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Microchip Technology 1N5921BUR-1/TR
- Part No.:
- 1N5921BUR-1/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AB, MELF (Glass)
- Datasheet:
-
1N5921BUR-1/TR.pdf
- Description:
- DIODE ZENER 6.8V 1.25W DO213AB
- Quantity:
- Payment:
- Shipping:
Inventory:4,337
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Product details
Overview
1N5921BUR-1 from Microsemi is a 1.5 W metallurgically bonded glass MELF surface-mount Zener diode with nominal Zener voltage of 6.8 V, dynamic impedance of 2.5 Ω at 55.1 mA test current, and maximum Zener current of 220 mA. It operates across –65 °C to +175 °C junction temperature and is used for precision voltage regulation in high-density power supply feedback loops and reference circuits.
For engineers reviewing the 1N5921BUR-1 datasheet, 1N5921BUR-1 pinout, 1N5921BUR-1 application, or 1N5921BUR-1 equivalent, key selection factors include its hermetic DO-213AB package, MIL-PRF-19500 screening capability, low thermal resistance (40 °C/W junction-to-end cap), RoHS-compliant plating, and specified capacitance vs. voltage behavior per Figure 2.
Technical Context
This device functions as a two-terminal voltage reference operating in reverse breakdown, with Zener voltage defined at IZT = 55.1 mA and characterized by tight tolerance options (1%, 2%, 5%, 10%). Its metallurgically enhanced tungsten slug construction ensures stable thermal performance and low parasitic inductance.
The DO-213AB MELF package enables high-reliability surface mounting without leads, supporting applications requiring hermetic sealing, radiation hardness (per MicroNote 050), and ESD immunity per MIL-STD-750 Method 1020. Capacitance is specified across the Zener voltage range (Figure 2), critical for noise-sensitive regulation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 6.8 V at IZT = 55.1 mA - defines stable regulation point under nominal bias |
| Dynamic Impedance (ZZT) | 2.5 Ω - determines output voltage variation under load current changes |
| Max Power Dissipation (PD) | 1.5 W @ TEC ≤ 115 °C - sets thermal design margin for PCB layout and heatsinking |
| Junction-to-End Cap Rθ | 40 °C/W - enables accurate end-cap temperature-based derating per Figure 1 |
| Reverse Current (IR) | 5.0 µA @ VR = 5.0 V - confirms low leakage below knee voltage for standby efficiency |
| Knee Current (IZK) | 1.0 mA - identifies minimum current for stable regulation onset |
| Forward Voltage (VF) | 1.2 V max @ 200 mA - relevant for polarity verification and surge protection circuit analysis |
Pinout & Package
DO-213AB (MELF) glass package: hermetically sealed voidless hard glass body with tungsten slugs; cathode indicated by single band; tin/lead or RoHS-compliant matte tin plating over copper; weight ≈ 0.05 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unbanded end) | Current entry terminal in forward bias; referenced ground node in Zener regulation | Must be held at lower potential than cathode during regulation; connects to feedback node or ground return path |
| Cathode (banded end) | Current exit terminal in forward bias; regulated output node in Zener operation | Connected to voltage source input side; defines regulated reference potential relative to anode |
Key Features
| Feature | Design Value |
|---|---|
| Metallurgically bonded internal contacts | Reduces thermal resistance and improves long-term stability under thermal cycling |
| Hermetic glass MELF construction | Eliminates moisture ingress and intermetallic degradation, enabling >175 °C storage |
| MIL-PRF-19500 screening availability | Supports high-reliability aerospace and defense programs requiring qualified component sourcing |
| Specified capacitance vs. VZ | Enables predictable high-frequency noise filtering in feedback paths (see Figure 2) |
| ESD immunity per MIL-STD-750 Method 1020 | Allows handling without special precautions in standard assembly environments |
Applications
| Switch-Mode Power Supply Feedback | Industrial Sensor Reference |
|---|---|
Use Scenario: Regulates output voltage in isolated flyback or forward converter feedback loop using optocoupler-coupled error amplifier. IC Role / Device Role / Timing Role: Zener diode provides precise 6.8 V reference for TL431 or similar shunt regulator IC. Use Value: Low dynamic impedance (2.5 Ω) minimizes output voltage drift under varying load and line conditions. |
Use Scenario: Supplies stable excitation voltage to bridge-based pressure or strain sensors in factory automation systems. IC Role / Device Role / Timing Role: Functions as primary voltage reference for ratiometric ADC measurement chains. Use Value: Hermetic MELF package ensures long-term drift < ±0.5% over 10 years at 85 °C ambient. |
| Avionics Power Sequencing | Radiation-Hardened Backup Reference |
Use Scenario: Generates reset threshold for power-on sequencing logic in airborne computing modules. IC Role / Device Role / Timing Role: Zener clamps enable precise voltage detection for POR circuits with discrete comparators. Use Value: MIL-PRF-19500 screening option supports DO-254 compliance for safety-critical subsystems. |
Use Scenario: Serves as secondary reference in satellite payload power management where TID > 100 krad required. IC Role / Device Role / Timing Role: Standby voltage reference activated during main regulator fault or radiation event. Use Value: Inherent radiation hardness (MicroNote 050) eliminates need for shielding or redundancy overhead. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5921B | Same electrical specs but axial DO-41 package; no tape-and-reel; non-RoHS default | Requires through-hole assembly; unsuitable for high-density SMT layouts | Select when legacy board rework or hand-soldering is required and leaded packaging is acceptable |
| SMBG5921B | Same VZ, IZT, ZZT; SMB package; higher RθJA (150 °C/W); RoHS compliant | Lower power density; less thermally robust in compact enclosures | Choose for cost-sensitive consumer designs where MELF handling is impractical and thermal margins exceed 25 °C |
Compared with 1N5921BUR-1, 1N5921B lacks surface-mount compatibility and RoHS compliance, while SMBG5921B trades hermetic reliability and thermal performance for lower assembly cost and wider footprint tolerance - making the 1N5921BUR-1 optimal for space-constrained, high-reliability, or radiation-aware designs.
Availability
1N5921BUR-1 is available at Aetrix Electronics and suitable for switch-mode power supplies, industrial sensor references, avionics power sequencing, and radiation-hardened backup references requiring stable component supply, traceable sourcing, and long-lifecycle support.
Supply support for 1N5921BUR-1 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
Microsemi Corporation (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, mixed-signal, and RF solutions for aerospace, defense, and industrial markets.
The 1N5921BUR-1 belongs to Microsemi's metallurgically bonded MELF Zener series designed specifically for applications demanding hermetic sealing, extended temperature operation, and MIL-PRF-19500 qualification - targeting mission-critical power regulation and reference stability.
FAQ
What is the Zener voltage tolerance for 1N5921BUR-1?
The 1N5921BUR-1 has a nominal Zener voltage of 6.8 V with a standard tolerance of 5% ('B' suffix), meaning the actual VZ falls between 6.46 V and 7.14 V at IZT = 55.1 mA and TEC = 30 °C. Tighter tolerances (2%, 1%) are available via custom nomenclature but not standard for this TR-suffixed part.
Is 1N5921BUR-1 RoHS compliant?
Yes, the '-1' suffix in 1N5921BUR-1 indicates RoHS-compliant matte tin plating over copper terminals, verified per Microsemi documentation T4-LDS-0300-1 Rev. 1. This applies to both the standard and tape-and-reel (TR) configurations.
Can 1N5921BUR-1 be used in place of 1N5921B in existing designs?
No direct substitution is recommended: 1N5921BUR-1 uses DO-213AB MELF packaging while 1N5921B uses DO-41 axial leads. PCB footprints, thermal management, and assembly processes differ significantly. A redesign is required to migrate from 1N5921B to 1N5921BUR-1.
What is the maximum steady-state power dissipation for 1N5921BUR-1 at 25 °C ambient?
The 1N5921BUR-1 is rated for 1.25 W at TA = 25 °C when mounted on FR4 with 1 oz Cu and the recommended footprint. At end-cap temperature ≤ 115 °C, it delivers full 1.5 W - requiring thermal design based on RθJEC = 40 °C/W, not RθJA.
Does 1N5921BUR-1 support MIL-PRF-19500 screening?
Yes, MIL-PRF-19500 screening is available for the 1N5921BUR-1 series per the manufacturer's documentation, though it requires explicit ordering with appropriate reliability level suffixes (e.g., MQ, MX) and is not included in the base TR-suffixed commercial part number.
1N5921BUR-1/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-213AB, MELF (Glass)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 6.8 V
- Tolerance:
- ±5%
- Power - Max:
- 1.25 W
- Impedance (Max) (Zzt):
- 2.5 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 5.2 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-213AB (MELF, LL41)
1N5921BUR-1/TR FAQ
1.How can I place an order for 1N5921BUR-1/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5921BUR-1/TR 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 1N5921BUR-1/TR reliable?
The price and inventory of 1N5921BUR-1/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5921BUR-1/TR is usually 5 days.
3.What payment methods are accepted for 1N5921BUR-1/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5921BUR-1/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5921BUR-1/TR?
1N5921BUR-1/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5921BUR-1/TR 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 1N5921BUR-1/TR?
For technical support, including 1N5921BUR-1/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5921BUR-1/TR requirements.
6.How does Aetrix verify that 1N5921BUR-1/TR is sourced from the original manufacturer or authorized distributors?
All 1N5921BUR-1/TR 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 1N5921BUR-1/TR meets industry standards.
7.What is the process for return or replacement of 1N5921BUR-1/TR?
All 1N5921BUR-1/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N5921BUR-1/TR, 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 1N5921BUR-1/TR part is unused and in its original packaging.
Return procedure for 1N5921BUR-1/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5921BUR-1/TR Tags
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