Slide 1: Digital to Analogue Conversion: the mcp4275

Lecture 10

Uli Raich

UCC semester 2017/2018

Slide 2: Analogue versus digital

Up to now we only treated digital signals:

• on/off for the LEDs
• on/off to read the LED state
• Powering or not powering coils to generate magnetic fields in a stepping motor

• Temperatures are changing continuously and not in steps
• Pressure is an analogue value
• Distance, time, current, resistance … are all analogue values

Slide 3: Converting from digital to analogue

Since our computer is a digital device we must

• Convert digital values to analogue voltage levels
  Digital to Analogue Conversion (DAC)
• … and we must convert external analogue values to digital
  Analogue to Digital Conversion (ADC)

Slide 4: Digital to analogue conversion

A digital to analogue converter does not really convert into a continuous waveform
Since we have digital values as a base, there will be steps in the output waveform
The size of these steps depends on the resolution of the DAC
What is the smallest step a 12 bit DAC can produce on a 0..5V scale?

-- Uli Raich - 2017-10-31

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