Is there a pin-compatible replacement for FTR07D390K?

No direct drop-in replacement matching the 7mm size was identified. FTR10D390K is electrically compatible but its larger 10mm body means it is not a guaranteed form-fit replacement without checking board layout.

What risks should I check before replacing FTR07D390K?

First, check the physical board space to ensure a larger 10mm varistor will fit. Second, for any alternative, verify the varistor voltage and maximum clamping voltage meet your circuit's protection requirements.

FTR07D390K Alternatives, Datasheet & Cross Reference | FTR Qiaoguang

Finding a replacement for the FTR07D390K 7mm varistor involves checking key voltage ratings and physical size. While some parts offer upgraded current and energy handling, verifying board space is crucial.

AI replacement insight

Package riskhigh

Most alternatives are 10mm diameter vs target's 7mm, requiring board layout verification.

Electrical risklow

FTR10D390K is an electrical match or upgrade, but other candidates have mismatched voltages.

Can it be replaced directly?

No direct drop-in replacement matching the 7mm size was found. FTR10D390K is functionally equivalent but requires a physical fit check due to its larger 10mm diameter.

Best replacement path

FTR10D390K offers identical voltage protection with higher surge capability, but is physically larger (10mm vs 7mm).

Main risk

The primary risk is physical incompatibility; candidates are often larger than the 7mm target part.

Recommended alternatives

Functionally equivalent with superior surge/energy ratings, but physically larger (10mm vs 7mm).

View details

Alternative comparison matrix

Feature / factor	FTR07D390K	FTR10D390K	FTR10D470K	Compatibility / risk
Package	7mm	10mm	10mm	10mm — Candidate is physically larger, requires board space verification.; FTR10D470K: Candidate is physically larger.
Voltage	77V	77V	93V	77V / 93V — Maximum clamping voltage is identical.; FTR10D470K: Higher clamping voltage offers less protection.
Current	250A	500A	500A	500A — Higher surge current capability is an upgrade.; FTR10D470K: Higher surge current capability.
Power	2.1J	4.6J	-	4.6J — Higher energy absorption is an upgrade.

Application & sourcing insights

Questions & answers

FTR10D390K is the best functional alternative, offering identical voltage protection and superior surge ratings. However, it has a larger 10mm diameter compared to the 7mm original, so you must verify it fits on your PCB.