EUROQUARTZ CX4

EURO QUARTZ
CX4 CRYSTAL
Ultra-miniature Low Profile SMD
Fundamental Mode: 600kHz to 1.4MHz
Designed for low power applications
Overtone: 1.8432MHz to 2.5MHz
Smallest available package in this frequency range
FEATURES
Hermetically sealed, ceramic package
Excellent ageing characteristics
Full Military testing available
DESCRIPTION
CX4 crystals are leadless devices designed for surface mounting on
PCBs or hybrid substrates. The crystal has been designed for low
power applications.
OUTLINE & DIMENSIONS
SPECIFICATION
Specifications stated are typical at 25°C unless otherwise indicated.
Specifications may change without notice.
Parameters
Fundamental
Frequency (Hz):
Motional Resistance R1 (kΩ):
Overtone
600K
1.0M
1.4M
1.8432M
2.4576M
300
400
600
500
1000
1.5
Motional Resistance R1 Max. (kΩ):
3kΩ
Motional Capacitance C1 (Ff):
3.5
2.0
1.3
3.5
Quality Factor Q (k):
250
200
150
80
45
Shunt Capacitance C0 (pF):
1.0
0.8
0.7
1.0
0.8
Standard Calibration Tolerance1:
±500ppm (±0.5%)
±1000ppm (±0.1%)
±10000ppm (±1.0%)
3µW maximum
7pF
35°C
-0.035ppm/°C2
Drive Level:
Load Capacitance CL2:
Turning Point2:
Temperature Coefficient (k):
Note: Frequency f at temperature T is related to frequency Fo at
turning point temperature To by:
f-fo
=k(T-To)2
fo
Functional mode:
Extensional
Ageing, First year:
±5pppm maximum
Shock, survival:
1500g, 0.3ms, ½ sine
Vibration, survival:
20g rms, 10~2000Hz random
Operating Temperature Range
Commercial:
-10° to +70°C
Industrial:
-40° to +85°C
Military:
-55 to +125°C
Storage Temperature Range:
-55° to +125°C
Maximum Process Temperature:
+260°C for 20 seconds
1.
2.
Dim. H
Glass
Lid
Ceramic
Lid
SM1
SM2
SM3
SM4
SM5
1.14
1.17
1.22
1.17
1.22
1.27
1.30
1.35
1.30
1.35
PACKAGING OPTIONS
Tighter tolerance available
Other values available
CX4 crystals are available either tray packed (<250pcs) or tape and
reel (>250 pieces).
16mm tape, 178mm or 330mm reels (EIA 418).
HOW TO ORDER CX4 CRYSTALS
CX4 - S
-
'S' if special,
custom design.
Otherwise leave
blank
C
-
Blank = glass lid
C = ceramic lid
SM1
-
Terminations
SM1 = Gold plated *
SM2 = Solder plated
SM3 = Solder dipped
SM4 = Solder plated *
SM5 = Solder dipped *
* = Lead free
1.8432M,
Frequency
K = kHz
M = MHz
500
Calibration
Tolerance
@25°C
(in ppm)
/
I
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 [email protected] www.euroquartz.co.uk
EURO QUARTZ
CX4 CRYSTAL
Ultra-miniature Low Profile SMD
Fundamental Mode: 600kHz to 1.4MHz
Overtone: 1.8432MHz to 2.5MHz
CRYSTAL EQUIVALENT CIRCUIT
R1 Motional Resistance
C1 Motional Capacitance
L1 Motional Inductance
C0 Shunt Capacitance
CONVENTIONAL CMOS PIERCE OSCILLATOR CIRCUIT
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 CD and CG provides the additional phase shift to sustain
oscillation. The oscillation frequency (fO) is 15 to 250ppm above the
crystal's resonant frequency (fS).
Drive Level
RA is used to limit the crystal's drive level by forming a voltage divider
between RA and CD. RA also stabilizes the oscillator against changes in
the amplifier's output resistance (RO). RA 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 (CL). CL is
approximately equal to:
CL =
CD x CG
CD + CG
+ CS
Note: CD and CG include stray layout-induced capacitance 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.
The oscillation frequency (fO) is approximately equal to:
TERMINATIONS - PLATING
Designation
SM1
SM2
SM3
SM4
SM5
fO = fS
Termination
Gold Plated (Lead Free)
Solder Plated
Solder Dipped
Solder Plated (Lead Free)
Solder Dipped (Lead Free)
1+
C1
2(C O + C L )
Where
FS = Series resonant frequency of the crystal
C1 = Motional Capacitance
CO = Shunt Capacitance
EUROQUARTZ LIMITED Blacknell Lane CREWKERNE Somerset UK TA18 7HE
Tel: +44 (0)1460 230000 Fax: +44 (0)1460 230001 [email protected] www.euroquartz.co.uk