Getting Started

Chapter 9 – Digital Meets Analog – ADC and DAC

depend s
analog is
change
atomic,
step in
way.

ng his head, said, “Son, a difference that

hat

p there in philosopher heaven Heraclitus and Democritus

each other a big hug.

e wa lue
hatev
ways t d
weaknesses, we will examine successive approximation since that is what the

s on your perspective. To electronics, Heraclitus was right and the world i

and you can’t step in the same river twice since the only constant

. To computers, Democritus was right, the world is digital (well, he said
but it’s the same thing philosophically speaking) and you can theoretically
the same river twice if you arrange the atoms (bits) of the river the same

Another professor of mine, also shaki
makes no difference is no difference!” So Let’s drop this right here and say t
the world we want to control is analog and the world we will use to control it is
digital, and somewhere u
can give

Analog to Digital Conversion by Successive Approximation

W nt to measure voltage, and in the real world, voltages can be any va
w er, they represent a continuum of electromotive force. There are many
o conv rte an analog signal to a digital value each having strengths an

AVR uses.

10 -bit DAC

Analog Input

Successive Approximation

Register

ComparatAnalogor

Control Logic

Data Registers

Oscillator

Start Conversion

End Conversion

Figure 27: 10-bit successive approximation ADC Figure...................................