Low power MEMS oscillators for sensor applications

Vacuum Packaged Low-Power Resonant MEMS Strain Sensor

“…2(b) with the design approach adapted from previous work on low-power crystal oscillators [30]. An automatic gain control (AGC) circuit [11,31] is added to minimize the power consumption by setting the transconductance, gm, at the critical point. The AGC circuitry also helps prevent driving the MEMS resonator into the non-linear regime.…”

“…A CMOS circuit based on Pierce topology [11,30] is employed due to its simplicity, stability and potential for power minimization with the gain provided by a single transistor. Fig.…”

“…Traditional foil gauges and piezoresistive strain gauges are usually associated with significant static power dissipation, both in the transducer element as well as in the associated interface circuitry. While MEMS resonant strain gauges have promised significantly lower power consumption [11] than traditional foil gauges, a low-power implementation has not yet been reported to date.…”

“…This requirement puts a significant constraint on the power demand of the sensors themselves [1,5,6]. Silicon micromachined resonant sensors have emerged as a potential candidate to address this requirement [7][8][9][10][11]. They have the inherent potential of being compatible with batch fabrication, miniaturization and can also be co-integrated with CMOS circuitry in a small form-factor package.…”

“…A low power front-end interface circuit [11] for such resonators thus has broad applicability to a variety of sensing contexts. This would enable ultra-low power operation for both the MEMS sensors as well as the interface circuit in order to address practical applications.…”