High Sensitive, Linear and Thermostable Pressure Sensor Utilizing Bipolar Junction Transistor for 5 kPa

Research of pressure sensor chip utilizing novel electrical circuit with bipolar-junction transistor-based (BJT) piezosensitive differential amplifier with negative feedback loop (PDA-NFL) for 5 kPa differential range was done. The significant advantages of developed chip PDA-NFL in the comparative analysis of advanced pressure sensor analogs, which are using the Wheatstone piezoresistive bridge, are clearly shown. The experimental results prove that pressure sensor chip PDA-NFL with 4.0x4.0 mm² chip area has sensitivity S = 11.2 ± 1.8 mV/V/kPa with nonlinearity of 2K_NLback = 0.11 ± 0.09 %/FS (pressure is applied from the back chip side) and 2K_NLtop = 0.18 ± 0.09 %/FS (pressure is applied from the top chip side). All temperature characteristics have low errors, because the precision elements balance of PDA-NFL electric circuit was used. Additionally, the burst pressure is 80 times higher than the working range.