Abstract
A kind of differential amplifier having negative conductance circuit includes one differential input pair; one current source connected to the differential input pair; the first and the second transistors, which are provided with the first conductance and are connected to the differential input pair for use as the first active load; the third and the fourth transistors, which are provided with the second conductance and are connected to the differential input pair for use as the second active load; and two output terminals, which are respectively led out from the differential input pair. The ratio between the first conductance and the second conductance is larger than 1 such that the gain of amplifier is greatly increased without changing its frequency bandwidth under the same operation voltage and consumed power.