This paper presents a silicon oscillator suitable for low-cost and low-power wireless sensing applications. With the comparisons of ring oscillators in different temperature coefficients, the frequency of an internal ring oscillator is estimated and parameterized by a second-order polynomial. Accordingly, the output clock is compensated in a frequency division fashion. The oscillator is implemented in 90-nm CMOS technology with an area of 0.04mm2. Operating at 0.6V, the output frequency is within 200±1kHz over the temperature range of -25°C to 125°C with power consumption of 48μW.