Method and apparatus for balancing detection sensitivity in producing a differential signal

An interface circuit for interfacing with a sensor having a pair of transduction elements organized and arranged for respectively producing first and second electrical signals, which are substantially 180 degrees out of phase and which are each associated with a respective one of a pair of output terminals, where each one of the pair of transduction elements has a potential difference in sensitivity to a detected stimulus, which can manifest in the first and second electrical signals that are being respectively produced by the pair of transduction elements of the sensor, that have a difference in amplitude, the interface circuit comprising:

• a bias voltage generator having one or more bias output voltage terminals, where a respective one of one or more DC bias voltages is produced at each of the bias output voltage terminals, which are adapted to be coupled to the pair of transduction elements of the sensor;
• an amplifier circuit having a first input terminal adapted to be coupled to a first one of the pair of output terminals of the sensor and having a second input terminal adapted to be coupled to a second one of the pair of output terminals of the sensor, the amplifier circuit producing at a pair of output terminals a differential output signal;
• and
• a compensation circuit coupled to the amplifier circuit for producing a balance signal based on an output signal being produced by the amplifier circuit, wherein the balance signal compensates for any difference in amplitude in the first and second electrical signals that are adapted to be received by the amplifier circuit from the sensor.

A method comprising:

• producing one or more DC bias voltages and supplying the produced DC bias voltages to a sensor, which includes a pair of transduction elements;
• detecting by the sensor a stimulus, where within the sensor the pair of transduction elements are organized and arranged for respectively producing first and second electrical signals, which are substantially 180 degrees out of phase in response to the detected stimulus, where each one of the pair of transduction elements have a potential difference in sensitivity to the detected stimulus, which can manifest in the first and second electrical signals that are being respectively produced by the pair of transduction elements of the sensor, that have a difference in amplitude;
• producing at a pair of output terminals of an amplifier circuit a differential output signal, based upon receipt of the first and second electrical signals from the sensor;
• determining by a compensation circuit a balance signal based on an output signal being produced by the amplifier circuit, where the balance signal compensates for any difference in amplitude in the first and second electrical signals that are received by the amplifier circuit from the sensor;
• and
• applying the balance signal to the sensor.