How a DAC operates?

[Miguelón]

Hi everybody!

I’m beginning to learn how a DAC works on its basic principles, just found some articles that first address to how an ADC works.

So far so good, I begin to read the basic circuit of the SAR, but at first 5 minutes appears a control DAC to weight the voltage input. It seems to turn on circles!

Any advice to where I should begin? DAC or ADC?

 

[Purité Audio]

You don’t really need to know how it works but you do need to understand its measurements.
Keith

 

[RandomEar]

Maybe this is helpful? Not yure at what stage of learning you are and what your technical background is. Otherwise, this book looks pretty comprehensive.

 

[JustJones]

If you're looking at audio ADC I believe sigma delta is used not SAR.

you need a place to start after having reviewed the fundamentals of ADC specs, try looking at block diagrams on some of the larger semiconductor sites. There you may find a starting point for parameters that experienced designers have recommended for those applications. Sigma-Deltas can be found in precision measurement devices, weigh scales, communications systems, audio, and more. SARs are great general purpose ADCs that you can find in data-loggers, bridge sensors, temperature sensors, among other things.

Pipeline ADCs are found in applications requiring high speeds, such as wireless communications, instrumentation, test and measurement equipment, imaging systems, radar, and data acquisition.

Sigma Delta ADC vs. SAR vs. Pipeline: How to Choose

Assuming that you are familiar with the fundamental specifications of an ADC and what they mean, the next step is to know your entire signal chain well and then work to fit the ADC to the requirements.

www.analogictips.com

 

[Miguelón]

Maybe this is helpful? Not yure at what stage of learning you are and what your technical background is. Otherwise, this book looks pretty comprehensive.

Thanks for the link and the book!

 

[Miguelón]

You don’t really need to know how it works but you do need to understand its measurements.
Keith

Not need, just curiosity

 

[Miguelón]

If you're looking at audio ADC I believe sigma delta is used not SAR.

Sigma Delta ADC vs. SAR vs. Pipeline: How to Choose

Assuming that you are familiar with the fundamental specifications of an ADC and what they mean, the next step is to know your entire signal chain well and then work to fit the ADC to the requirements.

www.analogictips.com

I begun with an article which started with SAR, I know by popular culture that Sigma Delta is the most used ADC microcontroller

 

[Miguelón]

If you're looking at audio ADC I believe sigma delta is used not SAR.

Sigma Delta ADC vs. SAR vs. Pipeline: How to Choose

Assuming that you are familiar with the fundamental specifications of an ADC and what they mean, the next step is to know your entire signal chain well and then work to fit the ADC to the requirements.

www.analogictips.com

I see, the central idea of sigma-delta is to transform the input number into a density of pulses equal to the number, producing a current average of the desired voltage.

Very interesting, thanks again!

 

[Blumlein 88]

https://www.analog.com/en/resources/technical-articles/sigmadelta-adcs-tutorial.html

This also might help with the Sigma Delta ADC.

I think a better question is do you know in principle how a regular ladder ADC and DAC work? That makes it a little simpler to understand digital audio in general. Then if you know this, learning how sigma delta devices accomplish the same thing differently is simpler to get your head around.

 

[DVDdoug]

To get a rough idea about ADC you could learn about how comparators work. A comparator compares an input voltage to a reference reference voltage and if the input is greater than the reference it puts-out digital-one.

You could build an ADC from comparators but it wouldn't be practical (for the kind of resolution needed for audio) because you'd need one one for every step, not just one per bit.

I believe comparators may be part of how ADCs & DACs work but they aren't used in such a simple way with fixed references.

 

[Miguelón]

do you know in principle how a regular ladder ADC and DAC work?

Nope, is precisely what I’m curious to know. How binary numbers can be transformed in a voltage output. First at the operational stage at ultimately, perhaps, at the electronics

POST EDIT: I see PWM works on more simple way, easier to understand how it acts on the sawtooth waveform

 

[Miguelón]

To get a rough idea about ADC you could learn about how comparators work. A comparator compares an input voltage to a reference reference voltage and if the input is greater than the reference it puts-out digital-one.

You could build an ADC from comparators but it wouldn't be practical (for the kind of resolution needed for audio) because you'd need one one for every step, not just one per bit.

I believe comparators may be part of how ADCs & DACs work but they aren't used in such a simple way with fixed references.

I red a little bit about comparators and how an ADC works, but time ago.

Now I have more time and some little bit more knowledge on binary operations and basic logic gates, some more also on electronics. And more patience, I abandoned the article too soon.

All basic things are welcome, I will search about comparators also.

 

[Blumlein 88]

Start here and then proceed to section 13 and 14 for the DAC part after this initial ADC part.

https://www.electronics-tutorials.ws/combination/analogue-to-digital-converter.html

 

[Miguelón]

Start here and then proceed to section 13 and 14 for the DAC part after this initial ADC part.

https://www.electronics-tutorials.ws/combination/analogue-to-digital-converter.html

Thanks, now I have some lectures to entertain my curiosity for a while. Usually I learn in a quite eclectic way, searching here and there and after a while finding a way…

I see comparators are like logic comparators but inputs being voltages. I had red something about op-amps also when I red about balanced signals.

Many beginners as me, I think, confound balanced with symmetric signals.

 

[DonH56]

There are a number of articles here on ASR about basic sampling theory, DACs, and so forth. See the article ToC linked in my signature, or repeated below.

Recommended reading for new comers and inquisitive minds.

I am sorry for the late reply. But I really appreciate your advice. Covid has put much time back on the shelf for the moment and I have found this forum to be accessible albeit new info in every aspect. When Im not disturbing others with my lack of faith in eyeliner I drift off to dreaming of...

www.audiosciencereview.com

 

[Miguelón]

There are a number of articles here on ASR about basic sampling theory, DACs, and so forth. See the article ToC linked in my signature, or repeated below.

Recommended reading for new comers and inquisitive minds.

I am sorry for the late reply. But I really appreciate your advice. Covid has put much time back on the shelf for the moment and I have found this forum to be accessible albeit new info in every aspect. When Im not disturbing others with my lack of faith in eyeliner I drift off to dreaming of...

www.audiosciencereview.com

More interested in the basic transformation from transistor bit signals on voltage output than on the spurious phenomenon and its correction, but is a good didactic exposition. Always admired Amir’s and other member dedication to diffuse their knowledge.

On of the tremendous advantage of being member in ASR, and the reason I contribute economically, is how barely any question is carefully considered by expert or non experts members (I’m non expert and gave some advices, when they were right were accepted, and were they were wrong corrected).

Is like an ecosystem of knowledge, little fishes we are eaten by big ones, but instead of dying we return wiser

 

[Scytales]

You can also watch this lecture from Jamie Angus on the AES UK youtube channel :

 

[Miguelón]

You can also watch this lecture from Jamie Angus on the AES UK youtube channel :

Thanks! Video lectures are more engaging than dry articles, love them!

 

[Scytales]

Lectures and reading must go hand to hand !

 

[Miguelón]

Lectures and reading must go hand to hand !

Totally agree, but I think from time to time animations can help a lot and is refreshing to see a human being explaining things on video.

Years ago, since I have mathematics formation, I wished to learn general relativity on a formal basis. Not learning how solve problems on this theory but going above the divulgation level and feel the mechanism on the equations.

Articles are extremely hard on the topic, even with my undergraduate formation, and two courses of MIT and another university (I don’t remember) helped me to support the weight of the articles in a more comprehensive way.

Teachers on the topic were Leonard Suskind and Alexander Fluorny, if anyone is by any reason interested in this fascinating theory