A Continuous-Time Collocated Force-Feedback and Readout Front-End for MEM Gyroscopes

An Interface ASIC for MEMS Vibratory Gyroscopes With a Power of 1.6 mW, 92 dB DR and 0.007°/s/<inline-formula> <tex-math notation="LaTeX">$\sqrt {\rm {Hz}} $ </tex-math> </inline-formula> Noise Floor Over a 40 Hz Band

“…V DD,HV represents not only the constant DC part of V Drive but is also used as supply voltage for the quadrature control amplifiers and the middle electrode biasing amplifier, which generate the voltages V Quad and V Mid , as shown in Fig. 1 [16]. These circuit parts and the C FC1,2 represent the capacitive and resistive load for the DCP modeled as C L and R L according to Fig.…”

“…In [21] a concept is presented, which separates the electrodes for quadrature compensation and enables the usage of the quadrature electrodes in order to apply feedback voltages. However, combining high voltages required for quadrature compensation and AC voltages for the feedback generation, results in an increased power consumption of the HV amplifiers generating these AC voltages [16]. The CT collocated feedback in this work applies the feedback voltages to the sense electrodes C S1,2 in the low voltage domain.…”

“…This relaxes the requirements on these amplifiers [16]. For the implementation of the CT collocated-CI a fully differential difference amplifier is used and shown in Fig.…”

“…Therefore, the voltage applied at the sensor and hence the generated feedback force does not change. The implementation of the CI and of the feedback as well as the compensation voltage generation is presented in [16].…”

“…In this work, the mechanical frequency of the sense mass equals f d . This is achieved by electrical spring softening [16] obtained with an on-chip generated high voltage on C Q1,2 . After ensuring match mode, also the center frequency f c of the filter resonator is adjusted to match f d ( f c = f d ).…”