| 摘要 |
PURPOSE:To prevent effectively the generation of distortion, by constituting an input circuit of upper bits with a parallel circuit consisting of an AND circuit and an NAND circuit and controlling switching of the AND circuit and the NAND circuit by an MSB signal. CONSTITUTION:The input circuit of an upper bit 16 weighted with 2<2> is constituted with the parallel circuit consisting of the second gate circuit consisting of an NAND circuit 32 and the third gate circuit consisting of an AND circuit, and changeover of these gate circuits is controlled by an MSB signal 15 to prevent effectively the generation of distortion which is a trouble especially for a small signal. Input circuits of lower bits 17 and 18 are constituted with only the first gate circuits consisting of inverters 28 and 25 to simplify the circuit, and thus, the circuit is superior in characteristic as the whole and is produced inexpensively. A D/A converter having similar constitution can be obtained also when the input digital signal consists of >=4 optional bits. |
