BAS40LT1 Equivalent & Substitute Parts

Part Overview

The BAS40LT1 is a Schottky diode rated for 40 V DC reverse voltage with 120 mA average rectified current in a surface mount SOT-23-3 (TO-236) package. This component is classified as obsolete, which necessitates identification of equivalent and substitute parts for ongoing design requirements and production continuity. Active alternatives with identical or enhanced electrical characteristics are available from multiple manufacturers.

Substiute Parts

BAS40LT1

onsemiIn Stock: 8112BAS40LT1 Datasheet

Current PartRFQ

BAS40LT1G

onsemiIn Stock: 605347BAS40LT1G Datasheet

DirectRFQ

BAS40-00-E3-08

Vishay General Semiconductor - Diodes DivisionIn Stock: 1620BAS40-00-E3-08 Datasheet

SimilarRFQ

BAS40-TP

Micro Commercial CoIn Stock: 27834BAS40-TP Datasheet

SimilarRFQ

BAS40E6327HTSA1

Infineon TechnologiesIn Stock: 2169BAS40E6327HTSA1 Datasheet

SimilarRFQ

BAS40E6433HTMA1

Infineon TechnologiesIn Stock: 872BAS40E6433HTMA1 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BAS40LT1 is determined by the following critical parameters:

Mandatory Compatibility Criteria:

• Voltage - DC Reverse (Vr) (Max): 40 V minimum
• Package / Case: TO-236-3, SC-59, SOT-23-3
• Mounting Type: Surface Mount
• Technology: Schottky

Current Rating Considerations:

• Direct equivalents maintain 120 mA average rectified current
• Enhanced substitutes provide 200 mA average rectified current, which is backward compatible with 120 mA applications

Electrical Performance:

• Forward voltage (Vf) at 40 mA: 1 V maximum
• Reverse leakage current: specifications range from 1 µA to 200 nA depending on manufacturer
• Capacitance: 5 pF at rated voltage

Substitute parts are grouped into two categories: direct equivalents (BAS40LT1G, BAS40E6327HTSA1, BAS40E6433HTMA1) and enhanced-current alternatives (BAS40-00-E3-08, BAS40-TP) that provide higher current ratings within the same package and voltage class.

Parameter Comparison

Engineering Selection Recommendations

Direct Equivalent (Recommended for Pin-Compatible Replacement):

BAS40LT1G from onsemi is the direct equivalent to the obsolete BAS40LT1. This part maintains identical electrical specifications (40 V, 120 mA, 1 V forward voltage) and package configuration. The primary advantage is active product status with ROHS3 compliance, addressing regulatory requirements. Inventory availability is substantial (605,300 pcs), ensuring supply continuity.

Current-Enhanced Alternatives (For Designs Tolerating Higher Current Ratings):

BAS40-00-E3-08 (Vishay) and BAS40-TP (Micro Commercial Co) provide 200 mA average rectified current while maintaining 40 V reverse voltage and identical forward voltage characteristics. These parts are suitable for applications where the original 120 mA rating provides insufficient margin or where design evolution permits higher current capability. Both are ROHS3 compliant and actively produced.

Infineon Alternatives (For Specific Sourcing Requirements):

BAS40E6327HTSA1 and BAS40E6433HTMA1 from Infineon Technologies are direct electrical equivalents with 120 mA ratings and identical voltage specifications. These parts are ROHS3 compliant and actively produced, offering alternative sourcing channels. Reverse recovery time specification (100 ps) is provided for high-frequency applications.

Compliance Consideration:

All substitute parts listed are ROHS3 compliant, addressing environmental and regulatory requirements. The original BAS40LT1 is RoHS non-compliant; substitution with any listed alternative resolves this compliance gap.

Frequently Asked Questions (FAQ)

Q: Can BAS40-00-E3-08 or BAS40-TP be used as direct replacements for BAS40LT1?

A: Yes. Both parts are electrically compatible. They share identical 40 V reverse voltage rating, 1 V forward voltage specification, and SOT-23-3 package. The 200 mA current rating is higher than the original 120 mA specification, making these parts suitable for applications where the original part operated below its maximum current rating. Pin configuration is identical.

Q: What is the difference between BAS40LT1G and the Infineon alternatives?

A: BAS40LT1G, BAS40E6327HTSA1, and BAS40E6433HTMA1 are all direct electrical equivalents with 120 mA ratings. The primary differences are manufacturer sourcing and reverse recovery time specification. Infineon parts specify 100 ps reverse recovery time, while onsemi does not provide this parameter for the BAS40LT1G. All three are ROHS3 compliant and actively produced.

Q: Is the SOT-23-3 package identical across all substitute parts?

A: Yes. All listed substitute parts use the SOT-23-3 package designation (also referenced as TO-236-3 or SC-59). Pin configuration and footprint are identical, enabling direct PCB-level substitution without layout modification.

Q: Why is BAS40LT1 classified as obsolete?

A: The BAS40LT1 is marked obsolete by onsemi. The active equivalent BAS40LT1G provides identical functionality with improved compliance status (ROHS3 compliant versus non-compliant). Substitution to BAS40LT1G is recommended for new designs and production continuity.

Q: Can I use a 200 mA rated part in a circuit designed for 120 mA?

A: Yes. A higher current-rated component is suitable for applications designed for lower current. The 200 mA parts (BAS40-00-E3-08, BAS40-TP) will operate within specification in circuits requiring 120 mA or less. Verify that forward voltage and reverse voltage specifications remain acceptable for the application.

Q: What is the moisture sensitivity level for these parts?

A: All listed parts, including the original BAS40LT1, have Moisture Sensitivity Level (MSL) of 1 (Unlimited). This indicates no moisture sensitivity restrictions during storage or handling.

Q: Are all substitute parts RoHS compliant?

A: All substitute parts listed are ROHS3 compliant. The original BAS40LT1 is RoHS non-compliant. Substitution with any listed alternative resolves RoHS compliance requirements for new designs and production.