CY25901 Datasheet, PDF (1/5 Pages) Cypress Semiconductor – Spread Spectrum Clock Generator

CY25901
Spread Spectrum Clock Generator
Features
• Supports clock requirements for Spread Spectrum
• 40-MHz Spread Spectrum clock output
• Reference clock output
• Two spread bandwidths: 1%, 3%
• External clock or Cera-Lock input
• 3.3V operation
• 8-pin SOIC package
Description
The CY25901 clock generator provides a low-electromagnetic
interference (EMI) clock output. It features Spread Spectrum
technology, a modulation technique designed specifically for
reducing EMI at the fundamental frequency and its harmonics.
Table 1. Function Table
SSSEL
0
1
X (don’t care)
SSON
0
0
1
REFOUT
XIN
XIN
XIN
CLKOUT (Spread Spectrum)
CY25901SC
CY25901SC-1
= XIN ± 0.35% (0.7% center)
= XIN ± 0.5% (1.0% center)
= XIN ± 1.20% (2.4% center)
= XIN ± 1.5% (3.0% center)
= XIN (No Spread)
= XIN (No Spread)
Block Diagram
Pin Configuration
XIN
XOUT
SSON
SSSEL
Oscillator
PLL
SSCG
REFOUT
CLKOUT
CLKOUT ₁
VDD 2
VSS ₃
XIN ₄
8 ^SSON#
7 ^REFOUT
6 ^SSSEL
5 ^XOUT
Cypress Semiconductor Corporation • 3901 North First Street • San Jose, CA 95134 • 408-943-2600
Document #: 38-07521 Rev. **
Revised February 18, 2003