This paper compares the time precision of different digitally controlled delay cells. Other design metrics as delay, signal integrity, power and area are also considered. Because these elements have very different delay resolution and ranges, the precision metric is the cell’s uncertainty, given as the ratio between jitter and cell delay, considering both thermal and power supply noise. The comparison is based on circuit simulation, in a 180nm technology, using the SPECTRE tool from Cadence. The comparison results will help the designer to choose the most appropriate delay cell for low uncertainty design.