Switched closed loop read-out methods and systems for resonant sensing platforms

A closed loop system comprising:

• a sensor for receiving drive signals during excitation time periods and generating sense signals during measurement time periods;
• signal conditioning circuitry coupled to the sensor during the measurement time periods, the signal conditioning circuitry to condition sensed signals;
• and
• phase locked loop (PLL) circuitry coupled to the signal conditioning circuitry, the PLL circuitry is switched in a time domain between first and second states with input circuitry of the PLL circuitry to sample conditioned sense signals during the measurement time periods to lock into a frequency of conditioned sensed signals during the first state.

A read-out method for operating a sensing device, comprising:

• switching, with processing logic, driving circuits to an enabled state for a sensing device by coupling the driving circuits to the sensing device;
• switching, with the processing logic, sensing circuits to a disabled state for the sensing device by decoupling sensing circuits from the sensing device;
• and
• during a drive period, supplying a drive signal to the sensing device for an excitation period to cause mechanical oscillations of suspended beams of the sensing device.