BZX85C91-TAP Equivalent & Substitute Parts

Part Overview

The BZX85C91-TAP is a 91 V, 1.3 W Zener diode manufactured by Vishay General Semiconductor - Diodes Division in a through-hole DO-204AL (DO-41) axial package. This component is classified as obsolete, though 692 pieces remain in stock as new original inventory. The part carries AEC-Q101 automotive qualification and is ROHS3 compliant.

Due to the obsolete product status of the BZX85C91-TAP, equivalent and substitute Zener diodes with 91 V nominal voltage are available from active product lines. Substitutes are selected based on matching or exceeding the electrical performance parameters while maintaining compatible package configurations and operating characteristics.

Key Parameters

Parameter	BZX85C91-TAP	Unit
Voltage - Zener (Nom)	91	V
Tolerance	±5%	—
Power - Max	1.3	W
Impedance (Max)	250	Ohms
Current - Reverse Leakage @ Vr	500 nA @ 68 V	—
Operating Temperature Range	-55°C to 175°C	—
Mounting Type	Through Hole	—
Package / Case	DO-204AL, DO-41, Axial	—
Grade	Automotive	—
Qualification	AEC-Q101	—

Substitute Part Grouping Explanation

Substitution of the BZX85C91-TAP is determined by the following critical parameters:

Primary Matching Criteria:

Zener voltage: 91 V nominal
Package type: DO-204AL (DO-41) axial for through-hole applications, or DO-213AB for surface-mount alternatives
Impedance: Maximum 250 Ohms (lower impedance values are acceptable)
Operating temperature range: Minimum -55°C to 175°C coverage

Secondary Compatibility Factors:

Power dissipation: Minimum 1.3 W (equal or greater values are acceptable)
Tolerance: ±5% or tighter (±1%, ±5%, ±10% are acceptable; ±20% represents reduced precision)
Reverse leakage current: Lower values indicate improved performance

Substitute parts are grouped into three categories:

Direct Through-Hole Equivalents (1 W to 1.25 W): Parts maintaining DO-204AL packaging with power ratings from 1 W to 1.25 W. These provide direct pin-compatible replacement with reduced or equivalent power handling.
Enhanced Through-Hole Substitutes (2 W to 3 W): Parts with increased power dissipation capability in DO-204AL packaging, suitable for applications requiring higher thermal margin.
Surface-Mount Alternative (1 W): The 1N4763AUR in DO-213AB package for designs utilizing surface-mount technology.

Parameter Comparison

Part Number	Manufacturer	Vz (Nom)	Tolerance	Power (Max)	Zzt (Max)	Mounting Type	Package	Temp Range	Status
BZX85C91-TAP	Vishay	91 V	±5%	1.3 W	250 Ω	Through Hole	DO-204AL	-55 to 175°C	Obsolete
1N4763G	Microsemi	91 V	±10%	1 W	250 Ω	Through Hole	DO-204AL	-65 to 175°C	Active
1N4763AG	Microsemi	91 V	±5%	1 W	250 Ω	Through Hole	DO-204AL	-65 to 175°C	Active
1N4763AUR	Microchip	91 V	±5%	1 W	250 Ω	Surface Mount	DO-213AB	-65 to 175°C	Active
1N5948BG	Microsemi	91 V	±5%	1.25 W	200 Ω	Through Hole	DO-204AL	-65 to 175°C	Active
1N5948DG	Microsemi	91 V	±1%	1.25 W	200 Ω	Through Hole	DO-204AL	-65 to 175°C	Active
2EZ91D/TR12	Microsemi	91 V	±20%	2 W	125 Ω	Through Hole	DO-204AL	-65 to 150°C	Active
2EZ91D/TR8	Microsemi	91 V	±20%	2 W	125 Ω	Through Hole	DO-204AL	-65 to 150°C	Active
3EZ91D/TR12	Microsemi	91 V	±20%	3 W	115 Ω	Through Hole	DO-204AL	-65 to 150°C	Active
3EZ91D/TR8	Microsemi	91 V	±20%	3 W	115 Ω	Through Hole	DO-204AL	-65 to 150°C	Active
3EZ91DE3/TR12	Microsemi	91 V	±20%	3 W	115 Ω	Through Hole	DO-204AL	-65 to 150°C	Active

Engineering Selection Recommendations

For Direct Replacement in Active Designs:

The 1N5948BG and 1N5948DG are the primary substitutes for the BZX85C91-TAP. Both maintain through-hole DO-204AL packaging and deliver 1.25 W power dissipation, exceeding the original 1.3 W specification. The 1N5948DG offers superior tolerance at ±1%, compared to the original ±5%. Both parts are in active production status with substantial inventory availability (798 and 984 pieces respectively).

For Precision-Critical Applications:

The 1N5948DG is selected when voltage tolerance of ±1% is required. This part provides the tightest tolerance specification among all substitutes and maintains compatibility with the original through-hole mounting configuration.

For Tolerance-Flexible Applications:

The 1N4763AG provides an active-status alternative with ±5% tolerance matching the original specification, though at reduced power rating (1 W). This part is suitable for applications where the 1.3 W power specification is not a limiting constraint.

For Enhanced Thermal Performance:

The 2EZ91D/TR12, 2EZ91D/TR8, 3EZ91D/TR12, 3EZ91D/TR8, and 3EZ91DE3/TR12 series offer 2 W to 3 W power dissipation in the same DO-204AL package. These parts are selected when circuit design requires increased thermal margin or higher power handling capability. The 3EZ91DE3/TR12 is ROHS3 compliant, matching the original part's environmental certification.

For Surface-Mount Designs:

The 1N4763AUR provides a 91 V, 1 W Zener diode in DO-213AB (MELF) surface-mount package. This part is selected for PCB designs utilizing surface-mount assembly technology.

Compliance Considerations:

All substitute parts are RoHS non-compliant except 3EZ91DE3/TR12, which carries ROHS3 compliance matching the original BZX85C91-TAP. Applications requiring RoHS compliance must specify 3EZ91DE3/TR12. All parts maintain REACH Unaffected status and EAR99 export classification consistent with the original component.

Frequently Asked Questions (FAQ)

Q: Can the 1N4763AG directly replace the BZX85C91-TAP in all applications?

A: The 1N4763AG is a direct through-hole replacement in terms of package and pinout. However, it delivers 1 W maximum power dissipation compared to the original 1.3 W. Applications operating near the 1.3 W thermal limit require evaluation. The 1N5948BG or 1N5948DG are preferred for applications requiring the full 1.3 W power specification.

Q: What is the difference between 1N5948BG and 1N5948DG?

A: Both parts are identical in electrical performance and package configuration. The primary difference is tolerance: 1N5948BG specifies ±5% tolerance, while 1N5948DG specifies ±1% tolerance. Select 1N5948DG for applications requiring tighter voltage regulation.

Q: Why do the 2EZ and 3EZ series have ±20% tolerance?

A: The 2EZ and 3EZ series are designed for applications where higher power dissipation is the primary requirement. The ±20% tolerance reflects the design philosophy of these higher-power devices. Applications requiring both high power and tight tolerance should specify 1N5948DG with 1.25 W capability and ±1% tolerance.

Q: Is the 1N4763AUR suitable for through-hole PCB designs?

A: No. The 1N4763AUR is packaged in DO-213AB (MELF), a surface-mount configuration. This part requires surface-mount assembly equipment and PCB design modifications. For through-hole designs, select 1N4763AG, 1N5948BG, or 1N5948DG.

Q: What is the operating temperature difference between the original part and substitutes?

A: The BZX85C91-TAP operates from -55°C to 175°C. Most substitutes extend the lower temperature limit to -65°C, providing improved cold-temperature performance. The 2EZ and 3EZ series reduce the upper limit to 150°C. Applications operating above 150°C must use 1N4763G, 1N4763AG, 1N4763AUR, 1N5948BG, or 1N5948DG.

Q: Which substitute offers the best RoHS compliance?

A: The 3EZ91DE3/TR12 is ROHS3 compliant, matching the original BZX85C91-TAP certification. All other substitutes are RoHS non-compliant. Applications requiring RoHS compliance must specify 3EZ91DE3/TR12.

Q: Can I use a higher-power substitute like the 3EZ91D/TR12 in place of the BZX85C91-TAP?

A: Yes. The 3EZ91D/TR12 maintains the same 91 V zener voltage and DO-204AL package. The increased power rating (3 W versus 1.3 W) provides additional thermal margin and does not degrade circuit performance. However, the ±20% tolerance is less precise than the original ±5%. Verify that the application tolerates ±20% voltage variation.

Q: What is the impedance difference between substitutes, and does it matter?

A: The original BZX85C91-TAP specifies 250 Ohms maximum impedance. The 1N5948 series reduces this to 200 Ohms, while the 2EZ and 3EZ series further reduce it to 125 Ohms and 115 Ohms respectively. Lower impedance improves voltage regulation and reduces output impedance. This is a beneficial characteristic and does not create compatibility issues.

Q: Are there any automotive-grade substitutes available?

A: The original BZX85C91-TAP carries AEC-Q101 automotive qualification. The provided substitute list does not include automotive-grade alternatives. Applications requiring AEC-Q101 qualification must continue using the BZX85C91-TAP or contact the manufacturer for automotive-qualified substitutes.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message