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Microchip Technology 1N5937BUR-1/TR
- Part No.:
- 1N5937BUR-1/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AB, MELF (Glass)
- Datasheet:
-
1N5937BUR-1/TR.pdf
- Description:
- DIODE ZENER 33V 1.25W DO213AB
- Quantity:
- Payment:
- Shipping:
Inventory:7,665
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Product details
Overview
1N5937BUR-1/TR from Microsemi is a 1.5 W surface-mount Zener diode in DO-213AB (MELF) glass package, rated for 33 V ±5% Zener voltage at 11.4 mA test current, with 33 Ω dynamic impedance, 1.0 µA reverse leakage at 25.1 V, and maximum Zener current of 45 mA. It serves voltage regulation in high-density power supply rails and precision reference circuits.
For engineers reviewing the 1N5937BUR-1/TR datasheet, 1N5937BUR-1/TR pinout, 1N5937BUR-1/TR application, or 1N5937BUR-1/TR equivalent, this page delivers verified electrical specs, thermal resistance (40 °C/W junction-to-end cap), RoHS-compliant plating, MIL-PRF-19500 screening availability, and MELF package mechanical data per Microsemi T4-LDS-0300-1 Rev. 1.
Technical Context
This device operates as a two-terminal voltage regulator in reverse-biased breakdown mode, with Zener voltage specified at end-cap temperature (TEC = 30 °C) and measured 90 s after DC current application. Its metallurgically bonded tungsten slug construction ensures low thermal resistance and stable regulation across -65 to +175 °C junction temperature range.
The 1N5937BUR-1/TR exhibits 33 Ω dynamic impedance (ZZT) at 11.4 mA IZT and 1.0 µA reverse leakage (IR) at VR = 25.1 V, supporting stable regulation under varying load and temperature. Capacitance is characterized per Figure 2 in the datasheet and correlates with Zener voltage.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 33 V ±5% at IZT = 11.4 mA - defines nominal regulation point with tight tolerance for precision references. |
| Power Dissipation | 1.5 W @ TEC ≤ 115 °C - supports continuous operation in thermally constrained SMT layouts. |
| Dynamic Impedance (ZZT) | 33 Ω - determines output voltage variation under load transients; lower than many 33 V Zeners in same power class. |
| Reverse Leakage (IR) | 1.0 µA @ VR = 25.1 V - enables low-power standby regulation without excessive quiescent loss. |
| Junction Temp Range | -65 to +175 °C - qualifies for extended industrial, aerospace, and downhole applications. |
| Thermal Resistance (RθJEC) | 40 °C/W - allows direct thermal path to PCB copper or heatsink via end-cap mounting. |
| Forward Voltage (VF) | 1.2 V max @ 200 mA - ensures predictable forward conduction during transient overvoltage events. |
Pinout & Package
Package: DO-213AB (MELF) - hermetically sealed voidless hard glass case with tungsten slugs; cathode indicated by single band; RoHS-compliant matte tin plating over copper; weight ≈ 0.05 g; tape-and-reel packaging per EIA-481-B (12 mm tape, "TR" suffix).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Positive terminal in forward bias; negative terminal in Zener regulation | Connected to lower-potential node during regulation; must be routed with adequate current-carrying capacity for IZM = 45 mA. |
| Cathode | Negative terminal in forward bias; positive terminal in Zener regulation | Marked with band; connected to higher-potential rail; requires thermal relief on PCB for heat dissipation via end-cap contact. |
Key Features
| Feature | Design Value |
|---|---|
| Metallurgically bonded internal contacts | Reduces thermal resistance and improves long-term stability vs. standard wire-bonded Zeners. |
| Hermetic glass seal | Prevents moisture ingress and parametric drift in humid or corrosive environments. |
| MIL-PRF-19500 screening option | Enables use in defense/aerospace programs requiring qualified high-reliability discrete components. |
| ESD immunity per MIL-STD-750 Method 1020 | Eliminates need for external ESD protection in handling and assembly for production lines. |
| Low capacitance profile | Capacitance scales with Zener voltage (see Fig. 2); ~2.5 pF typical for 33 V devices - minimizes signal coupling in RF-adjacent circuits. |
Applications
| Industrial Power Supply Regulation | Test & Measurement Reference |
|---|---|
Use Scenario: Stabilizing +33 V auxiliary rail in programmable logic controller (PLC) backplane power modules. IC Role / Device Role / Timing Role: Two-terminal shunt regulator maintaining voltage within ±5% across 1–45 mA load range and -40 to +85 °C ambient. Use Value: Eliminates need for active LDO or feedback loop; leverages 33 Ω ZZT and 40 °C/W RθJEC to hold regulation despite board-level thermal gradients. | Use Scenario: Providing stable 33 V reference for 16-bit DAC calibration circuitry in portable multimeters. IC Role / Device Role / Timing Role: Precision voltage reference source with <1 µA leakage and ±5% VZ tolerance, operating at 11.4 mA IZT. Use Value: Enables sub-0.1% full-scale accuracy by minimizing drift from temperature and aging-enhanced by hermetic glass package and metallurgical bond. |
| Aerospace Avionics Biasing | High-Density Telecom Front-End |
Use Scenario: Biasing photodiode amplifiers in radiation-hardened satellite telemetry receivers. IC Role / Device Role / Timing Role: Radiation-tolerant shunt regulator supplying stable bias to op-amp input stages; qualified per Microsemi MicroNote 050. Use Value: Inherent radiation hardness avoids derating or shielding overhead; MIL-PRF-19500 screening ensures lot traceability and burn-in compliance. | Use Scenario: Voltage clamping and rail stabilization in compact 48 V to 3.3 V intermediate bus converters for 5G base station radios. IC Role / Device Role / Timing Role: Low-parasitic shunt element placed directly at point-of-load to suppress switching noise and overshoot. Use Value: MELF geometry minimizes inductance vs. SMA/SMB packages; 0.05 g mass and 2.39–2.67 mm diameter enable placement in <3 mm² footprint zones. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5937BRLG | Same 33 V/1.5 W spec, but in DO-41 axial package; no MELF thermal performance; leaded form factor. | Preferred for through-hole prototyping or legacy designs where rework access matters more than density or thermal efficiency. | Select when board assembly uses wave soldering or manual repair is required; avoid in high-vibration or high-density SMT-only assemblies. |
| SMBG5937B | Same 33 V/1.5 W rating in SMB package; higher RθJA (~150 °C/W); larger footprint; tabbed SMT but non-hermetic plastic body. | Better suited for cost-sensitive consumer power supplies where hermeticity and radiation tolerance are not required. | Choose for volume production where JEDEC-standard SMB footprint simplifies layout reuse; not recommended for high-reliability or high-temp environments. |
Compared with 1N5937BUR-1/TR, the 1N5937BRLG offers easier hand-soldering but sacrifices thermal performance and density, while SMBG5937B trades hermetic reliability and MELF low-inductance for lower cost and broader distributor availability-neither is pin-compatible due to differing packages.
Availability
1N5937BUR-1/TR is available at Aetrix Electronics and suitable for industrial power supply regulation, test & measurement reference design, and aerospace avionics biasing requiring stable component supply, consistent Zener voltage tolerance, and hermetic reliability.
Supply support for 1N5937BUR-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 analog, mixed-signal, and radiation-hardened components for defense, aerospace, and industrial markets.
The 1N59xxBUR-1 series belongs to Microsemi's precision Zener diode product line, engineered for applications demanding hermetic sealing, MIL-PRF-19500 qualification, low thermal resistance, and stable regulation across extreme temperatures.
FAQ
What is the Zener voltage tolerance and test current for the 1N5937BUR-1/TR?
The 1N5937BUR-1/TR has a Zener voltage of 33 V with ±5% tolerance, measured at a test current (IZT) of 11.4 mA under end-cap temperature control (TEC = 30 °C). This specification is confirmed in Table on Page 3 of Microsemi T4-LDS-0300-1 Rev. 1, and the 1N5937BUR-1/TR must be biased at this current to achieve rated regulation accuracy.
Does the 1N5937BUR-1/TR support MIL-PRF-19500 screening?
Yes, the 1N5937BUR-1/TR supports optional screening per MIL-PRF-19500, as explicitly stated in the Features section of the Microsemi datasheet. Screening is available upon request with appropriate part number suffixes and is documented in Microsemi MicroNote 129 for reliability level coding. The base 1N5937BUR-1/TR is commercial-grade unless enhanced screening is ordered.
What is the maximum Zener current (IZM) and how is it derived for the 1N5937BUR-1/TR?
The maximum Zener current (IZM) for the 1N5937BUR-1/TR is 45 mA, calculated from its 1.5 W power rating and 33 V nominal Zener voltage (PD/VZ ≈ 45.5 mA). The datasheet lists 45 mA directly in the Electrical Characteristics table, reflecting safe continuous operation at rated power with proper thermal management via the end-cap.
Is the 1N5937BUR-1/TR RoHS compliant?
Yes, the 1N5937BUR-1/TR is RoHS compliant, as indicated by the "e3" suffix in its full nomenclature (1N5937BUR-1/TR e3 per Microsemi part numbering convention). The device uses matte tin plating over copper and meets exemption 7a for lead in high-melting-temperature type solders, per the datasheet's Mechanical and Packaging section.
What is the thermal resistance junction-to-end cap (RθJEC) for the 1N5937BUR-1/TR, and why does it matter?
The thermal resistance junction-to-end cap (RθJEC) for the 1N5937BUR-1/TR is 40 °C/W, per Maximum Ratings table on Page 1 of the datasheet. This low value enables efficient heat transfer from the silicon junction to the PCB copper via the MELF end-cap, critical for sustaining 1.5 W dissipation without exceeding 175 °C junction temperature in compact layouts.
1N5937BUR-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):
- 33 V
- Tolerance:
- ±5%
- Power - Max:
- 1.25 W
- Impedance (Max) (Zzt):
- 33 Ohms
- Current - Reverse Leakage @ Vr:
- 1 µA @ 25.1 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)
1N5937BUR-1/TR FAQ
1.How can I place an order for 1N5937BUR-1/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5937BUR-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 1N5937BUR-1/TR reliable?
The price and inventory of 1N5937BUR-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 1N5937BUR-1/TR is usually 5 days.
3.What payment methods are accepted for 1N5937BUR-1/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5937BUR-1/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5937BUR-1/TR?
1N5937BUR-1/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5937BUR-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 1N5937BUR-1/TR?
For technical support, including 1N5937BUR-1/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5937BUR-1/TR requirements.
6.How does Aetrix verify that 1N5937BUR-1/TR is sourced from the original manufacturer or authorized distributors?
All 1N5937BUR-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 1N5937BUR-1/TR meets industry standards.
7.What is the process for return or replacement of 1N5937BUR-1/TR?
All 1N5937BUR-1/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N5937BUR-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 1N5937BUR-1/TR part is unused and in its original packaging.
Return procedure for 1N5937BUR-1/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5937BUR-1/TR Tags
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