# digital integrator

#### Chainsaw

Joined Oct 19, 2007
1
I'm building an 8-bit digital integrator that will...well... do the same thing an analog integrator does... integrates! I'm only allowed to use discrete parts, with the exception of: an ADC on the front and a DAC on the back. I am having a great deal of difficulty finding literature pertaining to the subject. I know how an analog integrator works, but I'm having a little trouble figuring out how to apply this to the discrete field. Where do I start?

Thanks,

-Joe

#### beenthere

Joined Apr 20, 2004
15,819
If analog integration can be done with a capacitor accumulating charge, and therefore voltage over time, what do you think the digital equivalent might be?

#### BlackBox

Joined Apr 22, 2007
20
A digital integrator shuld be as simple as an adder. Figure this: the integral (according to Riemann) of a function is the sum of infinite rects with null area.

So if you sample and hold a signal some of these rects (the ones in the same sample/hold period) will have the same width and height, so the area of that period will be:

sample * sample_period

if you add these up for all samples you have the discrete integral.

You just have to use some logic to add all the samples from the A/D Converter up and divide them by the sampling frequency...

Or use a microcontroller