| 摘要 |
<p>A digital synthesizer for producing a digital frequency signal includes a phase accumulator for repeatedly accumulating a phase value to generate samples of a digital sawtooth signal and a look-up table of digital samples for converting the digital sawtooth signal to a digital waveshape signal. In order to reduce the effect of noise resulting from the truncation of the phase accumulator output for addressing the look-up table, a (first order) sigma-delta modulator is provided for processing the digital sawtooth signal samples output from the phase accumulator before being input to the look-up table. <IMAGE></p> |
