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[on:]

I watch Collin on youtube make his own 8bit DAC!!! Using resistors to divide the voltage (or just watch the video)

 


-- 8bit shift register should do the job nicely, so what about 2 shift registers? 16bit DAC?? surely not? right?

[Reply #1 on:]

P.S if you want a giggle, turn on the CC (like teletext) "english automatic settings" option

Collin talks about Bit Burgers at some point lol (it's google's speech to text engine at fault lol)

[Reply #2 on:]

so what about 2 shift registers? 16bit DAC?? surely not? right?

Works in just the same way

There exist complete R2R components like
- http://www.ece.uidaho.edu/ee/classes/ECE340/Notes/R2R.pdf -
or - http://www.newark.com/bourns/4310r-r2r-103lf/resistor-ladder-n-w-10-10kohm-2/dp/75K9799 -

16 bitters too
- http://www.semiconwell.com/r_net/swr2r16b.htm

[Reply #3 on:]

That's what people meant when they said R2R.

It is practically impossible to build a 8-bit or higher R2R: the resistors required would be too expensive / impossible to get.

[Reply #4 on:]

@dhenry
Is that also true for the components that have a build in R2R? I assume they are calibrated?

[Reply #5 on:]

When you have the luxury of being able to laser trim the R2R network, as a semiconductor fab would have, they are very practical. You can buy 0.1% resistors which will get you a little past 8 bits for around $1.50 each. Home building a 16 bit R2R network would likely take hours of hand sorting with a VERY precise resistor bridge or lots of $$$.

[Reply #6 on:]

The English closed captioning is pretty funny - lots of errors there.

DACs with R2Rs can be laser trimmed at the factory for accurate level at the output:

http://www.analog.com/en/digital-to-analog-converters/audio-da-converters/ad1851/products/product.html

A part like that can be purchased for ~$12 at Digikey
http://www.digikey.com/product-detail/en/AD1851RZ/AD1851RZ-ND/936661

There's also some good information links there too, such as
http://dkc1.digikey.com/us/en/tod/ADI/DataConverterFundamentals/DataConverterFundamentals.html

[Reply #7 on:]

This one on DAC architecture is pretty interesting.
http://dkc1.digikey.com/us/en/tod/ADI/DACArchitectures/DACArchitectures.html

[Reply #8 on:]

DACs without voltage output, i.e. current output DACs, are essentially just precisely trimmed R2R networks, and can be had for less than you can build your own. Much more compact, too.  

[Reply #9 on:]

Can find all kinds of interesting things here:

http://www.digikey.com/PTM/PTMMaster.page?site=us&lang=en

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