Patent ID: 8723593

Claim:
A bias voltage generation circuit which generates a bias voltage to be supplied to a current source of a differential circuit through which a variable bias current flows, comprising: a first current source one end of which is connected to a first power source; a first transistor which is diode connected and is connected to the other end of the first current source; a second transistor which is connected between the first transistor and a second power source and includes a control electrode connected to a control electrode of the first transistor; a second current source one end of which is connected to the first power source; a third transistor which is connected to the other end of the second current source; a fourth transistor which is connected between the third transistor and the second power source and includes a control electrode connected to the second current source; a first output point which is connected to the control electrode of the first transistor and a control electrode of the third transistor and outputs a first bias voltage; a second output point which is connected to the control electrode of the fourth transistor and the second current source and outputs a second bias voltage; and a bias voltage adjusting circuit which adjusts the first bias voltage in accordance with a control input.