33 µH, 185 mA — what the ratings mean for the BOM
The LBC2518T330M is a 33 µH unshielded wirewound inductor from Taiyo Yuden's LB, C Type series, rated for 185 mA continuous current. The 1.5 Ohm DCR sets a DC power loss of about 51 mW at full rated current — a figure that factors into thermal budget for the board, especially in a 1007 (2518 Metric) footprint where heat dissipation is limited by the small pad area. The self-resonant frequency of 15 MHz means this inductor behaves inductively well below that point; above it, parasitic capacitance dominates. For a buck converter switching at 500 kHz to 2 MHz, the 33 µH value and SRF provide adequate filtering margin without the winding capacitance resonating with the switching harmonics.
NRND — what it means for procurement
For a production line already qualified on this inductor, the NRND status means the supply window is finite.
Package and board-fit
It is a surface-mount drum core, unshielded — the ferrite core material is open, so magnetic flux radiates from the sides. Keep sensitive traces or low-impedance loops at least one package width away to avoid coupling. The inductance is tested at 2.52 MHz, which is the standard test frequency for this value range per the series specification.