| 摘要 |
PURPOSE:To suppress the approximate error of the function amplifier smaller, by constituting the amplifier with the first variable amplifier, separate function amplifier, second variable amplifier, and control amplifier and controlling the amplification factor of two variable amplifiers with the output of the control amplifier. CONSTITUTION:The input voltage x is fed to the first variable amplifier of the amplification factor g(a), the output of the amplifier 4 is to the separation function amplifier 5 having the amplification factor f(x), and the output of the amplifier 5 is fed to the second variable amplifier 6 having the amplification factor h(a). The amplification factor of the amplifiers 4 and 6 is controlled with the output of the control amplifier 7 depending on the input voltage x. When the input voltage x is comparatively small, and when the control amplifier 7 controls the amplifier 4 to g(a)=1/a, amplifier 6 to h(a)=1/f(1/f), the output of the amplifier 6 is f(x). When x is comparatively larger, and when the amplifier 7 controls the amplification factor of the amplifiers 4 and 6 so that g(a)=1 and h(a)=1, the output is f(x). Accordingly, the apporximation due to a number of polygonal lines is independently of the amplitude of x, and the error can be less. |
