Is there a pin-compatible replacement for 1N5819WS S4?

Yes, parts like `1N5819WS` and `B5819WS` are available in the same SOD-323 package. However, pin compatibility does not guarantee electrical performance. Always verify the datasheet.

What risks should I check before replacing 1N5819WS S4?

Key risks are higher forward voltage (Vf), which increases power loss; lower power dissipation (Pd), which can cause overheating; and slower reverse recovery time (trr) in high-frequency circuits.

1N5819WS S4 Alternatives, Datasheet & Cross Reference | JSMSEMI

The 1N5819WS S4 is a 40V, 350mA Schottky diode in a compact SOD-323 package, used for fast switching and rectification. Finding a substitute requires matching its Schottky characteristics, particularly low forward voltage and fast recovery time.

AI replacement insight

Electrical riskhigh

Forward voltage and power dissipation can vary significantly, impacting efficiency and reliability.

Package risklow

SOD-323 is a standard package, ensuring mechanical compatibility.

Sourcing riskmedium

Common part numbers have many vendors, but specs are not always consistent.

Can it be replaced directly?

No drop-in replacement is guaranteed without datasheet verification. The base part `1N5819WS` is the closest, but manufacturer variations exist.

Best replacement path

Start with other `1N5819WS` versions, verifying the manufacturer's datasheet. If unavailable, `B5819WS` is a viable option requiring review of power and Vf specs.

Main risk

Electrical performance mismatch, especially higher forward voltage or lower power dissipation.

Recommended alternatives

A cross-vendor family alternative in the same package with similar voltage, but current and power ratings must be verified.

View details

Alternative comparison matrix

Feature / factor	1N5819WS S4	1N5819WS	B5819WS	Compatibility / risk
Package	SOD-323	SOD-323	-	SOD-323 — Package matches.
Polarity Or Type	Schottky	Schottky	-	Schottky — Diode type matches.
Voltage	40V	40V	-	40V — Voltage rating matches.
Current	0.35A	0.35A to 1.0A	-	1.0A — Higher current rating.
Power	400mW	Varies by Mfr	-	0.25W — Lower power dissipation is a risk.
Forward Voltage	~0.6V @ 0.2A	-	~0.9V @ 1A	~0.9V @ 1A — Higher forward voltage increases power loss.

Application & sourcing insights

Questions & answers

The base part number `1N5819WS` from various manufacturers is the best starting point, but specs must be verified. `B5819WS` is another common alternative, but check for lower power ratings.