Patent ID: 7109796

Claim:
An amplifier circuit with adjustable gain, comprising: an in put terminal pair configured to receive a differential input signal; an output configured to output an amplified version of the differential input signal; a control input configured to supply a gain factor to the amplifier circuit; a cascode stage connected to the output and comprising two cascode transistors coupled together at a control terminal thereof; a plurality of differential amplifiers connected together in parallel, each comprising a respective differential input connected to the input terminal pair, a respective differential output connected to the cascode stage, and a respective activation input, and wherein each differential amplifier further comprises two differential amplifier transistors coupled to a current mirror transistor, and wherein the current mirror transistor is coupled to the activation input and, together with the differential amplifier transistors, is configured to supply a reference current based on a signal at the activation input; and an actuation unit comprising an input connected to the control input of the amplifier circuit, and a plurality of outputs, a respective one of which is connected to the activation input of a respective differential amplifier, and configured to selectively activate one or more differential amplifiers based on the gain factor supplied at the control input.