Differences between power module inductors, magnetic beads, and zero-ohm resistors

[bellaroiet]

inductance

Inductors are energy storage components of power modules, and are mostly used in power filter circuits, LC oscillating circuits, medium and low frequency filter circuits, etc., and their application frequency range rarely exceeds 50MHz.

magnetic beads

The material of the magnetic bead is iron-magnesium or iron-nickel alloy. These materials have high resistivity and magnetic permeability. Under high frequency and high impedance, the capacitance value between the inner coils of the inductor will be the smallest.

Magnetic beads are usually only suitable for high-frequency circuits, such as some RF circuits, PLLs, oscillator circuits, circuits containing ultra-high frequency memory, etc., all need to add magnetic beads to the input part of the power module. In effect, ferrite beads are high frequency attenuators for RF energy. Essentially, the bead is a "dissipative device" that converts high frequency energy into heat. Therefore, in performance, it can only be interpreted as a resistance, not an inductance.

Zero Ohm Resistance

The zero-ohm resistor has no function in the circuit, it is only on the PCB for debugging convenience or compatible design.

When the parameters of the matching circuit are uncertain, replace it with 0ohm. When actually debugging, determine the parameters, and then replace them with components of specific values. When you want to measure the current consumption of a certain part of the circuit, you can remove the 0ohm resistor and connect an ammeter, which is convenient for measuring the current consumption.

Zero-ohm resistors can be used as jumpers, and act as inductors or capacitors under high-frequency signals; used as inductors, mainly to solve EMC problems; in addition, they also have the function of fuses.