FS791 Datasheet, PDF (1/9 Pages) Cypress Semiconductor – Low EMI Spectrum Spread Clock

92/94
FS791/92/94
Features
• Spread Spectrum Clock Generator (SSCG) with 1x, 2x
and 4x outputs
• 80- to 140-MHz operating frequency range
• Modulates external clocks including crystals, crystal
oscillators, and ceramic resonators
• Programmable modulation with simple R-C external
loop filter (LF)
• Center spread modulation
• 3–5 Volt power supply
• TTL/CMOS compatible outputs
• Low short-term jitter
• Low Power Dissipation;
— 3.3 VDC = 73 mW—typical
— 5.0 VDC = 225 mW—typical
• Available in 8-pin SOIC package
.
Low EMI Spectrum Spread Clock
Applications
• Desktop/Notebook computers
• VGA, XGA, and SXGA LCD displays
• High-speed printers and copiers
• CD-ROM, VCD, and DVD
• Embedded systems
• Networking, LAN/WAN
• Modems
Benefits
• Programmable EMI reduction
• Fast time-to-market
• Lower cost of compliance
• No degradation in Rise/Fall time
• Lower component and PCB layer count
Block Diagram
Xin
1
10 pF.
Xout
2
10 pF.
VDD
8
Power Contol
Logic
Reference
Divider
Modulation
Control
Input Control
Loop Filter 4
Phase
Detector
10 pF.
VCO
VCO / N
Counter
and
Mux
5
VSS
3
7
S1
S0
Pin Configuration
Xin
Xout
S1
LF
1
8
2 _FS79x 7
3
6
4
5
VDD
S0
FSOUT
VSS
FSOUT
6
Cypress Semiconductor Corporation • 3901 North First Street • San Jose • CA 95134 • 408-943-2600
Document #: 38-07343 Rev *A
Revised December 28, 2002