EURO
QUARTZ
Ultra-Miniature SMD Crystal
FEATURES
Frequency Range 30kHz to 250kHz
High shock resistance
Low ageing
Designed for low power applications
Full MIL testing available
CX4VSM CRYSTAL
30kHz to 250kHz
OUTLINE & DIMENSIONS
DESCRIPTION
CX3VSM crystals are leadless devices designed for surface mounting
on PCBs or hybrid substrates. The crystals are intended for use in
Pierce (single inverter) oscillator circuits.
SPECIFICATION
Specifications stated are typical at 25°C unless otherwise indicated.
Specifications may change without notice.
Parameters
Frequency (Hz):
Motional Resistance R1 (kΩ):
Motional Capacitance C1 (fF):
QualityFactor Q (k):
Load Capacitance (pF)
1
:
Turning Point (°C)
1
:
Fundamental
32.768
50
2.3
40
9
25
100
18
1.07
85
8
10
Overtone
200
2.4
2.2
140
5
29
Standard Calibration Tolerance for 32.768kHz (2)
Glass Lid:
Ceramic Lid:
±30ppm
(0.003%)
±100ppm
(0.01%)
±100ppm
(0.01%)
±1000ppm
(0.1%)
±1000ppm
(0.1%)
±10000ppm
(1.0%)
Dim. H
SM1
SM2
SM3
SM4
SM5
Glass
Lid
1.14
1.17
1.22
1.17
1.22
Ceramic
Lid
Drive Level:
Temperature Coefficient (k):
Ageing, first year:
0.5µW max.
-0.035ppm/°C
2
5ppm max.
1.27
1.30
1.35
1.30
1.35
Note: Frequency f at temperature T is related to frequency Fo at
turning point temperature To by:
f-fo
=k(T-To)
2
fo
Shock, survival:
Vibration, survival:
Operating Temperature Range
Commercial:
Industrial:
Military:
Storage Temperature Range:
Maximum Process Temperature:
1.
2.
5000g, 0.3ms, ½ sine
20g rms, 20~2000Hz random
-10° to +70°C
-40° to +85°C
-55 to +125°C
-55° to +125°C
+260°C for 20 seconds
Other values available
Tighter tolerances available
PACKAGING OPTIONS
CX4VSM crystals are available either tray packed (<250pcs) or tape
and reel (>250 pieces).
16mm tape, 178mm or 330mm reels (EIA 418).
HOW TO ORDER CX4VSM CRYSTALS
CX4V - S
'S' if special,
custom design.
Otherwise leave
blank
-
C
Blank = glass lid
C = ceramic lid
-
SM1
-
32.768K,
Frequency
K = kHz
100
Calibration
Tolerance
@25°C
(in ppm)
/
I
Terminations
SM1 = Gold plated *
SM2 = Solder plated
SM3 = Solder dipped
SM4 = Solder plated *
SM5 = Solder dipped *
* = Lead free
Temp. Range
C = -10° ~ +70°C
I = -40° ~ +85°C
M = -55° ~ +125°C
S = Customer specified
EUROQUARTZ LIMITED Blacknell Lane CREWKERNE Somerset UK TA18 7HE
Tel: +44 (0)1460 230000 Fax: +44 (0)1460 230001 info@euroquartz.co.uk www.euroquartz.co.uk
EURO
QUARTZ
Ultra-Miniature SMD Crystal
CRYSTAL EQUIVALENT CIRCUIT
CX4VSM CRYSTAL
30kHz to 250kHz
TYPICAL APPLICATION FOR A
PIERCE OSCILLATOR
The low profile CX miniature crystal is ideal for use in 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 Pierce oscillator is
shown above. The crystal is effectively inductive and in a Pi network
circuit with C
D
and C
G
provides the additional phase shift to sustain
oscillation. The oscillation frequency (f
O
) is 15 to 250ppm above the
crystal's 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 amplifier's output resistance (R
O
). 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
R1 Motional Resistance
C1 Motional Capacitance
L1 Motional Inductance
C0 Shunt Capacitance
CONVENTIONAL CMOS PIERCE OSCILLATOR CIRCUIT
Note: C
D
and C
G
include stray layout-induced capacitance 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
O
) is approximately equal to:
TERMINATIONS - PLATING
Designation
Termination
f
O
= f
S
Where
1+
C
1
2(C
O
+ C
L
)
SM1
SM2
SM3
SM4
SM5
Gold Plated (Lead Free)
Solder Plated
Solder Dipped
Solder Plated (Lead Free)
Solder Dipped (Lead Free)
F
S
= Series resonant frequency of the crystal
C
1
= Motional Capacitance
C
O
= Shunt Capacitance
EUROQUARTZ LIMITED Blacknell Lane CREWKERNE Somerset UK TA18 7HE
Tel: +44 (0)1460 230000 Fax: +44 (0)1460 230001 info@euroquartz.co.uk www.euroquartz.co.uk
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