Important Digital Logic and Design Short Questions
Chapter: 44
Question 1:
Explain the concept of quantization in analogue to digital conversion.
Answer:
Quantization is the process of converting an analogue signal into a digital representation by dividing the signal into discrete levels. The number of bits used determines the accuracy of the digital representation.
Chapter: 44
Question 2:
What is the role of the Sample and Hold circuit in A/D conversion?
Answer:
The Sample and Hold circuit samples the analogue signal at regular intervals and maintains the sampled value stable long enough for the A/D converter to process it into a digital value.
Chapter: 44
Question 3:
How does the Nyquist Criteria relate to the sampling frequency?
Answer:
The Nyquist Criteria states that the sampling frequency must be at least twice the maximum frequency of the analogue signal to accurately represent the signal without aliasing.
Chapter: 44
Question 4:
Describe how a Flash A/D Converter operates.
Answer:
A Flash A/D Converter uses a resistor ladder to create reference voltages, which are compared against the input voltage by multiple comparators. The outputs are then encoded into a binary value by a priority encoder.
Chapter: 44
Question 5:
What is the primary advantage of Flash A/D Converters?
Answer:
The primary advantage of Flash A/D Converters is their high-speed operation, as they perform conversion in parallel and provide almost instantaneous binary output.
Chapter: 44
Question 6:
How does a Dual-Slope A/D Converter differ from a Flash A/D Converter?
Answer:
A Dual-Slope A/D Converter is slower and uses an integrating process to convert the analogue input, whereas a Flash A/D Converter uses parallel comparators for rapid conversion. The Dual-Slope Converter is often used for its precision in applications like digital voltmeters.
Chapter: 45
Question 7:
What is a Successive-Approximation Analog to Digital Converter (A/D converter)?
Answer:
A Successive-Approximation A/D converter is a device that converts analog values to binary values. It uses a Successive Approximation Register (SAR), a Digital to Analog Converter (DAC), and a Comparator.
Chapter: 45
Question 8:
How does the Successive-Approximation A/D converter determine the binary value of an analog signal?
Answer:
The converter applies the analog signal to the comparator and uses the SAR to adjust the binary input. It compares the DAC output with the analog signal to set or reset the bits until the final binary value is obtained.
Chapter: 45
Question 9:
What are the main components of a Successive-Approximation A/D Converter?
Answer:
The main components are the Successive Approximation Register (SAR), Digital to Analog Converter (DAC), and Comparator.
Chapter: 45
Question 10:
What is the primary advantage of a Successive-Approximation A/D converter over a Dual-Slope A/D converter?
Answer:
It has a fixed conversion time and is generally faster than the Dual-Slope A/D converter.