Hi everyone:
I was wondering if the external capacitors for matching Cload are "always" neccesary when attaching a crystal to a microcontroller? If the internal capacitance of the microcontroller oscillator is the same as the specified in the datasheet of the crystal, then I don't see reasons for the external capacitors (those two ones connected between the the leads of the crystal and ground).
The other question is about the ESR indicated in the crystal datasheet. If this ESR indicated in the datasheet of the crystal is slightly higher than the one indicated as maximum for the crystal in the datasheet of the microcontroller, how could it affect the frequency?
Is there any way to correct that ESR of the crystal with an external passive component (resistor or something)?
Thanks!