Signal isolator Selection - How to select a signal isolator

In addition to clarifying the role of the signal isolator and integrating it into the front and back left and right end jacks, there are also many major parameters such as accuracy, output ripple, temperature drift, functional loss, and response speed that must be carefully selected by customers. Signal isolator selection.

1. Accuracy

The accuracy of the signal isolator is a very critical main parameter, and the height of the accuracy is immediately related to whether the signal isolator can be used normally. The accuracy of the signal isolator can better reflect the design scheme and manufacturing level of the signal isolator. Customers should use products with high precision when adopting.

2. Output ripple

The main parameters that harm the accuracy of the signal isolator are also output ripple. The output ripple is caused by the signal isolator using the DC/DC power supply circuit to protect the switching power supply during the work of the signal isolator to the signal isolator internal power supply circuit power supply system, the input data signal must first use the DC/DC power supply circuit to configure the communication AC data signal and then go through the protection part of the power circuit to protect the data signal. The protected data signal is converted into DC data signal output after modulation and demodulation. The signal isolators with CPU as the key also have differential signals. The amount of such high frequency communication within the signal isolator is what causes the output ripple. The frequency of this high frequency communication is generally several hundred KHZ, and the harmonic current is more, which is difficult to completely clean up the environmental pollution of the data signal. If the output ripple is high, the deviation of the data signal collected by the automatic control system analog input typing template is large, especially for the analog input typing template with high speed typing. Therefore, when selecting a signal isolator, it is necessary to specify the peak -* high value of the output ripple as low as possible. Signal isolator selection.

3. Temperature drift

The temperature drift is caused by the heat generated by the signal isolator when it is working, which causes the performance parameters of the electronic components applied in the signal isolator to decrease, resulting in the output value of the signal isolator to change. When selecting a signal isolator, specify the temperature drift value as low as possible.

4. Power consumption

Functional loss refers to the electromagnetic energy consumed when the signal isolator is working. It involves the calorific value of the product during work, and this main parameter is closely related to the service life, credibility and appearance design and installation method of the signal isolator. When using signal isolators, choose products with low functional loss. The circuit principle of the signal isolator selects new technology applications are: the output part can dynamically adjust the output power according to the size of the load responsive load technology; Protection part of the current mutual inductance output power compensation technology; Switching power supply part of the main parameters of the power supply switch adjustable regulated power supply technology.

If the functional loss of the product is large, the heat generated during the work of the product is large, resulting in a high temperature inside the product shell. The electronic components that constitute the product are in the natural environment of high temperature for a long time, which will cause the main parameters of the op amp circuit to grow, the resistance value of the resistor to change, and the capacitor to expand. This problem will reduce the characteristics of the product, and even cause common failures and ineffectiveness of the product.

5. Response speed

Response speed refers to the time between the output of the product and the output of the product to properly represent the change in the output. The less the response speed, the more appropriate to reflect the transformation of the output, reasonable monitoring and manipulation of the process. The less response speed is required when picking a signal isolator, the better. Signal isolator selection.