直接数字频率合成器（Direct Digital synthesizer）是从相位概念出发直接合成所需波形的一种频率合成技术。一个直接数字频率合成器由相位累加器、加法器、波形存储ROM、D/A转换器和低通滤波器（LPF）构成-Direct digital frequency synthesizer (Direct Digital synthesizer) is the concept of direct synthesis from the requirements phase of a waveform synthesizer technology. A direct digital frequency synthesizer by the phase accumulator, adder, waveform storage ROM, D/A converter and low pass filter (LPF) constitute