Correct Answer - Option 4 : Parallel comparator type
For n-bit conversion, the conversion time for different ADC are:
Counter type ADC: (2n – 1) Tclk
Successive approx. time ADC: n Tclk
Flash type ADC: Tclk
(Flash Type ADC is also known as Parallel comparator type)
Dual slope ADC: (2n+1 – 1) Tclk
The fastest type of Analog to Digital converter is the Flash type / Parallel comparator type.
Important points:
- Counter type ADC and successive approximate ADC uses DAC
- Counter type ADC uses linear search and successive approximation type ADC uses binary search
- Ring counter is used in successive approximation type ADC
- Flash type ADC is the fastest ADC
- Flash type ADC requires no counter
- For an n-bit ADC, flash type ADC requires (2n – 1) comparators
- Dual slope ADC is the most accurate.
