| 摘要 |
PURPOSE:To obtain a buffer amplifier circuit which is low in its output impedance and also executes an electrostatic protection by providing an electrostatic protecting circuit between an output terminal and an inversion input terminal of an MOS differential amplifier. CONSTITUTION:A non-inversion input terminal 2 of an MOS differential amplifier 1 is connected to an external input terminal 5, an electrostatic protecting circuit 7 is connected between an output terminal 4 and an inversion input terminal 3, and the output terminal 4 is connected to an external output terminal 6. By forming a buffer amplifier circuit in this way, the output impedance viewed from the external output terminal 6 is not influenced by a resistance value of the electrostatic protecting circuit 7. Also, the inversion input terminal 3 is connected to the external output terminal 6 through the electrostatic protecting circuit 7, therefore, the protection against static electricity is executed sufficiently. In this way, it is possible to obtain a buffer amplifier circuit which is low in its output impedance and also executes an electrostatic protection. |
