A flash Analog-to-Digital Converter (ADC) determines the digital equivalent of an analog input by comparing the input voltage against multiple reference voltages simultaneously. Each comparison requires a comparator circuit.
The minimum number of comparators required for an N-bit flash ADC is determined by the number of quantization levels needed. For N bits, there are possible output codes. Each code transition requires a comparison point.
The formula to calculate the minimum number of comparators (C) for an N-bit flash ADC is:
Given that the flash ADC is 6-bit, we have N = 6.
Substitute N = 6 into the formula:
Calculate the value:
Therefore, the minimum number of comparators required for a 6-bit flash ADC is 63.
In successive approximation converter input to the comparator is through
Assertion (A) : Dual slope (A/D) converter is the most preferred conversion technique employed in most of the digital multimeters.
Reason (R) : Dual slope (A/D) converter provides high accuracy while at the same time suppresses the HUM effect on the input signal.
A dual slope A to D converter has the following :
(a) a differentiator
(b) a comparator
(c) an integrator
(d) a binary counter
Out of above, following is correct :
For A to D converters, following statements are given :
(a) It is the process of converting time varying input to discrete output levels.
(b) Flash type A/D conversion are slow in nature.
(c) The quantisation error depends upon the step size of quantisation.
(d) Flash type A/D conversion is a simultaneous conversion.
Which of the above are correct ?