Successive Approximation ADC and Fixed Conversion Time

Successive Approximation ADC
Successive Approximation ADC is a type of analog-to-digital converter that uses a binary search algorithm to convert an analog signal into a digital signal. It is one of the most commonly used ADCs because of its high accuracy and speed. The conversion process in a successive approximation ADC is done by comparing the input signal with a reference voltage and then adjusting the reference voltage until it matches the input signal.

Fixed Conversion Time
Fixed conversion time is the time it takes for an ADC to convert an input signal into a digital signal. In an ADC with a fixed conversion time, the conversion time is constant and does not change with the input signal.

Answer
The correct answer is option 'C' - Successive Approximation converter. Successive Approximation ADC has a fixed conversion time because the conversion process is done in a fixed number of steps, regardless of the input signal. The conversion time in a successive approximation ADC depends on the number of bits used for the conversion. For example, a 10-bit successive approximation ADC will take a fixed amount of time to convert an input signal into a 10-bit digital signal, regardless of the input signal.

Other types of ADCs, such as counter type digital ramp and tracking type, do not have a fixed conversion time. In a counter type digital ramp ADC, the conversion time depends on the rate at which the digital ramp is counted. In a tracking type ADC, the conversion time depends on the rate at which the input signal changes. Finally, dual slope ADCs have a fixed conversion time for a given input signal, but the conversion time can vary with different input signals.