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*
+
_
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
0
)**
35
O
C
Temperature Coefficient (k) -0.035 ppm/
O
C
2
Aging, first year
5 ppm MAX
Shock, survival
1000 g peak, 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
* Tighter frequency calibration available.
** 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
[
C
1
2(C
0
+ C
L
)
]
(2)
TERMINATIONS
Designation
SM1
SM2
SM3
Termination
Gold Plated
Solder Plated
Solder Dipped
= 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
M
R
A
500
/
Blank = Glass Lid
C = Ceramic Lid
“S” if special or
custom design.
Blank if Std.
SM1 = Gold Plated
SM2 = Solder Plated
SM3 = Solder Dipped
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 B
S
YS
ERT
T
E
M
C
IFIC
T
A
N
IO
RSG Electronic Components GmbH - Sprendlinger Landstr. 115 - 63069 Offenbach - Germany - www.rsg-electronic.de
IS
O
90
01
RSG [ RSG ELECTRONIC COMPONENTS GMBH ]
