| Author |
Message |
corex
Joined: Mar 02, 2010
Posts: 100
Location: Las Vegas
|
 Posted: Tue May 15, 2012 4:03 pm Post subject:
Locate an 8-bit R/2R ladder? |
  |
|
I found this 6-bit R/2R ladder by Murata, and they make an 8-bit version but Mouser doesn't carry it. Anyone know where I could find something like this?
For my application, I'd rather not use a parallel DAC. If I can't find an 8-bit ladder I will probably just hand-wire a less precise one with discrete resistors. |
|
|
Back to top
|
|
 |
JingleJoe
Joined: Nov 10, 2011
Posts: 789
Location: Lancashire, England
Audio files: 14
|
| Posted: Wed May 16, 2012 2:56 am Post subject:
|
|
|
I'd just suggest you make your own from resistors, I doubt it will be much less accurate and besides, you can get something like 0.1% tolerance resistors inexpensively, surely that's accurate enough?
_________________
As a mad scientist I am ruled by the dictum of science: "I can't really be certain but I think I might have an idea"
Green Dungeon Alchemist Laboratories |
|
|
Back to top
|
|
|
corex
Joined: Mar 02, 2010
Posts: 100
Location: Las Vegas
|
| Posted: Wed May 16, 2012 10:01 am Post subject:
|
|
|
| JingleJoe wrote: | | I'd just suggest you make your own from resistors, I doubt it will be much less accurate and besides, you can get something like 0.1% tolerance resistors inexpensively, surely that's accurate enough? |
That's my backup plan, if I can't find a 10-pin SIP. |
|
|
Back to top
|
|
|
JovianPyx
Joined: Nov 20, 2007
Posts: 1079
Location: West Red Spot, Jupiter
Audio files: 123
|
| Posted: Thu May 17, 2012 1:33 pm Post subject:
|
|
|
The DAC08 is still available, though it's a DIP not a SIP. It's also available in several SMD (FWIW). It's "parallel" in the same sense that an R2R is parallel - that is, it's not a serial DAC. It needs the 8 wires for the 8 bits you would supply to an R2R. The DAC08 does not contain a set of flipflops, just the analog circuitry required.
_________________
FPGA Synth Stuff
FatMan Mods
dsPIC Synth Stuff
I am formerly known as ScottG here
Time flies like a banana.
Fruit flies when you're having fun.
BTW, Do these genes make my ass look fat?
|
|
|
Back to top
|
|
|
corex
Joined: Mar 02, 2010
Posts: 100
Location: Las Vegas
|
| Posted: Fri May 18, 2012 3:13 pm Post subject:
|
|
|
| JovianPyx wrote: | | The DAC08 is still available, though it's a DIP not a SIP. It's also available in several SMD (FWIW). It's "parallel" in the same sense that an R2R is parallel - that is, it's not a serial DAC. It needs the 8 wires for the 8 bits you would supply to an R2R. The DAC08 does not contain a set of flipflops, just the analog circuitry required. |
This looks like a good suggestion, thanks! I'll read up. I had looked at a couple of parallel 8-bit DACs, but the ones I looked at required a clock signal and so weren't exactly similar to an R/2R. The DAC08 eschews the clock requirement, although it looks like it does add a few passive components for the biasing network. I'll have to order a couple and try it out. |
|
|
Back to top
|
|
|
Uncle Krunkus
Moderator
Joined: Jul 11, 2005
Posts: 4737
Location: Nambucca Heads, Australia
Audio files: 51
G2 patch files: 1
|
| Posted: Sat May 19, 2012 5:53 am Post subject:
|
|
|
I'll second the motion for hand rolled R/2R networks. Everyone of them has it's own unique sound. A bit of resistor testing never hurt anyone!! 
_________________
If we thought and said hateful, discouraging, demeaning things to our friends,.....
We would lose our friends.
So,.........
Do you really want to lose yourself? |
|
|
Back to top
|
|
|
funkomatic
Joined: Jan 29, 2010
Posts: 1
Location: Texas
|
| Posted: Mon May 28, 2012 3:00 pm Post subject:
Re: Locate an 8-bit R/2R ladder? |
|
|
Pretty sure this will do the job: Bourns Part # 4116R-R2R-104. I found it at Direct Components:
http://www.directics.com/search.html |
|
|
Back to top
|
|
|
corex
Joined: Mar 02, 2010
Posts: 100
Location: Las Vegas
|
| Posted: Tue May 29, 2012 3:18 pm Post subject:
Re: Locate an 8-bit R/2R ladder? |
|
|
Thanks for finding that. I found the Bourns datasheet. It looks like "4116R-3-R1/R2" is the relevant diagram? A little confusing, almost like two ladders connected overlapping? But it does seem like you can wire an 8-bit DAC out of it.
That vendor seems to really want a salesman to call you which doesn't give me much hope for a onesy-twosy order. |
|
|
Back to top
|
|
|
|
Forum index » DIY Hardware and Software
FAQ
Calendar
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
Chat Room
