Method for calibration of a system with time-multiplexed sensors
View Patent ↗A sense channel signal processing block is time-domain multiplexed among multiple MEMS devices and utilizes an anti-aliasing filter disposed after track-and-hold switches, to prevent the bandwidth of the sense channel from being limited by the anti-aliasing filter. A multiplexed signal processor architecture performs dynamic calibration of all sensor error signals in response to environmental changes.
1. A sense channel apparatus comprising:
a) a plurality of input switches for receiving analog signals from a plurality of MEMS devices, respectively;
b) a plurality of output switches;
c) a zero-IF mixer operatively coupled intermediate the plurality of input switches and the plurality of output switches;
d) a common signal processing module operatively coupled intermediate the zero-IF mixer and the plurality of output switches, the signal processing module configured to at least partially derive a parameter signal from an analog signal from one of the plurality of MEMS devices; and
e) a calibration module configured to generate a calibration signal at least partially derived from the parameter signal associated with one of the plurality of MEMS devices and further configured to provide the generated calibration signal to one of the plurality of MEMS devices in a multiplexed, time domain manner, wherein calibration signals are generated for the plurality of MEMS devices, respectively.
2. The apparatus of claim 1 , wherein the zero-IF mixer has a trans-impedance amplifier.
3. The apparatus of claim 2 wherein at least one of the MEMS devices comprises a gyroscope.
4. The apparatus of claim 1 further comprising a timing generator module for providing timing signals to the signal processing module and the calibration module.
5. The apparatus of claim 1 , wherein the calibration signal is updated to a particular MEMS device of the plurality of the MEMS devices during a phase when an output of the particular MEMS device is inactive.