TYPICAL APPLICATION
FOR A PIERCE OSCILLATOR
SPECIFICATIONS
Specifications are typical at 25OC unless otherwise noted.
Specifications are subject to change without notice.
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 CD and CG provides the additional
phase shift necessary to sustain oscillation. The oscillation
frequency (f0) is 15 to 150 ppm above the crystal’s series
resonant frequency (fS).
Frequency Range
Functional Mode
Calibration Tolerance*
800 kHz - 1.35 MHz
Extensional
+_ 500 ppm (0.05%)
+_ 1000 ppm (0.1%)
+_ 10000 ppm (1.0%)
7 pF (Unless specified by customer)
Load Capacitance
Motional Resistance (R1)
5 kΩ MAX
Drive Level
Motional Capacitance (C1) 1.2fF
R is used to limit the crystal’s drive level by forming a
A
Quality Factor (Q)
Shunt Capacitance (C0)
Drive Level
150 k
1.0 pF
W MAX
35OC
voltage divider between RA and CD. RA also stabilizes the
oscillator against changes in the amplifiers output
resistance (R0). RA should be increased for higher voltage
operation.
3
µ
Turning Point (T )**
0
Temperature Coefficient (k) -0.035 ppm/OC2
Load Capacitance
The CX crystal calibration tolerance is influenced by the
effective circuit capacitances, specified as the load
capacitance (CL). CL is approximately equal to:
Aging, first year
Shock, survival
Vibration, survival
Operating Temp. Range
5 ppm MAX
1,000 g peak, 0.3 ms,1/2 sine
10 g RMS, 20-1,000 Hz random
-10OC to +70OC (Commercial)
CD x CG
=
+
(1)
CL
CS
-40OC to +85OC (Industrial)
CD + CG
-55OC to +125OC (Military)
-55OC to +125OC
NOTE: CD and CG include stray layout to ground and CS
is the stray shunt capacitance between the crystal
terminal. In practice, the effective value of CL will be less
than that calculated from CD, CG and CS values because
of the effect of the amplifier output resistance. CS should
be minimized.
Storage Temp. Range
Max Process Temperature 260OC for 20 sec.
Note: Frequency f at temperature T is related to frequency f0
at turning point temperature T0 by:
2
f-f0
f0
=
k(T-T )
0
The oscillation frequency (f0) is approximately equal to:
* Tighter tolerances available.
** Other values available.
C1
=
+
(2)
f0 fS
1
[
]
PACKAGING
2(C0 + CL)
CX6SM - Tray Pack
Where
= Series resonant frequency of the crystal
= Motional Capacitance
= Shunt Capacitance
fS
C1
C0
- Tape and Reel
(Reference tape and reel data sheet 10109)
TERMINATIONS
CONVENTIONAL CMOS
PIERCE OSCILLATOR CIRCUIT
Designation
SM1
SM2
Termination
Gold Plated
Solder Plated
Solder Dipped
Rf
SM3
BUFFER
HOW TO ORDER CX6SM CRYSTALS
OSC
Freq (f
CX6
S
C
SM1
1.0M,
500
/
M
RA
AMPLIFIER
CX6
Calibration
Tolerance
@ 25OC
Operating Temp. Range:
Frequency
K = kHz
M=MHz
C
I
= -10OC to +70OC
= -40OC to +85OC
“S” if special or
custom design.
Blank if Srd.
M = -55OC to +125OC
(in ppm)
SM1 = Gold Plated
SM2 = Solder Plated
SM3 = Solder Dipped
S
= Customer Specified
CG
CD
Blank = Glass Lid
C = Ceramic Lid
10133 - Rev B
E
RSG Electronic Components GmbH - Sprendlinger Landstr. 115 - 63069 Offenbach - Germany - www.rsg-electronic.de
RSG [ RSG ELECTRONIC COMPONENTS GMBH ]
