A 66 W 86 ppm C Fully-Integrated 6 MHz Wienbridge Oscillator With a 172 dB Phase Noise FOM

This paper presents the design of a new Wienbridge topology. Its phase noise performance, low temperature dependency and low power consumption make it suitable for use in wireless sensor nodes and time-based sensor readout circuitry. The noise as well as temperature behavior of the oscillator is explained using extensive calculations. Measurements on 7 samples of the same batch show a temperature stability of 86 ppm/^degC and a measured spread of 0.9% at an oscillation frequency of 6 MHz. The circuit consumes 66 muW and is realized in a 65 nm technology measuring 150 mum by 200 mum. The measured phase noise figure of merit is 172 dB at a frequency offset of 100 kHz.