Needs validationlow risk
Strong candidate with similar package size and upgraded current ratings; requires footprint verification.
Best Alternatives to SM3521-4R7MT
Finding a replacement for the SM3521-4R7MT, a 4.7µH power inductor, involves balancing electrical upgrades with physical compatibility. While several functional alternatives exist with better current ratings, none are a direct drop-in replacement, requiring careful review of package dimensions and PCB layout.
AI replacement insight
Package riskhigh
No candidate shares the exact 3521 package. All require land pattern verification or redesign.
Electrical riskmedium
Most candidates have higher DCR, which could impact circuit efficiency and thermals. This must be evaluated in the application.
Can it be replaced directly?
No direct drop-in replacement has been identified. All reviewed candidates have different package footprints that require PCB layout verification or modification.
Best replacement path
VLS3012HBX-4R7M is the most promising due to its similar package size. If board space is not a constraint, VLS6045EX-4R7M-H offers a significant electrical performance upgrade.
Main risk
The primary risk is package incompatibility, requiring PCB redesign. A secondary risk is increased DC Resistance (DCR) in some candidates, which can lower power efficiency.
Recommended alternatives
6Alternative comparison matrix
| Feature / factor | SM3521-4R7MT | VLS3012HBX-4R7M | VLS6045EX-4R7M-H | XRIM252012S4R7MBCA | Compatibility / risk |
|---|---|---|---|---|---|
| Inductance | 4.7µH | 4.7µH | 4.7µH | 4.7µH | 4.7µH — Inductance matches.; VLS6045EX-4R7M-H: Inductance matches.; XRIM252012S4R7MBCA: Inductance matches.; WPN252010U4R7MT: Inductance matches. |
| Saturation Current A | 1.6A | 2.51A | 5.8A | 2.4A | 2.51A / 5.8A / 2.4A / 1.9A — Higher saturation current.; VLS6045EX-4R7M-H: Significantly higher saturation current.; XRIM252012S4R7MBCA: Higher saturation current is a safe upgrade.; WPN252010U4R7MT: Higher saturation current. |
| Current A | 1.0A | 2.01A | 4.2A | 1.8A | 2.01A / 4.2A / 1.8A / 1.4A — Higher thermal current rating.; VLS6045EX-4R7M-H: Significantly higher thermal current rating.; XRIM252012S4R7MBCA: Higher thermal current rating.; WPN252010U4R7MT: Higher thermal current rating. |
| Dcr Ohm | 0.135Ω | 0.201Ω | 0.027Ω | 0.15Ω | 0.201Ω / 0.027Ω / 0.15Ω / 0.2Ω — Higher DCR may reduce efficiency.; VLS6045EX-4R7M-H: Much lower DCR improves efficiency.; XRIM252012S4R7MBCA: Higher DCR may reduce efficiency.; WPN252010U4R7MT: Higher DCR may reduce efficiency. |
| Package | 3521 (3.5x3.0mm) | 3012 (3.0x3.0mm) | 6045 | 2520 | 3012 (3.0x3.0mm) / 6045 / 2520 — Very similar size, but footprint must be verified.; VLS6045EX-4R7M-H: Much larger package requires significantly more board space.; XRIM252012S4R7MBCA: Smaller package requires PCB layout change.; WPN252010U4R7MT: Smaller package requires PCB layout change. |
Application & sourcing insights
Questions & answers
The best alternative depends on your design constraints. For the closest physical fit, consider VLS3012HBX-4R7M, but verify the land pattern. For the best electrical performance where board space is available, VLS6045EX-4R7M-H is a strong upgrade.