The Cypress CY25568 is a Spread Spectrum Clock Generator (SSCG) IC used for the purpose of reducing Electro
Magnetic Interference (EMI) found in today’s high-speed digital electronic systems.
The CY25568 uses a Cypress proprietary Phase-Locked Loop (PLL) and Spread Spectrum Clock (SSC)
technology to synthesize and modulate the frequency of the digital clock. By frequency modulating the clock, the
measured EMI at the fundamental and harmonic frequencies is greatly reduced.
This reduction in radiated energy can significantly reduce the cost of complying with regulatory agency
requirements and improve time to market without degrading system performance.
The CY25568 input frequency range is 4 to 32 MHz and accepts clock, crystal and ceramic resonator inputs. The
output clocks can be programmed to produce 1x, 2x and 4x multiplication of the input frequency with Spread
Spectrum. A separate non-modulated reference clock is also provided.
The use of 2x or 4x frequency multiplication eliminates the need for higher order crystals and allows the user to
generate up to 128 MHz Spread Spectrum Clock (SSC) by using only first order crystals. This will reduce the cost
while improving the system clock accuracy, performance and complexity
Center Spread or Down Spread frequency modulation can be selected by the user based on 4 discrete values of
Spread % for each Spread Mode with the option of a Non-Spread mode for system test and verification purposes.
The CY25568 is available in a 16 pin SOIC (150-mil.) package with a commercial operating temperature range of
0 to 70°C. Contact Cypress for availability of -25 to +85°C Industrial Temperature Range Operation. Refer to
CY25811/12/14 products for 8-pin SOIC package versions of the CY25568.