Stmicroelectronics S.a.

Stmicroelectronics International N.v.

St-ericsson Sa

Sebastien Dedieu

Marc Houdebine

Abhirup Lahiri

Frederic Paillardet

Emmanuel Chataigner

Jean-Francois Larchanche

A method includes a) counting whole periods of a signal during a first period of a reference signal, b) repeating step a) for each period of the reference signal until a first duration is equal to a first quantity of periods of the reference signal, and c) determining a first average of the whole periods. The method also includes repeating at least one of steps a) to c) and at each repetition shifting a start of the counting of step a) by at least one period of the reference signal, and in steps b) and c) accounting for whole periods of the signal already counted during the at least one preceding group of steps a) and b). The method includes determining a second average of the first averages, and determining the frequency of the signal from the second average and the frequency of the reference signal.

Method and device for measuring the frequency of a signal

In some embodiments, a phase locked loop includes a voltage-controlled oscillator whose output is fed back to a first input of a phase comparator via a fractional divider controlled by a delta-sigma modulator. The method of doubling the frequency of the initial reference signal of the phase locked loop involves generating, from the initial reference signal and the output signal furnished by the voltage-controlled oscillator, a secondary reference signal having edges of a first type synchronized with each of the rising and falling edges of the initial reference signal and edges of a second type between the edges of the first type, and a furnishing of the secondary reference signal at a second input of the phase comparator operating on the edges of the first type.

Method and device for doubling the frequency of a reference signal of a phase locked loop

A method can be used for contactless communication of an object with a reader using active load modulation. A main clock signal is generated within the object. The generating includes a calibration phase and a transmission phase. The calibration phase includes locking an output signal of a controlled main oscillator onto a phase and frequency of a secondary clock signal received from the reader and estimating a frequency ratio between a frequency of the output signal of the main oscillator and a reference frequency of a reference signal originating from a reference oscillator. The transmission phase includes only frequency-locking the output signal of the main oscillator onto the frequency of the reference signal corrected by the estimated frequency ratio.

Method of contactless communication between an object and a reader by active load modulation

A multiple phase oscillator includes a master oscillator that injection locks a first ring oscillator. The free-running frequency of the first ring oscillator is adjustable through a control signal. A second ring oscillator has a same structure as the first ring oscillator and is connected to operate in a free-running mode. The free-running frequency of the second ring oscillator is adjustable through the control signal. A control loop senses the output of the second ring oscillator and adjusts the control signal so that the free-running frequency of the second ring oscillator matches a desired value.

Low-noise multiple phase oscillator

An oscillator () comprises a tank circuit (), a first transistor (M) and a second transistor (M), and the second transistor (M) occupies an area of silicon that is smaller than an area of silicon occupied by the first transistor (M). A switching apparatus (Sw. . . Sw) selects either one of a first oscillator topology and a second oscillator topology, where in the first oscillator topology, the tank circuit () is coupled to the first transistor (M) in a first feedback configuration to provide feedback around the first transistor (M), and in the second oscillator topology, the tank circuit () is coupled to the second transistor (M) in a second feedback configuration that is different to the first feedback configuration to provide feedback around the second transistor (M).

Oscillator having dual topology

An electronic circuit element has two capacitance values selected by means of a main control signal. The electronic circuit element comprises two variable-capacitance electronic components connected in parallel and each receiving opposite intermediate control signals, derived from the main control signal. The two variable-capacitance components are differentiated by a configuration parameter. The electronic circuit element exhibits a variation in capacitance corresponding to a difference between respective variations in capacitance of the two variable-capacitance electronic components during an inversion of the main control signal. The variation in capacitance of the electronic circuit element may be less than 5 attoFarads.

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La Terrasse, France

Sebastien Dedieu