Patent ID: 8497741

Claim:
A device comprising: an RC oscillator circuit operable to provide a tunable output frequency, the oscillator circuit including a bias circuit switchable between first and second modes of operation, one of which has less drift in oscillator bias current relative to the other mode; drift compensation circuitry operable to compensate for drift in the oscillator output frequency in a closed-loop mode of operation based on a comparison of the oscillator output frequency with a reference frequency; and a processor operable to compensate for temperature-based drift in the oscillator frequency in an open-loop mode of operation based on a measured temperature value in a vicinity of the oscillator circuit, wherein the bias circuit includes a proportional-to-absolute-temperature branch and a complementary-to-absolute-temperature branch, wherein in the first mode of operation, only the proportional-to-absolute-temperature branch is enabled, and wherein in the second mode of operation, both the proportional-to-absolute-temperature branch and the complementary-to-absolute-temperature branch are enabled.