Inductance, current, and the DC resistance trade-off
The LBC3225T101KR is a 100 µH wirewound inductor from Taiyo Yuden's LB, C Type series, rated for 150 mA continuous current with a 1.4 Ohm maximum DC resistance. In a buck converter output filter, the 150 mA rating sets the load ceiling; the 1.4 Ohm DCR means I²R loss hits about 31.5 mW at full current, which the 1210 body dissipates without exceeding the 105°C upper limit in still air. The 6 MHz self-resonant frequency marks the upper bound for usable inductance — above that the winding capacitance dominates and the impedance drops.
Layout and thermal considerations for an unshielded 1210
Keep sensitive traces — especially feedback nodes and analog signal lines — at least one body width away to avoid coupling. The 2.70 mm seated height leaves clearance under low-profile enclosures. The 1.4 Ohm DCR at 150 mA produces about 31.5 mW of copper loss. In a 105°C ambient, the part's temperature rise stays within the rated envelope when the PCB copper pour provides a modest heat sink. No derating curve is published, so treat the 150 mA as the hard limit across the full temperature range.