Is there a pin-compatible replacement for US1B?

ES2J, HS1M, and US2M are offered in the same SMA (DO-214AC) package and are likely pin-compatible. However, some manufacturers offer these parts in different packages (like SMB), so verifying the datasheet is critical.

What risks should I check before replacing US1B?

The main risk is mismatching the reverse recovery time (Trr); a slower diode can cause failure in switching circuits. Also, verify the package is DO-214AC (SMA), as some alternatives are sold in the different-sized SMB package.

US1B Alternatives, Datasheet & Cross Reference | Diotec Semiconductor

US1B is a 100V, 1A fast recovery rectifier in a common SMA package, used in high-frequency applications. Finding a replacement requires matching the reverse recovery time (Trr) of 50ns.

AI replacement insight

Electrical riskmedium

Slower reverse recovery time in some candidates requires application-specific analysis.

Package riskmedium

Some candidates have conflicting package data (SMA vs. SMB), requiring verification.

Sourcing risklow

Multiple manufacturers produce viable alternatives for this common diode type.

Can it be replaced directly?

Yes, several potential replacements for US1B exist, such as ES2J, HS1M, and US2M. However, they have parametric differences, primarily in reverse recovery time, and require careful datasheet review.

Best replacement path

The best replacement path is to select an upgrade like ES2J, which offers better performance (faster Trr, higher V/I), provided the package is confirmed to be the correct SMA (DO-214AC) size.

Main risk

The primary risk is using a diode with a significantly slower reverse recovery time (Trr), which can degrade performance in high-frequency switching applications.

Recommended alternatives

A potential upgrade with higher voltage/current and faster switching, but package verification is critical.

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Alternative comparison matrix

Feature / factor	US1B	ES2J	HS1M	US2M	Compatibility / risk
Package	DO-214AC (SMA)	DO-214AC (SMA)	DO-214AC (SMA)	DO-214AC (SMA)	DO-214AC (SMA) — Package matches artifacts, but some evidence points to SMB. Verification required.; HS1M: Package and pin count match.; US2M: Package matches artifacts, but some evidence points to SMB. Verification required.
Voltage	100V	600V	1000V	1000V	600V / 1000V — Higher voltage rating provides more design margin.; HS1M: Significantly higher voltage rating.; US2M: Significantly higher voltage rating.
Current	1.0A	2.0A	1.0A	2.0A	2.0A / 1.0A — Higher current rating provides more design margin.; HS1M: Current rating matches.; US2M: Higher current rating provides more margin.
Reverse Recovery Time	50ns	35ns	75ns	75ns	35ns / 75ns — Faster recovery time is a performance upgrade.; HS1M: Slower recovery time may impact high-frequency performance.; US2M: Slower recovery time may impact high-frequency performance.

Application & sourcing insights

Questions & answers

ES2J is a potential upgrade with higher voltage/current ratings and faster recovery time, but its package must be verified. HS1M and US2M are also options with higher ratings but slightly slower recovery times.