| 摘要 |
The analog signal generator consists of a code word generating unit (1) for N bits, and an analog-numerical converter (2) with its input coded for N-M bits, M being smaller than N. It also has a sigma-delta modulator (21) with overflows, and the bus at the output from the unit is separated into M high order bits coding a usable signal and N-M low order bits including the truncation error. The N-M low order bits enter the sigma-delta modulator, the output of which is added to the usable signal by a numerical addition unit (23), and the result provides the input signal for the analog-numerical converter. The order of the modulator is raised so that the amplitude of the output signal is close to or above that of the usable signal. |
