| 摘要 |
PURPOSE:To obtain an analog converting output with low cost and high quality by changing a stepwise output waveform by a D/A converter into a slow waveform through linear approximation while using a low-order LPF. CONSTITUTION:Digital data sampled and coded by a prescribed sampling frequency is converted into a step-shaped signal A of a level in response to each code by the D/A converter and sampled D, E by sampling signals B, C phase- shifted by T/2. Then a signal F from a substractor 13 is integrated (G) by an integration device 14, the result is added to a hold output E of a sample-and- hold circuit 12 and an analog signal output is obtained via an LPF16. Since generation of spurious radiation is decreased, the LPF of the next stage is enough for less number of stages. |
