CX4 CRYSTAL
Fundamental Mode: 600 kHz to 1.4 MHz
Overtone: 1.8432 MHz - 2.5 MHz
Ultra-Miniature Low Profile
Surface Mount Quartz Crystal
DESCRIPTION
STATEK’s CX4 quartz crystals are hermetically sealed in an
ultra-miniature low profile surface mount ceramic package.
This high quality quartz resonator forms the basis of a stable
oscillator.
FEATURES
XXX
SX
Ceramic Lid Shown
PACKAGE DIMENSIONS
D
actual size
side view
Designed for low power applications in this frequency
range
Smallest available package in this frequency range
Hermetically sealed ceramic package
Excellent aging characteristics
Full military testing to MIL-PRF-3098 available
Designed and manufactured in the USA
APPLICATIONS
B
C
D
E
A
TOP
F
BOTTOM
Medical
Pacemaker, defibrillator and hearing aid
Industrial, Computer & Communications
PCMCIA (FAX, Modem and LAN)
Smart Card
Military & Aerospace
Airborne hybrid computer
Low power system clock
Hybrid multi-chip modules
TYP.
DIM
A
B
C
D
E
F
DIM “C”
MAX
SM1
SM2/SM4
SM3/SM5
inches
0.197
0.072
-
0.036
0.020
0.025
mm
5.00
1.83
-
0.91
0.51
0.64
inches
0.210
0.085
0.046
-
-
MAX.
mm
5.33
2.16
1.16
-
-
see below
GLASS LID
inches
0.045
0.046
0.048
mm
1.14
1.17
1.22
CERAMIC LID
inches
0.050
0.051
0.053
mm
1.27
1.30
1.35
EQUIVALENT CIRCUIT
SUGGESTED LAND PATTERN
0.059 (1.5)
C
0
1
L
1
C
1
R
1
2
0.092 (2.3)
R
1
Motional Resistance L
1
Motional Inductance
C
1
Motional Capacitance C
0
Shunt Capacitance
0.160 (4.0)
inches (mm)
10161 Rev B
STATEK CORPORATION 512 N. MAIN ST., ORANGE, CA 92868 714-639-7810 FAX: 714-997-1256
www.statek.com
SPECIFICATIONS
TYPICAL APPLICATION
FOR A PIERCE OSCILLATOR
Specifications are typical at 25
O
C unless otherwise noted.
Specifications are subject to change without notice.
Parameters
Frequency, (Hz)
Motional Resistance, R
1
(Ω)
Motional Resistance, R
1
MAX
Motional Capacitance, C
1
(fF)
Quality Factor, Q (k)
Shunt Capacitance, C
0
(pF)
Standard Calibration
Tolerance
1
3.5
250
1.0
+
_
+
_
+
_
Fundamental
600 K 1.0 M
300
400
600
3KΩ
2.0
200
0.8
1.3
150
0.7
Overtone
500
1000
1.4 M 1.8432 M 2.4576 M
3.5
80
1.0
1.5
45
0.8
The CX4 family of surface mount crystals are ideal for
small, high density, battery operated portable products. The
CX4 crystal designed in a Pierce oscillator (single inverter)
circuit provides very low current consumption and high
stability. A conventional CMOS Pierce oscillator circuit is
shown below. The crystal is effectively inductive and in a PI-
network circuit with C
D
and C
G
provides the additional
phase shift necessary to sustain oscillation. The oscillation
frequency (f
0
) is 50 to 250 ppm above the crystal’s series
resonant frequency (f
S
).
Drive Level
R
A
is used to limit the crystal’s drive level by forming a
voltage divider between R
A
and C
D
. R
A
also stabilizes the
oscillator against changes in the amplifiers output
resistance (R
0
). R
A
should be increased for higher voltage
operation.
Load Capacitance
The CX4 crystal calibration tolerance is influenced by the
effective circuit capacitances, specified as the load
capacitance (C
L
). C
L
is approximately equal to:
C
L
=
C
D
x C
G
C
D
+ C
G
+
C
S
_
500 ppm (
+
0.05%)
_
1000 ppm (
+
0.1%)
_
10000 ppm (
+
1.0%)
Drive Level
3
µW
MAX
Load Capacitance, C
L
2
7pF
Turning Point, T
0
2
35
O
C
Temperature Coefficient, k
-0.035 ppm/
O
C
2
TYP
Note: Frequency f at temperature T is related to frequency f
0
at
turning point temperature T
0
by: f-f
0
2
=
k(T-T
0
)
f
0
Functional Mode
Extensional
Aging, first year
5ppm MAX
Shock, survival
1500 g, 0.3 ms,
1
/
2
sine
Vibration, survival
20 g RMS, 10-2,000 Hz random
Operating Temp. Range
-10
O
C to +70
O
C (Commercial)
-40
O
C to +85
O
C (Industrial)
-55
O
C to +125
O
C (Military)
Storage Temp. Range
-55
O
C to +125
O
C
(1)
NOTE: C
D
and C
G
include stray layout to ground and C
S
is the stray shunt capacitance between the crystal
terminal. In practice, the effective value of C
L
will be less
than that calculated from C
D
, C
G
and C
S
values because
of the effect of the amplifier output resistance. C
S
should
be minimized.
The oscillation frequency (f
0
) is approximately equal to:
f
0
=
f
S
1
+
Where f
S
C
1
C
0
Max Process Temperature
1. Tighter tolerances available
2. Other values available
260 C for 20 sec.
O
[
C
1
2(C
0
+ C
L
)
]
(2)
NOTE: All values subject to change without notice.
TERMINATIONS
Designation
SM1
SM2
SM3
SM4
SM5
CX4
Termination
Gold Plated
Solder Plated
Solder Dipped
Solder Plated (Lead Free)
Solder Dipped (Lead Free)
= Series resonant frequency of the crystal
= Motional Capacitance
= Shunt Capacitance
CONVENTIONAL CMOS
PIERCE OSCILLATOR CIRCUIT
R
f
BUFFER
OSC
Freq (f
O
)
PACKAGING OPTIONS
- Tray Pack
- Tape and Reel
(Reference tape and reel data sheet 10109)
AMPLIFIER
R
A
HOW TO ORDER CX4 CRYSTALS
CX4
S
C
C = Ceramic Lid
Blank = Glass Lid
SM1 = Gold Plated
“S” if special or SM2 = Solder Plated
custom design. SM3 = Solder Dippe
d
Blank if standard SM4 = Solder Plated (Lead Free)
SM5 = Solder Dipped (Lead Free)
SM1
1.8432M , 500
Frequency
K = kHz
M = MHz
/
I
Calibration Operating Temp. Range:
Tolerance C = -10
O
C to +70
O
C
@25
O
C
I
= -40
O
C to +85
O
C
(in ppm) M = -55
O
C to +125
O
C
S = Customer Specified
C
G
CX4
XTAL
C
D
10161 Rev B
STATEK CORPORATION 512 N. MAIN ST., ORANGE, CA 92868 714-639-7810 FAX: 714-997-1256 www.statek.com
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