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What are the constants for R and C when using RC oscillation?

Latest Updated:08/09/2007

Question:

(Clock)   What are the constants for R and C when using RC oscillation? [2007/08/09]

Answer:

Use 33pF for C. The constant for R is determined based on an evaluation of your system.
For reference values, click the Group of your MCU below and refer to the standard characteristics.

Click here:
4518    4519    4508    4509
4552    4553    4556     4559

However, keep in mind that the RC oscillation frequency characteristics listed in the user's manual are example measurements resulting from tests performed on our evaluation boards using standard samples. RC oscillation frequency is greatly affected by the parasitic capacitance of the evaluation board. Perform adequate frequency confirmation on the board of your application device before deciding on the final constant. (#105582)

Suitable Products
4508
4509
4559