Discrete amplitude calibration of oscillators in frequency synthesizers

A method of calibrating an amplitude of an oscillator comprising:

• setting a configurable tail current source of the oscillator to a maximum current setting;
• and
• reducing the current setting of the configurable tail current source in discrete steps until the amplitude of the oscillator would fall below a target.

A wireless communication device comprising:

• frequency synthesizer that generates waveforms, wherein the frequency synthesizer comprises an oscillator including a configurable tail current source, a phase locked loop that controls a frequency of an oscillating signal of the oscillator, and an amplitude calibration unit that calibrates the configurable tail current source when the phase locked loop is disabled in order to achieve a desired amplitude of the oscillating signal;
• and
• a mixer that mixes the waveforms.

A wireless communication device comprising:

• frequency synthesizer that generates waveforms, wherein the frequency synthesizer comprises an oscillator including a configurable tail current source, circuitry that sets the configurable tail current source of the oscillator to a maximum current setting, and circuitry that reduces the current setting of the configurable tail current source in discrete steps until an oscillating signal of the oscillator is below a target;
• and
• a mixer that mixes the waveforms.

An apparatus comprising:

• circuitry that detects a signal amplitude of an oscillator for an input parameter prior to enabling a phase locked loop;
• and
• circuitry that adjusts the oscillator to achieve a desired signal amplitude.

An apparatus comprising:

• circuitry that sets a configurable tail current source of an oscillator to a maximum current setting;
• and
• circuitry that reduces the current setting of the configurable tail current source in discrete steps until an amplitude of an oscillating signal of the oscillator is below a target.

An oscillator comprising:

• an oscillator tank that generates an oscillating voltage signal;
• and
• a configurable tail current source that defines an amplitude of the oscillating voltage signal, wherein the configurable tail current source includes a set of switched unit current sources that can be selectively activated to adjust the amplitude.