PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS840-77
77.76MHZ, LVCMOS/LVTTL
OSCILLATOR REPLACEMENT
GENERAL DESCRIPTION
FEATURES
The ICS840-77 is a SONET Oscillator Replacement and a member of the HiPerClocks TM
HiPerClockS™
family of high performance devices from ICS.
The ICS840-77 uses a 19.44MHz crystal to
synthesize 77.76MHz. The ICS840-77 has
excellent jitter performance. The ICS840-77 is packaged in
a small 8-pin TSSOP, making it ideal for use in systems with
limited board space.
• One LVCMOS/LVTTL output, 15Ω output impedence
IC
S
• Crystal oscillator interface designed for 19.44MHz,
18pF parallel resonant crystal
• Output frequency: 77.76MHz
• Random jitter: 2.82ps (typical)
• Deterministic jitter: 0.205ps (typical)
• 3.3V operating supply
• 0°C to 70°C ambient operating temperature
• Available in both standard and lead-free RoHS-compliant
packages
BLOCK DIAGRAM
OE
PIN ASSIGNMENT
Pullup
VDD
XTAL_OUT
XTAL_IN
OE
77.76MHz
Q0
19.44MHz
XTAL_IN
Clock
Synthesizer
1
2
3
4
8
7
6
5
Q1
Q0
VDDO
GND
ICS840-77
8-Lead TSSOP
4.40mm x 3.0mm x 0.925mm package body
G Package
Top View
XTAL_OUT
Q1
ICS840-77
8-Lead SOIC
3.90mm x 4.92mm x 1.37mm body package
M Package
Top View
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.
840AG-77
www.icst.com/products/hiperclocks.html
REV. A NOVEMBER 7, 2005
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