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Home > Products > Discrete Semiconductor Products > Diodes > Zener > Single Zener Diodes

onsemi 1N6012B

Name: 1N6012B
Brand: onsemi
SKU: 1N6012B
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 1N6012B

Manufacturer:: onsemi

Category:: Single Zener Diodes

Package:: DO-204AH, DO-35, Axial

Datasheet:: 1N6012B.pdf

Description:: DIODE ZENER 33V 500MW DO35

Quantity:: RFQ Add To RFQ list

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Inventory:2,261

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Product details

Overview

1N6012B from Fairchild Semiconductor is a 33 V ±5% Zener diode in DO-35 glass package, rated for 500 mW power dissipation at TL ≤ 75°C with 4.0 mW/°C derating, 88 Ω zener impedance at 5 mA test current, and 0.1 mA leakage current at 25 V reverse voltage. It provides precise voltage regulation in low-power reference and protection circuits.

For engineers reviewing the 1N6012B datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal limits, package dimensions, cathode identification, and direct alternatives for voltage reference design, overvoltage clamping, and bias stabilization.

Technical Context

The 1N6012B operates as a silicon planar Zener diode with sharp reverse breakdown at nominal 33 V, specified under thermal equilibrium conditions (TL = 30°C ±1°C, 3/8″ lead length). Its 5 mA test current ensures stable V_Z measurement while maintaining low dynamic impedance.

Designed for through-hole mounting in DO-35 glass encapsulation, it features a cathode band marking and supports operation across –65°C to +200°C junction/storage temperature range. Forward voltage is capped at 1.2 V max at 200 mA, confirming standard PN-junction behavior.

Key Specifications

Parameter	Value and Actual Design Meaning
V_Z @ I_Z	31.35–34.65 V (min–max at 5 mA; ±5% tolerance enables stable reference within 1.35 V window)
P_D	500 mW @ TL ≤ 75°C (defines maximum continuous power in free-air lead-temperature-limited condition)
Z_Z @ I_Z	88 Ω (low dynamic impedance ensures minimal output voltage variation under load current changes)
I_R @ V_R	0.1 mA @ 25 V (confirms tight leakage control below rated Zener voltage, critical for low-current bias networks)
T_J/T_STG	–65°C to +200°C (enables use in automotive under-hood, industrial motor controls, and high-temp sensor interfaces)
Forward V_F	1.2 V max @ 200 mA (standard silicon diode conduction threshold, usable for polarity protection or series rectification)

Pinout & Package

DO-35 glass axial package with cathode identified by a single color band on the body. Leads are tinned copper-clad steel, suitable for wave or hand soldering. Overall length: 4.0–4.5 mm; diameter: 1.8–2.2 mm; lead diameter: 0.4–0.5 mm.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward conduction terminal / Zener breakdown return path	Connected to lower-potential node in shunt regulator; carries full load current during regulation
Cathode	Zener breakdown terminal / Reference voltage output	Marked with band; supplies regulated 33 V to circuit node when reverse-biased above V_Z

Key Features

Feature	Design Value
±5% V_Z tolerance	Enables predictable reference accuracy without post-production trimming in cost-sensitive consumer and industrial designs
DO-35 glass package	Provides hermetic sealing and stable long-term V_Z drift (<0.05%/1000 hrs), ideal for mission-critical analog references
88 Ω Zener impedance	Minimizes output voltage deviation under ±1 mA load current shifts-critical for ADC reference buffers
–65°C to +200°C operating range	Supports deployment in engine control units, downhole tools, and aerospace power conditioning without derating penalties

Applications

Power Supply Voltage Reference	Overvoltage Clamp Circuit
Use Scenario: Stabilizing feedback node of linear regulator or op-amp reference input in 24 V industrial power supply. IC Role / Device Role / Timing Role: Shunt voltage reference providing fixed 33 V reference point for error amplifier comparison. Use Value: Maintains ±0.5% output regulation despite ±10% input ripple and 50 mA load step, due to low Z_Z and tight V_Z tolerance.	Use Scenario: Protecting microcontroller I/O pin from transient surges on 24 V CAN bus interface line. IC Role / Device Role / Timing Role: Reverse-biased clamping element diverting ESD or inductive kick energy to ground. Use Value: Limits voltage to ≤34.7 V peak (V_Z max) before breakdown, preventing latch-up in 3.3 V logic inputs.
Temperature-Stable Bias Network	Low-Power Sensor Excitation
Use Scenario: Generating stable bias current for RTD or thermistor bridge in HVAC ambient temperature sensor. IC Role / Device Role / Timing Role: Fixed-voltage source establishing known current through precision resistor network. Use Value: Delivers <10 ppm/°C effective reference stability over –40°C to +85°C, enabled by low TCR of DO-35 package and tight V_Z spec.	Use Scenario: Supplying excitation voltage to piezoresistive pressure sensor in battery-powered medical wearable. IC Role / Device Role / Timing Role: Low-quiescent-current voltage source powering sensor bridge with minimal standby drain. Use Value: Draws only 0.1 mA leakage at 25 V, extending battery life beyond 5 years in always-on monitoring mode.

Power Supply Voltage Reference

Overvoltage Clamp Circuit

Use Scenario: Stabilizing feedback node of linear regulator or op-amp reference input in 24 V industrial power supply.

IC Role / Device Role / Timing Role: Shunt voltage reference providing fixed 33 V reference point for error amplifier comparison.

Use Value: Maintains ±0.5% output regulation despite ±10% input ripple and 50 mA load step, due to low Z_Z and tight V_Z tolerance.

Use Scenario: Protecting microcontroller I/O pin from transient surges on 24 V CAN bus interface line.

IC Role / Device Role / Timing Role: Reverse-biased clamping element diverting ESD or inductive kick energy to ground.

Use Value: Limits voltage to ≤34.7 V peak (V_Z max) before breakdown, preventing latch-up in 3.3 V logic inputs.

Temperature-Stable Bias Network

Low-Power Sensor Excitation

Use Scenario: Generating stable bias current for RTD or thermistor bridge in HVAC ambient temperature sensor.

IC Role / Device Role / Timing Role: Fixed-voltage source establishing known current through precision resistor network.

Use Value: Delivers <10 ppm/°C effective reference stability over –40°C to +85°C, enabled by low TCR of DO-35 package and tight V_Z spec.

Use Scenario: Supplying excitation voltage to piezoresistive pressure sensor in battery-powered medical wearable.

IC Role / Device Role / Timing Role: Low-quiescent-current voltage source powering sensor bridge with minimal standby drain.

Use Value: Draws only 0.1 mA leakage at 25 V, extending battery life beyond 5 years in always-on monitoring mode.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
1N4749A	33 V ±5%, 1 W rating, DO-41 package, 30 Ω Z_Z, higher power but larger footprint	Preferred where >500 mW dissipation or PCB space allows DO-41; unsuitable for DO-35-restricted layouts	Select 1N4749A only if thermal margin exceeds 500 mW and board real estate permits larger case.
BZX55C33	33 V ±5%, 500 mW, DO-35, 80 Ω Z_Z, tighter leakage (0.1 μA vs. 0.1 mA), same footprint	Better for ultra-low-leakage biasing (e.g., high-impedance op-amp inputs); identical mechanical fit	Choose BZX55C33 when leakage must be <1 μA; otherwise 1N6012B offers proven field reliability and broader distributor stock.

Compared with 1N4749A and BZX55C33, the 1N6012B balances legacy compatibility, DO-35 footprint constraint adherence, and sufficient Zener impedance for general-purpose regulation-making it optimal for space-constrained industrial controls where 500 mW power handling suffices.

Availability

1N6012B is available at Aetrix Electronics and suitable for industrial power supplies, automotive sensor interfaces, and medical device voltage references requiring stable component supply, long-lifecycle support, and DO-35 form factor compliance.

Supply support for 1N6012B 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016. Its legacy Zener diodes remain widely deployed in industrial and automotive systems.

The 1N6012B belongs to Fairchild's 1N5985B–1N6025B Zener family, engineered for precision voltage regulation in cost-sensitive, high-reliability applications where DO-35 packaging and ±5% tolerance meet system-level accuracy requirements.

FAQ

What is the nominal Zener voltage and tolerance of the 1N6012B?

The 1N6012B has a nominal Zener voltage of 33 V with a ±5% tolerance, meaning its actual breakdown voltage falls between 31.35 V and 34.65 V when measured at 5 mA test current and thermal equilibrium (TL = 30°C ±1°C). This tolerance band is confirmed in the Fairchild 1N5985B–1N6025B datasheet Rev. C2, Table on page 2.

What is the maximum power dissipation and derating behavior of the 1N6012B?

The 1N6012B is rated for 500 mW power dissipation at lead temperature (TL) ≤ 75°C with 3/8″ lead length. Above 75°C, it derates linearly at 4.0 mW/°C. This thermal limit is defined in the Absolute Maximum Ratings table of the Fairchild datasheet and applies to continuous DC operation in free-air conditions.

Does the 1N6012B have a specified forward voltage, and what is its value?

Yes, the 1N6012B specifies a maximum forward voltage (V_F) of 1.2 V at 200 mA forward current. This parameter confirms standard silicon PN-junction behavior and supports use in polarity protection or low-current rectification roles alongside its primary Zener function.

How is the cathode identified on the 1N6012B DO-35 package?

The cathode of the 1N6012B is marked by a single color band on the glass body of the DO-35 package. Per Fairchild's top-marking specification (page 3 of the datasheet), this band aligns with industry-standard polarity identification and must be oriented toward the higher-potential node in shunt regulator configurations.

What is the Zener impedance and leakage current specification for the 1N6012B?

The 1N6012B exhibits a Zener impedance (Z_Z) of 88 Ω measured at 5 mA test current, and a maximum leakage current (I_R) of 0.1 mA at 25 V reverse voltage. These values are documented in the Electrical Characteristics table on page 2 of the Fairchild 1N5985B–1N6025B Rev. C2 datasheet.

1N6012B Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: DO-204AH, DO-35, Axial

Packaging:: Bulk

Product Status:: Obsolete

Voltage - Zener (Nom) (Vz):: 33 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 88 Ohms

Current - Reverse Leakage @ Vr:: 100 nA @ 25 V

Voltage - Forward (Vf) (Max) @ If:: 1.2 V @ 200 mA

Operating Temperature:: -65°C ~ 200°C

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: DO-35

1N6012B FAQ

1.How can I place an order for 1N6012B through Aetrix?

Please submit a Request for Quotation (RFQ) for 1N6012B on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 1N6012B reliable?

The price and inventory of 1N6012B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N6012B is usually 5 days.

3.What payment methods are accepted for 1N6012B?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N6012B transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 1N6012B?

1N6012B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 1N6012B order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 1N6012B?

For technical support, including 1N6012B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N6012B requirements.

6.How does Aetrix verify that 1N6012B is sourced from the original manufacturer or authorized distributors?

All 1N6012B products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 1N6012B meets industry standards.

7.What is the process for return or replacement of 1N6012B?

All 1N6012B units undergo pre-shipment inspection (PSI). If there is an issue with 1N6012B, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 1N6012B part is unused and in its original packaging.

Return procedure for 1N6012B:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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