Good news - new signal...

[shobley]

OK well I finally managed to get a TLV5618 DAC working with an Arduino board. What a nightmare that was... So I can replace my noisy old ladder DAC with a proper 12-bit one.

So I now have a 0 - 4.9v signal coming out of a DAC, and I need to make it -5 to +5v. Does anyone have any good ideas how to do this? I tried hooking it up to the TL082 circuit I used with my ladder, but all I can get now is a constant +15v from the output...

Strange...

Any ideas would be greatly appreciated...

Steve

[drlava]

check out the schematics in the open source dac thread:

http://www.photonlexicon.com/forums/...ead.php?t=3225

[The_Doctor]

Also, look up standard procedures for sound output in pro gear, DAC to differential. Mostly, just an opamp. Gain of 2, and the other input 'grounded' to a -2.5V reference. Most of those use 2.25V, but the idea is the same. Tweaking the offset of the amp should be enough to make the symmetry right if you have a -2.5V reference. Most op-amps are easy to tweak, even if they don't provide specific pins for it. Just mix the output of a preset pot divider across the supply, via a 10M resistor, into one input. Might have to modify values, but that idea will work.

[shobley]

Thanks, I *almost* understand - but could you draw a quick schematic of the opamp, just so I'm sure.

I fried one of my TL082 chips today, through inexperience - it went with a very dramatic pop...

[allthatwhichis]

... a very dramatic pop...