The pressure sensor is the most commonly used device in industrial practice, which senses the pressure signal and converts it into an electrical output。Pressure sensors are usually composed of pressure sensing elements and signal processing units, and are widely used in various industrial automatic control scenarios, as well as gas, liquid filtration and measurement flow control fields。

In the common working architecture of pressure sensors,The Wheatstone Bridge(also known as single-arm bridge) occupies an important position。This bridge circuit is composed of four resistors, and the technical architecture is relatively simple but the effect is remarkable。Its basic composition consists of four resistors (R1, R2, R3, Rx), respectively known as the resistance of the bridge arm, connected in a bridge mode。

Of these four resistors, at least one is a sensitive resistance to be measured, and the rest are comparison resistors with known resistance values。As shown in the figure below, when the bridge is balanced, that is, when the resistance product of the two relative bridge arms is equal (R2·R3=R1·Rx), there is no voltage output。If there is a change in any resistance, the bridge will be unbalanced and produce an output voltage。Through this deterministic relationship between the resistance value of the resistance to be measured and the comparison resistance, we can accurately determine the resistance value of the resistance to be measured in the bridge。

The Wheatstone Bridge

However, the signal output from the bridge is usually weak and can be affected by ambient noise and interference。Therefore, in the application of pressure sensors, the role of signal conditioning chip is crucial。

The signal conditioning chip can amplify, filter and digitize the weak differential voltage signal output by the receiving bridge to improve the reliability and accuracy of the signal。The processed digital signal can be output to the microcontroller or other data processing equipment through SPI, I2C and other digital interfaces for further use。

The combination of the Wheatstone bridge and the signal conditioning chip creates a sensor system capable of accurately measuring pressure changes。To ensure the stability and reliability of the pressure sensor, the system is usually packaged in a miniaturized package for integration into a variety of applications。

For pressure sensors, key technical parameters such as accuracy, high stability, reliability and low power consumption are very important。These parameters include: pressure value input and output accuracy, long-term stability and low power consumption, small pressure change sensitivity and linearity, rapid response from pressure changes to signal stability output, and whether the sensor has a wide temperature range, will directly affect the performance and service life of the sensor。

Therefore, when selecting a signal conditioning chip, it is necessary to ensure that it can meet the final application scenario and actual needs。

CS32A01X is a high performance signal conditioning SoC chip designed for pressure sensors with high integration, high precision and high performance. It has multi-channel analog input, high performance processor and rich peripheral interface, and adopts miniaturized package design。The core can be inLong-lasting operation in industrial-grade environments, it shows excellent performance when processing complex sensor signals。

Specifically, the CS32A01X has the following outstanding advantages in pressure sensor applications:

1.High precision measurement:Built-in 24-bit high-performance ADC module, sampling rate up to 8k, to ensure accurate acquisition of sensor output signals。At the same time, it supports up to 8 external channels and 10 internal channels to meet the needs of multi-sensor simultaneous measurement。

2.High stability:Advanced design and manufacturing processes ensure that the output signal remains highly stable under prolonged use or environmental changes, with an annual rate of change as low as ±0.1%FS or less。

3.Quick response capability:With fast response time, it can quickly capture pressure changes and output stable signals, suitable for dynamic environment measurement。

4.Wide temperature working range:Low temperature bleach reference voltage output design to ensure normal operation and stable performance in a wide temperature range of -40~85℃/105℃。

5.Diversified output options:Analog output support LED driver module,DACMultiple modes, such as OPA and constant current and constant voltage source;The digital output supports I2C, SPI, UART, PWM and other interfaces, which is convenient to connect with various microcontrollers and processors。

6.Rich on-chip resources:In addition to superior performance and functionality, it offers a complete system-on-chip solution, including a powerful ARM® M0 core and ample Flash and SRAM resources for data processing and storage。

CS32A01X series pressure sensor application block diagram