Method of adjusting the resonance frequency of an l-c resonant circuit and resonant circuit
AssigneeSTMicroelectronics S.r.l.
InventorsGiuseppe Cusmai, Matteo Repossi, Guido Albasini, Francesco Svelto
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Abstract
An L-C resonant circuit with an adjustable resonance frequency, having a capacitor and a first inductor electrically coupled together and a second inductor magnetically coupled to the first inductor. Additionally, there is a control circuit to sense a signal representing a first current flowing through the first inductor and to force through the second inductor a second current that is a replica of the first current for setting the adjustable resonance frequency of the L-C resonant circuit.
Claims20
1-7. (canceled)
An L-C resonant circuit with an adjustable resonance frequency comprising:
- a capacitor and a first inductor electrically coupled together,
- a second inductor magnetically coupled to said first inductor;
- and
- a control circuit to sense a signal representing a first current flowing through said first inductor and to force through said second inductor a second current that is a replica of the first current for setting the adjustable resonance frequency of the L-C resonant circuit.
An amplifier comprising:
- an input stage;
- and
- an L-C resonant circuit biased by said input stage and comprising a capacitor and a first inductor electrically coupled together,
- a second inductor magnetically coupled to said first inductor, and
- a control circuit to sense a signal representing a first current flowing through said first inductor and to force through said second inductor a second current that is a replica of the first current for setting a resonance frequency of the L-C resonant circuit.
An oscillator to resonate at an adjustable resonance frequency and to generate two output differential voltages in quadrature to each other, the oscillator comprising:
- a first and a second differential amplifier to generate a differential output signal, each differential amplifier comprising an input stage controlled by a differential input signal to be amplified, and
- an L-C resonant circuit with an adjustable resonance frequency biased by said input stage, said L-C resonant circuit comprising a capacitor and a first inductor electrically coupled together a second inductor magnetically coupled to said first inductor, and
- a control circuit to sense a signal representing a first current flowing through said first inductor and to force through said second inductor a second current that is a replica of the first current for setting the adjustable resonance frequency of the L-C resonant circuit,
- said input stage of the first differential amplifier being controlled by a differential output signal of the second differential amplifier;
- said input stage of the second differential amplifier being controlled by a differential output signal of the first differential amplifier.
A method of adjusting a resonance frequency of an L-C resonant circuit comprising a capacitor, a first inductor electrically coupled to the capacitor, and a second inductor magnetically coupled with the first inductor, the method comprising:
- forcing through the second inductor a second current that is a replica of a first current flowing through the first inductor;
- and
- establishing at least one of a scale factor and a phase of the second current as a function of the resonance frequency of the L-C resonant circuit.
Dependencies are inferred from the claim text.