ICS840002-01 Datasheet, PDF (1/12 Pages) Integrated Circuit Systems – FEMTOCLOCKS™ CRYSTAL-TO LVCMOS/LVTTL FREQUENCY SYNTHESIZER

Integrated
Circuit
Systems, Inc.
ICS840002-01
FEMTOCLOCKS™ CRYSTAL-TO-
LVCMOS/LVTTL FREQUENCY SYNTHESIZER
GENERAL DESCRIPTION
FEATURES
The ICS840002-01 is a 2 output LVCMOS/LVTTL
ICS
Synthesizer optimized to generate Ethernet
HiPerClockS™ _{reference clock frequencies and is a member of}
the HiPerClocks^TM family of high performance
clock solutions from ICS. 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 ICS840002-01 uses
ICS’ 3^rd generation low phase noise VCO technology and can
achieve 1ps or lower typical random rms phase jitter, easily
meeting Ethernet jitter requirements. The ICS840002-01 is
packaged in a small 16-pin TSSOP package.
• Two LVCMOS/LVTTL outputs @ 3.3V,
17Ω typical output impedance
• Selectable crystal oscillator interface
or LVCMOS/LVTTL single-ended input
• 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)
Phase noise:
Offset
Noise Power
100Hz ............... -97.4 dBc/Hz
1kHz .............. -120.2 dBc/Hz
10kHz .............. -127.6 dBc/Hz
100kHz .............. -126.1 dBc/Hz
• Full 3.3V or 3.3V core/2.5V output supply mode
• -30°C to 85°C ambient operating temperature
• Available in both standard and lead-free RoHS compliant
packages
FREQUENCY SELECT FUNCTION TABLE
Inputs
Output Frequency
F_SEL1 F_SEL0 M Divider Value N Divider Value ^{(25MHz Ref.)}
0
0
25
4
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
ICS840002-01
Q1
16-Lead TSSOP
4.4mm x 5.0mm x 0.92mm
package body
G Package
Top View
MR ^Pulldown
840002AG-01
www.icst.com/products/hiperclocks.html
1
REV. B JANUARY 13, 2006