Custom inductor manufacturer tells you
What is the inductor saturation current?How does it relate to the temperature rise current?Following the Chinese axial inductor factory to understand together:
Inductance is one of the three most commonly used passive components, including resistance and capacitance.It is mainly used as energy storage element in power conversion circuit, inductive load and noise filter element in radio frequency circuit.
Inductors are classified as winding inductors, thin film inductors and laminated inductors.Structurally, it is divided into shielded and unshielded inductors.The installation method is mainly divided into two categories: surface SMT and perforation.From the application mainly have the low frequency signal, the power and the radio frequency inductance and so on;In terms of materials, there are mainly magnetic and non-magnetic materials, among which magnetic materials include ferrite and iron-based magnetic powder core, etc., and non-magnetic materials mainly include non-magnetic ceramics, etc., among which ferrite and iron-based magnetic powder core inductors are mainly used in low, medium and high frequencies, and non-magnetic ceramic inductors are mainly used in radio frequency applications.
The technical indicators of inductance mainly include inductance L, dc resistance DCR, saturation current Isat and temperature rise current Irms, self-resonance frequency SRF and quality factor Q, etc.
Definition of saturation current
What needs to be explained here is the definition of saturation current.When the current flowing over the inductance increases gradually, the magnetic core will gradually enter the saturation state and the inductance value will gradually decrease.When the core is fully saturated, the inductance drops to a very small value equivalent to that of hollow wound wires.The saturation current is usually defined as the current value when the inductance drops by 20%.For the inductance shown in the figure below, the saturation current Isat value is about 3.6a.Some manufacturers define saturation current as a 10% or 30% drop in inductance.You need to pay attention to this when comparing inductance from different manufacturers.
Definition of temperature rise current
The temperature rise current of the inductor Irms refers to the working current of the inductor when the temperature of the inductor rises compared with the ambient temperature.Because the temperature rise is related to the energy consumed by the inductor, and the energy is related to the effective value of the current, the temperature rise current is usually labeled as Irms. Generally, most manufacturers define the temperature rise current value of the inductor when the temperature rises by 40C.Some manufacturers will give the current values of 20C and 40C temperature rise respectively, and even give the following temperature rise current curve.
As can be seen from the temperature rise current curve above, the temperature rise current of the inductor is about 1.8a when the temperature rise is 20C, and 2.9a when the temperature rise is 40C.
It should be noted that the temperature rise current and its curve are closely related to the actual measurement conditions, and there is no unified testing method and standard in the world.Generally, the measurement of the temperature rise current of the inductance requires the inductance to be welded to the PCB board for measurement. Therefore, the width of the line on the PCB board, the thickness of the PCB copper foil and the test time will affect the test result of the temperature rise current.In addition, the use conditions of inductors in the system will also have a great impact on the performance of inductors, especially the temperature rise characteristics.For example, if the inductor is in the system close to a device that generates a lot of heat, such as a CPU or radiator, the temperature rise current of the inductor will be reduced accordingly.If the inductor is close to the vent hole of the system, the temperature rise current will be increased accordingly.
Therefore, the temperature rise current only provides a reference for the system designer. In practice, it is better to test the actual temperature and temperature rise of the inductor.
The saturation current and temperature rise current of the inductor provide more technical information about the inductor to the designer from two different technical aspects. The designer has a deep understanding of these two indexes, which will be of great help to improve the performance and reliability of the system design.
Specializing in the production of various types of color ring inductors, beaded inductors, vertical inductors, tripod inductors, patch inductors, bar inductors, common mode coils, high-frequency transformers and other magnetic components.
Post time: May-09-2020