NRND status and what it means for your BOM
TDK has designated the ACM4520V-421-2P-TL00 as Not Recommended for New Design (NRND). This means the part remains available for existing production but is not intended for new design-ins. For a BOM that already carries this order code, the NRND flag signals a planning window: confirm your volume horizon and evaluate whether a last-time-buy or a migration to a current-series alternative fits your program timeline.
420 Ohms at 100 MHz — the suppression target
The core filtering spec is 420 Ohms impedance at 100 MHz. This is a power-line common-mode choke — the impedance peak is tuned for conducted EMI suppression in the 100 MHz band, which covers the switching noise from DC-DC converters and the clock harmonics typical in automotive and industrial power rails. The 2-line configuration handles a differential pair or a single power-and-return pair.
1.4 A continuous with 55 mOhm DCR
Rated for 1.4 A continuous current with a maximum DC resistance of 55 mOhm. At full rated current, the resistive loss is roughly 108 mW — negligible for most power budgets, but the DCR matters for voltage drop in a low-voltage rail.
Qualified to AEC-Q200, the passive-component stress-test standard for automotive electronics. The horizontal 4-pad surface-mount package measures 4.70 mm x 4.50 mm with a 2.00 mm seated height — a compact footprint for dense PCB layouts in ECU and BMS designs.