Methods and apparatus are disclosed to generate an oscillating output signal having a voltage swing greater than a voltage swing across nodes of active devices. An example oscillator includes a tank to generate an oscillating output signal in response receiving an edge of an enable signal; a feedback generator including a first gain stage forming a first feedback loop with the tank, the first feedback loop providing a first charge to maintain the oscillating output signal and a second gain stage forming a second feedback loop with the tank, the second feedback loop providing a second charge to maintain the oscillating output signal, the first and second charges combining with the oscillating output signal to generate a high voltage swing; and an attenuator connected between the tank and the feedback generator to isolate the tank from active components of the feedback generator.

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.

A sine wave generator includes a resonator circuit, a control circuit and a pulse generator. The resonator circuit is configured to receive energy pulses and to generate a resonator sinusoidal signal responsively to the energy pulses. The control circuit is configured to estimate a signal measure of the resonator sinusoidal signal, or of a signal derived from the resonator sinusoidal signal. The pulse generator is configured to generate the energy pulses responsive to the signal measure estimated by the control circuit, and to drive the resonator circuit with the energy pulses.

A voltage controlled oscillator (VCO) circuit employing digital amplitude control of the output oscillating signal and method of operation. The digital control is provided by an analog to digital converter (ADC) element that is shared among many other operating blocks in a system. In a configuration, the oscillator current is obtained by implementing transistors in a linear region and controlling them digitally. The optimum amplitude detection is performed by measuring the DC voltage at the common mode nodes in the oscillator, and is realized using reduced time compared to an extensive frequency measurement over a long time window. The digital control is implemented using an on-chip regulator, and employs digital controls for adjusting the current consumption which leads to low on-chip area overhead, low cost, and a scalable implementation. In an implementation, a one-time code can be obtained for optimum phase noise operation when providing the digital amplitude control.

A calibration circuit for calibrating a peak detector configured to detect a signal peak amplitude of an oscillator, including: a calibration oscillator configured to be supplied by at least two different supply voltages to generate respective calibration signals; a calibration peak detector configured to detect a calibration signal peak amplitude of each of the calibration signals; and a logic circuit configured to calibrate the peak detector based on the detected calibration signal peak amplitudes.

A sine wave generator includes a resonator circuit, a control circuit and a pulse generator. The resonator circuit is configured to receive energy pulses and to generate a resonator sinusoidal signal responsively to the energy pulses. The control circuit is configured to estimate a signal measure of the resonator sinusoidal signal, or of a signal derived from the resonator sinusoidal signal. The pulse generator is configured to generate the energy pulses responsive to the signal measure estimated by the control circuit, and to drive the resonator circuit with the energy pulses.

A voltage controlled oscillator (VCO) circuit employing digital amplitude control of the output oscillating signal and method of operation. The digital control is provided by an analog to digital converter (ADC) element that is shared among many other operating blocks in a system. In a configuration, the oscillator current is obtained by implementing transistors in a linear region and controlling them digitally. The optimum amplitude detection is performed by measuring the DC voltage at the common mode nodes in the oscillator, and is realized using reduced time compared to an extensive frequency measurement over a long time window. The digital control is implemented using an on-chip regulator, and employs digital controls for adjusting the current consumption which leads to low on-chip area overhead, low cost, and a scalable implementation. In an implementation, a one-time code can be obtained for optimum phase noise operation when providing the digital amplitude control.

Methods and apparatus generate an oscillating output signal having a voltage swing greater than a voltage swing across nodes of active devices. An example oscillator includes a tank to generate an oscillating output signal in response receiving an edge of an enable signal; a feedback generator including a first gain stage forming a first feedback loop with the tank, the first feedback loop providing a first charge to maintain the oscillating output signal and a second gain stage forming a second feedback loop with the tank, the second feedback loop providing a second charge to maintain the oscillating output signal, the first and second charges combining with the oscillating output signal to generate a high voltage swing; and an attenuator connected between the tank and the feedback generator to isolate the tank from active components of the feedback generator.

A calibration circuit for calibrating a peak detector configured to detect a signal peak amplitude of an oscillator, including: a calibration oscillator configured to be supplied by at least two different supply voltages to generate respective calibration signals; a calibration peak detector configured to detect a calibration signal peak amplitude of each of the calibration signals; and a logic circuit configured to calibrate the peak detector based on the detected calibration signal peak amplitudes.

A current control device for a differential circuit is provided. The current control device includes a differential circuit that generates differential signals comprising a positive signal and a negative signal in opposite phases, an amplitude detection circuit detecting an amplitude of the differential signal and outputting first and second detection voltages, an error amplification circuit controlling the differential circuit on the basis of an error voltage between the first and second detection voltages, and a current control circuit controlling the amplitude detection circuit on the basis of any one of the first and second detection voltages.