Analog Circuits - Types of ADC

ADC is an integral part of embedded applications. There are several types of ADC available in the market. The type of ADC used depends on the application requirements. Some of the factors which determine the type of ADC to be used are:

• Power Consumption
• Speed
• Resolution
•  Availability (biggest problem with the current component scenario). However, you need not worry if you are working on a hobby project :-)
• Accuracy

To select on ADC, we must have clear understanding of what we have to achieve:

• What are the signal levels
• At what rate signal is going to change
• what impedance path signal is going to take
• how much time ADC takes to convert

Here is an architecture of Successive approximation ADC which is commonly seen in the micro controllers.

If the speeds of various ADC are compared,

Pipeline ADC > SAR ADC > Sigma-Delta ADC