FTR14D391K
FTR
Needs validationmedium risk
Electrically upgraded alternative with higher surge rating, but larger physical size requires board space verification.
Best Alternatives to FTR07D391K
FTR07D391K is a 7mm disk MOV with a 390V varistor voltage for overvoltage protection. While no direct drop-in replacements are confirmed, several alternatives exist that require careful review of physical size, surge current rating, and clamping voltage before use.
AI replacement insight
Package riskmedium
Some alternatives have different disk diameters (14mm or 5mm vs target's 7mm), requiring a board layout check.
Electrical riskhigh
Candidates may have lower surge ratings (downgrade) or higher clamping voltages (reduced protection), requiring circuit analysis.
Can it be replaced directly?
No direct, drop-in replacement has been verified. All candidates have significant differences in physical size or key electrical parameters that require engineering review.
Best replacement path
The best upgrade is FTR14D391K, which offers superior surge protection, provided the larger 14mm package fits. For a same-size alternative, VDR-07D431K is an option if the circuit tolerates a higher clamping voltage.
Main risk
The primary risks are physical incompatibility due to different disk sizes, or electrical failure from using a part with a lower surge rating or inadequate circuit protection from a part with a higher clamping voltage.
Recommended alternatives
3Alternative comparison matrix
| Feature / factor | FTR07D391K | FTR14D391K | VDR-07D431K | VDR-05D391K | Compatibility / risk |
|---|---|---|---|---|---|
| Package | Radial Lead Disk | Radial Lead Disk | Radial Lead (Disk) | 5mm | Radial Lead Disk / Radial Lead (Disk) / 5mm — Package type matches, but disk diameter is larger.; VDR-07D431K: Package and 7mm disk diameter match.; VDR-05D391K: Smaller disk diameter (5mm vs 7mm) is likely not an issue. |
| Application | 7mm | 14mm | - | - | 14mm — Larger disk diameter requires physical clearance check. |
| Voltage | 390V | 390V | 710V | 390V | 390V / 710V — Varistor voltage matches.; VDR-07D431K: Higher clamping voltage reduces protection margin.; VDR-05D391K: Varistor voltage matches. |
| Current | 1200A | 4500A | 1.2kA | 400A | 4500A / 1.2kA / 400A — Higher surge current rating provides more robust protection.; VDR-07D431K: Peak surge current matches.; VDR-05D391K: Significantly lower surge current rating. |
| Power | 26J | 100J | - | 12J | 100J / 12J — Higher energy absorption capability.; VDR-05D391K: Significantly lower energy rating. |
Application & sourcing insights
Questions & answers
The best alternative depends on your design constraints. FTR14D391K is an electrical upgrade with a higher surge rating, but it is physically larger (14mm disk). If board space is not an issue, it is a strong candidate.