BLM21BB331SH1D屬于濾波器的鐵氧體磁珠芯片。由村田制作所制造生產的BLM21BB331SH1D鐵氧體磁珠和芯片鐵氧體磁芯是旨在防止高頻噪聲或 EMI（電磁干擾）的設備。這些鐵氧體磁芯用于放置在電路內。關鍵特征包括濾波器類型（差分、信號或電源）、線路數、最大額定電流、阻抗和指定頻率，以及安裝類型（自由懸掛、表面貼裝或通孔）。

The chip ferrite beads BLM series is designed to

function nearly as a resistor at noise frequencies,

which greatly reduces the possibility of resonance and

leaves signal wave forms undistorted.

BLM series is effective in circuits without stable

ground lines because BLM series does not need a

connection to ground.

The nickel barrier structure of the external

electrodes provides excellent solder heat resistance.

BLM_B series can minimize attenuation of the signal

waveform due to its sharp impedance characteristics.

Various impedances are available to match signal

frequency.