Explanation: The number of comparator required almost doubles for each added bit. For example – 2 -bit ADC requires three comparators, 3 -bit ADC needs seven comparators and a 4 -bit ADC requires fifteen comparators. 8. Drawback of counter type A/D converter
A. Counter clears automatically
B. More complex
C. High conversion time
D. Low speed
Answer:A
Explanation: The number of comparator required almost doubles for each added bit. For example – 2 -bit ADC requires three comparators, 3 -bit ADC needs seven comparators and a 4 -bit ADC requires fifteen comparators. 8. Drawback of counter type A/D converter
A. Counter clears automatically B. More complex C. High conversion time D. Low speed
Explanation: In counter type ADC counter frequency is kept low enough to give sufficient time for DAC to settle and for the comparator for respond. So, low speed is the most serious drawback. 9. Calculate the conversion time of a 12-bit counter type ADC with 1MHz clock frequent to convert a full scale input?