The accuracy of oscillator's frequency

[caosl]

hi,all
I need a 100Khz square wave oscillator.The measure of formerly designed one has a large departure to spec.It's architecture is composed of a current reference,a mosfet capacitor,a comparator.The deviation may be caused by current or mosfet capacitor.Could anyone tell me a better method to improve the oscillation frequency's accuracy? Thanks very very much.

 

[chang830]

the xtal oscillator is very accurate if it is availble to you.

For you design, it is indeed varied much because of the PVT corners. But you can trim it into the spec.