ICS840021I Datasheet, PDF (1/11 Pages) Integrated Circuit Systems – FEMTOCLOCKS™ CRYSTAL-TO LVCMOS/LVTTL FREQUENCY SYNTHESIZER

Integrated
Circuit
Systems, Inc.
ICS840021I
FEMTOCLOCKS™ CRYSTAL-TO-
LVCMOS/LVTTL CLOCK GENERATOR
GENERAL DESCRIPTION
The ICS840021I is a Gigabit Ethernet Clock
ICS
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.
FEATURES
• 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 /V = 3.3V
DD DDA
V_DD/V_DDA = 2.5V
• -40°C to 85°C ambient operating temperature
• Lead-Free package fully RoHS compliant
BLOCK DIAGRAM
OE
25MHz
XTAL_IN
OSC
Phase
VCO
÷5
Q0
XTAL_OUT
Detector
÷25
(fixed)
PIN ASSIGNMENT
VDDA 1
OE 2
XTAL_OUT 3
XTAL_IN 4
8 VDD
7 Q0
6 GND
5 nc
ICS840021I
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