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Microchip Technology 1N4959US/TR
- Part No.:
- 1N4959US/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- SQ-MELF, E
- Datasheet:
-
1N4959US/TR.pdf
- Description:
- DIODE ZENER 11V 5W E-MELF
- Quantity:
- Payment:
- Shipping:
Inventory:85
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Product details
Overview
1N4959US/TR from Microsemi is a surface-mount, hermetically sealed, voidless-glass 5 W Zener diode with nominal Zener voltage of 11 V at 125 mA test current, ±5% tolerance (no suffix), and maximum dynamic impedance of 2.5 Ω at IZT. It operates from −65 °C to +175 °C and is qualified to MIL-PRF-19500/356 for high-reliability voltage regulation in aerospace power conditioning circuits.
For engineers reviewing the 1N4959US/TR datasheet, 1N4959US/TR pinout, 1N4959US/TR application, or 1N4959US/TR equivalent, this part delivers military-grade thermal stability, radiation hardness per MicroNote 050, ESD immunity per MIL-STD-750 Method 1020, and robust surge capability (19 A @ 8.3 ms) - critical for avionics reference and overvoltage clamp design.
Technical Context
This Zener regulator uses triple-layer passivation and Category I internal metallurgical bonds to ensure long-term stability under thermal cycling and radiation exposure. Its voidless-glass hermetic seal eliminates moisture ingress and interfacial delamination risks common in plastic-packaged Zeners.
The device exhibits low temperature coefficient (±0.07 %/°C), tight regulation (ΔVZ ≤ 0.8 V between 10–50% IZM), and low reverse leakage (10 μA at 8.4 V), enabling precision clamping in wide-temperature-range analog front-ends and power supply feedback loops.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 11 V at IZT = 125 mA - stable reference point for feedback networks requiring ±5% initial accuracy |
| Power Dissipation | 5 W @ TEC = 140 °C - supports continuous operation in high-ambient industrial or avionics enclosures |
| Dynamic Impedance ZZ | 2.5 Ω at IZT - ensures minimal output voltage shift under load transients in regulation circuits |
| Max Reverse Leakage IR | 10 μA at VR = 8.4 V - preserves low quiescent current in battery-backed or low-power monitoring systems |
| Surge Current IZSM | 19 A (8.3 ms half-sine) - withstands lightning-induced transients in MIL-STD-461-compliant power inputs |
| Operating Temperature | −65 °C to +175 °C - enables deployment in engine-mounted sensors or space-grade power converters |
| Thermal Resistance | 7 °C/W junction-to-end-cap - allows direct thermal coupling to heatsink or PCB copper for sustained 5 W dissipation |
Pinout & Package
Package: Hermetically sealed voidless hard glass case with tungsten slugs; end caps are copper with Sn/Pb finish; polarity indicated by cathode band; weight 539 mg; tape-and-reel compliant per EIA-481-B.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential node in shunt regulation; must handle 1.5 V forward drop at 1 A |
| Cathode | Zener breakdown terminal | Connected to regulated voltage rail; marked by visible band; carries full Zener current during regulation |
Key Features
| Feature | Design Value |
|---|---|
| Voidless hermetic glass seal | Eliminates moisture-induced parameter drift and long-term reliability degradation in humid or vacuum environments |
| Category I metallurgical bond | Ensures mechanical integrity and thermal cycle survivability exceeding 1000 cycles from −65 °C to +175 °C |
| Nonsensitive to ESD | Withstands >4 kV HBM without parameter shift - simplifies handling in uncontrolled assembly environments |
| Inherent radiation hardness | Qualified per MicroNote 050 for total ionizing dose (TID) up to 100 krad(Si) - suitable for LEO satellite power systems |
| MIL-PRF-19500/356 qualification | Meets screening, testing, and traceability requirements for JAN, JANTX, JANTXV, and JANS versions |
Applications
| Aerospace Power Conditioning | Avionics Reference Voltage |
|---|---|
|
Use Scenario: Regulating +15 V and −15 V analog supply rails in flight control computers exposed to −55 °C to +70 °C ambient and vibration. IC Role / Device Role / Timing Role: Shunt voltage reference providing stable bias for op-amps and ADC drivers. Use Value: Maintains <±1% output variation across temperature and lifetime due to hermetic seal and low αVZ. |
Use Scenario: Generating precise 11 V reference for analog-to-digital conversion in inertial measurement units (IMUs). IC Role / Device Role / Timing Role: Primary voltage reference source for ratiometric sensor excitation and signal scaling. Use Value: Delivers <10 ppm/°C drift and <2.5 Ω dynamic impedance to minimize code-width error in 16-bit ADC systems. |
| Defense Radar Power Protection | Satellite DC-DC Converter Feedback |
|
Use Scenario: Clamping transient overvoltages on radar transmitter power bus during EMP events. IC Role / Device Role / Timing Role: Fast-response surge suppressor absorbing 19 A surges without failure. Use Value: Survives repeated 8.3 ms surges per MIL-STD-461G CS115 while maintaining post-surge VZ within spec. |
Use Scenario: Providing isolated feedback voltage to secondary-side controller in radiation-hardened DC-DC converters. IC Role / Device Role / Timing Role: Radiation-tolerant Zener reference in optocoupler-coupled feedback loop. Use Value: Operates reliably at 100 krad(Si) TID with no parametric shift - eliminates need for redundant references. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4959US (no /TR) | Same electrical specs and package; differs only in packaging - bulk vs. tape-and-reel | No functional difference; /TR denotes tape-and-reel delivery for automated SMT placement | Select 1N4959US/TR when using pick-and-place equipment; choose 1N4959US for manual prototyping or low-volume hand-soldering |
| 1N5968US | 5.6 V Zener, same 5 W rating, identical package and MIL-PRF-19500/356 qualification but different VZ and tighter thermal coefficient (±0.04 %/°C) | Used where lower reference voltage and enhanced tempco are required - not interchangeable with 1N4959US/TR without circuit redesign | Choose 1N5968US only when system requires 5.6 V regulation; do not substitute for 11 V functionality |
Compared with 1N4959US/TR, the 1N4959US offers identical performance in bulk form but lacks SMT-ready packaging, while 1N5968US provides a lower-voltage alternative with superior temperature coefficient but requires board-level redesign for voltage compatibility.
Availability
1N4959US/TR is available at Aetrix Electronics and suitable for aerospace power conditioning, avionics reference voltage generation, and defense radar power protection requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for 1N4959US/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 (now part of Microchip Technology) designs high-reliability analog and mixed-signal semiconductors for aerospace, defense, and industrial markets, with emphasis on radiation-hardened and MIL-spec components.
The 1N4959US/TR belongs to Microsemi's legacy MIL-PRF-19500/356-qualified Zener series, engineered specifically for mission-critical voltage regulation where failure is not an option - including launch vehicle power systems and nuclear instrumentation.
FAQ
What is the Zener voltage tolerance for 1N4959US/TR?
The 1N4959US/TR has a nominal Zener voltage of 11 V with a standard tolerance of ±5%, as indicated by the absence of a tolerance suffix (e.g., "C" for ±2% or "D" for ±1%). This tolerance applies at 25 °C and IZT = 125 mA, and is maintained across its full operating temperature range due to its low temperature coefficient of ±0.07 %/°C.
Is 1N4959US/TR suitable for surface-mount assembly?
Yes, the 1N4959US/TR is explicitly designed for surface-mount assembly. It uses the "E" package (also known as "D-5B"), features tape-and-reel packaging per EIA-481-B, and includes solderable copper end caps with Sn/Pb finish. Its voidless-glass construction ensures reliability through reflow profiles up to 235 °C peak temperature.
Does 1N4959US/TR meet military specifications?
Yes, the 1N4959US/TR is qualified to MIL-PRF-19500/356 and supports JAN, JANTX, JANTXV, and JANS screening levels. It undergoes rigorous environmental testing including thermal shock, vibration, and hermeticity verification, and is rated for operation from −65 °C to +175 °C - meeting requirements for Class H and Class K military applications.
What is the maximum surge current rating for 1N4959US/TR?
The 1N4959US/TR is rated for a nonrepetitive peak Zener surge current (IZSM) of 19 A at an 8.3 ms half-sine waveform. This rating is validated per MIL-STD-750 Method 3011 and enables reliable transient suppression in MIL-STD-461G CS115-compliant power systems without degradation of Zener voltage or dynamic impedance.
How does the voidless-glass construction improve reliability of 1N4959US/TR?
The voidless-glass hermetic seal in the 1N4959US/TR eliminates internal air pockets that could expand or contract with temperature cycling, preventing microcrack formation and parameter drift. Combined with triple-layer passivation and Category I metallurgical bonds, it ensures zero moisture ingress and stable Zener voltage over 20+ years in harsh environments - a key requirement for satellite and airborne systems.
1N4959US/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- SQ-MELF, E
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 11 V
- Tolerance:
- ±5%
- Power - Max:
- 5 W
- Impedance (Max) (Zzt):
- 2.5 Ohms
- Current - Reverse Leakage @ Vr:
- 10 µA @ 8.4 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 1 A
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- E-MELF
1N4959US/TR FAQ
1.How can I place an order for 1N4959US/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4959US/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 1N4959US/TR reliable?
The price and inventory of 1N4959US/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4959US/TR is usually 5 days.
3.What payment methods are accepted for 1N4959US/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4959US/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4959US/TR?
1N4959US/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4959US/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 1N4959US/TR?
For technical support, including 1N4959US/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4959US/TR requirements.
6.How does Aetrix verify that 1N4959US/TR is sourced from the original manufacturer or authorized distributors?
All 1N4959US/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 1N4959US/TR meets industry standards.
7.What is the process for return or replacement of 1N4959US/TR?
All 1N4959US/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4959US/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 1N4959US/TR part is unused and in its original packaging.
Return procedure for 1N4959US/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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