840001AK-31 www.icst.com/products/hiperclocks.html REV. A MAY 4, 2005
1
Integrated
Circuit
Systems, Inc.
ICS840001-31
FEMTOCLOCKS™ C RYSTAL-TO-
LVCMOS/LVTTL FREQUENCY SYNTHESIZER
PRELIMINARY
GENERAL DESCRIPTION
The ICS840001-31 is a two output LVCMOS/
LVTTL Synthesizer and a member of the
HiPerClocks
TM
family of high performance
devices from ICS. One output is the LVCMOS/
LVTTL main synthesized clock output (Q) and one
output is a three-state LVCMOS/LVTTL reference clock
(REF_CLK) output at the frequency of the crystal oscillator.
The device can accept 26.5625MHz and 40MHz crystals and
can synthesize 106.25MHz or 100MHz outputs. The
ICS840001-31 has excellent <1ps phase jitter performance
over the 637kHz – 10MHz integration range. The ICS840001-
31 is packaged in a 3mm x 3mm 16-pin VFQFN, making it
ideal for use on space constrained boards.
FEATURES
• (2) LVCMOS/LVTTL outputs, 20Ω typical output impedence
(1) Main clock output (Q)
(1) Three-state reference clock output (REF_CLK)
• Crystal oscillator interface can accept 26.5625MHz or
40MHz 18pF parallel resonant crystals
• Output frequency range: 106.25MHz or 100MHz
• VCO range: 490MHz to 640MHz
• RMS phase jitter @ 106.25MHz, using a 26.5625MHz crystal
(637kHz - 10MHz): 0.38ps (typical)
• 3.3V operating supply
• 0°C to 70°C ambient operating temperature
HiPerClockS™
ICS
BLOCK DIAGRAM PIN ASSIGNMENT
OSC
Phase
Detector
VCO
490MHz - 640MHz
÷6
1 = ÷15 (default)
0 = ÷24
XTAL_IN
XTAL_OUT
OE
Q
M
(Pullup)
ICS840001-31
16-Lead VFQFN
3mm x 3mm x 0.95 package body
K Package
Top View
OE
XTAL_IN
XTAL_OUT
M
Q
VDDO
GND
VDD
nc
nc
nc NC
V
DDA
nc nc REF_CLK
1
2
3
4
12
11
10
9
5 6 7 8
16 15 14 13
REF_CLK
(Pullup)
FUNCTION TABLE
stupnIstuptuO
noitacilppA
latsyrCM EO
OCV
)zHM(
Q
)zHM(ycneuqerF
KLC_FER
)zHM(ycneuqerF
5265.62005.73652.601Z-hgiHlennahCerbiF
04)gnitaolFro(1)gnitaolFro(100600104)ISCS(dehcattAlaireS
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.