Data converters: ADCs

What is ADC?

• An electronic integrated circuit which transforms a signalfrom analog (continous) to digital (discrete) form.
• Analog signals are directly measurable quantities
• Digital signals only have to states. For digital computer we refer to binary states, 0, 1

Application of ADC

• ADC are used virtually everywhere where an analog signal has to be processed, stored, or transported in digital form
• Some examples of ADC usage are digital volt meters, cell phone, thermocouples and digital oscilloscope
• Microcontrollers commonly use 8, 10, 12 or 16 bit ADCs

ADC process

2 steps:

1. Sampling and holding (S/H)
2. Quantizing and Encoding (Q/E)

Holding signal benefits the accuracy of the A/D conversion

Minimum samling rate should be at least twice the highest data frequency of the analog signal

Quantizing and Encoding

Resolution:

The smallest change in analog signal that will result in change in the digital output

$$ \Delta V= \frac{V_r}{2^N} $$

V - reference voltage range