BLM15EG121SN1D

• 120 Ohm Impedance at 100 MHz Test frequency, 25 Percent Tolerance
• Rated for 1.5 A DC and RMS Current
• Low 95 M Ohm DC Resistance for Minimal Rail Voltage Drop
• 0402 Imperial / 1005 Metric case, 1 Mm X 0.5 Mm X 0.5 Mm
• Single-line, Single-Circuit Multilayer Ferrite Construction
• Operating Range -55 C to 125 C, Lead-free, RoHS compliant, NRND Lifecycle Status

The BLM15EG121SN1D is a Murata multilayer ferrite bead rated at 120 Ohm impedance measured at 100 MHz, with 25 percent tolerance. The BLM15EG121SN1D carries up to 1.5 A of DC current with only 95 m Ohm of DC resistance, in an 0402 imperial (1005 metric) case. A ferrite bead behaves as a low-resistance conductor at DC and as a lossy impedance at high frequency, dissipating noise energy rather than reflecting it.

Ferrite beads are placed in series with a supply rail or signal line to suppress high-frequency conducted noise and stop it propagating between subsystems, a common requirement for passing EMC emissions testing. Parts like the BLM15EG121SN1D isolate noisy digital rails from sensitive analog, RF or clock supplies, and are used on USB and interface lines to keep radiated noise off cables. The 1.5 A rating and 95 m Ohm DCR suit real power rails rather than signal-only use. Because this part is marked NRND, buyers are typically supporting existing production or sourcing for legacy builds rather than new designs.