Patent ID: 8676148

Claim:
A differential amplifier circuit, comprising: a source follower circuit configured to receive a first signal of differential signals; and a common source circuit connected in series with the source follower circuit and configured to receive a second signal of the differential signals, wherein the source follower circuit comprises: a first transistor configured to receive the first signal; and a second transistor configured to receive the second signal, and the common source circuit comprises: a third transistor connected in series with the first transistor and configured to receive the second signal; and a fourth transistor connected in series with the second transistor and configured to receive the first signal, wherein the first transistor, the second transistor, the third transistor and the fourth transistor are N-channel field-effect transistors, and wherein a first connection point between the first transistor and the third transistor is configured to generate a first output of differential outputs, and a second connection point between the second transistor and the fourth transistor is configured to generate a second output of differential outputs, and further comprising a first bias voltage setting circuit that sets a bias voltage of each of the first transistor and the second transistor; a second bias voltage setting circuit that sets a bias voltage of each of the third transistor and the fourth transistor; and a third bias voltage setting circuit that sets a bias voltage of each of the fifth transistor and the sixth transistor.