What is the importance in putting capcitor across crystal

[bskumar7080]

Hi all,
Why we need capacitors in parallel with crystal in microcontroller circuit , Is it necessary to add capacitors


Regards
Sivakumar

 

[IanP]

Virtually all microcontrollers use Pierce-Gate topology, and there is no parallel capacitor attached to the crystal ..
Instead, there are two load capacitors on both sides of crystal and the theory behind it is described in a greater detail in the appnote:

**broken link removed**

IanP
:wink:

 

[JohnRocks]

Hi dears,
The importance of putting in parallel is that it is key to match the crystal's load capacitance required. You can also use the combination of both the series and parallel capacitors but regarding the capacitance value available.
Also you can add external capacitors to modify the load capacitance.
Thanks.