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Nexperia USA Inc. BZX84-B12/DG/B3,21
- Part No.:
- BZX84-B12/DG/B3,21
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BZX84-B12/DG/B3,21.pdf
- Description:
- DIODE ZENER 12V 250MW TO236AB
- Quantity:
- Payment:
- Shipping:
Inventory:2,545
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Product details
Overview
BZX84-B12/DG/B3,21 from Nexperia is a 12 V, 250 mW surface-mount Zener diode in SOT23 package with ±5% tolerance, 100 nA maximum leakage at 9.5 V, and 15 Ω dynamic impedance, used for voltage regulation and overvoltage protection in low-power sensor interfaces and microcontroller I/O clamping circuits.
For engineers reviewing the BZX84-B12/DG/B3,21 datasheet, BZX84-B12/DG/B3,21 pinout, BZX84-B12/DG/B3,21 application, or BZX84-B12/DG/B3,21 equivalent, key selection criteria include Zener voltage accuracy, power dissipation limit, leakage current at sub-breakdown bias, dynamic impedance under regulation, and SOT23 thermal derating behavior in PCB-constrained layouts.
Technical Context
This Zener diode operates in reverse breakdown to maintain stable reference voltage across its cathode-anode terminals. Its 12 V nominal Zener voltage is specified at 5 mA test current, with dynamic impedance measured at 15 Ω to quantify regulation stiffness under load variation.
The device uses planar epitaxial technology for tight voltage tolerance and low leakage. Its SOT23 package supports reflow soldering per JEDEC J-STD-020, with thermal resistance of 500 K/W (junction-to-ambient) limiting continuous power to 250 mW at 25 °C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 12 V ±5% at IZ = 5 mA - defines precise clamping threshold for 3.3 V/5 V system rail protection |
| Power Dissipation (Ptot) | 250 mW at Tamb = 25 °C - sets maximum continuous energy handling before thermal runaway |
| Dynamic Impedance (ZZ) | 15 Ω at IZ = 5 mA - determines output voltage deviation under ±1 mA load change |
| Reverse Leakage (IR) | ≤100 nA at VR = 9.5 V - ensures minimal quiescent current in standby sensor nodes |
| Package | SOT23 - enables high-density placement on compact PCBs with standard pick-and-place compatibility |
| Thermal Resistance (RthJA) | 500 K/W - requires derating to ~125 mW at 75 °C ambient for reliable long-term operation |
Pinout & Package
SOT23 package with three terminals: anode (pin 1), cathode (pin 2), and unused terminal (pin 3). Cathode marked by band; pin 3 is internally unconnected and electrically isolated.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Anode | Connected to lower-potential node during Zener operation; reverse-biased relative to cathode |
| Pin 2 | Cathode | Connected to regulated voltage node; marked by band; carries full Zener current |
| Pin 3 | NC | No internal connection; must remain unconnected to avoid parasitic coupling or mechanical stress |
Key Features
| Feature | Design Value |
|---|---|
| Tight voltage tolerance | ±5% ensures predictable clamping without post-assembly calibration in cost-sensitive designs |
| Low leakage current | ≤100 nA at 9.5 V minimizes battery drain in always-on IoT endpoint circuits |
| Standard SOT23 footprint | Enables drop-in replacement across multiple Zener families without PCB redesign |
| JEDEC-compliant reflow profile | Supports automated assembly with peak temperature up to 260 °C for high-yield manufacturing |
Applications
| Microcontroller I/O Protection | Sensor Signal Conditioning |
|---|---|
Use Scenario: Clamping 3.3 V GPIO lines against ESD transients and supply rail overshoot in industrial controllers. IC Role / Device Role / Timing Role: Zener diode acting as bidirectional voltage limiter between I/O pin and ground. Use Value: Prevents latch-up and gate oxide damage by limiting pin voltage to ≤12.6 V during 8 kV HBM events. | Use Scenario: Stabilizing reference voltage for analog front-end amplifiers in temperature/humidity sensors. IC Role / Device Role / Timing Role: Providing low-noise 12 V reference for op-amp biasing and ADC reference scaling. Use Value: Enables <±0.6 V regulation error over 0–70 °C due to tight 5% tolerance and low ZZ. |
| USB Port Overvoltage Clamp | Low-Power Battery Monitor |
Use Scenario: Protecting USB data line receivers from 12 V accidental insertion into 5 V VBUS lines. IC Role / Device Role / Timing Role: Reverse-biased Zener shunting excess voltage to ground before receiver IC input stage. Use Value: Limits transient voltage to 12.6 V within 10 ns response time, meeting IEC 61000-4-2 Level 3 immunity. | Use Scenario: Monitoring lithium coin-cell voltage decay in wearable health devices. IC Role / Device Role / Timing Role: Acting as precision voltage threshold detector via comparator input biasing. Use Value: Triggers low-battery alert at 2.7 V with ±0.135 V hysteresis using resistor divider + BZX84-B12. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMSZ5242B-TP | Same 12 V ±5%, but 500 mW rating and SOD-123 package | Higher power handling supports 10 mA regulation current; larger footprint limits density | Select when >250 mW dissipation or higher surge current capability is required |
| BZX84-C12,215 | Same SOT23 package and 12 V rating, but ±10% tolerance and higher leakage (≤5 µA) | Lower cost variant suitable for non-critical biasing where voltage drift <±1.2 V is acceptable | Select for cost-driven consumer electronics where tighter tolerance is unnecessary |
Compared with MMSZ5242B-TP, BZX84-B12/DG/B3,21 offers superior board space efficiency and lower leakage, while BZX84-C12,215 trades tolerance and leakage for unit cost reduction-making the DG/B3 variant optimal for precision low-power regulation where size and quiescent current matter.
Availability
BZX84-B12/DG/B3,21 is available at Aetrix Electronics and suitable for microcontroller I/O protection, sensor signal conditioning, and USB port overvoltage clamp applications requiring stable component supply and consistent parametric performance across production batches.
Supply support for BZX84-B12/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 high-volume, high-reliability discrete and logic devices, serving automotive, industrial, and consumer markets with ISO/TS 16949-certified manufacturing.
The BZX84 series belongs to Nexperia's precision Zener diode product line, engineered for stable voltage reference and clamping in space-constrained, low-power electronic systems.
FAQ
What is the maximum reverse current before breakdown for BZX84-B12/DG/B3,21?
The device exhibits ≤100 nA reverse leakage at 9.5 V, well below its 12 V Zener voltage. Breakdown begins near 11.4 V (95% of nominal), with full regulation established at 5 mA test current. This low pre-breakdown current ensures minimal loading on source circuits during standby operation.
Can BZX84-B12/DG/B3,21 be used in series for higher voltage clamping?
No-series connection is not recommended. Each diode's ±5% tolerance compounds, and mismatched dynamic impedances cause uneven voltage sharing. For >12 V clamping, use a single higher-voltage Zener (e.g., BZX84-B15) or dedicated TVS array designed for coordinated breakdown.
Is the SOT23 pinout compatible with other BZX84 variants?
Yes-BZX84-B12/DG/B3,21 uses standard SOT23 pinout: pin 1 = anode, pin 2 = cathode, pin 3 = NC. All BZX84-x variants share identical pin assignment and mechanical dimensions, enabling direct substitution across voltage grades without layout changes.
How does thermal derating affect usable power at 60 °C ambient?
With RthJA = 500 K/W, power must be derated linearly: Pmax = 250 mW × (1 − (60 − 25)/500) = ~162.5 mW. Exceeding this risks junction temperature rise beyond 150 °C, accelerating parametric drift and reducing long-term reliability.
BZX84-B12/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 V
- Tolerance:
- ±2%
- 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-B12/DG/B3,21 FAQ
1.How can I place an order for BZX84-B12/DG/B3,21 through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84-B12/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-B12/DG/B3,21 reliable?
The price and inventory of BZX84-B12/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-B12/DG/B3,21 is usually 5 days.
3.What payment methods are accepted for BZX84-B12/DG/B3,21?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84-B12/DG/B3,21 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84-B12/DG/B3,21?
BZX84-B12/DG/B3,21 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84-B12/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-B12/DG/B3,21?
For technical support, including BZX84-B12/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-B12/DG/B3,21 requirements.
6.How does Aetrix verify that BZX84-B12/DG/B3,21 is sourced from the original manufacturer or authorized distributors?
All BZX84-B12/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-B12/DG/B3,21 meets industry standards.
7.What is the process for return or replacement of BZX84-B12/DG/B3,21?
All BZX84-B12/DG/B3,21 units undergo pre-shipment inspection (PSI). If there is an issue with BZX84-B12/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-B12/DG/B3,21 part is unused and in its original packaging.
Return procedure for BZX84-B12/DG/B3,21:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX84-B12/DG/B3,21 Tags
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