DAC8560: Initial accuracy tolerance of dac8560

Ramakrishna,

It is somewhat unconventional for a DAC datasheet to include an initial accuracy specification. Recently we started adding something somewhat similar to this in our datasheets that we refer to as total unadjusted error (TUE), which we usually show at room temperature as well as over the full operating temperature of the device.

For older parts where this specification is not included in the datasheet, or perhaps for devices that were intended for applications where this specification isn't relevant, a hand calculation must be performed in order to estimate the TUE. There is a blog post that explains this process here: e2e.ti.com/.../dac-essentials-how-accurate-is-your-dac

There are several different approaches you may apply, either using the RSS technique on typical figures, using the RSS technique on maximum figures, or using direction summation of either typical or maximum figures. There isn't really any definitively right or wrong way to do this, it just depends on your level of skepticism concerning what is published in a given datasheet. I will say from internal experience that all of these values are heavily guard-banded and, for direct summation to apply, you would have to assume they all go in the same direction which is unlikely for most specifications so I always advocate RSS analysis for a more accurate estimation of accuracy.

Concerning typical figures versus maximum figures, on several of the older datasheets "typical" values best reflect performance at room temperature while the max values are more indicative of accuracy over the entire operating temperature span. This is true for DAC8560 as the top line of the Electrical Characteristics table sas "-40C to 105C (unless otherwise noted)".

With all of that said, per my calculations the typical (or room temp) TUE would be 0.2% FSR and the maximum (over temp) would be 0.52% FSR.

Thanks Kevin, for clarifying Dac8560 initial accuracy issue. I know now that TUE for the DAC8560, is bet 0.2 to 0.5%.  I was excited by the data sheet internal reference accuracy of 0.02% and wanted to confirm the same. as per data sheet. Is it 0.02% typical?

My main interest is to know about internal reference accuracy minimum and maximum figures at room temperature, not overall DAC accuracy as per TUV .

Ramakrishna,

Per the Electrical Characteristics table the reference output voltage initial accuracy is 0.004% typical, +/-0.1% maximum.