Microcontroller Crystal Accuracy

[hioyo]

May I know how to select XTAL accuracy for a microcontroller clock source

 

[crutschow]

Entirely depends upon how accurate a clock frequency you need.
What are you doing with the micro that requires an accurate clock?

 

[KlausST]

Hi,

I agree with crutschow.

If you need high accuracy:
* Then most important information is in the XTAL datasheet
* next important information is in the microcontroller datasheet (mainly stray capacitance)

Most simple circuit is: Microcontroller, XTAL, 2 capacitors.
--> For high accuracy: don´t use the capacitor recommendation from the microcontroller datasheet, but choose capacitors like recommended in the XTAL datasheet. Maybe the XTAL manufacturer provides an application note how to get high accurate frequency.

Also mind that PCB layout as well as proper power supply bypassing has impact on accuracy.

Klaus