| 摘要 |
PURPOSE:To synthesize a waveform, whose frequency and amplitude are stable, regardless of a small scale by using a ROM as a digital signal generating circuit which outputs amplitude values as digital data in time division. CONSTITUTION:Digital data of amplitude values at the same time of plural signal waveforms different in frequency are outputted in time division and in order by a ROM3. The output of the ROM3 is attenuated with a prescribed attenuation factor by an attenuator 6 after being converted by a D/A converter 4. The output of the attenuator 6 is given to one input terminal of an adder 7. Since the preceding sample holding value is given to the other input terminal of this adder 7, the output of the attenuator 6 is added successively and is held in a sample and hold circuit 9. Thus, the waveform whose frequency and amplitude are stable is synthesized regardless of a small scale. |
