Integrated
Circuit
Systems, Inc.
ICS840021I
F
EMTO
C
LOCKS
™C
RYSTAL
-
TO
-
LVCMOS/LVTTL C
LOCK
G
ENERATOR
F
EATURES
•
1 LVCMOS/LVTTL output, 15Ω output impedence
•
Crystal oscillator interface designed for 25MHz,
18pF parallel resonant crystal
•
Output frequency: 125MHz
•
VCO range: 560MHz to 680MHz
•
RMS phase jitter @ 125MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.48ps (typical) (3.3V)
Offset
Noise Power
100Hz ............... -97.8 dBc/Hz
1kHz .............. -124.6 dBc/Hz
10kHz .............. -132.5 dBc/Hz
100kHz .............. -131.1 dBc/Hz
•
Voltage supply modes:
V
DD
/V
DDA
= 3.3V
V
DD
/V
DDA
= 2.5V
•
-40°C to 85°C ambient operating temperature
•
Lead-Free package fully RoHS compliant
G
ENERAL
D
ESCRIPTION
The ICS840021I is a Gigabit Ethernet Clock
Generator and a member of the HiPerClocks
TM
HiPerClockS™
family of high performance devices from ICS. The
ICS840021I uses a 25MHz crystal to synthesize
125MHz. The ICS840021I has excellent phase
jitter performance, over the 1.875MHz – 20MHz integration
range. The ICS840021I is packaged in a small 8-pin TSSOP,
making it ideal for use in systems with limited board space.
ICS
B
LOCK
D
IAGRAM
OE
25MHz
XTAL_IN
P
IN
A
SSIGNMENT
V
DDA
OE
XTAL_OUT
XTAL_IN
1
2
3
4
8
7
6
5
V
DD
Q0
GND
nc
OSC
XTAL_OUT
Phase
Detector
VCO
÷5
Q0
ICS840021I
÷25
(fixed)
8-Lead TSSOP
4.40mm x 3.0mm x 0.925mm package body
G Package
Top View
840021AGI
www.icst.com/products/hiperclocks.html
1
REV. A MAY 19, 2005
ICS [ INTEGRATED CIRCUIT SYSTEMS ]
