Patent ID: 6714075
Filing Date: 2004-03-30
Classification: H03F,H03G,H03H

Abstract:
A variable gain amplifier comprising:an input node pair receiving a differential signal; a first output node pair; a voltage-current converter for outputting a differential current corresponding to a voltage between one and the other of the input node pair to the first output node pair; a plurality of first resistances connected in series between one and the other of the first output node pair; a first current source connected between a power supply node receiving the supply voltage and one of the first output node pair; a second current source connected between the power supply node and the other of the first output node pair; a second output node pair receiving a voltage at the first output node pair; a third output node pair; and a switch circuit for connecting an interconnection node among interconnection nodes connecting the plurality of first resistances to one of the third output node pair and connecting another interconnection node among the interconnection nodes connecting the plurality of first resistances to the other of the third output node pair.