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Microchip Technology 1N5940BUR-1/TR
- Part No.:
- 1N5940BUR-1/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AB, MELF (Glass)
- Datasheet:
-
1N5940BUR-1/TR.pdf
- Description:
- DIODE ZENER 43V 1.25W DO213AB
- Quantity:
- Payment:
- Shipping:
Inventory:8,986
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Product details
Overview
1N5940BUR-1/TR from Microsemi is a 1.5 W surface-mount Zener diode in DO-213AB (MELF) glass package, rated for 43 V ±5% Zener voltage at 8.7 mA test current, with 53 Ω dynamic impedance, 32.7 mA maximum Zener current, and -65 °C to +175 °C junction temperature range. It delivers stable voltage regulation in high-density power supply feedback loops and precision reference circuits.
For engineers reviewing the 1N5940BUR-1/TR datasheet, 1N5940BUR-1/TR pinout, 1N5940BUR-1/TR application, or 1N5940BUR-1/TR equivalent, this page provides verified electrical parameters, thermal resistance (40 °C/W junction-to-end cap), RoHS-compliant plating, MIL-PRF-19500 screening eligibility, hermetic glass construction, and ESD immunity per MIL-STD-750 Method 1020.
Technical Context
This device operates as a reverse-biased voltage reference with specified knee current (IZK = 0.25 mA) and regulated impedance (ZZK = 53 Ω) near breakdown. Its metallurgically bonded tungsten slugs and voidless glass seal ensure low thermal resistance and long-term stability under thermal cycling.
The 1N5940BUR-1/TR exhibits 1.2 V forward voltage at 200 mA and maintains regulation across 1.0 µA to 32.7 mA reverse current range, with capacitance of ~950 pF at VR = 1.0 V (per Figure 2). It is not sensitive to ESD and inherently radiation-hardened per MicroNote 050.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 43 V ±5% at IZT = 8.7 mA - defines precise regulation point for feedback networks |
| Power Dissipation | 1.5 W @ TEC ≤ 115 °C - supports continuous operation in compact thermal environments |
| Dynamic Impedance (ZZT) | 53 Ω at IZT - determines output voltage variation under load current changes |
| Junction-to-End Cap Rθ | 40 °C/W - enables accurate thermal modeling when mounted on copper end caps |
| Reverse Current (IR) | 1.0 µA @ VR = 32.7 V - ensures minimal leakage in high-impedance bias networks |
| Forward Voltage (VF) | 1.2 V max @ IF = 200 mA - confirms low-loss conduction during transient forward events |
| Operating Temperature | -65 °C to +175 °C - qualified for aerospace, downhole, and extended industrial environments |
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 | Positive terminal in forward bias; grounded node in Zener regulation | Connected to system ground or low-impedance return path during voltage reference operation |
| Cathode | Negative terminal in forward bias; regulated output node in Zener mode | Banded end; connected to feedback node or reference rail requiring stable 43 V |
Key Features
| Feature | Design Value |
|---|---|
| Metallurgically bonded internal contacts | Reduces thermal resistance and improves long-term reliability vs. standard wire-bonded MELF diodes |
| Hermetic glass sealing | Prevents moisture ingress and parameter drift in humid or corrosive environments |
| MIL-PRF-19500 screening option | Enables use in military/aerospace applications requiring controlled process and lot traceability |
| ESD immunity (MIL-STD-750 Method 1020) | Eliminates need for external ESD protection in handling and assembly stages |
| RoHS-compliant plating (e3 suffix) | Meets EU Directive 2011/65/EU without compromising solderability or intermetallic formation |
Applications
| Switch-Mode Power Supply Feedback | Industrial Sensor Reference |
|---|---|
Use Scenario: Regulating output voltage in isolated flyback converters using optocoupler feedback. IC Role / Device Role / Timing Role: Zener reference providing stable 43 V threshold to drive optocoupler LED. Use Value: Tight 5% tolerance and low ZZT (53 Ω) minimize output voltage drift across line/load/temperature. |
Use Scenario: Providing excitation voltage for RTD or strain gauge bridge circuits in PLC analog input modules. IC Role / Device Role / Timing Role: Precision voltage reference sourcing stable bias current for ratiometric measurements. Use Value: Hermetic glass package prevents parameter shift due to humidity exposure in factory-floor environments. |
| Aerospace Power Monitoring | Downhole Oilfield Electronics |
Use Scenario: Overvoltage clamp and reference in avionics DC-DC converter supervision circuitry. IC Role / Device Role / Timing Role: Zener clamping node protecting monitoring ICs during transients; also used as calibration reference. Use Value: Radiation hardness (MicroNote 050) and -65 °C to +175 °C rating support operation in unheated aircraft bays. |
Use Scenario: Voltage regulation in high-temperature logging tools deployed at >150 °C wellbore depths. IC Role / Device Role / Timing Role: Primary reference for ADC biasing and sensor excitation in extreme thermal environments. Use Value: Metallurgical bonding and glass seal maintain parameter stability where polymer-packaged devices degrade rapidly. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5940BRLG | Same 43 V Zener, DO-213AB package, but lead-free matte tin plating (e3) and tape-and-reel packaging per EIA-481-B. | No screening or MIL-PRF-19500 compliance; intended for commercial RoHS-constrained designs. | Select when RoHS compliance and automated placement are required without military-grade screening. |
| SMBG5940B | Same 43 V Zener, but in SMB (DO-214AA) plastic surface-mount package; higher RθJA (120 °C/W), lower surge rating. | Not hermetically sealed; unsuitable for high-humidity, radiation, or extended-temperature applications. | Select only for cost-sensitive consumer applications where thermal and environmental robustness are secondary. |
Compared with 1N5940BUR-1/TR, 1N5940BRLG offers identical electrical performance with RoHS-compliant plating and standard tape-and-reel delivery, while SMBG5940B trades hermeticity and thermal performance for lower cost and larger footprint compatibility - making the original ideal for high-reliability, high-temperature, or radiation-exposed systems.
Availability
1N5940BUR-1/TR is available at Aetrix Electronics and suitable for switch-mode power supplies, industrial sensor references, aerospace power monitoring, and downhole oilfield electronics requiring stable component supply, long-lifecycle assurance, and traceable sourcing.
Supply support for 1N5940BUR-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 high-voltage analog components for defense, aerospace, and industrial markets.
The 1N5940BUR-1/TR belongs to Microsemi's legacy 1N59xxBUR-1 Zener series, engineered for applications demanding hermetic sealing, extended temperature operation, and MIL-PRF-19500 qualification capability - particularly in mission-critical power regulation and reference functions.
FAQ
What is the Zener voltage tolerance for 1N5940BUR-1/TR?
The 1N5940BUR-1/TR has a Zener voltage tolerance of ±5%, specified at 43 V with 8.7 mA test current (IZT) and end-cap temperature maintained at 30 °C. This tolerance is confirmed in the Electrical Characteristics table on Page 3 of the T4-LDS-0300-1 datasheet and applies to all units within the UR-1 reliability grade.
Is 1N5940BUR-1/TR RoHS compliant?
Yes, the "e3" suffix in the full part number 1N5940BUR-1/TR indicates RoHS-compliant matte tin plating over copper. The device meets EU Directive 2011/65/EU requirements and is solderable per MIL-STD-750 Method 2026, as stated in the Mechanical and Packaging section of the datasheet.
Can 1N5940BUR-1/TR be used in high-reliability aerospace applications?
Yes - the 1N5940BUR-1/TR supports optional screening per MIL-PRF-19500, features hermetic glass construction, and is inherently radiation-hardened per Microsemi MicroNote 050. Its -65 °C to +175 °C operating range and metallurgically bonded contacts make it suitable for aerospace power monitoring and avionics subsystems.
What is the thermal resistance of 1N5940BUR-1/TR?
The 1N5940BUR-1/TR has a junction-to-end cap thermal resistance (RθJEC) of 40 °C/W, measured with the end cap held at ≤115 °C. Its junction-to-ambient resistance (RθJA) is 120 °C/W when mounted on FR4 with 1 oz copper and the recommended footprint - values confirmed in the Maximum Ratings table on Page 1.
Does 1N5940BUR-1/TR require external ESD protection?
No - the 1N5940BUR-1/TR is non-sensitive to ESD per MIL-STD-750 Method 1020, as documented in the Applications/Benefits section. Its hermetic glass package and metallurgical construction eliminate the need for additional ESD suppression during handling or PCB assembly.
1N5940BUR-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):
- 43 V
- Tolerance:
- ±5%
- Power - Max:
- 1.25 W
- Impedance (Max) (Zzt):
- 53 Ohms
- Current - Reverse Leakage @ Vr:
- 1 µA @ 32.7 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)
1N5940BUR-1/TR FAQ
1.How can I place an order for 1N5940BUR-1/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5940BUR-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 1N5940BUR-1/TR reliable?
The price and inventory of 1N5940BUR-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 1N5940BUR-1/TR is usually 5 days.
3.What payment methods are accepted for 1N5940BUR-1/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5940BUR-1/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5940BUR-1/TR?
1N5940BUR-1/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5940BUR-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 1N5940BUR-1/TR?
For technical support, including 1N5940BUR-1/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5940BUR-1/TR requirements.
6.How does Aetrix verify that 1N5940BUR-1/TR is sourced from the original manufacturer or authorized distributors?
All 1N5940BUR-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 1N5940BUR-1/TR meets industry standards.
7.What is the process for return or replacement of 1N5940BUR-1/TR?
All 1N5940BUR-1/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N5940BUR-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 1N5940BUR-1/TR part is unused and in its original packaging.
Return procedure for 1N5940BUR-1/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5940BUR-1/TR Tags
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