| 摘要 |
PURPOSE:To make high-precision conversion possible with a simple constitution, by reducing the number of resistors concerning directly the conversion precision of input/output when the circuit is constituted with differential operational amplifiers, switching elements, and resistors. CONSTITUTION:In case that input voltage Ei is applied to input terminal 1, diode 9 is turned on if Ei is positive, and voltage Ei is subjected to impedance conversion by operational amplifier 11 as it is and appears at output terminal 12. That is, Ei= Eo, (Ei>0) is true. Next, if voltage Ei is negative, diode 9 is turned on, and voltage EN generated at output terminal 10 becomes -(R7/R6)Ei, (Ei<0), and this voltage EN is subjected to impedance conversion as it is and becomes output voltage Eo. If resistances R6 and R7 are equal, Eo=-Ei, (Ei<0) is true, and voltage Eo is obtained as the absolute value of voltage Ei. In this case, the conversion precision is dependent upon resistance values of R6 and R7 and is not dependent upon the precision of many resistances, so that high-precision conversion can be secured with a simple constitution. |
