BZX79C56 Equivalent & Substitute Parts

Part Overview

The BZX79C56 is a through-hole zener diode rated at 56 V nominal with 500 mW maximum power dissipation and ±5% tolerance. Manufactured by onsemi in DO-35 axial package configuration, this component is classified as obsolete. Due to its obsolete product status, equivalent substitute parts from active manufacturers are necessary to maintain design continuity and ensure long-term component availability for new production and field replacements.

Substiute Parts

BZX79C56

onsemiIn Stock: 1123BZX79C56 Datasheet

Current PartRFQ

BZX79-C56,113

NXP SemiconductorsIn Stock: 400972BZX79-C56,113 Datasheet

DirectRFQ

BZX79-C56,133

Nexperia USA Inc.In Stock: 30243BZX79-C56,133 Datasheet

DirectRFQ

BZX79-C56,143

NXP SemiconductorsIn Stock: 368326BZX79-C56,143 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BZX79C56 is based on the following critical electrical and mechanical parameters:

Electrical Equivalence Criteria:

• Voltage - Zener (Nom): 56 V (exact match required)
• Tolerance: ±5% (exact match required)
• Impedance (Max): 200 Ohms (exact match required)
• Current - Reverse Leakage @ Vr: 50 nA @ 39.2 V (exact match required)
• Operating Temperature Range: -65°C to 200°C (exact match required)

Mechanical Compatibility Criteria:

• Mounting Type: Through Hole (exact match required)
• Package / Case: DO-204AH, DO-35, Axial (exact match required)

The substitute parts BZX79-C56,113, BZX79-C56,133, and BZX79-C56,143 meet all electrical parameters and mechanical requirements. These parts are manufactured by NXP Semiconductors (Nexperia) and maintain active product status, ensuring continued availability and supply chain reliability. The primary difference is reduced maximum power dissipation (400 mW versus 500 mW), which is acceptable in applications where the circuit design operates within the lower power envelope.

Parameter Comparison

Engineering Selection Recommendations

All three substitute parts (BZX79-C56,113, BZX79-C56,133, and BZX79-C56,143) are direct functional equivalents for the obsolete BZX79C56. Selection among these substitutes should be based on the following factors:

Product Status and Supply Chain: All substitute parts carry active product status from NXP Semiconductors or Nexperia USA Inc., ensuring continued manufacturing and availability. This addresses the primary limitation of the obsolete BZX79C56.

Regulatory Compliance: All substitute parts maintain REACH Unaffected status, consistent with the original component. BZX79-C56,133 carries additional RoHS3 compliance certification.

Packaging and Inventory: BZX79-C56,113 and BZX79-C56,143 are supplied in bulk packaging, while BZX79-C56,133 is supplied in Tape & Box format. Selection depends on procurement volume and assembly process requirements. Inventory levels are substantial across all three options, supporting immediate availability.

Power Dissipation Consideration: The substitute parts are rated at 400 mW maximum power dissipation compared to the original 500 mW rating. This difference is acceptable for applications where circuit design ensures operation within the 400 mW envelope. Applications requiring the full 500 mW dissipation capability must conduct thermal analysis to confirm compatibility.

Frequently Asked Questions (FAQ)

Q: Can BZX79-C56,113, BZX79-C56,133, and BZX79-C56,143 be used interchangeably with BZX79C56?

A: Yes, these parts are electrically and mechanically equivalent for the critical parameters: 56 V nominal zener voltage, ±5% tolerance, 200 Ohms maximum impedance, identical reverse leakage characteristics, and identical operating temperature range. All are through-hole components in DO-35 axial package configuration. The primary difference is reduced maximum power dissipation (400 mW versus 500 mW), which is acceptable in applications designed to operate within the lower power rating.

Q: What is the difference between the three substitute part numbers?

A: BZX79-C56,113, BZX79-C56,133, and BZX79-C56,143 are all manufactured by NXP Semiconductors or Nexperia USA Inc. and share identical electrical specifications. The differences are in packaging format (bulk versus Tape & Box) and inventory availability. The suffix designations (113, 133, 143) indicate different packaging and distribution channels from the same manufacturer family. Electrical performance is identical across all three variants.

Q: Are there any compliance or regulatory differences between the original and substitute parts?

A: All parts maintain REACH Unaffected status. BZX79-C56,133 carries additional RoHS3 compliance certification. The original BZX79C56 and all substitutes carry EAR99 ECCN classification and identical HTSUS codes (8541.10.0050), indicating no regulatory barriers to substitution.

Q: What is the impact of the 100 mW power reduction in the substitute parts?

A: The substitute parts are rated at 400 mW maximum power dissipation compared to the original 500 mW. This difference is acceptable for applications where the circuit design ensures operation within the 400 mW envelope. Applications requiring sustained operation at or near 500 mW dissipation must verify that the substitute part's thermal characteristics remain within acceptable limits for the specific application environment.

Q: Can I use these substitute parts in new designs?

A: Yes. All substitute parts carry active product status and are suitable for new design implementations. The active status ensures long-term availability and supply chain continuity, making them preferable to the obsolete original part for new production.

Q: Are there any differences in forward voltage characteristics?

A: The original BZX79C56 specifies 1.5 V maximum forward voltage at 100 mA. The substitute parts specify 900 mV maximum forward voltage at 10 mA. These measurements are taken at different current levels and are not directly comparable. Both specifications fall within acceptable ranges for zener diode forward conduction characteristics and do not affect substitution compatibility.