Is there a pin-compatible replacement for RB751S-40?

No pin-compatible replacements were identified in this analysis. Candidates with similar electrical characteristics were found in larger packages like SMA or SMB, which are not drop-in compatible with the SOD-523 footprint.

What risks should I check before replacing RB751S-40?

The primary risk is package mismatch, which requires a PCB redesign. You must also verify the forward voltage (Vf) at your operating current and the reverse leakage current (Ir), as these can impact circuit efficiency and performance.

RB751S-40 Alternatives, Datasheet & Cross Reference | Yangjie Technology

RB751S-40 is a 40V, 30mA Schottky diode in a compact SOD-523 package, ideal for signal rectification. Finding a pin-compatible replacement requires matching the package and key electrical parameters.

AI replacement insight

Package riskhigh

All viable electrical alternatives are in different packages (SMA, SMB) requiring a board spin.

Electrical riskmedium

Even with a package match, forward voltage (Vf) and reverse leakage (Ir) must be verified for the specific application.

Can it be replaced directly?

No direct, pin-compatible replacements for RB751S-40 were found. All electrically similar candidates were in different, larger packages.

Best replacement path

Search for Schottky diodes in a SOD-523 package with Vr >= 40V and Io >= 30mA.

Main risk

Package incompatibility is the main risk; no direct drop-in replacements were found, requiring a PCB redesign for any alternative.

Recommended alternatives

An upgraded functional alternative (60V, 5A) but in a non-compatible SMB package.

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Alternative comparison matrix

Feature / factor	RB751S-40	SS56B	SSL56B	VS-15MQ040NTRPBF	Compatibility / risk
Package	SOD-523	DO-214AA (SMB)	DO-214AA (SMB)	DO-214AC (SMA)	DO-214AA (SMB) / DO-214AC (SMA) — Not a drop-in replacement. Requires PCB redesign.; SSL56B: Not a drop-in replacement. Requires PCB redesign.; VS-15MQ040NTRPBF: Not a drop-in replacement. Requires PCB redesign.
Polarity Or Type	Schottky	Schottky	Schottky	Schottky	Schottky — Functionally similar diode type.; SSL56B: Functionally similar diode type.; VS-15MQ040NTRPBF: Functionally similar diode type.
Voltage	40.0V	60.0V	60.0V	40.0V	60.0V / 40.0V — Higher voltage rating provides more margin.; SSL56B: Higher voltage rating provides more margin.; VS-15MQ040NTRPBF: Voltage rating matches.
Current	0.03A	5.0A	5.0A	1.5A	5.0A / 1.5A — Significantly higher current rating.; SSL56B: Significantly higher current rating.; VS-15MQ040NTRPBF: Significantly higher current rating.

Application & sourcing insights

Questions & answers

Finding a direct, pin-compatible alternative to the RB751S-40 requires a Schottky diode in the same SOD-523 package with at least 40V reverse voltage and 30mA current. Functional alternatives exist in different packages but require board redesign.