Resonance-based MEMS temperature sensors for temperature compensation of mems capacitive accelerometer

Demirhan, Gülşah
The idea of the proposed study is using the resonator structure as a temperature sensor together with controller circuitry. That is to say, the study consists of two branches; one is PI controller output which would be used as a temperature sensor and the other is preamplifier output which would be used as carrier generator to the accelerometer readout circuitry. The proposed resonator is analyzed in detail in terms of dynamics, simulation models and theoretical investigations. The implemented resonator is shown to satisfy the estimated performance parameters with measurements conducted using various test setups. The functionality of concept is verified with additional tests. In other words, it is gathered repeatable temperature sensitivity data from both the accelerometer and the resonating temperature sensor. Then, initially the temperature sensitivity of the accelerometer output with the controller output of the resonating accelerometer is compensated. Once the attempt in the first step is succeed, the temperature compensation network is disassembled and the resonator output to the accelerometer package as the carrier signal is fed. This eliminates the need for an external carrier waveform generated by a standard clock generator, which can be one of the dominant noise sources injected into the accelerometer system. After this new interconnection is made, the temperature sensitivity of the accelerometer is measured. By doing that, it is aimed to observe that the temperature sensitivity of the accelerometer is the same as before compensation, while it is driven by the resonator output as the carrier signal. Finally, the compensation network will be re-assembled while still feeding the accelerometer with the output of the resonator, and it is tried to repeat the compensated accelerometer response that was previously observed at the first step. The best system level test results showed that the temperature sensitivity is improved from -32 mg/°C to -1.6 µg/°C for -35 µg/√Hz noise floor, 16 µg bias instability and 122 dB dynamic range.


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Citation Formats
G. Demirhan, “Resonance-based MEMS temperature sensors for temperature compensation of mems capacitive accelerometer,” M.S. - Master of Science, Middle East Technical University, 2016.