Patent ID: 8040187

Claim:
A semiconductor integrated circuit device comprising: an amplification portion including a first transistor configured to inversely amplify an input signal inputted to a gate and output the inversely amplified input signal from a drain; a cascode current source including the first transistor, a second transistor having a drain connected to a source of the first transistor and a source connected to a reference potential point to supply a bias current to the first transistor, a third transistor having a gate to which only a DC component out of an AC component and the DC component included in a voltage applied to the gate of the first transistor is applied, a fourth transistor having a gate connected to a gate of the second transistor, and a current source, and configured to control the bias current based on a current flowing into the current source; and a first element portion configured to block an AC signal and pass through a DC signal between the drain of the first transistor and the gates of the first and third transistors.