Blood pressure sensing circuit diagram of BP01 pressure sensor

As shown in the figure below, this circuit uses a BP01 pressure sensor and an operational amplifier MAX4472. The BP01 pressure sensor is specially designed to detect blood pressure and is mainly used for portable electronic blood pressure monitors. It uses a precision thick-film ceramic chip and nylon plastic package, which has the characteristics of high linearity, low noise and small external stress; it adopts internal calibration and temperature compensation methods to improve measurement accuracy, stability and repeatability. Within the full range, The accuracy is ±1%, and the zero-point offset is not greater than ±300μV. MAX4472 is a low-power amplifier chip from MAXIM that integrates four operational amplifiers. In this system, the internally integrated operational amplifier A is connected to a constant current source to provide a constant current for the pressure sensor. The operational amplifier B, operational amplifier C, and operational amplifier D form a differential input and single-ended output amplifier circuit, and are directly input to ADC0 to monitor the DC component of blood pressure.