BAS21S Equivalent & Substitute Parts

Part Overview

The BAS21S is a general-purpose diode array manufactured by Diodes Incorporated, configured as 1 pair series connection in a surface mount SOT-23-3 package. This component is rated for 250 V DC reverse voltage and 200 mA average rectified current per diode. The BAS21S is classified as obsolete, making identification of suitable substitute components necessary for ongoing design support and procurement continuity.

Substiute Parts

BAS21S

Diodes IncorporatedIn Stock: 125412BAS21S Datasheet

Current PartRFQ

BAV23C-7-F

Diodes IncorporatedIn Stock: 155125BAV23C-7-F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BAS21S is determined by the following critical parameters:

Package Compatibility: The substitute must use the same surface mount package (TO-236-3, SC-59, SOT-23-3) to ensure mechanical and electrical compatibility with existing PCB layouts.

Voltage Rating: The substitute must support the maximum DC reverse voltage requirement of the application. The BAS21S operates at 250 V maximum; substitutes with equal or higher voltage ratings are acceptable.

Current Rating: The substitute must handle the average rectified current per diode. The BAS21S is rated for 200 mA; substitutes with equal or higher current ratings are acceptable.

Forward Voltage: The substitute must maintain forward voltage characteristics within acceptable operating parameters to preserve circuit performance.

Diode Configuration: The internal connection topology (series, common cathode, common anode) must be compatible with the circuit design.

Compliance: The substitute must maintain RoHS3 compliance and REACH unaffected status to meet regulatory requirements.

Parameter Comparison

Engineering Selection Recommendations

The BAV23C-7-F is the manufacturer-recommended substitute for the obsolete BAS21S. Both components are manufactured by Diodes Incorporated and share identical package geometry (SOT-23-3), forward voltage characteristics, and reverse recovery time specifications.

Voltage Consideration: The BAV23C-7-F has a maximum DC reverse voltage rating of 200 V compared to the BAS21S rating of 250 V. Applications operating at voltages exceeding 200 V require verification that the BAV23C-7-F voltage rating is sufficient for the intended circuit.

Current Capability: The BAV23C-7-F provides 400 mA average rectified current per diode, exceeding the BAS21S specification of 200 mA. This higher current rating provides additional design margin.

Configuration Difference: The BAS21S uses a series connection configuration, while the BAV23C-7-F uses a common cathode configuration. Circuit topology must be evaluated to confirm compatibility with the different internal connection scheme.

Compliance Status: Both components maintain ROHS3 compliance and REACH unaffected status. The BAV23C-7-F is actively manufactured, ensuring long-term availability and supply chain continuity compared to the obsolete BAS21S.

Temperature Range: The BAV23C-7-F extends the lower operating temperature limit to -65°C, providing broader environmental operating capability than the BAS21S.

Frequently Asked Questions (FAQ)

Q: Can the BAV23C-7-F directly replace the BAS21S in all applications?

A: Direct replacement requires verification of two factors: (1) the application maximum voltage does not exceed 200 V, as the BAV23C-7-F is rated 50 V lower than the BAS21S, and (2) the circuit design is compatible with the common cathode configuration of the BAV23C-7-F versus the series connection of the BAS21S. Pin-to-pin package compatibility is confirmed.

Q: What is the primary difference between the BAS21S and BAV23C-7-F configurations?

A: The BAS21S contains two diodes in series connection, while the BAV23C-7-F contains two diodes with a common cathode configuration. These different internal topologies affect how the components function within a circuit and must be evaluated against the specific application requirements.

Q: Are both components RoHS compliant?

A: Yes, both the BAS21S and BAV23C-7-F are ROHS3 compliant and REACH unaffected, meeting current regulatory requirements for electronic components.

Q: Why is the BAS21S classified as obsolete?

A: The BAS21S is no longer in active production. The BAV23C-7-F is the active equivalent from the same manufacturer, providing equivalent or superior electrical performance in the same package.

Q: What packaging options are available for the BAV23C-7-F?

A: The BAV23C-7-F is supplied in Cut Tape (CT) and Digi-Reel® packaging formats, both in the SOT-23-3 surface mount package.

Q: How do the forward voltage characteristics compare?

A: Both components specify identical forward voltage of 1.25 V maximum at 200 mA, ensuring consistent circuit behavior in forward-biased conditions.

Q: Is the higher current rating of the BAV23C-7-F (400 mA vs. 200 mA) a concern?

A: No. The higher current rating of the BAV23C-7-F provides additional design margin and does not create compatibility issues. The component operates safely at the lower current levels required by BAS21S applications.