What is a spread spectrum (SS) PLL?
For efficient use of frequency bandwidth, FCC guidelines dictate that consumer products (such as PCs and cell phones) limit their electromagnetic emission to an FCC-defined power spectrum mask. Since a major source of electromagnetic emission is a system’s clock, it is often necessary to “spread” these clock signals over a frequency band. The process of spreading is equivalent to wide-band frequency modulation. In doing so, the peak emitted clock power at a given frequency is reduced because clock power is no longer concentrated at a single frequency. TCI provides silicon-proven, low jitter, low power, and very large multiplication range SS PLLs that provide fine controllability of bandwidth, modulation depth and spreading rate.
