Quartz crystal resonators

Quartz crystal resonators:

Doubly rotated crystal selection:

The choice of which doubly rotated crystal cut to use is dependent upon a number of factors including the desired operating temperature. FC-cut, IT-cut and SC-cut crystals have widely different lower and upper turning point temperatures and therefore the choice of crystal cut and oven temperature should be closely coordinated.	Type of cut	Turn point	Typical turning point
	FC	Upper	+55°C to +75°C
	IT	Upper	+85°C to +105°C
	SC	Lower	+60°C to +80°C
	SCM1	Lower	+65°C to +85°C
	SCM2	Lower	+85°C to +100°C

 

See before table for ordering information:

Note that the nine digit CRYSTAL CODE addresses only the six parameters outlined above. Unless otherwise specified by the customer, the values of any additional parameters will be per the latest revision of MIL-PRF-3098.

If the crystal requirements cannot be fully described by the nine digit code, a unique deviation number will be assigned by the factory

 

MODE

HOLDER

CAL. TOL.

TEMPERATURE STABILITY OR TOTAL TOLERANCE

OPERATING TEMP.

CIRCUIT CONDITION

Code

Desc.

Code

Desc.

Code

Desc.

Code

Desc.

Code

Desc.

Code

Desc.

Code

Desc.

A

Fund.

35

HC-35/U

0

Standard

X

+/-1.5ppm

X

+/-2ppm stability

X

+15ºC to +35ºC

00

Series resonance

B

3rd

36

HC-36/U

1

Surface mount

A

+/-2ppm

Y

+/-3ppm stability

Y

+10ºC to +40ºC

01

Parallel resonance load capacity of 100pF or more Advise actual value

C

5th

37

HC-37/U

2

Surface mount

B

+/-5ppm

Z

+/-4ppm stability

Z

+5ºC to +45ºC

D

7th

40

HC-40/U

3

Slimline

C

+/-7ppm

B

+/-5ppm stability

A

+0ºC to +50ºC

E

9th

42

HC-42/U

4

Modified can height

D

+/-10ppm

C

+/-7ppm stability

B

-5ºC to +55ºC

10 to 90

Parallel resonance load capacity in pF

F

11th

43

HC-43/U

5

Modified can height

E

+/-15ppm

D

+/-10ppm stability

D

-10ºC to +60ºC

45

HC-45/U

6

Modified can height

F

+/-20ppm

E

+/-15ppm stability

E

-15ºC to +65ºC

99

Calibration at reference temperature in customer’s oscillator

47

HC-47/U

7

Four point mount

G

+/-25ppm

F

+/-20ppm stability

F

-20ºC to +70ºC

48

HC-48/U

8

Modified can height

H

+/-30ppm

G

+/-25ppm stability

G

-25ºC to +75ºC

49

HC-49/U

9

Modified can height

J

+/-40ppm

H

+/-30ppm stability

H

-30ºC to +80ºC

50

HC-50/U

M

+/-50ppm

J

+/-40ppm stability

J

-40ºC to +90ºC

51

HC-51/U

K

+/-100ppm

M

+/-50ppm stability

M

-55ºC to +105ºC

52

HC-52/U

L

+/-70ppm stability

U

+50ºC to +60ºC oven

90

SM1

K

+/-100ppm stability

L

+55ºC to +65ºC oven

N

+/-150ppm stability

T

+60ºC to +70ºC oven

S

Specific curve

N

+65ºC to +75ºC oven

T

+/-20ppm (4) (B)*

P

+70ºC to +80ºC oven

U

+/-25ppm (4) (C)*

R

+75ºC to +85ºC oven

V

+/-30ppm (4) (D)*

S

+80ºC to +90ºC oven

W

+/-50ppm (4) (F)*

V

+85ºC to +95ºC oven

P

+/-100ppm (4) (H)*

W

+90ºC to +100ºC oven

R

+/-200ppm (4) (M)*

C

+95ºC to +105ºC oven

0

Turn over point in oven range

0

Not specified

*Corresponding calibration codes

 

Eg. A357DFE-32 @ 20M is translated as follows:

A = Fundamental mode of operation

35 = HC-35/U holder

7 = Four point mount for improved g-sensitivity

D = Calibration tolerance of +/-10ppm at the reference temperature

F = Temperature stability of +/-20 ppm, with respect to the frequency measured at the reference temperature

E = Temperature range of -15°C to +65°C, over which the temperature stability is effective

32 = When present, these two digits specify parallel resonance operation and the load capacitance in pF (i.e. 32pF)

20M = Nominal frequency of 20MHz