Stmicroelectronics S.r.l.

Raffaele Enrico Furceri

Marco Zamprogno

Andrea Barbieri

Luca Molinari

Giacomo Langfelder

Pasquale Flora

Matteo Gianollo

Techniques to be described herein are based upon the combination of a digital lock-in amplifier approach with a numerical method to yield accurate estimations of the amplitude and phase of a sense signal obtained from a movement sensor associated with a resonant MEMS device such as a MEMS mirror. The techniques described herein are efficient from a computational point of view, in a manner which is suitable for applications in which the implementing hardware is to follow size and power consumption constraints.

Method to estimate phase and amplitude for control of a resonant MEMS mirror

A bridge driver circuit applies a bias voltage across first and second input nodes of a resistive bridge circuit configured to measure a physical property such as pressure or movement. A sensing circuit senses drive current, bias current and common mode current for the bridge driver and sums the sensed currents to generate a source current. The source current is processed to determine a normalized resistance and temperature of the resistive bridge circuit and from which a temperature dependent sensitivity of the resistive bridge circuit is determined. A voltage output at first and second output nodes of the resistive bridge circuit is processed to determine a value of the physical property. This processing further involves applying a temperature correction in response to the determined temperature dependent sensitivity.

Resistive bridge sensor with temperature compensation

Growing community of inventors

Milan, Italy

Raffaele Enrico Furceri