EUROQUARTZ CX-2C-SM21.0B Cx miniature crystal Datasheet

CX MINIATURE CRYSTALS
CX-2-SM
EUROQUARTZ
Telephone:
+44(0)1460 230000
Fax:
+44(0)1460 230001
Email: [email protected]
Web: www.euroquartz.co.uk
Page
760kHz to 1.35MHz
LOW-PROFILE
SMD CRYSTAL
1 of 2
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General Description
The miniature CX-2-SM quartz crystal is a high quality leadless
device suitable for mounting on printed circuit boards or hybrid
substrates. The CX-2-SM is hermetically sealed in a rugged,
leadless ceramic package. The crystal has been designed for
surface-mounting on printed circuit boards or hybrid circuits. The
crystal is manufactured using a photo-lithographic process,
yielding consistently high quality production parts.
A
760kHz to 1.35MHz
Extensional
A ±0.05% (±500ppm)
B ±0.1%
C ±1.0%
7pF
Load Capacitance:
5kW max.
Motional Resistance (R1):
1.2fF
Motional Capacitance (C1):
150k
Quality Factor (Q):
1.0pF
Shunt Capacitance (C0):
3mW max.
Drive Level:
35°C
Turning Point (T0)**:
Note: Frequency (f) deviation from frequency (f0) @ turning point
temperature (T0):
f-fo k(T-To)2
=
fo
-0.035ppm/°C2
Temperature Coefficient:
±5ppm max.
Ageing, first year:
1000g 0.3ms, ½ sine
Shock, survival:
10g rms, 20-1,000Hz random
Vibration, survival:
-10°~+70°C (commercial)
Operating Temperature:
-40°~+85°C (industrial)
-55°~+125°C (military)
-55°C~+125°C
Storage Temperature:
260°C for 20 seconds
Process Temperature:
2
I
H
G
B
C
3 F
D
E
Terminal 1 is electrically connected to terminal 3
Outline
CX-2-SM Package Dimensions
Dimension
Typical
(mm)
Maximum
(mm)
A
6.60
B
2.39
2.74
C
-
see below
D
0.89
1.14
E
1.50
1.75
F
1.27
1.52
G
2.67
2.92
H
3.94
4.19
I
5.33
5.59
Dimension
“C”
Glass Lid
(mm max.)
Specification
Frequency Range:
Functional Mode:
Calibration Tolerance*:
1
(TO P)
Extensional mode
High shock resistance
Designed for low-power applications
Compatible with hybrid or PC board packaging
Low ageing
Full military environmental testing available
Ideal for battery operated applications
6.99
Specifications are typical at 25°C unless otherwise indicated.
*
**
Tighter frequency calibration available
Other turning point available
Ceramic Lid
(mm max.)
SM1
1.65
1.91
SM2
1.70
1.96
SM3
1.78
2.03
Equivalent Circuit
1
L1
C1
R1
Solder Pad Layout
2
2.67
C0
2.87
R 1 Motional Resistance
L 1 Motional Inductance
C 1 Motional Capacitance C0 Shunt Capacitance
1
2
0.6
CX MINIATURE CRYSTALS
CX-2-SM
EUROQUARTZ
Telephone:
+44(0)1460 230000
Fax:
+44(0)1460 230001
Email: [email protected]
Web: www.euroquartz.co.uk
Page
760kHz to 1.35MHz
LOW-PROFILE
SMD CRYSTAL
2 of 2
Circuit Design
Typical Pierce Oscillator Application
The low profile CX miniature surface-mount crystal is ideal for small,
battery operated portable products. The CX crystal design in a Pierce
oscillator (single inverter) circuit has a very low current consumption
with high stability. A conventional HCMOS Pierce oscillator circuit is
shown below. The crystal is effectively inductive and in a Pi network
with C1 and C2 which provides the additional phase-shift necessary
to sustain oscillation. The oscillation frequency (f0) is 15ppm to
150ppm above the crystal’s series resonant frequency (FS).
Conventional HCMOS Pierce Oscillator Circuit
Rf
Amplifier
CS
Buffer
Osc.
Freq. (Fo)
RA
Drive Level
RA is used to limit the crystal’s drive level by forming a voltage
divider between RA and C1. RA also stabilizes the oscillator against
changes in the amplifiers output resistance (R0). RA should be
increased for higher voltage operation.
C1
CX-2
C2
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:
C x C2
CL = 1
C
C1 + C2 + S
NOTE: C1 and C2 include stray layout capacitance to ground. CS is
the stray shunt capacitance between the crystal terminals. In
practice, the effective valus of CL will be less than that calculated
from C1, C2, and CS values due to the effect of the amplifier output
resistance. CS should be minimized.
The oscillation frequency (f0) is approximately equal to:
f 0 = f S 1+
C1
2(C0 + CL )
Where FS = Series resonant frequency of the crystal
C1 = Motional Capacitance
C0 = Shunt Capacitance
Terminations
Packaging
CX-2-SM -
Designation
Bulk Pack (Standard)
- 16mm tape, 178mm or 330mm reels (Optional)
per EIA 481
- Tray Pack (Optional)
Termination
SM1
Gold Plated
SM2
Nickel, Solder Plated
SM3
Nickel, Solder Plated and Solder Dipped
Order Code
CX-2
C = Ceramic Lid
Blank = Glass Lid
“S” if special
or custom design
Blank if standard
-SM1
SM1
SM2
SM3
Frequency
( A
1.0MHz
Calibration
Tolerance*
@ 25°C
A, B, C
*For other calibration
tolerances enter
figure in ppm
/
I
)
Temperature
Range:
C = Commercial
I = Industrial
M = Military
S = Specify
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