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

Nexperia USA Inc. BZX84-C12/DG/B3,21

Name: BZX84-C12/DG/B3,21
Brand: Nexperia USA Inc.
SKU: BZX84-C12/DG/B3,21
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BZX84-C12/DG/B3,21

Manufacturer:: Nexperia USA Inc.

Category:: Single Zener Diodes

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: BZX84-C12/DG/B3,21.pdf

Description:: DIODE ZENER 12.05V 250MW TO236AB

Quantity:: RFQ Add To RFQ list

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Inventory:9,650

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Product details

Overview

BZX84-C12/DG/B3,21 from Nexperia is a surface-mount 12 V Zener diode with 250 mW power dissipation, ±5% voltage tolerance, and 100 nA maximum reverse leakage at 8 V. It operates in standard voltage regulation and overvoltage protection circuits for low-power consumer and industrial control modules.

For engineers reviewing the BZX84-C12/DG/B3,21 datasheet, BZX84-C12/DG/B3,21 pinout, BZX84-C12/DG/B3,21 application, or BZX84-C12/DG/B3,21 equivalent, key selection criteria include Zener voltage accuracy, thermal stability under bias, package thermal resistance, and compatibility with automated SMT assembly on FR-4 PCBs.

Technical Context

This Zener diode uses planar epitaxial technology to achieve stable breakdown characteristics across -65 °C to +150 °C ambient temperature. Its 12 V nominal Zener voltage is specified at test current I_ZT = 5 mA, with dynamic impedance of 25 Ω max at that condition.

The device exhibits a positive temperature coefficient of +0.075 %/°C above 5 V, enabling predictable voltage drift in temperature-critical bias networks. Its low capacitance (40 pF max at 0 V) supports use in low-frequency reference and clamping applications without signal distortion.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	12 V ±5% at I_ZT = 5 mA - ensures precise DC bias point in voltage reference chains
Power Dissipation (P_tot)	250 mW at T_amb = 25 °C - limits continuous regulation current to ~20 mA in ambient air
Dynamic Impedance (Z_ZT)	≤25 Ω at I_ZT = 5 mA - maintains voltage stability against load current variations
Reverse Leakage (I_R)	≤100 nA at V_R = 8 V - minimizes quiescent current in high-impedance sensing nodes
Package	SOT23 (TO-236AB) - enables 0.65 mm pitch SMT placement and 250 °C reflow compatibility
Thermal Resistance (R_thJA)	625 K/W - defines junction-to-ambient rise per watt, critical for derating in enclosed assemblies

Pinout & Package

Package: SOT23 (TO-236AB), 3-terminal plastic surface-mount package with cathode band marking.

Pin/Terminal	Circuit Role	Design Meaning
Anode (Pin 1)	Forward conduction terminal	Connected to lower-potential node in reverse-biased Zener configuration
Cathode (Pin 2)	Zener breakdown terminal	Marked with band; connected to higher-potential node for regulation
NC / Not Connected (Pin 3)	Unused internal lead	No electrical connection; isolated from die for mechanical support only

Key Features

Feature	Design Value
Low dynamic impedance	25 Ω max at 5 mA - improves regulation accuracy under varying load conditions
Tight voltage tolerance	±5% - reduces binning requirements in production calibration workflows
High surge capability	3 A peak forward current (IFSM) - withstands transient inrush during power-up sequencing
Extended temperature range	-65 °C to +150 °C - supports operation in automotive engine bay and industrial motor drive environments

Applications

USB Port Protection

Microcontroller Reset Circuit

Use Scenario: Clamping 5 V USB VBUS line against ESD transients and overvoltage events.

IC Role / Device Role / Timing Role: Zener diode acts as shunt overvoltage protector, diverting excess energy to ground before IC damage occurs.

Use Value: 12 V breakdown prevents false triggering while allowing safe margin above 5.5 V max USB specification.

Use Scenario: Generating clean reset threshold for 3.3 V microcontrollers using resistor divider and Zener clamp.

IC Role / Device Role / Timing Role: Provides stable reference voltage to enable/disable reset logic based on supply rail integrity.

Use Value: ±5% tolerance ensures reset assertion within 2.9 V–3.1 V window across temperature and unit variation.

Industrial Sensor Biasing

LED Current Regulation

Use Scenario: Supplying stable excitation voltage to bridge-based pressure sensors in PLC analog input modules.

IC Role / Device Role / Timing Role: Functions as precision voltage reference in ratiometric measurement paths.

Use Value: 25 Ω dynamic impedance limits output voltage shift to <10 mV under 0.4 mA sensor bias current variation.

Use Scenario: Setting constant current for indicator LEDs in HMI panels via series Zener-resistor configuration.

IC Role / Device Role / Timing Role: Maintains fixed voltage drop across current-setting resistor independent of LED forward voltage spread.

Use Value: 12 V rating allows use with common 12 V supply rails while accommodating 2–3 V LED V_F ranges.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BZX84-C12,215	Same Zener voltage and package; ±5% tolerance; 350 mW P_tot rating	Higher power handling allows up to 29 mA continuous regulation current	Select when sustained >20 mA regulation current or higher thermal margin is required
MMSZ5242B-TP	12 V ±5%; SOD-123 package; 500 mW P_tot; 30 Ω Z_ZT	Larger footprint; higher power but lower board density	Prefer for manual repair or high-reliability aerospace designs where thermal robustness outweighs size constraints

Compared with BZX84-C12/DG/B3,21, the BZX84-C12,215 offers greater power headroom in the same SOT23 footprint, while MMSZ5242B-TP trades compactness for enhanced thermal performance and legacy qualification-making each suitable for distinct layout and reliability priorities.

Availability

BZX84-C12/DG/B3,21 is available at Aetrix Electronics and suitable for USB interface protection, microcontroller reset generation, industrial sensor biasing, and LED current regulation requiring stable component supply and consistent parametric performance across production lots.

Supply support for BZX84-C12/DG/B3,21 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

Nexperia is a global semiconductor expert focused on essential efficiency technologies, delivering high-performance, reliable discrete and logic devices for automotive, industrial, and consumer markets.

The BZX84 series belongs to Nexperia's general-purpose Zener diode product line, engineered for cost-effective, space-constrained voltage regulation and protection in high-volume SMT applications.

FAQ

What is the maximum reverse voltage this Zener diode can withstand before breakdown?

The BZX84-C12/DG/B3,21 has a nominal Zener voltage of 12 V with ±5% tolerance, meaning breakdown occurs between 11.4 V and 12.6 V at test current I_ZT = 5 mA. Its absolute maximum reverse voltage rating is not defined separately-the device is intended for operation strictly within its specified Zener region, not as a blocking diode.

Can this part be used in place of a 10 V Zener for voltage reference purposes?

No-this part is specifically rated for 12 V Zener breakdown and is not interchangeable with 10 V variants. Substituting it would shift reference voltage by +2 V, violating circuit thresholds in reset generators, ADC references, or comparator trip points calibrated for 10 V.

Is the SOT23 package lead-free and RoHS compliant?

Yes, the BZX84-C12/DG/B3,21 is manufactured with lead-free terminations and complies with EU RoHS Directive 2011/65/EU and REACH SVHC regulations. The SOT23 package meets JEDEC J-STD-020 moisture sensitivity level 1 (MSL1) for unlimited floor life at ≤30 °C/85% RH.

How does temperature affect its Zener voltage stability?

This device exhibits a positive temperature coefficient of +0.075 %/°C above 5 V. Over a -40 °C to +125 °C operating range, its 12 V nominal voltage shifts approximately ±100 mV-within typical tolerance bands for non-precision biasing and protection functions.

BZX84-C12/DG/B3,21 Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

Series:: -

Package/Case:: TO-236-3, SC-59, SOT-23-3

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Voltage - Zener (Nom) (Vz):: 12.05 V

Tolerance:: ±5%

Power - Max:: 250 mW

Impedance (Max) (Zzt):: 25 Ohms

Current - Reverse Leakage @ Vr:: 100 nA @ 8 V

Voltage - Forward (Vf) (Max) @ If:: 900 mV @ 10 mA

Operating Temperature:: -65°C ~ 150°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: TO-236AB

BZX84-C12/DG/B3,21 FAQ

1.How can I place an order for BZX84-C12/DG/B3,21 through Aetrix?

Please submit a Request for Quotation (RFQ) for BZX84-C12/DG/B3,21 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 BZX84-C12/DG/B3,21 reliable?

The price and inventory of BZX84-C12/DG/B3,21 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX84-C12/DG/B3,21 is usually 5 days.

3.What payment methods are accepted for BZX84-C12/DG/B3,21?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84-C12/DG/B3,21 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BZX84-C12/DG/B3,21?

BZX84-C12/DG/B3,21 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BZX84-C12/DG/B3,21 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 BZX84-C12/DG/B3,21?

For technical support, including BZX84-C12/DG/B3,21 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84-C12/DG/B3,21 requirements.

6.How does Aetrix verify that BZX84-C12/DG/B3,21 is sourced from the original manufacturer or authorized distributors?

All BZX84-C12/DG/B3,21 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 BZX84-C12/DG/B3,21 meets industry standards.

7.What is the process for return or replacement of BZX84-C12/DG/B3,21?

All BZX84-C12/DG/B3,21 units undergo pre-shipment inspection (PSI). If there is an issue with BZX84-C12/DG/B3,21, 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 BZX84-C12/DG/B3,21 part is unused and in its original packaging.

Return procedure for BZX84-C12/DG/B3,21:

1.Submit a request within 90 days.

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

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