鈥?/div>
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
CLKOUT (Spread Spectrum)
SSSEL
0
1
X (don鈥檛 care)
SSON
0
0
1
REFOUT
XIN
XIN
XIN
CY25901SC
= XIN 鹵 0.35% (0.7% center)
= XIN 鹵 1.20% (2.4% center)
= XIN (No Spread)
CY25901SC-1
= XIN 鹵 0.5% (1.0% center)
= XIN 鹵 1.5% (3.0% center)
= XIN (No Spread)
Block Diagram
Pin Configuration
XIN
Oscillator
XOUT
REFOUT
CLKOUT
VDD
VSS
XIN
1
2
3
4
8
7
6
5
SSON#
REFOUT
SSSEL
XOUT
SSON
SSSEL
PLL
CLKOUT
SSCG
Cypress Semiconductor Corporation
Document #: 38-07521 Rev. **
鈥?/div>
3901 North First Street
鈥?/div>
San Jose
,
CA 95134
鈥?/div>
408-943-2600
Revised February 18, 2003
next