Thanks for your help!
Unfortunately, I specified the DAC8581 last December when the (then current) data sheet listed it as Active. Oh, well...these things happen.
Mainly, I need bipolar output, but the price is also critical. The alternate part suggested on the ti website is nearly 3 times as expensive, as are all of the other bipolar-out candidates I've found.
If it's not practical to use the DAC8581, I'll have to re-spec a unipolar part, plus a board spin. I already have a dual op amp on the board as a quasi-differential output buffer. Add 3 more resistors and a unipolar DAC will do.
I see that there is significant 'factory stock' in reels claimed by at least one disti--although my boss resists lifetime buys. Who should I contact to find out if an End Of Life or Last Buy date has been set for the DAC8581?
I guess what I should have asked is, "What's going on internally during tUPDAC."
Can I assume that it covers some internal analog process--and that it has nothing to do with the data latching from the shift register into the DAC register at the 16th SCLK fall?
If I understand your comments correctly, then starting a new SPI transaction after tWAIT will not destroy the current sample until the next 16th SCLK fall. This application will have no step-wise output changes and a microsecond or two of lag is not important.
Thanks again, Mark