FEDL87V2107-01
OKI Semiconductor
ML87V2107
Example of Using the Crystal Oscillation Section
The crystal oscillation section of this IC becomes available by the circuit configuration shown below.
Setting the XTSL pin to a High level will output the XTI and XTO oscillation clocks from OCLK, thereby
dispensing with OCLK input from the outside.
If the crystal oscillation section is used, it is recommended that the output of the CLKO pin be connected to the
next device (see figure below) and that the OCLK pin be left open. However, if the OCLK pin is connected, be
sure to place a damping resistor (R: around 47Ω to 100Ω) adjacent to the OCLK pin of the IC. Also, insert a
damping resistor for the CLKO pin as required.
VDD
R
61:OCLK
27:XTSL
ML87V2107
35:CLKO
38:XTI
39:XTO
OR
Next
Device
Rd=2.2kΩ
C1=8pF
C2=22pF
VSS
VSS
Note:
The above is an example where a KYOCERA CORP. CS-53F Series crystal is connected to Oki’s evaluation
board, and does not provide any guarantees for crystal oscillator operation under a customer’s operating
environment.
Each value of constants Rd, C1, and C2 in the peripheral circuit for crystal needs to be changed according to
the specification of the board pattern, parts layout, and/or crystal used.
Users are encouraged to fully examinine and verify the crystal oscillator operation.
It is recommended that the above described constants and oscillator operation be fully examined because they
depends on the manufacturer of the crystal used.
If a high accuracy is required for the clock for output operation, it is recommended that a clock with the
accuracy that satisfies the customer’s needs be supplied externally, not using the crystal oscillation circuit of
this IC.
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