说明：  AD9954: 400 MSPS, 14-Bit, 1.8 V CMOS, Direct Digital Synthesizer. IBIS model. The AD9954 is a direct digital synthesizer (DDS) that uses advanced technology, coupled with an internal high speed, high performance DAC to form a complete, digitally programmable, high frequency synthesizer capable of generating a frequency-agile analog output sinusoidal waveform at up to 160 MHz.