Patent ID: 6448854
Filing Date: 2002-09-10
Classification: H03F

Abstract:
A linear transconductance amplifier, comprising:a first transistor and a second transistor each having grounded source, the gates of the transistors constituting an input terminal pair; means for forming an addition current by adding currents substantially equal to drain currents of said first transistor and said second transistor; a constant current source for outputting a constant current; and means for forming a subtraction current by subtracting said addition current from said constant current, wherein one differential output current is formed by adding the drain current of said first transistor to a current almost a half of said subtraction current, and the other differential output current is formed by adding the drain current of said second transistor to a current almost a half of said subtraction current, and an input voltage applied to said input terminal pair is a differential voltage superimposed on a constant DC current voltage.