ICS557-05A Datasheet, PDF (1/12 Pages) Integrated Circuit Systems – Quad Differential PCI-Express Clock Source

QUAD DIFFERENTIAL PCI-EXPRESS CLOCK SOURCE
DATASHEET
ICS557-05A
Description
The ICS557-05A is a spread-spectrum clock generator that
supports PCI-Express requirements. It is used in PC or
embedded systems to substantially reduce
electro-magnetic interference (EMI). The device provides
four differential HCSL or LVDS high-frequency outputs with
spread spectrum capability. The output frequency and
spread type are selectable using external pins.
Features
• Packaged in 20-pin TSSOP
• Available in RoHS 5 (green) or RoHS 6 (green and lead
free) complaint package
• Supports PCI-Express applications
• Four differential spread spectrum clock outputs
• Spread spectrum for EMI reduction
• Uses external 25 MHz clock or crystal input
• Power down pin turns off chip
• OE control tri-states outputs
• Spread and frequency selection via external pins
• Spread Bypass option available
• Industrial temperature range available
Block Diagram
VDD
2
PD
OE
3
SEL[2:0]
X1
25 MHz
crystal or
clock
X2
Optional tuning crystal
capacitors
Spread
Spectrum/
Output
clock
selection
Clock
Oscillator
Spread
Spectrum
Circuitry
PLL Clock
Synthesis
2
GND
Rr(IREF)
CLKOUTA
CLKOUTA
CLKOUTB
CLKOUTB
CLKOUTC
CLKOUTC
CLKOUTD
CLKOUTD
IDT™ / ICS™ QUAD DIFFERENTIAL PCI-EXPRESS CLOCK SOURCE
1
ICS557-05A REV H 092407