DA6279D8.001

26 September 2017

6 (12)

RECOMMENDED CRYSTAL TEMPERATURE CHARACTERISTIC

Crystal cut angle determines crystal’s temperature characteristic. The cut angle can be selected to minimize

crystal’s temperature dependency in the temperature range of interest. Table 1 below shows theoretical AT-cut

crystal cut angles minimizing crystal batch temperature dependency at five different temperature ranges. In the

optimization calculations the inflection temperature of the crystal has been +29°C and cut angle control tolerance

±

Table 1. AT-

cut crystal cut angles to minimize crystal’s temperature dependency

Temperature range

AT crystal cut angle

Nominal crystal’s temperature

dependency

0°C…+60°C

1.13’

±1.1ppm (2.2ppm p-p)

-

10°C…+60°C

1.70

’

±2.1ppm (4.2ppm p-p)

-

20°C…+70°C

2.55

’

±3.8ppm (7.6ppm p-p)

-

30°C…+85°C

3.57

’

±6.3ppm (12.6ppm p-p)

-

40°C…+85°C

4.77

’

±9.7ppm (19.8ppm p-p)

Figure 3 below illustrates theoretical temperature characteristic of above five cut angle crystals for different

temperature ranges. The widest temperature range -40°

C…+85°C requires largest cut angle and the narrowest

temperature range 0°

C…+60°C smallest cut angle.

Figure 3. Temperature characteristic of five AT-cut crystals with different cut angles