Post by thread:[PIC] rfPIC INTOSC variations with VDD

Anyone know how the accuracy of the internal oscillator on a 12F675H varies with supply voltage? I only see initial accuracy listed in the datasheet; if there is a spec for this i am not finding it. The reason I am asking is this: I'm running the PIC off a 3V Li-Ion battery, using the same protocol as in their demo source code, xmit_demo.asm. each transmitted bit has a period of 1.2msec. To transmit a '1', the high-time is 400usec, low time 800usec. To transmit a logic '0', the high-time is 8usec, low time is 400usec. Timing is generated by the internal oscillator. So it would be useful/vital to know the effect of a decaying battery voltage on the oscillator accuracy to figure out the tolerances the receiver has to deal with, give a low battery alarm, etc. ____________________________________________