All of the MEMs sensors have an integrated analog signal processor. This circuit creates precision AC waveforms that are fed to the moveable fingers of the sensor, and then picked up by the fixed fingers. A demodulation circuit then senses the fine difference between the signals and generates a signal which is proportional to the movement of the fingers. In many of these devices, we then feed a DC signal back to the moveable fingers to re-center them. The restoring signal is proportional to the acceleration, and this technique actually provides better linearity than measuring the position directly. Most devices have an on-board temperature sensor for compensation. Many devices also include an ADC so that the output of the device is in digital format rather than analog. Some include interface logic to allow easier bus interface, and some include digital filtering with a simple DSP. For parts intended to be used for remote sensing, they will have a control processor for power management, and a few have a way to wake up upon motion detection.
We also provide more involved IMUs (inertial-measurement-unit) that are multi-chip devices with accelerometers, gyroscopes, magnetic sensors, and control processors.
Thanks for attending the seminar and asking a question. David Kress
All of the MEMs sensors have an integrated analog signal processor. This circuit creates precision AC waveforms that are fed to the moveable fingers of the sensor, and then picked up by the fixed fingers. A demodulation circuit then senses the fine difference between the signals and generates a signal which is proportional to the movement of the fingers. In many of these devices, we then feed a DC signal back to the moveable fingers to re-center them. The restoring signal is proportional to the acceleration, and this technique actually provides better linearity than measuring the position directly. Most devices have an on-board temperature sensor for compensation. Many devices also include an ADC so that the output of the device is in digital format rather than analog. Some include interface logic to allow easier bus interface, and some include digital filtering with a simple DSP. For parts intended to be used for remote sensing, they will have a control processor for power management, and a few have a way to wake up upon motion detection.
We also provide more involved IMUs (inertial-measurement-unit) that are multi-chip devices with accelerometers, gyroscopes, magnetic sensors, and control processors.
Thanks for attending the seminar and asking a question. David Kress
