Oscillator selection

[Murugesh_89]

If i need to operate with the frequency of 8Mhz and my micro controller has a internal oscillator for the same frequency. which
is the better option of the following two.
1. Using the internal oscillator of the microcontroller
2. Using a 8Mhz external crystal


Also if the internal oscillator of the microcontroller is used, will it have any negative effect in any manner?


Thanks,
Murugesh

 

[kripacharya]

The internal oscillator is not as accurate of steady as an external crystal. So it depends on your application which one you should use. Obviously the internal osc is easier & cheaper to use, at the slight loss of stability & accuracy. Usually you can trim the internal osc for better accuracy at a given temperature & voltage level, but the stability remains in question due to variations in these parameters.

 

[G4BCH]

Ignoring the extra cost of a crystal, if you can live with the accuracy and drift of the internal oscillator then use it. If you need the accuracy and stability of a crystal then that makes the decision for you.