Is there a pin-compatible replacement for BYG21M?

Several parts like MRA4007T3G-FS share the same SMA package and pinout, but they are likely general-purpose rectifiers, not fast recovery. Using them without verifying switching speed is risky.

What risks should I check before replacing BYG21M?

The most critical risk is the reverse recovery time (Trr). Also, verify the forward current rating is at least 1.5A and the reverse voltage is at least 1000V. A slower diode can cause circuit failure.

BYG21M Alternatives, Datasheet & Cross Reference | Luguang Electronic Technology Co., Ltd.

BYG21M is a 1000V, 1.5A fast recovery rectifier in an SMA package. Finding a direct replacement requires matching its 120ns reverse recovery time (Trr), a critical parameter for high-efficiency applications.

AI replacement insight

Electrical riskhigh

Mismatch in reverse recovery time (Trr) is critical.

Package risklow

SMA/DO-214AC is a standard package.

Sourcing riskmedium

Fast recovery diodes are more specific than general purpose ones.

Can it be replaced directly?

No direct drop-in replacement has been identified. Candidates like MRA4007T3G-FS match voltage and package but are likely standard recovery diodes, which are much slower.

Best replacement path

Find a fast recovery rectifier with VRRM ≥ 1000V, Io ≥ 1.5A, and Trr ≤ 120ns in an SMA/DO-214AC package.

Main risk

The primary risk is substituting a standard recovery diode for a fast recovery one, which can cause high switching losses, overheating, and circuit failure.

Recommended alternatives

Matches package, voltage, and has higher current, but is a general purpose diode, not fast recovery. Requires Trr verification.

View details

Alternative comparison matrix

Feature / factor	BYG21M	MRA4007T3G-FS	GS1M-AU-R2-000A1	Compatibility / risk
Package	SMA/DO-214AC	SMA/DO-214AC	SMA (DO-214AC)	SMA/DO-214AC / SMA (DO-214AC) — Package matches.; GS1M-AU-R2-000A1: Package matches.
Voltage	1000V	1000V	1000V	1000V — Reverse voltage matches.; GS1M-AU-R2-000A1: Reverse voltage matches.
Current	1.5A	2.0A	1.0A	2.0A / 1.0A — Higher current rating is generally safe.; GS1M-AU-R2-000A1: Lower current rating is a downgrade.
Diode Type	Fast Recovery	General Purpose	-	General Purpose — Target is a Fast Recovery diode.
Trr	120ns	Unknown	Unknown	Unknown — Reverse recovery time is a critical unverified parameter.; GS1M-AU-R2-000A1: Likely a standard recovery diode, much slower than target.

Application & sourcing insights

Questions & answers

The best alternative must be a fast recovery rectifier with ≥1000V reverse voltage, ≥1.5A forward current, and a reverse recovery time (Trr) of 120ns or less in an SMA package.