24-bit DAC as DC voltage source

Hello

Has any one tried out 24-bit DAC as voltage source? Perhaps 1ppm/C stable such voltage source on small OEM board will be ideal for many calibration applications.

I wonder if I can find a calibration system of this high resolution and stability. Any clue of such versatile commercial product?

I have seen few applications from linear technology for 20-bit DAC, but I need a commercial product of tested standard.