Pressure Measurement from five-channel low-power programmable sensor signal processor AD7714

Description: The AD7714 circuit consists of a pressure measurement system featuring the BP01 pressure sensor from Sensym. The BP01 is integrated into a bridge circuit, which produces a differential output voltage. When the sensor is subjected to its rated full-scale pressure of 40 kPa, it exhibits a differential output voltage sensitivity of 3 mV/V. With a +5V excitation voltage, the full-scale output range of the sensor is 15 mV. Additionally, the excitation voltage is regulated through 24 kΩ and 15 kΩ resistors, which provide a 1.92V reference voltage to the AD7714, ensuring that fluctuations in the excitation voltage do not induce measurement errors in the system.

The AD7714 is a precision analog-to-digital converter (ADC) designed for low-frequency applications, particularly in sensor interfacing. The integration of the BP01 pressure sensor within a bridge circuit allows for accurate pressure measurements by converting the mechanical pressure into a corresponding electrical signal. The bridge circuit configuration enhances the sensitivity and linearity of the measurement.

The differential output voltage generated by the BP01 sensor is critical for accurate readings, especially at the specified full-scale pressure of 40 kPa. The sensitivity of 3 mV/V indicates that for every volt of excitation, the output changes by 3 mV, allowing for fine resolution in pressure measurement. The +5V excitation voltage is essential for proper sensor operation, and the resulting full-scale output of 15 mV ensures that the ADC can effectively digitize the signal without losing resolution.

To maintain measurement integrity, the voltage reference provided to the AD7714 is stabilized at 1.92V through a voltage divider formed by 24 kΩ and 15 kΩ resistors. This reference voltage is crucial as it serves as a baseline for the ADC, allowing it to accurately interpret the sensor's output. The careful selection of resistor values ensures that variations in the excitation voltage do not adversely affect the measurements, thereby enhancing the reliability of the pressure measurement system.

Overall, the design of the AD7714 circuit with the BP01 pressure sensor is a robust solution for accurate pressure sensing, ensuring that external factors such as voltage fluctuations do not compromise the integrity of the measurements. This setup is particularly suitable for applications requiring high precision and reliability in pressure monitoring.AD7714 circuit constituted by a pressure measurement system is shown in Fig. BP01 is Sensym companys pressure sensors. The BP01 connected into a bridge circuit, from OUT +, OUT - ended output differential voltage. When applied to the pressure sensor rated full-scale pressure (in this case 40kPa), its differential output voltage sensitivity of 3mV/V. If a + 5V excitation voltage, the sensor full-scale output range of 15mV. The excitation voltage is also through 24k and 15k resistance partial pressure for the AD7714 provides 1.92V reference voltage, so the fluctuations in the excitation voltage will not cause measurement error of the system.