Raltron Electronics Corporation 10651 NW 19th St. Miami, Florida 33172 U.S.A.
Tel: 305-593-6033 Fax: 305-594-3973 e-mail: sales@raltron.com Internet: http://www.raltron.com
TUNING FORK CRYSTAL UNITS
SERIES R38, R26, AND R145
3 x 8, 2 x 6, 1 x 5 mm
COMMON FREQUENCIES ARE: 31.250 kHz, 31.500 kHz, 40.00 kHz, AND 76.800 kHz
FREQUENCY DEVIATION AT T IS GIVEN AS:
f/f = K(To - T), WHERE K IS PARABOLIC CURVATURE CONSTANT
OTHER LOAD CAPACITANCES ARE AVAILABLE
FEATURES
OUTLINE DRAWINGS
DESIGNED FOR TIME OF DAY CLOCKS APPLICATIONS
SMALL COMPACT SIZE WITH PERFORMANCE AND ECONOMY
EXCELLENT SHOCK AND ENVIRONMENTAL CHARACTERISTICS
PART NUMBERING SYSTEM
R145
R26
R38
SERIES
FREQUENCY
LOAD
CAPACITANCE
TOLERANCE
EXTENDED
TEMPERATURE
R38
R26
R145
IN kHz
IN pF
5 PPM
10 PPM
EXT
( 20 PPM ONLY)
-
-
-
-
EXAMPLES:
R38-32.768-6-10PPM
R26-32.768-12.5-EXT
SCALE NONE DIMENSION IN mm/INCH
SPECIFICATIONS
HOLDER TYPE
R38
R26
R145
R38, R26
NOMINAL FREQUENCY
32.768 kHz
32.768 kHz
32.768 kHz
30.00 kHz TO 153.6 kHz
FREQUENCY TOLERANCE
5 10 20 PPM
5 10 20 PPM
5 10 20 PPM
5 10 20 PPM
TURNOVER TEMPERATURE
25C 5C
25C 5C
25C 5C
25C 5C
PARABOLIC CURVATURE
CONSTANT (TYP)
-0.034 PPM/C
-0.034 PPM/C
-0.034 PPM/C
-0.034 PPM/C
LOAD CAPACITANCE
6 or 12.5 pF
6 or 12.5 pF
8.0 pF
6 or 12.5 pF
EQUIVALENT SERIES
RESISTANCE (MAX)
35k OHM
35k OHM
40k OHM
30k TO 50k OHM
DRIVE LEVEL (TYP)
1.0 W
1.0 W
1.0 W
1.0 W
MOTIONAL CAPACITANCE (TYP)
0.0035 pF
0.003 pF
0.0025 pF
.001 TO .004 pF
SHUNT CAPACITANCE (TYP)
1.6 pF
1.35 pF
1.0 pF
0.8 TO 1.7 pF
CAPACITANCE RATIO (TYP)
460
450
400
425 TO 800
AGING (FIRST YEAR MAX)
3 PPM
3 PPM
3 PPM
5 PPM
QUALITY FACTOR (TYP)
90000
70000
80000
FREQUENCY-PACKAGE SPECIFIC
INSULATION RESISTANCE (MIN)
500 M OHM
500 M OHM
500 M OHM
500 M OHM
OPERATING TEMPERATURE
RANGE
STORAGE TEMPERATURE
RANGE
SHOCK RESISTANCE
STANDARD PART NUMBER
R38-32.768-12.5
R26-32.768-12.5
R145-32.768-12.5
SEE PART NUMBERING SYSTEM
5 PPM MAXIMUM 75 cm DROP TEST IN 3 AXES ONTO A HARD SURFACE
OR 3000 g x 0.3 ms x SINEWAVE IN 3 AXES
-40C TO +85C
-20C TO +60C STANDARD
-40C TO +85C EXTENDED
3.10 MAX
.122 MAX
8
.2
0
M
A
X
.
323 M
A
X
10.
00
1
.
0
.
3
9
4
.
039
0.35 DIA
.014 DIA
1.10
.043
1.50 M A X
.059 M A X
4.
3
0
.
169
5.
10 M
A
X
.
201
M
A
X
0.2 D IA
.008 D IA
0.45
.018
2.10 MAX
.083 MAX
6
.2
0
M
A
X
.
244 M
A
X
5.
6
M
I
N
.
220 M
I
N
0.70
.028
0.26 DIA
.010 DIA
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