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ICS840002I-01 Datasheet, PDF (1/13 Pages) Integrated Circuit Systems – FEMTOCLOCKS™ CRYSTAL-TO LVCMOS/LVTTL FREQUENCY SYNTHESIZER
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ICS840002I-01
FEMTOCLOCKS™ CRYSTAL-TO-
LVCMOS/LVTTL FREQUENCY SYNTHESIZER
GENERAL DESCRIPTION
The ICS840002I-01 is a 2 output LVCMOS/LVTTL
ICS
Synthesizer optimized to generate Ethernet
HiPerClockS™ reference clock frequencies and is a member of
the HiPerClocksTM family of high performance
clock solutions from IDT. Using a 25MHz 18pF
parallel resonant crystal, the following frequencies can be
generated based on the 2 frequency select pins (F_SEL1:0):
156.25MHz, 125MHz, and 62.5MHz. The ICS840002I-01 uses
IDT’s 3rd generation low phase noise VCO technology and
can achieve 1ps or lower typical random rms phase jitter,
easily meeting Ethernet jitter requirements. The ICS840002I-
01 is packaged in a small 16-pin TSSOP package.
FREQUENCY SELECT FUNCTION TABLE
FEATURES
• Two LVCMOS/LVTTL outputs @ 3.3V,
17Ω typical output impedance
• Selectable crystal oscillator interface
or LVCMOS single-ended input
• Supports the following output frequencies:
156.25MHz, 125MHz and 62.5MHz
• Output frequency range: 56MHz - 175MHz
• VCO range: 560MHz - 700MHz
• Output skew: 12ps (maximum)
• RMS phase jitter at 156.25MHz (1.875MHz - 20MHz):
0.47ps (typical)
Offset
Noise Power
100Hz ............... -97.4 dBc/Hz
1kHz ............. -120.2 dBc/Hz
10kHz ............. -127.6 dBc/Hz
100kHz ............. -126.1 dBc/Hz
• Power supply modes:
Core/Output
3.3V/3.3V
3.3V/2.5V
2.5V/2.5V
• -40°C to 85°C ambient operating temperature
• Available in both standard (RoHS 5) and lead-free RoHS
(6) packages
F_SEL1
0
F_SEL0
0
Inputs
M Divider Value
25
N Divider Value
4
Output Frequency
(25MHz Ref.)
156.25
0
1
25
5
125
1
0
25
10
62.5
1
1
25
5
125
BLOCK DIAGRAM
OE Pullup
F_SEL1:0 Pullup:Pullup
nPLL_SEL Pulldown
nXTAL_SEL Pulldown
XTAL_IN 25MHz
OSC 0
XTAL_OUT
TEST_CLK Pulldown
1
2
Phase
Detector
VCO
F_SEL1:0
1
N
0 0 ÷4
0 1 ÷5
0
1 0 ÷10
1 1 ÷5
M = ÷25 (fixed)
PIN ASSIGNMENT
F_SEL0 1 16 F_SEL1
nXTAL_SEL 2 15 GND
TEST_CLK 3 14 GND
OE 4 13 Q0
MR 5 12 Q1
nPLL_SEL 6
1 1 VDDO
VDDA 7
10 XTAL_IN
VDD 8
9 XTAL_OUT
Q0
ICS840002I-01
16-Lead TSSOP
Q1 4.4mm x 5.0mm x 0.92mm
package body
G Package
Top View
MR Pulldown
840002AGI-01
1
REV. A OCTOBER 22, 2007