| 摘要 |
PURPOSE:To allow the titled circuit to be operated sufficiently even to an input signal of a low level by providing the 3rd differential circuit applying differential amplification in place of the 1st differential circuit and its switching control means when the 1st input signal is at a low level. CONSTITUTION:When the level of the 1st input signal 120a is at a low level, a transistor (TR) 137 is turned on, and when a TR 105 is turned off, a differential circuit 138 is operated. The output of the differential circuit 138 depend on load circuits 131, 132, its level characteristic is expanded toward the low level and the output of the differential circuit 138 is increased by increasing values of the load circuits 131, 132. Thus, a large output is inputted to a dual differential circuit 123 from the differential circuit 138 an a multiplication output 126a between the 1st input signal 120a and the 2nd input signal 121a is extracted sufficiently from an output terminal 126. |
