BZX79-B51,133 Equivalent & Substitute Parts

Part Overview

The BZX79-B51,133 is an active-status Zener diode manufactured by Nexperia USA Inc., rated for 51 V nominal Zener voltage with 400 mW maximum power dissipation. This through-hole component operates across a temperature range of -65°C to 200°C and is packaged in DO-204AH (DO-35) axial configuration. The device maintains ±2% voltage tolerance and is ROHS3 compliant with unlimited moisture sensitivity rating.

Substitute parts are identified when equivalent electrical performance can be achieved within the specified parameter ranges while maintaining functional compatibility in target applications. Alternative sources become necessary due to inventory availability, supply chain considerations, or design flexibility requirements.

Substiute Parts

BZX79-B51,133

Nexperia USA Inc.In Stock: 9486BZX79-B51,133 Datasheet

Current PartRFQ

BZX55C51-TAP

Vishay General Semiconductor - Diodes DivisionIn Stock: 40368BZX55C51-TAP Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BZX79-B51,133 is determined by the following critical parameters:

Primary Electrical Criteria:

• Zener voltage rating of 51 V (nominal)
• Maximum power dissipation capability equal to or greater than 400 mW
• Reverse leakage current characteristics compatible with circuit requirements
• Forward voltage characteristics suitable for the application

Mechanical & Packaging Criteria:

• Through-hole mounting configuration
• DO-204AH (DO-35) axial package format
• Physical dimensions compatible with PCB layout

Compliance & Environmental Criteria:

• ROHS3 compliance status
• Operating temperature range encompassing or exceeding -65°C to 200°C
• Moisture sensitivity level of 1 (Unlimited)

The BZX55C51-TAP qualifies as a substitute based on matching nominal Zener voltage (51 V), compatible package format (DO-204AH/DO-35), through-hole mounting, ROHS3 compliance, and superior power rating (500 mW versus 400 mW). Tolerance and impedance variations remain within acceptable substitution parameters for general-purpose Zener diode applications.

Parameter Comparison

Engineering Selection Recommendations

BZX79-B51,133 (Nexperia) is the primary component selection when:

• Tighter voltage tolerance (±2%) is required for precision voltage regulation
• Maximum operating temperature of 200°C is necessary
• Lower impedance variation is critical for circuit stability
• Original manufacturer specification compliance is mandated

BZX55C51-TAP (Vishay) is an acceptable substitute when:

• Higher power dissipation capability (500 mW) provides design margin
• Automotive-grade qualification (AEC-Q101) meets application requirements
• Voltage tolerance of ±5% is acceptable within circuit design parameters
• Lower impedance (125 Ohms) improves transient response characteristics
• Maximum operating temperature of 175°C satisfies thermal requirements

Both components maintain ROHS3 compliance, unlimited moisture sensitivity rating, and identical package format (DO-204AH/DO-35 axial). Both are active-status products with established supply availability.

Frequently Asked Questions (FAQ)

Q: Can BZX55C51-TAP directly replace BZX79-B51,133 in existing designs?

A: Direct substitution is permissible when circuit design tolerates ±5% voltage tolerance (versus ±2% of the original) and maximum operating temperature of 175°C (versus 200°C). The identical 51 V nominal rating, DO-35 package format, and through-hole mounting enable pin-for-pin compatibility. Higher power rating (500 mW) provides additional thermal margin.

Q: What are the key electrical differences between these parts?

A: Primary differences include voltage tolerance (±2% versus ±5%), maximum power dissipation (400 mW versus 500 mW), impedance (180 Ohms versus 125 Ohms), and maximum operating temperature (200°C versus 175°C). Nominal Zener voltage (51 V) and package format remain identical.

Q: Are both parts suitable for automotive applications?

A: BZX55C51-TAP carries automotive-grade designation with AEC-Q101 qualification. BZX79-B51,133 does not specify automotive qualification. Selection depends on application requirements and automotive compliance mandates.

Q: How do impedance differences affect circuit performance?

A: Lower impedance (125 Ohms for BZX55C51-TAP versus 180 Ohms for BZX79-B51,133) results in improved transient response and reduced output impedance variation across the operating current range. This characteristic benefits high-frequency or noise-sensitive applications.

Q: What is the significance of reverse leakage current specifications?

A: BZX79-B51,133 specifies 50 nA @ 35.7 V while BZX55C51-TAP specifies 100 nA @ 39 V. Lower leakage current in the original part may be critical for low-power standby circuits or high-impedance measurement applications. Higher leakage in the substitute remains within acceptable limits for standard voltage regulation applications.

Q: Are there temperature-related constraints for substitution?

A: BZX79-B51,133 operates to 200°C maximum; BZX55C51-TAP operates to 175°C maximum. Applications requiring operation above 175°C require the original part. Applications with maximum ambient temperature below 175°C can use either component.

Q: Do both parts meet RoHS and REACH compliance requirements?

A: Both BZX79-B51,133 and BZX55C51-TAP are ROHS3 compliant and REACH unaffected. Both carry identical compliance status for environmental and hazardous substance regulations.