Method and device for transmitting data by charge modulation
AssigneeInside Secure
InventorMichel Martin
Life of this patent
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Abstract
A contactless data transmission device includes an antenna circuit supplying an alternating voltage in the presence of an alternating excitation field, a charge modulation transistor having a control terminal receiving a charge modulation signal having at least one low state and one high state, and a conduction terminal receiving the alternating voltage. The device includes a circuit for supplying a boosted direct voltage greater than a peak value of the alternating voltage supplied by the antenna circuit, and a circuit for applying to the control terminal of the charge modulation transistor a charge modulation signal which, in the high state, has a voltage level equal to the boosted direct voltage.
Claims19
A contactless data transmission device comprising:
- an antenna circuit supplying an alternating voltage in the presence of an alternating excitation field;
- a charge modulation transistor having a control terminal receiving a charge modulation signal having at least one low state and one high state, and a conduction terminal receiving the alternating voltage;
- a rectifier circuit for producing, from the alternating voltage, an unboosted direct voltage, and a control circuit electrically powered by the unboosted direct voltage, for supplying a first charge modulation signal which, in the high state, has an unboosted voltage level;
- and
- a booster circuit for supplying a boosted direct voltage greater than a peak value of the alternating voltage, the booster circuit comprising a voltage adaptation circuit for transforming the first charge modulation signal into a second charge modulation signal which, in the high state, has a voltage level equal to the boosted direct voltage, the second charge modulation signal being applied to the control terminal of the charge modulation transistor.
A contactless data transmission method by inductive coupling and charge modulation, the method comprising:
- providing an antenna circuit supplying an alternating voltage in the presence of an alternating excitation field;
- providing a charge modulation transistor having a control terminal for receiving a charge modulation signal having at least one low state and one high state, and a conduction terminal linked to a terminal of the antenna circuit and receiving the alternating voltage supplied by the antenna circuit;
- providing a rectifier circuit for producing, from the alternating voltage, an unboosted direct voltage;
- providing a control circuit electrically powered by the unboosted direct voltage, for supplying a first charge modulation signal which, in the high state, has an unboosted voltage level;
- producing a boosted direct voltage greater than the peak value of the alternating voltage;
- transforming the first charge modulation signal into a second charge modulation signal which, in the high state, has a voltage level equal to the boosted direct voltage;
- and
- applying the second charge modulation signal to the control terminal of the modulation transistor.
Dependencies are inferred from the claim text.