Patent ID: 7375587

Claim:
A variable-gain amplifier, comprising: an amplifier stage; an attenuating network, that can receive an input signal; a plurality of transconductance stages connected between respective nodes of the attenuating network and said amplifier stage, wherein each of said transconductance stages comprises a differential circuit, configured for supplying differential currents to said amplifier stage; and a gain-control circuit for controlling said transconductance stages according to an electrical control quantity; wherein each of said transconductance stages comprises a current-divider circuit associated to said differential circuit and controlled by said gain-control circuit so as to divide said differential currents between said amplifier stage and a dispersion line in proportions that vary according to said control quantity; wherein said control circuit comprises a current-deviator circuit controlled by said electrical control quantity, for dividing a common current among said divider circuits of said transconductance stages proportionally to said electrical control quantity.