How to distinguish between shielded and unshielded?

Appearance distinction

The shielded inductor has a magnetic shielding structure on the outside, so it can be seen from the appearance that the coil winding must be an unshielded inductor, and the shielded inductor does not see the coil winding from the appearance.

However, there is one exception to note: it is not necessarily the shielding inductance that does not see the coil, or the I-shaped inductor with the thermal expansion sleeve.

Magnetic circuit composition

1. Shielded Inductor Magnetic circuit structure is closed magnetic circuit structure: The closed magnetic circuit structure is composed of magnetic material, the magnetic impedance is very small, and the magnetic core is a toroidal magnetic core, which is a closed magnetic circuit structure.

2. Unshielded Inductive Magnetic Circuit Structure is an open magnetic circuit structure: due to the exposed structure of the magnetic circuit, it has a very obvious air gap, and its impedance is relatively large, indicating that the magnetic core is a U-shaped or EE-type magnetic core.

Performance distinction

1. Due to the difference between the shielded inductor and the unshielded inductor magnetic shield structure, the shielded inductor has a larger volume than the unshielded inductor at the same inductor and operating current.

2. Unshielded inductors have high saturation, small volume and low impedance. Mainly focused on plug-in inductors, partial chip inductors GCD series (fastly replaced by shielded inductors), rod inductors.

3. Shielded inductors have the characteristics of high power, low resistance and high current. Mainly used in circuits with high requirements for EMC, involving signal transmission, intelligent computing, etc., such as mobile phones, computers, high-quality audio, and so on.