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onsemi 1N5921BG
- Part No.:
- 1N5921BG
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N5921BG.pdf
- Description:
- DIODE ZENER 6.8V 3W AXIAL
- Quantity:
- Payment:
- Shipping:
Inventory:5
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Product details
Overview
1N5921BG from onsemi is a 3 W axial-lead Zener diode with nominal Zener voltage of 6.8 V, maximum Zener impedance of 55.1 Ω at 2.5 mA test current, and surge rating of 98 W for 1 ms. It operates across −65 °C to +200 °C and is used for precision voltage regulation in power supply feedback loops, overvoltage protection circuits, and reference voltage generation.
For engineers reviewing the 1N5921BG datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, DO-41 package details, thermal derating behavior, leakage and impedance specs at defined test conditions, and real-world selection guidance against comparable Zener regulators.
Technical Context
The 1N5921BG uses a silicon-oxide passivated junction for stable breakdown characteristics and low leakage. Its Zener voltage is guaranteed at TL = 30 °C (measured 3/8″ from body), with ±5% tolerance (B suffix) and temperature coefficient of approximately +2.5 mV/°C in the 6–7 V range.
It supports steady-state dissipation of 3 W at TL = 75 °C with 24 mW/°C derating above that point, and 1 W at TA = 50 °C with 6.67 mW/°C derating. The device features Class 3 ESD robustness (>16 kV HBM) and is Pb-free (G suffix).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 6.8 V nominal (min 6.46 V, max 7.14 V @ IZT = 2.5 mA); defines regulated output level in shunt regulator designs |
| Zener Impedance (ZZT) | 55.1 Ω max @ IZT = 2.5 mA; determines regulation sensitivity to load current changes |
| Max DC Zener Current (IZM) | 220 mA; sets absolute upper limit for continuous conduction without thermal runaway |
| Reverse Leakage (IR) | 5 μA max @ VR = 5.2 V; ensures minimal quiescent current in standby or high-impedance bias networks |
| Surge Power Rating | 98 W @ 1 ms non-repetitive pulse; enables transient overvoltage clamping without failure |
| Operating Temperature Range | −65 °C to +200 °C; supports deployment in automotive under-hood, industrial motor drives, and aerospace power systems |
| Package | DO-41 (Case 59), axial-lead plastic; compatible with standard through-hole PCB assembly and manual soldering at 260 °C for 10 s |
Pinout & Package
Package: DO-41 (Case 59), axial-lead, transfer-molded thermosetting plastic. Cathode identified by polarity band. Mounting position unrestricted.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Zener breakdown terminal | Connected to regulated voltage node; reverse-biased during normal operation |
| Anode | Reference/return path | Typically tied to ground or lower-potential rail; completes current path during regulation |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Ensures tight regulation without post-production trimming; suitable for cost-sensitive BOMs requiring predictable VZ |
| Class 3 ESD rating (>16 kV HBM) | Eliminates need for external ESD protection in board-level handling and system integration |
| Surge rating of 98 W @ 1 ms | Withstands common power-line transients (e.g., IEC 61000-4-5 Level 3) without degradation |
| Pb-free (G suffix) and RoHS-compliant | Meets global environmental compliance requirements without sacrificing thermal or electrical performance |
| DO-41 footprint compatibility | Direct replacement for legacy 1 W Zeners in existing layouts while delivering 3× power capability |
Applications
| Power Supply Feedback Regulation | Overvoltage Clamp Protection |
|---|---|
Use Scenario: Stabilizing output voltage in linear regulators or flyback SMPS feedback paths using optocoupler-coupled secondary-side sensing. IC Role / Device Role / Timing Role: Shunt reference element providing precise 6.8 V threshold to error amplifier input. Use Value: Maintains ±1% output accuracy over line/load/temperature with minimal external components due to low ZZT and stable VZ. |
Use Scenario: Protecting microcontroller I/O pins or analog front-end inputs from ESD or inductive switching spikes. IC Role / Device Role / Timing Role: Fast-acting crowbar device clamping transient voltages above 6.8 V to safe levels. Use Value: Absorbs 98 W surges for 1 ms without failure, preventing latch-up or gate oxide damage in downstream ICs. |
| Voltage Reference for ADC/DAC | Current Source Biasing |
Use Scenario: Providing stable reference voltage to 12-bit SAR ADCs in industrial sensor signal chains operating from unregulated rails. IC Role / Device Role / Timing Role: Low-drift, low-noise voltage source replacing more expensive bandgap references where ±1% accuracy suffices. Use Value: Delivers <5 μA leakage and <55 Ω dynamic impedance, minimizing reference error contribution to total INL. |
Use Scenario: Setting bias current for LED drivers or op-amp input stages via constant-current sink configuration. IC Role / Device Role / Timing Role: Precision current-setting element using series resistor and fixed VZ drop. Use Value: Enables accurate 1% current matching across units without trimming, leveraging tight VZ tolerance and thermal stability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5226B | 500 mW rating, 3.3 V nominal, DO-35 package, higher ZZT (17 Ω @ 20 mA) | Lower power; suited for signal-level biasing, not power-stage regulation | Select when board space is constrained and power dissipation ≤0.5 W |
| 1N4734A | 1 W rating, 5.6 V nominal, DO-41 package, ±5% tolerance, ZZT = 5 Ω @ 45 mA | Lower voltage, lower power, tighter ZZT but limited surge capability (50 W @ 1 ms) | Select for cost-sensitive 5.6 V references where 3 W dissipation is unnecessary |
Compared with 1N5921BG, the 1N5226B offers smaller footprint but cannot sustain >0.5 W continuously, while the 1N4734A provides better low-current impedance yet lacks the 98 W surge margin critical for industrial power interfaces.
Availability
1N5921BG is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, and medical diagnostic equipment requiring stable component supply, long-term lifecycle support, and traceable Pb-free sourcing.
Supply support for 1N5921BG 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensors, and logic solutions for automotive, industrial, cloud, and consumer markets.
The 1N5921BG belongs to the 1N5913B Series of 3 W Zener regulators designed for high-reliability voltage reference and clamping in harsh-environment power systems where thermal stability and surge resilience are critical.
FAQ
What is the Zener voltage tolerance of the 1N5921BG?
The 1N5921BG has a ±5% Zener voltage tolerance, indicated by the "B" suffix in its part number. Its nominal Zener voltage is 6.8 V, with guaranteed minimum and maximum values of 6.46 V and 7.14 V respectively, measured at IZT = 2.5 mA and lead temperature TL = 30 °C. This tolerance ensures predictable regulation without calibration in cost-sensitive applications.
Can the 1N5921BG replace a 1 W Zener diode in an existing design?
Yes - the 1N5921BG uses the same DO-41 (Case 59) package as many 1 W Zeners, enabling direct PCB footprint reuse. However, its 3 W power rating allows higher sustained current or improved thermal margin. Engineers must verify that trace widths and heatsinking support the increased dissipation, especially above 75 °C lead temperature where derating begins at 24 mW/°C.
What is the maximum reverse leakage current for the 1N5921BG?
The 1N5921BG specifies a maximum reverse leakage current (IR) of 5 μA at VR = 5.2 V, per its datasheet. This low leakage ensures minimal error in high-impedance reference networks and preserves battery life in always-on monitoring circuits. Leakage remains well below 10 μA up to 80% of nominal VZ, supporting stable biasing in precision analog stages.
How does the 1N5921BG perform under transient surge conditions?
The 1N5921BG is rated for 98 W non-repetitive surge power at 1 ms pulse width, making it suitable for clamping IEC 61000-4-5 Level 3 surges. Its robust silicon-oxide passivated junction prevents localized thermal runaway during fast transients. For repetitive surges, designers must consult Figure 3 in the onsemi datasheet to ensure duty cycle and peak power remain within safe limits.
Is the 1N5921BG RoHS-compliant and halogen-free?
Yes - the "G" suffix in 1N5921BG explicitly denotes a Pb-free, RoHS-compliant package per onsemi's specifications. The device meets JEDEC standards for lead-free soldering (260 °C for 10 s at 1/16″ from case) and contains no intentionally added halogens. Full compliance documentation, including substance declarations, is available through onsemi's official product portal.
1N5921BG Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 6.8 V
- Tolerance:
- ±5%
- Power - Max:
- 3 W
- Impedance (Max) (Zzt):
- 2.5 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 5.2 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 200 mA
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- Axial
1N5921BG FAQ
1.How can I place an order for 1N5921BG through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5921BG 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 1N5921BG reliable?
The price and inventory of 1N5921BG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5921BG is usually 5 days.
3.What payment methods are accepted for 1N5921BG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5921BG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5921BG?
1N5921BG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5921BG 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 1N5921BG?
For technical support, including 1N5921BG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5921BG requirements.
6.How does Aetrix verify that 1N5921BG is sourced from the original manufacturer or authorized distributors?
All 1N5921BG 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 1N5921BG meets industry standards.
7.What is the process for return or replacement of 1N5921BG?
All 1N5921BG units undergo pre-shipment inspection (PSI). If there is an issue with 1N5921BG, 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 1N5921BG part is unused and in its original packaging.
Return procedure for 1N5921BG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5921BG Tags
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MMBZ5240B-7-F
Diodes Incorporated
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onsemi
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SMAJ4744A-TP
Micro Commercial Co
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