BZX85B3V3-TAP Equivalent & Substitute Parts

Part Overview

The BZX85B3V3-TAP is a Zener diode manufactured by Vishay General Semiconductor - Diodes Division, rated at 3.3 V nominal with 1.3 W maximum power dissipation. This component is packaged in DO-204AL (DO-41) axial through-hole configuration and is qualified to AEC-Q101 automotive standards. The part maintains Active product status and is RoHS3 compliant with REACH unaffected classification.

Substitute parts are identified when equivalent electrical performance can be achieved within the specified parameter tolerances while maintaining compatible mechanical packaging and operational characteristics. Alternative sources become necessary due to inventory availability, supply chain considerations, or specific application requirements within the defined electrical and thermal operating ranges.

Substiute Parts

BZX85B3V3-TAP

Vishay General Semiconductor - Diodes DivisionIn Stock: 725BZX85B3V3-TAP Datasheet

Current PartRFQ

1N4728A

Lumimax Optoelectronic TechnologyIn Stock: 202491N4728A Datasheet

MFR RecommendedRFQ

1N4728ATR

Fairchild SemiconductorIn Stock: 121671N4728ATR Datasheet

MFR RecommendedRFQ

1N746A

Microchip TechnologyIn Stock: 13801N746A Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BZX85B3V3-TAP is determined by the following critical parameters:

Primary Electrical Criteria:

• Zener voltage nominal rating of 3.3 V
• Through-hole axial mounting configuration compatible with DO-41 package family
• Operating temperature range that encompasses or exceeds the original specification

Secondary Electrical Criteria:

• Power dissipation capability (minimum 1.0 W acceptable for reduced-power applications)
• Impedance characteristics within acceptable variance
• Reverse leakage current specifications

Mechanical Compatibility:

• Package designation within DO-204AL, DO-41, or DO-35 axial families
• Through-hole lead configuration for PCB insertion

Compliance & Status:

• Active product status
• RoHS compliance status (RoHS3 or RoHS compliant acceptable)
• REACH unaffected classification

The three identified substitute parts (1N4728A, 1N4728ATR, 1N746A) satisfy the primary electrical criteria of 3.3 V nominal zener voltage and through-hole axial packaging. Variations in power rating, impedance, and temperature range are documented in the parameter comparison table to enable application-specific selection.

Parameter Comparison

Engineering Selection Recommendations

1N4728A (Lumimax Optoelectronic Technology)

This substitute maintains 3.3 V nominal zener voltage with ±5% tolerance and 1.0 W power rating in DO-41 axial packaging. The extended operating temperature range (-65 to 200°C) exceeds the original specification. RoHS compliance is confirmed. This part is suitable for applications where the 1.3 W power rating of the original is not fully utilized and where the wider temperature range provides operational margin.

1N4728ATR (Fairchild Semiconductor)

This substitute provides identical electrical specifications to the 1N4728A with 3.3 V nominal zener voltage, ±5% tolerance, and 1.0 W power rating in DO-41 axial packaging. Extended operating temperature range (-65 to 200°C) is provided. RoHS status is not specified in available documentation. This part is functionally equivalent to 1N4728A and suitable for equivalent application requirements.

1N746A (Microchip Technology)

This substitute maintains 3.3 V nominal zener voltage with ±5% tolerance but operates at reduced 400 mW power rating in DO-35 axial packaging. The operating temperature range (-65 to 175°C) matches the original upper limit. RoHS non-compliance status requires evaluation against application regulatory requirements. This part is suitable only for low-power applications where 400 mW dissipation is sufficient and where RoHS compliance is not mandated.

Selection Criteria Summary:

• For applications requiring full 1.3 W power capability: 1N4728A or 1N4728ATR are preferred substitutes
• For applications with RoHS3 compliance requirement: 1N4728A is the recommended substitute
• For low-power applications (≤400 mW): 1N746A is acceptable if RoHS non-compliance is permissible
• For automotive or high-reliability applications: Original BZX85B3V3-TAP with AEC-Q101 qualification is preferred

Frequently Asked Questions (FAQ)

Q: Can 1N4728A replace BZX85B3V3-TAP in all applications?

A: 1N4728A is electrically compatible for applications where power dissipation does not exceed 1.0 W. The original part is rated for 1.3 W maximum. If your circuit requires the full 1.3 W capability, verify that 1N4728A power rating is sufficient before substitution. Both parts maintain 3.3 V nominal zener voltage and through-hole DO-41 packaging.

Q: What is the difference between 1N4728A and 1N4728ATR?

A: Both parts are functionally equivalent with identical electrical specifications: 3.3 V nominal zener voltage, ±5% tolerance, 1.0 W power rating, and DO-41 axial packaging. The primary difference is manufacturer (Lumimax versus Fairchild Semiconductor). Selection between these two is based on supplier availability and inventory considerations.

Q: Why does 1N746A have lower power rating?

A: 1N746A is rated at 400 mW maximum power dissipation compared to 1.3 W for the original part. This reflects different die design and thermal characteristics. 1N746A is suitable only for applications where power dissipation remains below 400 mW. Additionally, 1N746A uses DO-35 packaging, which is physically smaller than the DO-41 package of the original part.

Q: Is the tolerance difference between ±2% and ±5% significant?

A: The original BZX85B3V3-TAP specifies ±2% tolerance, while all substitute parts specify ±5% tolerance. For applications requiring tighter voltage regulation, the original part provides superior accuracy. For general-purpose applications, ±5% tolerance is typically acceptable. Verify your circuit design requirements before selecting a substitute with wider tolerance.

Q: Can I use 1N746A as a direct replacement?

A: 1N746A is not a direct replacement due to three factors: (1) reduced power rating of 400 mW versus 1.3 W, (2) different package designation (DO-35 versus DO-41), and (3) RoHS non-compliance status. Physical PCB layout modifications may be required due to package differences. Use 1N746A only in low-power applications where these limitations are acceptable.

Q: What is the operating temperature range difference?

A: The original BZX85B3V3-TAP operates from -55 to 175°C. Substitute parts 1N4728A and 1N4728ATR extend the lower limit to -65°C and upper limit to 200°C, providing wider operational margin. 1N746A matches the original upper limit of 175°C but extends the lower limit to -65°C. For applications operating near temperature extremes, verify that the selected part's range encompasses your requirements.

Q: Are all substitute parts RoHS compliant?

A: 1N4728A is confirmed RoHS compliant. 1N4728ATR RoHS status is not specified in available documentation. 1N746A is RoHS non-compliant. For applications requiring RoHS compliance, 1N4728A is the recommended substitute. Verify compliance requirements with your application standards before final part selection.

Q: What does AEC-Q101 qualification mean?

A: AEC-Q101 is an automotive qualification standard for discrete semiconductors. The original BZX85B3V3-TAP carries this qualification, indicating suitability for automotive applications. Substitute parts do not list AEC-Q101 qualification. For automotive or high-reliability applications, the original part is preferred. Substitute parts are suitable for general industrial and consumer applications.