Rejection of Power Supply Noise in Wheatstone Bridges : Application to   Piezoresistive MEMS
  This paper deals with the design of MEMS using piezoresistivity as transduction principle. It is demonstrated that when the sensor topology doesn't allow a perfect matching of strain gauges, the resolution is limited by the ability of the conditioning circuit (typically a Wheatstone bridge) to reject power supply noise. As this ability is strongly reduced when an offset voltage is present at the output of the bridge, the proposed architecture implements a feedback loop to control MOS transistors inserted in the Wheatstone bridge to compensate resistor mismatches. This feedback exhibits a very good offset cancellation and therefore a better resolution is achieved. 
El Mehdi Boujamaa (LIRMM), Yannick Soulie (LIRMM), Fr\'ed\'erick   Mailly (LIRMM), Laurent Latorre (LIRMM), Pascal Nouet (LIRMM)