CN0303: MEMS-Based Vibration Analyzer with Frequency Response Compensation

CIRCUIT FUNCTION AND BENEFITS
The circuit in Figure 1 offers a high linearity, low noise, wide-bandwidth vibration sensing solution. It is ideal for applications requiring a large dynamic range (±70 g, ±250 g or ±500 g) and a flat frequency response from dc to 22 kHz.The circuit provides a low power solution suitable for bearing analysis, engine monitoring and shock detection.

The Analog Devices, Inc. proprietary fifth-generation iMEMs® process enables the ADXL001 accelerometer to provide dynamic range that extends from ±70 g to ±500 g in combination with 22 kHz of bandwidth.

The AD8606 is a precision, low noise, dual op amp used to create an analog bi-quad filter that flattens the output frequency response of the accelerometer.

The ADXL001 output voltage is converted into a digital word by the AD7476 low power, single channel 12-bit SAR ADC.

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