Successive Approximation Analog-to-Digital Converter (ADC)

1. Successive Approximation Analog-to-Digital Converter (ADC) Presented by: Alex Pugh, Andrew Page, Nick Gabrisko https://en.wikipedia.org/wiki/Successive_approximation_ADC#/media/File:SA_ADC_block_diagram.png

2. What is it? One of most common methods of conversion when sample rate is under 10 MSPS (Megasamples per second) Ideal for multichannel data acquisition systems Resolutions between 8-16 bits

3. How does it work? Samples and holds analog signal For each bit, a successive approximation register analyzes it and outputs binary to a digital-to-analog converter that is dependent on the current bit and all previously approximated After the DAC, a comparator compares the voltage of the analog to the digital, and continually loops until they are equivalent

4. What is the point? It provides information that the arduino can easily understand. It has a low power consumption compared to one of its rival ADC’s, the flash ADC, at a trade-off of processing a little slower, but when it comes to data gathering with limited power supplies in battery packs, saving energy is far more important than more processing speed.

5. Examples of Usage ADXL326 Accelerometer GUVA UV sensor Microphone (Any sensor that plugs into analog pins)

6. Advantages and Disadvantages • Advantages: • Conversion time is very small and independent of the amplitude of the signal. • Good speed to power ratio • Disadvantages: • It may be fast, but it’s slower than a flash ADC, that uses a linear ‘voltage ladder’ and compares the input voltage to each ‘rung’ of the ladder • It’s a somewhat complex circuit

7. Sources https://myesp8266.blogspot.com/2015/12/various-accelorometers-adxl345-with.html http://ecetutorials.com/digital-electronics/successive-approximation-adc-analog-to-digital-converter/ http://www.electronics-tutorial.net/analog-integrated-circuits/data-converters/successive-approximation-type-adc/ https://en.wikipedia.org/wiki/Successive_approximation_ADC