The Noise Spectral Density for the high precision AD5780 family is shown here. The 1/f noise region up to 10Hz and the thermal noise at higher frequencies are indicated in the graph. This is a family of  16-, 18-, and 20-bit precision devices where low noise performance is key to achieving accurate linear performance. Essentially, the noise must be lower than the minimum voltage step or LSB. The AD5780 family is based on an R/2R core, the most suitable DAC architecture for achieving low noise. As shown in the graph here, the thermal noise of the on-chip resistors dominates the noise plot. In this case however, the noise is a mere 8nV per square root Hz, making it ideally suited for high precision, ultra-stable applications.