PRELIMINARY
FEMTOCLOCKS™ 680MHZ, CRYSTAL-TO-3.3V
DIFFERENTIAL LVPECL FREQUENCY SYNTHESIZER
ICS843202I
GENERAL DESCRIPTION
FEATURES
The ICS843202I is a 2 output LVPECL Synthesizer
• Two 3.3V LVPECL outputs
ICS
HiPerClockS™
optimized to generate Gigabit Ethernet and SONET
reference clock fre-quencies and is a member of
the HiPerClocksTM family of high performance clock
solutions from ICS. Using a 19.44MHz and 25MHz,
• Selectable crystal oscillator interface
or one differential recovered clock inputs
• Supports the following output frequencies: 155.52MHz
and 156.25MHz
18pF parallel resonant crystal, 155.52MHz and 156.25MHz
frequencies can be generated. The part also allows the use of
a recovered clock at QB output. The ICS843202I uses ICS’
FemtoClockTM low phase noise VCO technology and can achieve
1ps or lower typical RMS phase jitter. The ICS843202I is
packaged in a 32-pin LQFP package.
• VCO range: 560MHz - 680MHz
• RMS phase jitter @ 155.52MHz, using a 19.44MHz crystal
(12kHz - 13MHz): 0.86ps (typical)
• RMS phase jitter @ 156.25MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.56ps (typical)
SELBX FUNCTION TABLE
• Full 3.3V supply mode
Control Inputs
Outputs
nQB, QB
• -40°C to 85°C ambient operating temperature
SEL[1:0]
• Available in both standard and lead-free RoHS
compliant packages
00
01
10
11
High, Low
REC_CLK
156.25MHz based on XTAL_0
155.52MHz based on XTAL_1
BLOCK DIAGRAM
PIN ASSIGNMENT
Pullup
OEA
25MHz
XTAL_IN0
QA
VCO
625MHz
Phase
Detector
OSC
÷4
nQA
XTAL_OUT0
32 31 30 29 28 27 26 25
156.25MHz
VCCO_A
nc
1
2
3
4
5
6
7
8
24
23
22
21
20
19
18
17
OEA
VCC
÷25
ICS843202I
32-Lead LQFP
7mm x 7mm x 1.4mm
package body
Y Package
XTAL_IN1
XTAL_OUT1
nc
VCCA
SEL0
VEE
00
01
Pulldown
REC_CLK
QB
REC_CLK
nREC_CLK
OEB
VCC
Top View
Pullup
nREC_CLK
nQB
10
11
SEL1
19.44MHz
XTALIN1
VCCO_B
VCO
622.08MHz
Phase
Detector
OSC
9
10 11 12 13 14 15 16
÷4
XTAL_OUT1
155.52MHz
÷32
Pullup
SEL[1:0]
Pullup
OEB
The Preliminary Information presented herein represents a product in prototyping or pre-production.The noted characteristics are based on initial product
characterization.Integrated Circuit Systems, Incorporated (ICS) reserves the right to change any circuitry or specifications without notice.
IDT™ / ICS™ 680MHZ, LVPECL FREQUENCY SYNTHESIZER
1
ICS843202I REV A JULY 18, 2006