cy25100 pdf datasheet Field and Factory-Programmable Spread Spectrum Clock Generator for EMI Reduction

The CY25100 is a Spread Spectrum Clock Generator (SSCG) IC
used for the purpose of reducing EMI found in today’s
high-speed digital electronic systems.
The device uses a Cypress proprietary PLL and Spread
Spectrum Clock (SSC) technology to synthesize and modulate
the frequency of the input clock. By frequency modulating the
clock, the measured EMI at the fundamental and harmonic
frequencies are greatly reduced. This reduction in radiated
energy can significantly reduce the cost of complying with
regulatory agency (EMC) requirements and improve
time-to-market without degrading system performance.
The CY25100 uses a factory/field-programmable configuration
memory array to synthesize output frequency, spread%, crystal
load capacitor, reference clock output on/off, spread spectrum
on/off function and PD#/OE options.
The spread% is programmed to either center spread or down
spread with various spread percentages. The range for center
spread is from ±0.25% to ±2.50%. The range for down spread is
from –0.5% to –5.0%. Contact the factory for smaller or larger
spread % amounts if required.
The input to the CY25100 can be either a crystal or a clock
signal. The input frequency range for crystals is 8–30 MHz, and
for clock signals is 8–166 MHz.
The CY25100 has two clock outputs, REFCLK and SSCLK. The
non-spread spectrum REFCLK output has the same frequency
as the input of the CY25100. The frequency modulated SSCLK
output can be programmed from 3–200 MHz.
The CY25100 products are available in an 8-Pin SOIC and
TSSOP packages with commercial and industrial operating
temperature ranges.