| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an operational amplifier which is not large in the circuit scale, does not generate intermodulation distortion because a clock signal is not used, and has a small offset drift voltage. Ž<P>SOLUTION: An operational amplifier includes MOS transistors 1 to 5 and 20 to 24, a first operational amplifier 25, a bias terminal 9 and a reference voltage terminal 26. A differential amplifying circuit 12 that has a pair of input MOS transistors 1 and 2, a current source 5, a positive power supply terminal 11, and a negative power supply terminal 10 is included. A bias circuit 13 for controlling the current of the current source 5 is connected to the current source 5 of the differential amplifying circuit 12 so as to reduce the offset temperature drift. The bias circuit 13 is configured for controlling the current of the current source 5 so that the temperature characteristic of the current, supplied from the current source 5 to the pair of input MOS transistors 1 and 2, is identical to that of the temperature characteristic of the carrier mobility of the pair of input MOS transistors 1 and 2. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
