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Best Alternatives to BAS21S

Package: SOT-23GOODWORKDiodes - Rectifiers - SingleVoltage - DC Reverse (Vr) (Max): 250 VCurrent - Average Rectified (Io): 200 mAForward Voltage (Vf) (Max) @ If: 1250 mV @ 200 mAReverse Recovery Time (trr): 50 nsDiode Capacitance (CD): 5 pF @ 0V, 1MHz

BAS21S is a 250V, 200mA fast switching diode in a SOT-23 package, for general-purpose switching. Finding a replacement requires matching voltage, current, and reverse recovery time.

AI replacement insight

Electrical riskhigh

High if not using a BAS21-family part; voltage, current, and trr must match.

Package risklow

SOT-23 is a highly standardized package, making physical fit straightforward.

Can it be replaced directly?

Direct replacement for BAS21S should use only Datasheet verified or Strong match candidates; many approved options still require engineering review.

Best replacement path

Use another BAS21-family diode from a major manufacturer like onsemi (BAS21LT1G) or Panjit (BAS21_R1_00001).

Main risk

Using a part with a lower voltage rating (e.g., BAT54 or BAS70) or an incorrect internal configuration (e.g., BAV23 series arrays).

Recommended alternatives

2
BAS21LT1G package
BAS21LT1G

onsemi

Needs validationlow risk

A strong alternative with matching key electrical ratings and package from onsemi.

View details

Alternative comparison matrix

Feature / factorBAS21SBAS21LT1GBAS21_R1_00001Alt 3Compatibility / risk
PackageSOT-23SOT-23 (TO-236)SOT-23SOT-23 (TO-236) — Package is form-factor compatible.; BAS21_R1_00001: Package matches.
Voltage250V250V250V250V — Peak reverse voltage matches.; BAS21_R1_00001: Peak reverse voltage matches.
Current200mA200mA200mA200mA — Forward current matches.; BAS21_R1_00001: Forward current matches.
Trr50ns50ns50ns50ns — Reverse recovery time matches.; BAS21_R1_00001: Reverse recovery time matches.
Temperature-55°C to +150°C-55°C to +150°C-55°C to +150°C-55°C to +150°C — Operating temperature range matches.; BAS21_R1_00001: Operating temperature range matches.

Application & sourcing insights

Questions & answers

Verified drop-in options for BAS21S are limited in the current batch. Review candidates marked Strong match or Datasheet verified, and validate package, pinout, and electrical limits before committing a BOM change.