Thursday, April 4, 2013
Accelerometer Amplifier Circuit
This is a circuit for accelerometer amplifier. This is a simple circuit. Precision accelerometer needs inverting mode amplifier since they are usually charge-output devices. This amplifier is convert charges into voltage output. The circuit below is an example of accelerometer with DC servo. This circuit built by IC LT1113.
The charge from the transducer is converted to a voltage by C1, which should equal the transducer capacitance plus the input capacitance of the op amp. The low frequency bandwidth of the amplifier will depend on the value of R1 • C1 (or R1 (1 + R2/R3) for a Tee network). The noise gain will be 1 + C1/CT. The time constant of the servo (1/R5C5) should be larger than the time constant of the amplifier (1/R1C1).
[Schematic source: Linear Technology Application Notes]
The charge from the transducer is converted to a voltage by C1, which should equal the transducer capacitance plus the input capacitance of the op amp. The low frequency bandwidth of the amplifier will depend on the value of R1 • C1 (or R1 (1 + R2/R3) for a Tee network). The noise gain will be 1 + C1/CT. The time constant of the servo (1/R5C5) should be larger than the time constant of the amplifier (1/R1C1).
[Schematic source: Linear Technology Application Notes]
