Is there a pin-compatible replacement for BAT43W?

Several Schottky diodes like SD103AW S4 and STPS0540Z share the same SOD-123 package and pinout. However, none are electrically identical, and all require careful review, especially for reverse leakage current.

What risks should I check before replacing BAT43W?

Key risks include: 1) Higher reverse leakage current (IR) causing excess power drain, 2) Higher forward voltage (VF) reducing efficiency, and 3) Slower reverse recovery time (trr) affecting high-frequency performance.

BAT43W Alternatives, Datasheet & Cross Reference | SMC Diode Solutions

Finding a substitute for the BAT43W Schottky diode requires careful review of electrical parameters. While several parts match the SOD-123 package, key specs like reverse leakage and forward voltage often differ.

AI replacement insight

Electrical riskhigh

Most candidates have significantly higher reverse leakage and/or forward voltage.

Package risklow

All reviewed candidates use the same SOD-123 package.

Can it be replaced directly?

No direct drop-in replacement was found. All candidates have parametric differences, with reverse leakage current being the most common issue.

Best replacement path

SD103AW S4 is a potential alternative but requires validation due to higher forward voltage and reverse leakage.

Main risk

The primary risk is increased reverse leakage current, which can cause excessive power consumption or circuit malfunction.

Recommended alternatives

A 40V, 350mA Schottky diode in the same package, but has weaker electrical characteristics that require review.

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Alternative comparison matrix

Feature / factor	BAT43W	SD103AW S4	STPS0540Z	Compatibility / risk
Package	SOD-123	SOD-123	SOD-123	SOD-123 — Package matches target.; STPS0540Z: Package matches target.
Voltage	30V	40V	40V	40V — Higher voltage rating provides more margin.; STPS0540Z: Higher voltage rating.
Current	200mA	350mA	0.5A	350mA / 0.5A — Higher current rating.; STPS0540Z: Higher current rating.
Forward Voltage	0.45V @ 15mA	0.6V @ 200mA	-	0.6V @ 200mA — Higher Vf, will increase power loss.
Reverse Leakage	0.5µA	5µA	4mA @ 100°C	5µA / 4mA @ 100°C — 10x higher leakage current.; STPS0540Z: Extremely high leakage current (vs 0.5µA target).
Recovery Time	5ns	10ns	-	10ns — Slower switching speed.

Application & sourcing insights

Questions & answers

SD103AW S4 is a possible alternative in a SOD-123 package, but it has higher forward voltage and reverse leakage. Thorough testing in your application is required.