A piezoelectric transducer with sensitivity of 30 mV/kPa is intended to be used in the range of 0 kPa to 100 kPa. The readout

Q. A piezoelectric transducer with sensitivity of 30 mV/kPa is intended to be used in the range of 0 kPa to 100 kPa. The readout circuit has a peak noise amplitude of 0.3 mV and measured signals over the full pressure range are encoded with 10 bits. The smallest pressure that produces a non-zero output, in units of Pa, is approximately

              (A) 10              (B) 100                        (C) 240                       (D) 300

Ans: 100

Sol:

Given that,

Sensitivity = 30 mV/kPa

Range = 0 kPa to 100 kPa

Full scale voltage = 30 × 10-3 × 100 = 3 V

Noise of readout circuit = 0.3 mV

Vref = 3.0003V

Number of bits = n = 10