DIFFERENTIAL AMPLIFIER DEVICE

摘要

PURPOSE: To obtain a differential amplifier device in which a slew rate is improved and power consumption is decreased. CONSTITUTION: The device is provided with a drive transistor(TR) 3 supplying a current in a direction the same as that of a constant current source TR 21 of an output circuit 2 and a switch circuit 4 controlling on/off of the drive TR 3 in response to an output voltage Vx of the differential circuit 1 in addition to the differential circuit 1 and the output circuit 2. The switch circuit 4 provides a drive signal to the drive TR 3 to conduct it when the output voltage Vx of the differential circuit 1 is lower than a prescribed threshold voltage and stops the provision of the drive signal to the drive TR 3 to cut it off when the output voltage Vx of the differential circuit 1 is higher than the prescribed threshold voltage. The prescribed threshold voltage is set lower than the output voltage Vx of the differential circuit 1 when a current is going to flow to the control TR 22.