CX2SM CRYSTAL
760 kHz to 1.35 MHz
Low Profile Miniature
Surface Mount Quartz Crystal
DESCRIPTION
The CX2SM quartz crystals are leadless devices designed
for surface mounting on printed circuit boards or hybrid
substrates. They are hermetically sealed in a rugged,
miniature ceramic package. They are manufactured using
the STATEK-developed photolithographic process, and
were designed utilizing the experience acquired by
producing millions of crystals for industrial, commercial,
military and medical applications. Maximum process
temperature should not exceed 260
O
C.
FEATURES
actual size
side view
Glass Lid Shown
PACKAGE DIMENSIONS
B
1
Extensional mode
Ideal for use with microprocessors
Designed for low power applications
Compatible with hybrid or PC board
Low aging
Full military testing available
Ideal for battery operated applications
Designed and manufactured in the USA
EQUIVALENT CIRCUIT
C
D
E
2
G
3
F
H
I
A
TYP.
DIM
A
B
inches
0.260
0.094
-
0.035
0.059
0.050
0.105
0.155
0.210
mm
6.60
2.39
-
0.89
1.50
1.27
2.67
3.94
5.33
inches
0.275
0.108
0.045
0.069
0.060
0.115
0.165
0.220
MAX.
mm
6.99
2.74
1.14
1.75
1.52
2.92
4.19
5.59
C
0
1
L
1
C
1
R
1
2
C
D
E
F
G
H
I
see below
R
1
Motional Resistance L
1
Motional Inductance
C
1
Motional Capacitance C
0
Shunt Capacitance
SUGGESTED LAND PATTERN
DIM “C”
MAX
SM1
SM2/SM4
SM3/SM5
GLASS LID
inches
0.065
0.067
0.070
mm
1.65
1.70
1.78
CERAMIC LID
inches
0.075
0.077
0.080
mm
1.91
1.96
2.03
0.105 (2.67)
0.113
(2.87)
0.060 (1.52)
inches (mm)
GRID
COURTYARD
1
2
Note: Terminal 1 is electrically connected internally to terminal 3
0.060 (1.52)
10135 - Rev C
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.
Frequency Range
760 kHz - 1.35 MHz
Functional Mode
Extensional
+
_
500 ppm (0.05%)
Calibration Tolerance
1
+
_
1000 ppm (0.1%)
+
_
10000 ppm (1.0%)
Load Capacitance
7 pF
Motional Resistance (R
1
)
5 kΩ MAX
Motional Capacitance (C
1
) 1.2fF
Quality Factor (Q)
150 k
Shunt Capacitance (C
0
)
1.0 pF
Drive Level
3
µW
MAX
Turning Point (T )
2
35
O
C
0
Temperature Coefficient (k) -0.035 ppm/
O
C
2
Aging, first year
5 ppm MAX
Shock, survival
1000 g, 0.3 ms,
1
/
2
sine
Vibration, survival
10 g RMS, 20-1,000 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
Max Process Temperature 260
O
C for 20 sec.
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
1. Tighter frequency calibration available.
2. Other turning points available.
The low profile CX miniature surface mount crystal is ideal
for small, high density, battery operated portable products.
The CX 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 15 to 150 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 CX 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
(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
TERMINATIONS
[
C
1
2(C
0
+ C
L
)
]
(2)
Designation
SM1
SM2
SM3
SM4
SM5
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
PACKAGING OPTIONS
R
f
BUFFER
OSC
Freq (f
O
)
CX2SM
- Tray Pack
-16mm tape, 7” or 13” reels
(Reference tape and reel data sheet 10109)
HOW TO ORDER CX2SM CRYSTALS
CX2
S
C
SM1
1.0M
Frequency
K = kHz
M = MHz
Calibration
Tolerance
@ 25
O
C
(in ppm)
AMPLIFIER
I
R
A
,
500
/
Blank = Glass Lid
C = Ceramic Lid
“S” if special or
custom design.
Blank if Std.
SM1 = Gold Plated (Lead Free)
SM2 = Solder Plated
SM3 = Solder Dipped
SM4 = Solder Plated (Lead Free)
SM5 = Solder Dipped (Lead Free)
Operating Temp. Range:
C = -10
O
C to +70
O
C
I
= -40
O
C to +85
O
C
M = -55
O
C to +125
O
C
S = Customer Specified
C
G
CX2
C
D
10135 - Rev C
STATEK CORPORATION 512 N. MAIN ST., ORANGE, CA 92868 714-639-7810 FAX: 714-997-1256
www.statek.com
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