With the continuous development of industrial automation, on-site sensors are increasingly using analog signals for data transmission. This type of signal is different from ordinary digital signals, as it represents the measured or controlled physical quantity through continuously changing voltage or current. Because this type of signal carries a large amount of information, but is also very susceptible to environmental interference, it needs to be isolated during the transmission and control process of the signal. As a very important isolation technology, analog isolator modules can ensure the reliability and stability of transmitted signals. The following will introduce how to choose analog isolator modules from the following aspects.
1、 Understand the basic principles and performance indicators of analog isolator modules.
The basic principle of the analog isolator module is to achieve signal isolation and conversion through the operation of a transformer. By using the principle of electromagnetic induction, the input and output parts are isolated into two independent circuits, thus achieving the effect of signal isolation. When choosing an analog isolator module, it is necessary to understand some important performance indicators, such as isolation resistance, common mode rejection ratio, linearity, and so on. Among them, the isolation resistor is the impedance value between the resistors at the input and output terminals of the module. The larger it is, the better the isolation effect; The common mode rejection ratio (CMRR) represents the ability of an isolator to eliminate common mode signals from the input signal in the output signal. The larger the value, the better the isolation effect.
2、 Choose the appropriate model and brand based on actual needs.
When selecting analog isolator modules, it is necessary to choose the appropriate model and brand according to actual needs. The first thing to consider is the parameters and ranges of the input and output signals, such as voltage range, current range, input impedance, output load, and so on. Secondly, it is necessary to select the corresponding model based on the sampling rate and accuracy of the signal, which determine the processing capability and accuracy of the module for the signal. In addition, it is necessary to choose the appropriate brand and model based on the usage environment, such as modules that are suitable for harsh environments such as high temperature, cold, and humidity.
3、 Consider the stability and reliability of the module.
The stability and reliability of analog isolator modules are important factors to consider when selecting. The first thing to consider is the temperature drift and zero drift of the module, which determine the stability of the signal during long-term use of the module. Secondly, it is necessary to consider the anti-interference ability and seismic performance of the module, which directly affect its service life and reliability in harsh environments.
In summary, when selecting an analog isolator module, it is necessary to understand some necessary technical indicators and performance parameters, choose the appropriate model and brand according to actual needs, and also consider the stability and reliability of the module, so as to ensure that the module can fully meet the required functions and requirements in practical applications.
