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Gilbert Decaens

A first input receiving a voltage to be sampled formed by a terminal of a sampling capacitor. An amplifier has a first input connected to another terminal of the sampling capacitor and a second input connected to a reference voltage. The amplifier is supplied by a power supply configured to deliver a reduced current and to supply the amplifier in a first condition during a first period, deliver a rated current and to supply the amplifier in a second condition during a second period, the reduced current being lower than the rated current. During the first period, the first and second inputs of the amplifier are short-circuited.

Sampling device

The analog-to-digital converter includes a first stage in which a voltage to be converted is applied to the input of a first comparator. The first comparator delivers, on a first digital output, a first digital result representative of the comparison between the voltage to be converted and the comparison voltage. The first digital output is connected to a calculator of a first intermediate voltage. A second comparator compares the first intermediate voltage with the comparison voltage and delivers a second digital result on a second digital output terminal. The second digital output terminal is connected to a second calculator of residual voltage that is a function of the voltage to be converted, of first and second voltages and of the first and second digital results. The first calculator is formed by the second calculator.

Successive approximation analog-to-digital converter

The analog-to-digital converter comprises a first stage in which a voltage to be converted is applied to the input of a first comparator. The first comparator delivers a first digital result representative of the comparison between the voltage to be converted and the reference voltage on a first digital output. The first digital output is connected to means for calculating a first intermediate voltage. A second comparator compares the first intermediate voltage with the reference voltage and delivers a second digital result on a second digital output terminal. The digital output terminal is connected to second means for calculating a residual voltage according to the voltage to be converted, the first and second voltages and the first and second digital results.

Analog-to-digital converter on two bits with successive approximations

The acquisition circuit comprises a second and third electronic switch connected in series between a photodetector and a first input terminal of an amplifier. A reference voltage is applied to a second input terminal of the amplifier, the reference voltage being applied between the photodetector and the second electronic switch by means of a fourth electronic switch. An integration capacitor and a first electronic switch are connected in parallel between the first input terminal and an output terminal of the amplifier. A buffer capacitor is connected between a common terminal of the second and third electronic switches and a secondary voltage. The electrical capacitance of the buffer capacitor is at least equal to that of the integration capacitor.

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Grenoble, France

Gilbert Decaens