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
Fundamental
Overtone
Frequency Range, (Hz)
555 k 614 k 1.0 M 1.4 M1.8432 M 2.1M
Motional Resistance,R
1
(
Ω)
Motional Resistance,R
1
MAX
Motional Capacitance,C
1
(fF)
Quality Factor, Q (k)
Shunt Capacitance,C
0
(pF)
Calibration Tolerance*
+
_
+
_
+
_
600
275
500
775
300
475
3 kΩ
2.5
170
1.2
3.6
260
1.3
2.0
190
1.1
1.5
100
1.0
2.8
110
1.3
2.6
70
1.3
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 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 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
500 ppm (0.05%)
1000 ppm (0.1%)
Drive Level
10000 ppm (1.0%)
3
µW
MAX
Load Capacitance**
7 pF
Turning Point (T
0
)**
35
O
C
Temperature Coefficient (k) -0.035 ppm/
O
C
2
Note: Frequency f at temperature T is related to frequency f
0
2
at turning point temperature T
0
by: f-f
0
=
k(T-T
0
)
f
0
Function Mode
Aging, first year
Shock, survival
Vibration, survival
Operating Temp. Range
Extensional
5 ppm MAX
750 g peak, 0.3 ms,
1
/
2
sine
10 g RMS, 20-1,000 Hz random
-10
O
C to +70
O
C (Commercial)
-40
O
C to +85
O
C (Industrial)
-55
O
C to +125
O
C (Military)
-55
O
C to +125
O
C
260
O
C for 20 sec.
(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
+
Storage Temp. Range
Max Process Temperature
*Tighter tolerances available.
** Other values available.
[
C
1
2(C
0
+ C
L
)
]
(2)
TERMINATIONS
Designation
SM1
SM2
SM3
Termination
Gold Plated
Solder Plated
Solder Dipped
Where f
S
C
1
C
0
= Series resonant frequency of the crystal
= Motional Capacitance
= Shunt Capacitance
CONVENTIONAL CMOS
PIERCE OSCILLATOR CIRCUIT
R
f
BUFFER
OSC
Freq (f
O
)
PACKAGING OPTIONS
CX1SM
- Tray Pack
- Tape and Reel
(Reference tape and reel data sheet 10109)
HOW TO ORDER CX1SM CRYSTALS
CX1
S
C
SM1
1.0M,
Frequency
K = kHz
M = MHz
AMPLIFIER
R
A
500
/ M
Blank = Glass Lid
C = Ceramic Lid
SM1 = Gold Plated
SM2 = Solder Plated
SM3 = Solder Dipped
“S” if special or
custom design.
Blank if Std.
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
Calibration
S = Customer Specified
Tolerance
@ 25
O
C
(in ppm)
C
G
CX1
XTAL
C
D
10129 - 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 ]
