What type of synthesizer circuit uses a phase comparator, look-up table, digital-to-analog converter, and a low-pass antialias filter?

What type of synthesizer circuit uses a phase comparator, look-up table, digital-to-analog converter, and a low-pass antialias filter?

• A. A direct digital synthesizer
• B. A phase-locked loop
• C. An analog synthesizer
• D. A frequency modulation synthesizer

Answer: (A)

The correct choice is a direct digital synthesizer, which is a type of synthesizer that generates waveform signals directly from digital data. This method relies on several key components to produce high-quality audio signals. The phase comparator is used to compare the phase of an incoming signal with that of the oscillator output, enabling precise control over the frequency and phase of the generated signal. The look-up table holds the waveform data, which allows the synthesizer to access predefined waveforms like sine, square, or triangular waves efficiently. The digital-to-analog converter (DAC) is responsible for converting the digital signal from the look-up table into an analog waveform, making it usable in audio applications. Lastly, the low-pass antialias filter smooths out the output of the DAC, preventing high-frequency artifacts caused by the digital conversion process that can distort the audio signal. In contrast, a phase-locked loop primarily functions to maintain the frequency of an oscillator in lock with a reference frequency, rather than generating complex waveforms directly. An analog synthesizer typically involves voltage-controlled oscillators and does not inherently use digital components like a DAC. A frequency modulation synthesizer focuses on modulating a carrier wave's frequency rather than relying on the direct numeric representation of waveforms in digital

The correct choice is a direct digital synthesizer, which is a type of synthesizer that generates waveform signals directly from digital data. This method relies on several key components to produce high-quality audio signals.

The phase comparator is used to compare the phase of an incoming signal with that of the oscillator output, enabling precise control over the frequency and phase of the generated signal. The look-up table holds the waveform data, which allows the synthesizer to access predefined waveforms like sine, square, or triangular waves efficiently. The digital-to-analog converter (DAC) is responsible for converting the digital signal from the look-up table into an analog waveform, making it usable in audio applications. Lastly, the low-pass antialias filter smooths out the output of the DAC, preventing high-frequency artifacts caused by the digital conversion process that can distort the audio signal.

In contrast, a phase-locked loop primarily functions to maintain the frequency of an oscillator in lock with a reference frequency, rather than generating complex waveforms directly. An analog synthesizer typically involves voltage-controlled oscillators and does not inherently use digital components like a DAC. A frequency modulation synthesizer focuses on modulating a carrier wave's frequency rather than relying on the direct numeric representation of waveforms in digital