High-sensitivity MEMS pressure sensor utilizing bipolar junction transistor with temperature compensation

The paper presents MEMS pressure sensor chip utilizing novel electrical circuit with bipolar-junction transistor-based (BJT) differential amplifier with negative feedback loop (PDA-NFL). Pressure sensor chips with two circuits have been manufactured and tested: the first chip uses circuit with vertical n-p-n (V-NPN) BJTs and the second - circuit with horizontal p-n-p (L-PNP) BJTs. The demonstrated approach allows for increase of pressure sensitivity while keeping the same chip size regarding the chip with Wheatstone bridge circuit: 3.6X for circuit utilizing V-NPN BJTs and 2.4X for circuit utilizing L-PNP BJTs. Significant reduction of both noise and temperature instability of output signal has been demonstrated: output signal noise is about 15 mu V (U-sup = 5 V) and temperature errors have only 2-3 times higher values regarding the chip with Wheatstone bridge circuit. (C) 2019 Elsevier B.V. All rights reserved.