| 摘要 |
PURPOSE:To attain the gain adjustment around the boundary of regions of a gain control signal with sub-switches only, by overlapping the adjacent regions relating to the region of the gain control signal designated by main switches. CONSTITUTION:The main switches SA-SE and sub-switches S0-S7 are provided. The main switches designate a prescribed region in the gain control and the sub-switches designate a prescribed value in the region. A code converting circuit 9 generates a code corresponding to the main switches SA-SE switched selectively and the code is applied to a full adder 6. The selecting region of the main switches is formed so that each adjacent section is overlapped with each other. A selecting signal from the sub-switches S0-S7 is applied to the full adder 6 via an encoder 3. The full adder 6 outputs gain control signals C0-C4 designated with the main and the sub-switches. Thus, the minute adjustment at the boundary of the regions is attained with the sub-switches only. |
