| 摘要 |
PURPOSE:To attain addition or subtraction without causing distortion to a signal by using a drive current of an emitter coupled pair in common for a drive current of a feedback loop of a feedback buffer. CONSTITUTION:A signal inputted to a base of a transistor(TR) Q1 is V1+S1. Since a base-emitter voltage of TRs Q1, Q2 is equal to each other, the base voltage of the TR Q2 is V1+S1. On the other hand, a signal inputted to a base of a TR Q4 is V2+S2, and a DC voltage V2 is inputted to a base of a TR Q5. The output voltage is V1-R1I4+S1+S2 and it is a sum of the signals S1, S2 when only the AC signal is noticed. Thus, it is possible to apply addition or subtraction processing to plural kinds of signals without being affected of a temperature change and causing signal deterioration. |
