Characteristics and main uses of ferrite materials for high frequency transformers
The ferrite materials in high frequency transformers are all soft ferrite materials. Due to the high resistivity of the soft ferrite material, low high-frequency loss, easy mass production, good product consistency and low cost, it is currently the most widely used magnetic material in high-frequency transformers. Soft ferrite materials are mainly divided into two categories: Mn-Zn ferrite and Ni-Zn ferrite
Mn-Zn ferrite is used in high-frequency transformers whose working frequency is below 0.5~1MHz, and Ni-Zn ferrite is used in high-frequency transformers whose working frequency is above 1MHz. There are many varieties of Mn-Zn and Ni-Zn ferrite materials, and the material properties are also different. They are used in various high-frequency transformers and inductors with different requirements. Mainly include the following aspects:
① Power transformer, used for power transmission, voltage conversion and isolation, etc. The material is required to have high saturation magnetic induction and low power loss.
② Signal transmission transformer, used for undistorted transmission of AC or pulse signals, impedance matching, isolation, etc. The material is required to have high permeability, low hysteresis loss and low sensitivity to direct current.
③ The filter inductors in the telecommunication field require good stability and high Q value. The material loss is small, the temperature coefficient is very low in the specified temperature range, and the time is very stable.
④ Interference suppressor, which suppresses unwanted high-frequency interference signals and passes useful high-frequency signals. It is required to have high impedance (high permeability) in the frequency range covered.
⑤ The inductance of the delay pulse circuit is used to delay the pulse. The material is required to have high magnetic permeability.
⑥ Energy storage and smoothing circuit inductance. The material is required to have a high saturation magnetic induction value.
⑦ Tuning loop inductance has a certain passband. The material is required to have proper loss and better temperature stability
