Circuit Design
CX-6V-SM- Tray Pack (Standard)
- 16mm tape, 178mm or 330mm reels
(Optional) per EIA 481
Packaging
Order Code
CX-6
“S” if special
or custom design
Blank if standard
Frequency
SM1
SM2
SM3
Calibration
Tolerance*
@ 25°C
A, B, C
1.0MHz
-SM1
Temperature
Range:
C = Commercial
I = Industrial
M = Military
S = Specify
(A /
I )
C = Ceramic Lid
Blank = Glass Lid
*For other calibration
tolerances enter
figure in ppm
Typical Pierce Oscillator Application
The low profile CX miniature surface-mount crystal is ideal for small,
battery operated portable products. The CX crystal designed 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 C and C which provides the additional
phase-shift necessary to sustain oscillation. The oscillation frequency
(f ) is 15ppm to 150ppm above the crystal’s series resonant
frequency (F ).
R is used to limit the crystal’s drive level by forming a voltage
divider between R andC.R also stabilizes the oscillator against
changes in the amplifiers output resistance (R ). R should be
increased for higher voltage operation.
The CX crystal calibration tolerance is influenced by the effective
circuit capacitances, specified as the load capacitance (C .) C is
approximately equal to:
12
0
S
A
A1
A
0A
LL
Drive Level
Load Capacitance
C =
Cx C
C+ C
2
1
LS
C
+
NOTE: C and C include stray layout capacitance to ground. C is
the stray shunt capacitance between the crystal terminals. In
practice, the effective valus of C will be less than that calculated
fromC,C,and CS values due to the effect of the amplifier output
resistance. C should be minimized.
The oscillation frequency (f ) is approximately equal to:
12
S
L
12
S
0
Where F = Series resonant frequency of the crystal
C = Motional Capacitance
C = Shunt Capacitance
S
1
0
f =
C1
0 fS
2(C+ C)
0L
1+
Conventional HCMOS Pierce Oscillator Circuit
CX-2
Buffer
Amplifier
Osc.
Freq. (Fo)
C
C
C5
RB
R)
Terminations
Designation
SM1
Gold Plated
SM2
Nickel, Solder Plated
SM3
Nickel, Solder Plated and Solder Dipped
Termination
Solder Pad Layout
1.78
3.05
5.46
+44(0)1460 230000
+44(0)1460 230001
sales@euroquartz.co.uk
www.euroquartz.co.uk
Telephone:
Fax:
Email:
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EUROQUARTZ
CX MINIATURE CRYSTALS
Page
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CX-6V-SM
800kHz to 1.35MHz
ULTRA-LOW PROFILE
MINIATURE SMD CRYSTAL
CX-6V-SM
800kHz to 1.35MHz
ULTRA-LOW PROFILE
MINIATURE SMD CRYSTAL