A 200 mV full-scale dual-slope analog to digital converter (DS-ADC) has a reference voltage of 100 mV. The first integration time is set as 100 ms. The DS-ADC is operated in the continuous conversion mode. The conversion time of the DS-ADC for an input voltage of 123.4 mV (in ms, rounded off to one decimal place) is
Concept:
For a dual-slope analog to digital converter,
De-integration time, \({T_2} = \frac{{{V_i}}}{{{V_{Ref}}}} \times {T_1}\)
Where Vi = input voltage
VRef = reference voltage
T1 is the first integration time
Total conversion time = first integration time (T2) + de-integration time.
Calculation:
Given that, input voltage (Vi) = 123.4 mV
Reference voltage (VR) = 100mV
Integration time (T1) = 100 ms
De-integration time, \({T_2} = \frac{{123.4}}{{100}} \times 100 = 123.4\;ms\)
Total conversion time = 100 + 123.4 = 223.4 msImportant Questions from Analog To Digital Converters
Which is known as flash converter?
- The minimum number of comparators required in a 6-bit flash analog-to-digital converter is ________. (answer in integer)
- The number of comparator required for a 5 bit flash ADC is ____________.
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.
