor, the control terminal of the second switch transistor, and the second terminal of the comparator transistor.

A circuit includes an oscillator having a driver and a resonator. The driver receives a supply voltage at a supply input and provides a drive output to drive the resonator to generate an oscillator output signal. A power converter receives an input voltage and generates the supply voltage to the supply input of the driver. The power converter varies the supply voltage based on an adjust command supplied to a command input of the power converter. A detector monitors a voltage level of the oscillator output signal. A controller sets the adjust command to the power converter to control the supply voltage to the supply input of the driver such that the voltage level of the oscillator output signal is set at or above a predetermined threshold voltage.

A voltage-controlled oscillator, including a voltage-controlled LC resonator including at least one first output node; an amplifier including at least one first dual-gate MOS transistor including first and second gates, coupling the first output node to a second node of application of a reference potential; and a regulation circuit capable of applying to the second gate of the first transistor a bias voltage variable according to the amplitude of the oscillations of a signal delivered on the first output node of the oscillator.

Disclosed is an integrated circuit amplifier for use in a crystal oscillator. The circuit amplifier comprises a transistor; a voltage dependent capacitance circuit; and a node. The voltage dependent capacitance circuit comprises a device with a voltage dependent capacitance and a bias circuit. The node is connected to a terminal of the transistor and the integrated circuit amplifier is configured such that an intrinsic capacitance of the transistor is dependent on the mean voltage at the node. The node is connected to a terminal of the voltage dependent capacitance circuit and the integrated circuit amplifier is configured such that an effective capacitance of the node is dependent on the intrinsic capacitance of the transistor and the voltage dependent capacitance of said device. When in use, the voltage dependent capacitance circuit reduces the amount of change of the effective capacitance of the node when the mean voltage at the node changes.

An oscillator circuit comprises a crystal oscillator and an inverter. The input of the inverter is connected to the first terminal of the crystal oscillator and the output of the inverter is connected to the second terminal of the crystal oscillator, oscillator circuit is arranged to operate the inverter in its linear operating region. An amplitude regulator has an input connected to the input of the inverter, arranged to provide a first supply current I.sub.AREG to the inverter, where the magnitude of the first supply current is inversely dependent on a magnitude of a voltage at the inverter input. A digital-to-analogue converter is arranged to provide a second supply current I.sub.DAC to the inverter having a magnitude determined by a digital signal applied to a digital input of the digital-to-analogue converter.

Circuits and processes for locking a voltage-controlled oscillator (VCO) at a high frequency signal are described. A circuit may include a voltage-controlled oscillator configured to generate a high frequency signal based on a control signal, a dummy load parallel to the voltage-controlled oscillator and configured to receive the control signal via a switch, and a digital-to-analog converter coupled to the voltage-controlled oscillator where the control signal is generated based on an output of the digital-to-analog converter.

A frequency generation solution controls an oscillator amplitude using two feedback paths to generate high frequency signals with lower power consumption and lower noise. A first feedback path provides continuous control of the oscillator amplitude responsive to an amplitude detected at the oscillator output. A second feedback path provides discrete control of the amplitude regulating parameter(s) of the oscillator responsive to the detected oscillator amplitude. Because the second feedback path enables the adjustment of the amplitude regulating parameter(s), the second feedback path enables an amplifier in the first feedback path to operate at a reduced gain, and thus also at a reduced power and a reduced noise, without jeopardizing the performance of the oscillator.