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Microchip Technology 1N5946BUR-1/TR
- Part No.:
- 1N5946BUR-1/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AB, MELF (Glass)
- Datasheet:
-
1N5946BUR-1/TR.pdf
- Description:
- DIODE ZENER 75V 1.25W DO213AB
- Quantity:
- Payment:
- Shipping:
Inventory:9,949
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Product details
Overview
1N5946BUR-1/TR from Microsemi is a 1.5 W surface-mount Zener diode in DO-213AB (MELF) glass package, rated for 75 V Zener voltage at 5.0 mA test current, with 140 Ω dynamic impedance, 1.0 µA reverse leakage at 57 V, and maximum Zener current of 20 mA. It serves voltage regulation in high-density power supply rails and precision reference circuits requiring hermetic reliability.
For engineers reviewing the 1N5946BUR-1/TR datasheet, 1N5946BUR-1/TR pinout, 1N5946BUR-1/TR application, or 1N5946BUR-1/TR equivalent, key selection criteria include Zener voltage tolerance (±5%), thermal resistance (40 °C/W junction-to-end cap), RoHS-compliant matte tin plating, MIL-PRF-19500 screening availability, and low parasitic capacitance suitable for stable regulation across temperature and load variations.
Technical Context
This device operates as a two-terminal voltage reference diode, conducting in reverse breakdown to maintain stable 75 V output across 1.0–20 mA regulation current. Its metallurgically bonded tungsten slug construction ensures low thermal resistance and enhanced reliability under thermal cycling.
The DO-213AB MELF package provides hermetic glass sealing, non-ESD-sensitive operation per MIL-STD-750 Method 1020, and inherent radiation hardness per MicroNote 050 - critical for aerospace and defense applications where long-term parametric stability is required.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 75 V at IZT = 5.0 mA - defines nominal regulation point for feedback and reference design |
| Dynamic Impedance (ZZT) | 140 Ω - determines output voltage variation under load current changes |
| Max Power Dissipation (PD) | 1.5 W @ TEC ≤ 115 °C - sets thermal derating limit on PCB with standard footprint |
| Reverse Leakage (IR) | 1.0 µA @ VR = 57 V - ensures minimal quiescent current in standby mode |
| Junction Temp Range | −65 to +175 °C - supports operation in extended industrial and military environments |
| Thermal Resistance (RθJEC) | 40 °C/W - enables direct thermal path to end cap for efficient heat transfer |
| Forward Voltage (VF) | 1.2 V max @ 200 mA - relevant for polarity verification and ESD-safe handling |
Pinout & Package
DO-213AB (MELF) glass package: hermetically sealed cylindrical body with metallurgically bonded tungsten slugs; cathode indicated by single black band; leadless, symmetric terminals; weight ≈ 0.05 g; dimensions: BD = 2.39–2.67 mm, BL = 4.80–5.21 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unbanded end) | Current entry terminal in forward bias; referenced ground in Zener regulation | Connected to lower-potential node; used for polarity marking and solderability testing |
| Cathode (banded end) | Current exit terminal in forward bias; regulated output node in reverse breakdown | Connected to higher-potential rail; must be held positive relative to anode for Zener operation |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic glass MELF construction | Eliminates moisture ingress and long-term parameter drift in humid or high-reliability environments |
| Metallurgically enhanced internal contacts | Reduces interfacial thermal resistance and improves power cycling endurance vs. standard wire-bonded Zeners |
| MIL-PRF-19500 screening option | Enables qualification for space-grade and defense-critical systems when specified via source control drawing |
| RoHS-compliant matte tin plating | Ensures compatibility with lead-free reflow profiles while maintaining solderability per MIL-STD-750 Method 2026 |
| Low capacitance profile | Minimizes high-frequency noise coupling in precision analog references and switching regulator feedback paths |
Applications
| Industrial Power Supply Regulation | Aerospace Reference Circuitry |
|---|---|
Use Scenario: Stabilizing 75 V intermediate bus in isolated DC/DC converters for PLC I/O modules. IC Role / Device Role / Timing Role: Two-terminal shunt voltage regulator providing precise, temperature-stable reference for error amplifiers. Use Value: Maintains ±1% output accuracy over −40 to +105 °C due to low Zener voltage tempco and hermetic packaging. |
Use Scenario: Generating flight-critical 75 V bias for radiation-tolerant op-amp front-ends in satellite telemetry units. IC Role / Device Role / Timing Role: Radiation-hardened voltage clamp protecting downstream analog circuitry from transient overvoltage events. Use Value: Inherent radiation hardness (per MicroNote 050) and MIL-PRF-19500 screening ensure mission-critical reliability in LEO orbits. |
| Medical Imaging HV Bias Supply | Test & Measurement Calibration Reference |
Use Scenario: Providing stable 75 V bias for photomultiplier tube (PMT) gain control in portable X-ray detectors. IC Role / Device Role / Timing Role: Low-noise, low-capacitance Zener reference minimizing signal distortion in ultra-low-current analog chains. Use Value: 140 Ω dynamic impedance and <1 µA leakage preserve SNR in sub-picoamp PMT current measurement paths. |
Use Scenario: Serving as traceable 75 V calibration standard in benchtop multimeter reference subsystems. IC Role / Device Role / Timing Role: Primary voltage reference element in automated calibration fixtures requiring long-term drift <50 ppm/1000 hrs. Use Value: Metallurgically bonded structure and voidless glass seal deliver <0.1% parametric shift after 1000-hr life testing at 125 °C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5946B-TR | Same 75 V Zener rating but in DO-41 axial-leaded package; higher RθJA (200 °C/W); no MIL-PRF-19500 screening option | Suitable only for prototyping or non-SMT legacy designs; not viable for high-density or high-reliability SMT assemblies | Select only if through-hole assembly is mandatory and thermal derating margin allows |
| SMBG5946B | Same 75 V rating in SMB package; 1.0 W power rating; 200 °C/W RθJA; RoHS-compliant; no hermetic seal or MIL screening | Acceptable for commercial-grade consumer power supplies but lacks radiation hardness and long-term stability for aerospace/industrial use | Choose when cost and board space are prioritized over reliability and environmental robustness |
Compared with 1N5946BUR-1/TR, the 1N5946B-TR sacrifices surface-mount compatibility and hermetic reliability for axial-leaded ease-of-use, while SMBG5946B trades thermal performance and radiation tolerance for lower cost and smaller footprint - making 1N5946BUR-1/TR the sole choice for high-reliability, high-density, and mission-critical Zener regulation.
Availability
1N5946BUR-1/TR is available at Aetrix Electronics and suitable for industrial power supplies, aerospace avionics, and medical imaging equipment requiring stable component supply, long-lifecycle support, and traceable sourcing.
Supply support for 1N5946BUR-1/TR 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, radiation-hardened, and aerospace-grade analog and discrete components.
The 1N59xxBUR-1 series was designed specifically for high-density, high-reliability surface-mount voltage regulation in defense, space, and industrial systems where hermetic sealing, MIL-PRF-19500 compliance, and low thermal resistance are mandatory.
FAQ
What is the Zener voltage tolerance for 1N5946BUR-1/TR?
The 1N5946BUR-1/TR has a Zener voltage tolerance of ±5%, corresponding to the "B" suffix in its nomenclature. This means its measured VZ falls between 71.25 V and 78.75 V at IZT = 5.0 mA and TEC = 30 °C, enabling predictable regulation in precision feedback loops without additional trimming.
Does 1N5946BUR-1/TR support MIL-PRF-19500 screening?
Yes, 1N5946BUR-1/TR is available with MIL-PRF-19500 screening when ordered with appropriate reliability level suffixes (e.g., MQ, MX) per Microsemi's part nomenclature guide. Screening includes temperature cycling, burn-in, and parametric testing to meet Class H or K requirements for high-reliability applications.
What is the maximum steady-state power dissipation for 1N5946BUR-1/TR?
The 1N5946BUR-1/TR has a maximum steady-state power dissipation of 1.5 W when the end cap temperature (TEC) is maintained at ≤115 °C. At ambient temperature (TA) = 25 °C on FR4 with 1 oz Cu, the rated average power is 1.25 W due to higher thermal resistance to ambient (120 °C/W).
Is 1N5946BUR-1/TR RoHS compliant?
Yes, the "-1" suffix in 1N5946BUR-1/TR indicates RoHS compliance with matte tin plating over copper terminations. It meets JEDEC J-STD-609 Category 1a and passes solderability testing per MIL-STD-750 Method 2026, supporting lead-free reflow profiles up to 260 °C for 10 seconds.
How is polarity marked on 1N5946BUR-1/TR?
Polarity on 1N5946BUR-1/TR is marked by a single black cathode band on the glass body. The banded end is the cathode and must be held at a higher potential than the unbanded (anode) end during Zener regulation. This marking is consistent across all DO-213AB MELF devices in the 1N59xxBUR-1 series.
1N5946BUR-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):
- 75 V
- Tolerance:
- ±5%
- Power - Max:
- 1.25 W
- Impedance (Max) (Zzt):
- 140 Ohms
- Current - Reverse Leakage @ Vr:
- 1 µA @ 56 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)
1N5946BUR-1/TR FAQ
1.How can I place an order for 1N5946BUR-1/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5946BUR-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 1N5946BUR-1/TR reliable?
The price and inventory of 1N5946BUR-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 1N5946BUR-1/TR is usually 5 days.
3.What payment methods are accepted for 1N5946BUR-1/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5946BUR-1/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5946BUR-1/TR?
1N5946BUR-1/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5946BUR-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 1N5946BUR-1/TR?
For technical support, including 1N5946BUR-1/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5946BUR-1/TR requirements.
6.How does Aetrix verify that 1N5946BUR-1/TR is sourced from the original manufacturer or authorized distributors?
All 1N5946BUR-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 1N5946BUR-1/TR meets industry standards.
7.What is the process for return or replacement of 1N5946BUR-1/TR?
All 1N5946BUR-1/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N5946BUR-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 1N5946BUR-1/TR part is unused and in its original packaging.
Return procedure for 1N5946BUR-1/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5946BUR-1/TR Tags
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