RS18N50W

RS18N50W is an N-channel 500 V / 18 A MOSFET in TO-247. A pin-to-pin compatible substitute must match three things: V_DS ≥ 500 V, R_DS(on) ≤ 270 mOhm@10V, and the identical TO-247 footprint. Always verify avalanche rating and gate charge (Q_g ≈ 71 nC@10V) against your driver before swapping.

Three checks: (1) V_DS must be ≥ original with ~20% headroom for spikes; (2) R_DS(on) should be ≤ original, evaluated at your real operating temperature; (3) package must be identical (TO-220 ≠ TO-263). Also confirm gate charge (Q_g) and avalanche energy match, or re-test the driver.

Focus on V_DS (voltage rating), I_D (continuous current at your case temperature, not just 25 °C), R_DS(on) (conduction loss), and Q_g (switching speed / driver match). For inductive loads, also check avalanche rating.

Buy only from authorized or franchised channels. On receipt, check: (1) laser-etched markings that solvent will not remove; (2) batch / lot code consistent between label and device; (3) original reel or tube packaging; (4) request traceability documents (CoC, date code). For critical parts, third-party X-ray / decapsulation testing is recommended.

Most active ICs use a 4-digit date code YYWW (year + week, e.g. 2345 = 2023 week 45). The top mark is manufacturer logo + base part number + lot code. For SMD code lookup, search by "marking code + package" on AllDataSheet / Octopart / LCSC.

Package codes describe the physical form factor and pin layout — critical when sourcing, because electrically equivalent parts in different packages will not fit the PCB. Common: TO-220 (3-terminal power), SOT-23 (3-pin small signal), DIP / SOIC (through-hole / SMD ICs), QFP / QFN (MCUs, processors).

Three options: (1) the manufacturer’s recommended replacement; (2) franchised distributor legacy stock; (3) a functionally compatible cross-brand part — provided pinout and key parameters match. Always evaluate on a real board before mass swap.

We support both sample and volume orders. Minimum order quantity, stock availability and lead time are confirmed per inquiry — tell us your model and quantity and we will quote. Sample quantities for design validation are supported.

The full datasheet is linked on this page. For parts without a direct datasheet, we can locate the manufacturer document on request. Sample requests are supported — contact us with your model and quantity.