Question

What is successive Approximation, discuss them in detail.

Answer 1

A successive approximation ADC is a type of analog-to-digital converter that converts a continuous analog waveform into a discrete digital representation via a binary search through all possible quantization levels before finally converging upon a digital output for each conversion.

Fig: Successive approximation ADC block diagram

Key

• DAC = digital-to-analog converter
• EOC = end of conversion
• SAR = successive approximation register
• S/H = sample and hold circuit
• V_in = input voltage
• V_ref = reference voltage

Algorithm:

The successive approximation analog-to-digital converter circuit typically consists of four chief subcircuits:

1. A sample and hold circuit to acquire the input voltage (V_in).
2. An analog voltage comparator that compares V_in to the output of the internal DAC and outputs the result of the comparison to the successive approximation register (SAR).
3. A successive approximation register subcircuit designed to supply an approximate digital code of V_in to the internal DAC.
4. An internal reference DAC that, for comparison with V_REF, supplies the comparator with an analog voltage equal to the digital code output of the SAR_in.

I clearly explained and provided the block diagram for successive approximation ADC. Hope you understand. Thank you!!!