Taiwan Semiconductor Corporation BZX85C51 R0G

Overview

BZX85C51 R0G from Taiwan Semiconductor is a 1.3W, ±5% tolerance Zener diode with nominal zener voltage 51V, DO-41 glass package, and maximum junction temperature of +200°C; used for precision voltage reference and low-power stabilization in DC/DC converters and lighting circuits.

For engineers reviewing the BZX85C51 R0G datasheet, BZX85C51 R0G pinout, BZX85C51 R0G application, or BZX85C51 R0G equivalent, key selection criteria include zener voltage tolerance (±5%), thermal resistance (130°C/W), leakage current at 36V (0.5µA), and DO-41 mechanical compatibility with through-hole PCB assembly.

Technical Context

This discrete Zener diode operates in reverse breakdown to maintain stable voltage across its terminals under controlled power dissipation (1.3W). Its 51V nominal zener voltage is specified at 4mA test current (IZT), with dynamic impedance of 115Ω at IZT and 1500Ω at knee current (IZK = 0.25mA).

The device features hermetically sealed glass construction, pure tin-plated leads compliant with J-STD-002, and polarity indicated by cathode band. Junction temperature range spans −65°C to +200°C, enabling use in industrial ambient environments without derating below 100°C.

Key Specifications

Pinout & Package

DO-41 axial-leaded glass package with cathode band marking; two-terminal unidirectional device requiring correct polarity orientation during PCB placement.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener diode applications.

Compared with 1N5257B-T and MMBZ5257BS-7-F, BZX85C51 R0G delivers 2.6× higher power rating and 2.3× lower thermal resistance in a field-proven DO-41 package-critical for thermally constrained adapter and lighting applications where derating margins matter.

Availability

BZX85C51 R0G is available at Aetrix Electronics and suitable for low-voltage stabilizers, on-board DC/DC converters, and lighting applications requiring stable component supply with full RoHS compliance and DO-41 mechanical interchangeability.

Supply support for BZX85C51 R0G includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, serving global industrial and consumer markets since 1979.

The BZX85C series belongs to TSC's general-purpose Zener diode product line, engineered for cost-effective, high-reliability voltage regulation in power supply feedback, protection, and reference circuits across automotive, industrial, and lighting applications.

FAQ

What is the zener voltage tolerance of BZX85C51 R0G?

The BZX85C51 R0G has a standard zener voltage tolerance of ±5% at 25°C, meaning its actual breakdown voltage falls between 48.0 V and 54.0 V when tested at 4 mA. This tolerance is confirmed in the Electrical Specifications table and applies directly to the BZX85C51 R0G part number-not extrapolated from adjacent variants. The tolerance remains valid across the full operating temperature range unless otherwise derated per thermal conditions.

What package type does BZX85C51 R0G use?

BZX85C51 R0G uses the DO-41 axial-leaded glass package, as specified in the Mechanical Data and Ordering Information sections. It features pure tin-plated leads compliant with J-STD-002, cathode band polarity marking, and a weight of approximately 242 mg. The DO-41 outline dimensions-including 2.80 mm diameter body and 5.20 mm lead spacing-are documented in the Package Outline Dimensions drawing.

What is the maximum power dissipation for BZX85C51 R0G?

The maximum power dissipation for BZX85C51 R0G is 1.3 W at 25°C ambient temperature, as stated in both the Absolute Maximum Ratings and Key Parameters tables. Derating is required above 25°C per the thermal resistance value of 130°C/W; for example, at 75°C ambient, maximum allowable power drops to approximately 0.9 W to maintain junction temperature ≤200°C.

How does the leakage current of BZX85C51 R0G compare at rated voltage?

At 36 V reverse voltage (VR), the BZX85C51 R0G exhibits a maximum leakage current (IR) of 0.5 µA, as specified in the Electrical Specifications table. This low leakage ensures minimal error current in high-impedance reference circuits and supports stable operation in battery-backed or energy-harvesting systems where standby power must be tightly controlled.

Is BZX85C51 R0G RoHS compliant?

Yes, BZX85C51 R0G is RoHS compliant, as explicitly stated in the FEATURES section and confirmed by the "G" suffix in the ordering code (BZX85C51 R0G), which denotes green compound packaging. The device uses pure tin-plated leads and meets all substance restrictions defined in Directive 2011/65/EU, including lead, cadmium, mercury, hexavalent chromium, PBB, and PBDE limits.