Flashcards on Fundamentals of Digital Signal Processing
Fundamentals of Digital Signal Processing: Your Complete Guide
Tap to flip · Swipe to navigate
Analog-to-digital conversion
36 cards
Card 1
Question: What is an Analog-to-Digital Converter (ADC)?
Answer: A device that converts an analog signal (usually an electrical voltage) into a digital signal.
Card 2
Question: What are the two main phases of analog-to-digital conversion and what does each do?
Answer: Sampling: discretization in time, freezing the signal value at the sampling instant. Measuring (quantization): discretization in value, converting the
Card 3
Question: What factors determine ADC design?
Answer: Sampling rate, number of binary digits (resolution), and price.
Card 4
Question: What is the role of a Sample-and-Hold (S/H) circuit in ADCs?
Answer: Driven by a clock, it holds the signal value during the time needed for conversion, usually implemented with a capacitor and an electronic switch.
Card 5
Question: How does the technology choice for an ADC depend on performance requirements?
Answer: The technology is determined by required sampling rate (conversion time) and resolution.
Card 6
Question: Explain how an ADC transforms a continuous analog signal into the digital output shown as steps.
Answer: The S/H circuit produces a staircase signal by freezing samples; the measuring circuit quantizes each sample into a digital value, producing the digit
Card 7
Question: Give typical ADC resolutions and common usages for 8-, 10–12-, 16-, and 20–24-bit converters.
Answer: 8 bits (256 levels): telephony, TV video per color. 10–12 bits (1024–4096): microcontroller-built converters for device control and sensors. 16 bits (
Card 8
Question: Why are high resolution ADCs (beyond ~16 bits) often not practical?
Answer: Because the quantization step becomes comparable with thermal noise and higher resolutions are limited by technological noise and slower speeds.
Card 9
Question: What is a Digital-to-Analog Converter (DAC) and what are its conceptual phases?
Answer: A DAC transforms digital signals into analog signals. Conceptually it has two phases: converting numbers to physical samples and signal interpolation,
Card 10
Question: Why is an LP (low-pass) filter used after a DAC that produces a staircase signal?
Answer: To remove unwanted higher-frequency spectral components introduced by the staircase steps, yielding a smoother analog signal.