lu82562ex Intel Corporation, lu82562ex Datasheet - Page 64

• Manufacturer Part Number: lu82562ex
• Description: Dual Footprint
• Manufacturer: Intel Corporation

82562EZ(EX)/82547GI(EI) Dual Footprint Design Guide
56
Example 3.
Example 4.
Note: The following items should be noted for an ideal reference crystal on a typical printed circuit
board.
•
•
where
Given: The measured averaged center frequency is 24.99963 MHz (or 24,999,630 Hertz).
Given: The measured averaged center frequency is 25.00027 MHz (or 25,000,270 Hertz).
If the transmitter reference frequency is more than 8 ppm below the target frequency, then the
values for C1 and C2 are too big and they should be decreased. When tests are performed
across temperature, it may be acceptable for the center frequency deviation to be a little greater
than 8 ppm.
If the transmitter reference frequency is more than 8 ppm above the target frequency, then the
values for C1 and C2 are too small and they should be increased. When tests are performed
across temperature, it may be acceptable for the center frequency deviation to be a little greater
than 8 ppm.
FrequencyAccuracy ppm
FrequencyAccuracy ppm
x = Average measured frequency in Hertz and
y = Ideal reference frequency in Hertz
FrequencyAccuracy ppm
(
(
)
)
=
=
(
----------------------------------------------------------
(
----------------------------------------------------------
24999630 25000000
(
(
25000270 25000000
(
25000000 1000000
25000000 1000000
)
=
–
------------------------------- -
(
–
⁄
y 1000000
⁄
⁄
(
x y
–
)
)
)
)
)
=
)
=
–
10.8ppm
14.8ppm