1 Theory of Operation – Internal RC Oscillators

In production the internal RC oscillators are mostly calibrated at 3V/85°C. Refer to oscillator characteristics in the data sheet for the individual devices for information about the temperature and operating voltage used during calibration. If a design requires accuracy of +/-1% at operating voltages and temperatures other than what is offered by the standard factory calibration, it is possible to perform a secondary calibration of the RC oscillator. By doing this it is possible to obtain frequency accuracy within +/-1% at any operating voltage and temperature. A secondary calibration can thus be performed to improve or tailor the accuracy or frequency of the oscillator.