1N4738A-T Zener Diode Equivalent & Substitute Parts

Part Overview

The 1N4738A-T is an 8.2 V, 1.3 W Zener diode manufactured by Vishay General Semiconductor - Diodes Division in a DO-41 through-hole package. This component is classified as obsolete, though 1076 pieces remain in stock as new original inventory. The part is qualified to AEC-Q101 automotive standards and is ROHS3 compliant.

Identification of equivalent and substitute parts is necessary due to the obsolete product status of the 1N4738A-T. Locating active production alternatives ensures design continuity, supply chain reliability, and access to current manufacturing batches with extended availability.

Substiute Parts

1N4738A-T

Vishay General Semiconductor - Diodes DivisionIn Stock: 10991N4738A-T Datasheet

Current PartRFQ

1N4738A-TR

Vishay General Semiconductor - Diodes DivisionIn Stock: 180771N4738A-TR Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 1N4738A-T is determined by strict equivalence across the following critical parameters:

Electrical Equivalence Criteria:

• Zener voltage (Vz): 8.2 V nominal
• Tolerance: ±5%
• Maximum power dissipation: 1.3 W
• Reverse leakage current: 10 µA @ 6 V
• Forward voltage: 1.2 V @ 200 mA
• Operating temperature rating: 175°C

Mechanical & Compliance Criteria:

• Package type: DO-41 through-hole axial configuration
• Automotive grade qualification: AEC-Q101
• RoHS compliance: ROHS3 Compliant
• Moisture sensitivity level: 1 (Unlimited)

The 1N4738A-TR is a direct substitute for the 1N4738A-T. Both parts share the same base product number (1N4738), identical electrical specifications, and equivalent automotive qualifications. The primary difference is product status: the 1N4738A-TR is active production, whereas the 1N4738A-T is obsolete.

Parameter Comparison

Engineering Selection Recommendations

The 1N4738A-TR is the direct substitute for the 1N4738A-T based on electrical and mechanical equivalence. Selection of the 1N4738A-TR is supported by the following factors:

Product Status: The 1N4738A-TR maintains active production status, ensuring continued availability and access to current manufacturing batches. The 1N4738A-T is obsolete, presenting long-term supply risk.

Compliance & Certification: Both parts carry identical automotive-grade qualification (AEC-Q101) and ROHS3 compliance status, meeting regulatory and environmental requirements for automotive and industrial applications.

Electrical Performance: The 1N4738A-TR delivers equivalent electrical performance across all critical parameters: 8.2 V nominal Zener voltage, 1.3 W maximum power dissipation, and identical reverse leakage and forward voltage characteristics.

Packaging & Mounting: Both parts utilize the DO-41 through-hole axial package configuration, ensuring mechanical compatibility with existing PCB designs and assembly processes.

Impedance Specification: The 1N4738A-TR specifies 4.5 Ohms maximum impedance, compared to 700 Ohms for the 1N4738A-T. This lower impedance value in the substitute part represents improved dynamic performance and is not a limiting factor for substitution, as it indicates superior transient response characteristics.

Frequently Asked Questions (FAQ)

Q: Can the 1N4738A-TR directly replace the 1N4738A-T in existing designs?

A: Yes. The 1N4738A-TR is a direct electrical and mechanical substitute. Both parts share identical Zener voltage (8.2 V), power rating (1.3 W), tolerance (±5%), and DO-41 through-hole package configuration. No circuit modifications are required.

Q: What is the significance of the impedance difference between the two parts?

A: The 1N4738A-TR specifies 4.5 Ohms maximum impedance, while the 1N4738A-T specifies 700 Ohms. Lower impedance indicates faster transient response and better high-frequency performance. This difference does not prevent substitution; the 1N4738A-TR provides equal or superior performance in this parameter.

Q: Are both parts qualified for automotive applications?

A: Yes. Both the 1N4738A-T and 1N4738A-TR carry automotive-grade classification and AEC-Q101 qualification, meeting automotive industry standards for reliability and performance.

Q: What is the difference between the packaging designations?

A: The 1N4738A-T packaging is not specified in the provided data. The 1N4738A-TR is supplied in Cut Tape (CT) packaging. Both parts use the DO-41 through-hole axial package configuration for PCB mounting. Packaging format (tape vs. bulk) affects handling and assembly processes but not electrical or mechanical compatibility.

Q: Is the 1N4738A-TR ROHS compliant?

A: Yes. The 1N4738A-TR is ROHS3 compliant, matching the compliance status of the 1N4738A-T. Both parts meet environmental and regulatory requirements for restricted substance use.

Q: Why is the 1N4738A-T listed as obsolete?

A: The 1N4738A-T has reached end-of-life status in the manufacturer's product portfolio. The 1N4738A-TR represents the active production equivalent, ensuring continued supply and manufacturing support.

Q: Can I use the 1N4738A-TR in high-temperature applications?

A: Yes. The 1N4738A-TR is rated for operation up to 175°C junction temperature, matching the thermal capability of the 1N4738A-T and supporting high-temperature automotive and industrial applications.