Thanks for the reply. To provide 1/2vcc (2.9v I guess), a pair of 10k resistors or similar could be used for the input amp and summing amp at least. For the filter though, i'm not sure if that would affect it adversely, being a relatively high impedance ground? The TLE2426 would be ideal, but my supplier doesn't stock it
. I guess if the high impedance ground is an issue, a ground formed by potential divider but buffered by an op-amp would be more suitable?
EDIT: The LM317LZ 100MA would do by the looks of it if required.
For op-amp's, i'm looking here since this is my normal supplier and I like to use them:
**broken link removed**
If that is the low power version, what are the main drawbacks; apparently the normal one isn't stocked, though the single version is (expensive for 4). What is GBW
? If you find any other suitable ones available there let me know
. Requirement is that it is suitable for low voltage, has rail to rail swing (must be CMOS to do so?) and is suitable for audio (fairly low distortion, noise).
How I currently have the 4066's arranged is "shorting" to ground, so the DAC see's 0v on any of the LSBs when activated. I thought it would be bad to directly short, hence the 10k protection? I see what you mean about using 1/2vcc, that may be best, or at least different. Probably will try on breadboard to see.
A couple of other things, is that input to the ADC wired corrently? I couldn't figure it out
. Also, is that 40106 schmitt fast enough to produce 100ns pulses? If not, what might be a suitable gate (don't really need 6 either, lol)
Thanks again
EDIT: Perhaps the LMC660CN is more suitable? Didn't realise that was a quad. Has a good output swing and low distortion at least.