CY25000 Datasheet, PDF (1/10 Pages) Cypress Semiconductor – Programmable Spread Spectrum Clock Generator for EMI Reduction

CY25000
Programmable Spread Spectrum
Clock Generator for EMI Reduction
Features
Benefits
• Wide operating output (SSCLK) frequency range
— 3–200 MHz
• Programmable spread spectrum with nominal 30-kHz
modulation frequency
— Center spread: ±0.25% to ±2.5%
— Down spread: –0.5% to –5.0%
• Input frequency range
— External crystal: 8–30 MHz fundamental crystals
— External reference: 8–166 MHz Clock
• Integrated phase-locked loop (PLL)
• Programmable crystal load capacitor tuning array
• Low cycle-to-cycle Jitter
• 3.3V operation
• Spread spectrum On/Off function
• Power-down or Output Enable function
• Services most PC peripherals, networking, and consumer
applications.
• Provides wide range of spread percentages for maximum
EMI reduction, to meet regulatory agency Electro Magnetic
Compliance (EMC) requirements. Reduces development
and manufacturing costs and time-to-market.
• Eliminates the need for expensive and difficult to use higher
order crystals.
• Internal PLL to generate up to 200-MHz output. Able to
generate custom frequencies from an external crystal or a
driven source.
• Enables fine-tuning of output clock frequency by adjusting
C_Load of the crystal. Eliminates the need for external C_Load
capacitors.
• Suitable for most PC, consumer, and networking applica-
tions
• Application compatibility in standard and low-power
systems.
• Provides ability to enable or disable spread spectrum with
an external pin.
• Enables low-power state or output clocks to High-Z state.
Logic Block Diagram
XIN/CLKIN 1
XOUT 8
C_XOUT
OSC.
C_XIN
PLL
with
Modulation Control
Programmable Configuration
PD#/OE 3
SSON 7
24
VDD VSS
Output
Dividers
and
MUX
6 _REFCLK
5 SSCLK
Pin Configuration
CY25000
8-pin SOIC
XIN/CLKIN 1
VDD 2
PD#/OE 3
VSS 4
8
XOUT
7
SSON
6
REFCLK
5
SSCLK
Cypress Semiconductor Corporation • 3901 North First Street • San Jose, CA 95134 • 408-943-2600
Document #: 38-07424 Rev. *B
Revised September 26, 2003