Patent ID: 6906588

Claim:
A variable-gain amplifier with differential input and output, comprising: an attenuator block referenced to a common mode voltage of an output of the amplifier, receiving an input voltage and adapted to providing, on several outputs, voltages, each of which is equal to the input voltage attenuated according to a predetermined ratio, differential transconductor elements controllable by a current, each differential transconductor element having a first input connected to an output of the attenuator block, each differential transconductor element generating first and second positive currents and first and second negative currents, a current source assembly adapted to controlling the transconductance of each differential transconductor element according to an analog control signal, and an output block converting first and second input currents into a differential output voltage and providing a second input of each differential transconductor element with a feedback voltage depending on the output voltage, the first input current being equal to the sum of the first positive currents and of the second negative currents and the second input current being equal to the sum of the second positive currents and of the first negative currents.