PLL Clock Generator Single 16-Pin SOIC

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 reduces 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

• 4 to 32 MHz Input frequency range
• 4 to 128 MHz Output frequency range
• Accepts clock, crystal and resonator Inputs
• 1x, 2x and 4x frequency multiplication
• Non-modulated reference frequency output
• Center and down spread modulation
• Low power dissipation
  • 3.3 V = 52 mW-typ at 6 MHz
  • 3.3 V = 60 mW-typ at 12 MHz
  • 3.3 V = 72 mW-typ at 24 MHz
• Power-down mode
• Low cycle-to cycle jitter
  • 8 MHz = 195 ps-typ
  • 16 MHz = 175 ps-typ
  • 32 MHz = 100 ps-typ
• Available in 16-pin (150-mil.) SOIC package