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q2 spec
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q2 spec
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1
Question
is the process by which analog signals are converted to their digitized forms
Answer
Analog To Digital Conversion
2
Question
ADC occurs via 3 steps
Answer
Sampling, Quantization, Encoding
3
Question
The analog signal is sampled at regular intervals of time
Answer
Sampling
4
Question
must be at least twice the highest frequency of the signal
Answer
sampling rate (Nyquist Criterion)
5
Question
It is defined as the process of converting the continuous sample amplitude into a discrete amplitude. Thus by then, the signal will be discrete in both: time and amplitude
Answer
quantization
6
Question
The difference between the actual analog value and quantized digit value.
Answer
quantization error
7
Question
It is the process which assigns ones and zeros (stream of bits) for every quantization level.
Answer
encoding
8
Question
The number of bits assigned for each level (n) depends on the levels’ number (L); such that L=2n
Answer
encoding
9
Question
resolution of the ADC is the smallest detectable change in voltage
Answer
ideal ADC
10
Question
In an ideal analog-to-digital converter, the quantization error is uniformly distributed between –Δ/2 and Δ/2
Answer
ideal ADC
11
Question
full scale/level's number
Answer
Δ quantization step
12
Question
types of ADCs
Answer
direct conversion ADC, successive approximation register (SAR) ADC, integrating ADCs (single slope, dual slope, ramp ADC), sigma-delta ADC (oversampled)
13
Question
It is one of the most popular ADCs for 8-16 bits
Answer
SAR ADC (Successive Approximation Register)
14
Question
It has moderate conversion speeds. The conversion time is around 1µs.
Answer
SAR ADC (successive approximation register)
15
Question
It doesn’t consume a lot of power and its cost is low in comparison with the other types
Answer
SAR ADC (successive approximation register)
16
Question
It requires a sample, hold circuit, and it can have missing output codes.
Answer
SAR ADC
17
Question
A successive approximation ADC works by using a ___ and a ___ to perform a binary search to find the input voltage.
Answer
digital to analog converter; comparator
18
Question
is used to sample the analog input voltage and hold (e.g. keep a non-charging copy) the sampled value whilst the binary search is performed.
Answer
A sample and hold circuit (S&H)
19
Question
starts with the most significant bit (MSB) and works towards the least significant bit (LSB). For an 8-bit output resolution, 8 comparisons are needed, taking a least 8 cycles.
Answer
binary search
20
Question
samples the analog input on a rising edge of the sample signal. The comparator output is a logic 1 if the sampled analog voltage is greater than the output of the DAC, 0 otherwise.
Answer
sample and hold circuit
21
Question
Is the device which converts digital signals to analog ones
Answer
digital to analog conversion (DAC)
22
Question
consist of a network of resistors and analog switches
Answer
DAC
23
Question
switches control the currents or voltages that are derived from a particular reference voltage and provide analog output current
Answer
DAC
24
Question
types of DAC
Answer
weighted resistor DAC, R-2R DAC, general purpose DAC (DAC 0800), frequency to voltage converter, pulse width modulation
25
Question
8-bit DAC with 16 pins IC
Answer
general purpose (DAC 0800)
26
Question
conversion time around 100ns
Answer
general purpose (DAC 0800)
27
Question
types of adc errors
Answer
offset, gain, nonlinearity, temperature-dependent, load-dependent, hysteresis, resolution, missing code
28
Question
constant component of the error that is independent if the inputs
Answer
offset error
29
Question
difference between the actual transfer ratio and the ideal ratio
Answer
gain error / calibration error
30
Question
deviation of the output quantity from a specified linear reference
Answer
nonlinearity error