| 摘要 |
PROBLEM TO BE SOLVED: To control voltage amplitude of an output, independently of a reference potential by controlling switches with the respective bits of (n)-bit digital data, controlling the charging and discharging of electric charges to capacitors connected to the respective switches, and outputting an analog signal based upon an offset voltage as the reference potential. SOLUTION: A power source VH, a power source VL, an offset power source VB, and a power source VA are connected to a DAC. When VH>VL and when VH<VL, an analog signal which is opposite in phase is outputted to an output Vout. Switches SW0 to SWn-1 are connected to the power source VL, when input digital data D0 to Dn-1 are 0 (Lo) and to the power source VH, when the input digital data are 1 (Hi). A reset switch Res1 controls the charging of electric charges from the VB to capacitors (C,..., 2n-m-1C), corresponding to the higher-order (n-m) bits a reset switch Res2 controls are charging of electric charges from the VA to capacitors (C,..., 2m-1C) corresponding to the lower-order (m) bits. |
