Stmicroelectronics Gmbh

Stmicroelectronics S.r.l.

Davy Choi

Francesco Rizzini

Yamu Hu

Marco Garbarino

Deyou Fang

In one embodiment, a method for detecting functional state of a microelectromechanical (MEMS) sensor is described. The method includes monitoring an input common-mode feedback (ICMFB) voltage generated by an ICMFB circuit coupled to the MEMS sensor through a plurality of nodes. The method also includes determining, using the monitored ICMFB voltage, whether all of the plurality of nodes of the MEMS sensor are electrically connected to the ICMFB circuit.

Sensing an ICMFB output to detect functional state of a mems sensor

Sensing an ICMFB output to detect functional state of a MEMS sensor

An instrumentation amplifier includes first and second resistors for gain setting. The operational amplifiers within the instrumentation amplifier include selectively enabled current drive sources coupled to the amplifier output. The first and second resistors have variable resistances. A control circuit is configured to select the variable resistances of the first and second resistors to implement a fixed gain for the instrumentation amplifier and further selectively enable the current drive sources. The control circuit receives an indication of a downstream programmable gain (for example, from a downstream programmable gain amplifier). The variable resistances of the first and second resistors are selected to be scaled inversely with respect to the downstream programmable gain and the current drive sources are enabled proportionately with respect to the downstream programmable gain.

Fixed gain amplifier circuit

A bandgap voltage reference circuit includes a current generation stage configured to generate a proportional to absolute temperature (PTAT) current and a complementary to absolute temperature (CTAT) current and to generate a reference current by combining the PTAT and CTAT currents. An output stage is coupled to the current generation stage and configured to combine the PTAT current and the CTAT current to generate a bandgap voltage reference. A curvature correction circuit is configured to generate a curvature correction current that mirrors the reference current generated from the PTAT and CTAT currents. The curvature correction current has a ratio relative to the reference current given by a current ratio parameter having value that is less than one, equal to one, or greater than one. In this way the value of the current ratio parameter can be varied to cancel a non-linear dependence on temperature of the bandgap voltage reference, thereby providing a curvature-compensated bandgap voltage reference.

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Carrollton, TX, United States of America

Davy Choi