| 摘要 |
PURPOSE:To vary the ratio of an input signal level to an output signal level exponentially, by changing the amplification factor of an operational amplifying circuit through the opening and closing of a switch controlled with a digital control signal. CONSTITUTION:The titled controller consists of a circuit which outputs a plurality of switching digital control signals D0-D2 in parallel through the combination of a plurality of bits, and an operational amplifying circuit 2 which is connected with a plurality of switches S0-S2 switched with the plurality of digital control signals D0-D2 respectively, the amplification factor of which is changed through the combination of switching of the plurality of switches S0-S2, and in which the input and output signal levels can be varied exponentially. Thus, the switching of the switches S0-S2 is suitably combined with an output of, e.g. a microcomputer 5, an input signal is exponentially increased or decreased with a simple constitution, allowing to pick up an output signal. |
