841S104EGILF Datasheet, PDF (1/22 Pages) Integrated Device Technology – Crystal-to-HCSL 100MHz PCI ExpressTM Clock Synthesizer

Crystal-to-HCSL 100MHz
PCI Express^TM Clock Synthesizer
ICS841S104I
General Description
The ICS841S104I is a PLL-based clock synthesizer specifically
designed for PCI_Express™ Clock applications. This device
generates a 100MHz differential HCSL clock from an input reference
of 25MHz. The input reference may be derived from an external
source or by the addition of a 25MHz crystal to the on-chip crystal
oscillator. An external reference is applied to the XTAL_IN pin with
the XTAL_OUT pin left floating.The device offers spread spectrum
clock output for reduced EMI applications. An I²C bus interface is
used to enable or disable spread spectrum operation as well as
select either a down spread value of -0.35% or -0.5%.The
ICS841S104I is available in a lead-free 24-Lead package.
DATA SHEET
Features
• Four 0.7V current mode differential HCSL output pairs
• Crystal oscillator interface: 25MHz
• Output frequency: 100MHz
• RMS phase jitter @ 100MHz (12kHz – 20MHz): 1.145ps (typical)
• Cycle-to-cycle jitter: 20ps (maximum)
• I²C support with readback capabilities up to 400kHz
• Spread Spectrum for electromagnetic interference (EMI) reduction
• 3.3V operating supply mode
• -40°C to 85°C ambient operating temperature
• Available lead-free (RoHS 6) package
• PCI Express Gen 1, 2, 3 jitter compliant
HiPerClockS™
Block Diagram
25MHz
XTAL_IN
XTAL_OUT
OSC
SDATA ^Pullup
SCLK ^Pullup
IREF
Divider
PLL
Network
I²C
4
Logic
4
SRCT[1:4]
4
SRCC[1:4]
Pin Assignment
SRCT3 1
SRCC3 2
V_SS 3
VDD 4
SRCT2 5
SRCC2 6
SRCT1 7
SRCC1 8
VSS 9
VDD 10
VSS 11
IREF 12
24 SRCC4
23 SRCT4
22 VDD
21 SDATA
20 SCLK
19 XTAL_OUT
18 XTAL_IN
17 VDD
16 VSS
15 nc
14 VDDA
13 VSS
ICS841S104I
24-Lead TSSOP
4.4mm x 7.8mm x 0.925mm package body
G Package
Top View
ICS841S104EGI REVISION A JUNE 18, 2010
1
©2010 Integrated Device Technology, Inc.