EVAL-CN0350-PMDZ: Piezoelectric Sensor Signal Conditioning

The circuit shown in Figure 1 is a 12-bit, 1 MSPS data acquisition system utilizing only two active devices. The system processes charge input signals from piezoelectric sensors using a single 3.3 V supply and has a total error of less than 0.25% FSR after calibration over a ±10°C temperature range, making it ideal for a wide variety of laboratory and industrial measurements.

The small footprint of the circuit makes this combination an industry-leading solution for data acquisition systems where accuracy, speed, cost, and size play a critical role.

The circuit design allows single supply operation. The minimum output voltage specification of the AD8608 is 50 mV for a 2.7 V power supply and 290 mV for 5 V power supply with 10 mA load current, over the temperature range of -40°C to +125°C. A minimum output voltage of 45 mV to 60 mV is a conservative estimate for a 3.3 V power supply, a load current less than 1 mA, and a narrower temperature range.