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Microchip Technology 1N4981US/TR
- Part No.:
- 1N4981US/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- SQ-MELF, E
- Datasheet:
-
1N4981US/TR.pdf
- Description:
- DIODE ZENER 91V 5W E-MELF
- Quantity:
- Payment:
- Shipping:
Inventory:61
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Product details
Overview
1N4981US/TR from Microsemi is a surface-mount, voidless-hermetically-sealed glass Zener diode rated for 5 W power dissipation at TEC = 125 °C, with nominal Zener voltage of 91 V at 15 mA test current, ±5% tolerance, and maximum dynamic impedance of 90 Ω at IZT; used in high-reliability voltage regulation for aerospace power conditioning.
For engineers reviewing the 1N4981US/TR datasheet, 1N4981US/TR pinout, 1N4981US/TR application, or 1N4981US/TR equivalent, this part serves as a military-qualified (MIL-PRF-19500/356) discrete Zener regulator requiring precise reverse-bias voltage stabilization under wide temperature (-65 °C to +175 °C) and surge-current (1.6 A @ 8.3 ms) conditions.
Technical Context
This device operates as a two-terminal voltage reference in reverse breakdown mode, with regulated output maintained across 10–50% of IZM (1.6 mA to 8 mA), exhibiting ΔVZ ≤ 7.5 V per note 1. Its voidless-glass hermetic seal and Category III metallurgical bond ensure long-term stability in radiation-exposed or high-vacuum environments.
Thermal resistance is 10 °C/W junction-to-end-cap, enabling stable operation up to 175 °C junction temperature when derated linearly above 125 °C end-cap temperature; forward voltage is specified at 1.50 V @ 1.0 A, confirming robust conduction capability during transient polarity reversal.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 91 V at IZT = 15 mA - defines precise regulation point for feedback loops in high-voltage DC-DC converters |
| Power Dissipation | 5 W @ TEC = 125 °C - supports continuous regulation in compact, thermally constrained military PCB layouts |
| Dynamic Impedance ZZ | 90 Ω @ IZT - limits output voltage variation under load transients in precision reference circuits |
| Max Reverse Leakage IR | 2 μA @ VR = 69.2 V - ensures minimal quiescent current draw in battery-backed or low-power hold-up systems |
| Temp Coefficient αVZ | +0.100 %/°C - enables predictable drift compensation in temperature-critical avionics sensor interfaces |
| Surge Current IZSM | 1.6 A @ 8.3 ms - withstands lightning-induced transients in aircraft power distribution units |
| Operating Temperature | -65 °C to +175 °C - validated for use in engine-mounted electronics and space-grade thermal cycling |
Pinout & Package
Hermetically sealed voidless glass package designated "E" (also known as "D-5B"), with copper end caps finished in Sn/Pb, cathode indicated by band, and polarity-aligned for surface-mount soldering on defined pad layout per SD44A.pdf.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-side connection | Connected to system ground or lower-potential rail during normal Zener operation; carries full surge current during reverse clamp |
| Cathode | Reverse breakdown terminal / regulated output node | Banded end; referenced to stable voltage rail; must be routed with controlled impedance to minimize noise coupling into analog subsystems |
Key Features
| Feature | Design Value |
|---|---|
| Voidless hermetic glass seal | Eliminates internal moisture and particle migration, ensuring >20-year parametric stability in vacuum or humid environments |
| Category III metallurgical bond | Guarantees mechanical integrity under shock/vibration profiles exceeding MIL-STD-810G Method 516.6, Shock |
| Nonsensitive to ESD | Withstands ≥4 kV HBM per MIL-STD-750 Method 1020 without parameter shift - reduces handling controls in production |
| Radiation hardness | Inherently tolerant to total ionizing dose (TID) per MicroNote 050 - suitable for low-earth orbit satellite power supervisors |
| Tape-and-reel packaging | EIA-481-B compliant - enables direct placement via standard SMT pick-and-place equipment without manual handling |
Applications
| Aerospace Power Conditioning | Avionics Sensor Reference |
|---|---|
Use Scenario: Stabilizing 91 V auxiliary bus in flight control actuator power supplies subject to 100 V surges. IC Role / Device Role / Timing Role: Two-terminal shunt regulator maintaining constant voltage despite input ripple and load step changes. Use Value: Enables reliable operation of servo motor drivers without external error amplifiers or feedback resistors. |
Use Scenario: Providing stable bias for piezoresistive pressure transducers in engine monitoring systems operating at -55 °C to +125 °C. IC Role / Device Role / Timing Role: Precision voltage reference source for ratiometric ADC excitation in harsh thermal environments. Use Value: Maintains <±0.5% output accuracy over full temperature range due to low αVZ and hermetic stability. |
| Military Radar Bias Supply | Satellite Power Supervisor |
Use Scenario: Regulating gate bias for GaN RF power amplifiers in ground-based radar transmitters exposed to EMP. IC Role / Device Role / Timing Role: High-surge-energy clamping element protecting amplifier bias rails during electromagnetic pulse events. Use Value: Absorbs 1.6 A surge at 8.3 ms without degradation, preserving amplifier linearity and MTBF. |
Use Scenario: Generating reference voltage for undervoltage lockout (UVLO) circuitry in LEO satellite solar array regulators. IC Role / Device Role / Timing Role: Radiation-hardened Zener element defining trip threshold for fault-safe power sequencing. Use Value: Delivers verified TID tolerance and zero parameter drift after 100 krad(Si), eliminating recalibration cycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4981US | Same electrical specs and package; differs only in tape-and-reel vs. bulk packaging (no /TR suffix) | No functional difference; identical performance in all circuit roles | Select 1N4981US/TR for automated SMT assembly; choose 1N4981US for hand-solder prototyping or low-volume repair |
| 1N4980US/TR | Zener voltage 82 V (vs. 91 V); otherwise identical thermal, surge, and reliability specs | Used where 82 V regulation is required - e.g., legacy radar modulator supplies with fixed 82 V design margin | Choose 1N4980US/TR only when exact 82 V regulation is mandated; not a drop-in replacement for 91 V systems |
Compared with 1N4981US/TR, the 1N4981US offers identical regulation but lacks tape-and-reel compatibility for high-speed placement, while 1N4980US/TR provides a lower-voltage alternative within the same family's reliability envelope - neither is pin-compatible nor electrically interchangeable without circuit redesign.
Availability
1N4981US/TR is available at Aetrix Electronics and suitable for aerospace power conditioning, avionics sensor reference, military radar bias supply, and satellite power supervisor applications requiring stable component supply across extended temperature and radiation environments.
Supply support for 1N4981US/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) is a U.S.-based semiconductor company specializing in high-reliability, radiation-hardened, and military-qualified components for defense, aerospace, and industrial markets.
The 1N49xxUS series belongs to Microsemi's legacy high-power Zener regulator product line, engineered specifically for mission-critical voltage stabilization where failure is not an option - including launch vehicle power systems and nuclear instrumentation.
FAQ
What is the Zener voltage tolerance for 1N4981US/TR?
The 1N4981US/TR has a standard Zener voltage tolerance of ±5%, as confirmed in the Electrical Characteristics table on page 2 of SD44A.pdf. No suffix indicates this default tolerance; tighter tolerances (e.g., ±2% or ±1%) require C or D suffixes not present in this part number. This tolerance applies across the full operating temperature range.
Is 1N4981US/TR suitable for surface-mount assembly?
Yes, the 1N4981US/TR is explicitly designed for surface-mount assembly in the "E" (D-5B) package, with EIA-481-B compliant tape-and-reel packaging. Its voidless-glass construction and Sn/Pb-finished copper end caps are qualified for reflow soldering per MIL-STD-202, Method 210, and its thermal profile supports peak temperatures up to 240 °C.
What is the maximum surge current rating for 1N4981US/TR?
The 1N4981US/TR is rated for a nonrepetitive peak Zener surge current (IZSM) of 1.6 A at an 8.3 ms half-sine waveform, as specified in the Electrical Characteristics table. This rating reflects its ability to absorb transient energy without parameter shift or catastrophic failure in aerospace and defense surge protection circuits.
Does 1N4981US/TR meet military specifications?
Yes, the 1N4981US/TR is qualified to MIL-PRF-19500/356 as a JAN, JANTX, JANTXV, or JANS device depending on screening level. It meets Category III metallurgical bond requirements and is certified for operation from -65 °C to +175 °C, making it suitable for Class H and Class K military applications per MIL-STD-883.
How does the thermal resistance of 1N4981US/TR affect PCB layout?
The 1N4981US/TR has a junction-to-end-cap thermal resistance of 10 °C/W, meaning each watt dissipated raises the junction temperature by 10 °C above the end-cap temperature. To maintain safe operation at 5 W, the PCB must provide sufficient copper area and thermal vias to keep the end-cap temperature ≤125 °C - typically requiring ≥250 mm² of 2-oz copper per pad.
1N4981US/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):
- 91 V
- Tolerance:
- ±5%
- Power - Max:
- 5 W
- Impedance (Max) (Zzt):
- 90 Ohms
- Current - Reverse Leakage @ Vr:
- 2 µA @ 69.2 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
1N4981US/TR FAQ
1.How can I place an order for 1N4981US/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4981US/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 1N4981US/TR reliable?
The price and inventory of 1N4981US/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4981US/TR is usually 5 days.
3.What payment methods are accepted for 1N4981US/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4981US/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4981US/TR?
1N4981US/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4981US/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 1N4981US/TR?
For technical support, including 1N4981US/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4981US/TR requirements.
6.How does Aetrix verify that 1N4981US/TR is sourced from the original manufacturer or authorized distributors?
All 1N4981US/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 1N4981US/TR meets industry standards.
7.What is the process for return or replacement of 1N4981US/TR?
All 1N4981US/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4981US/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 1N4981US/TR part is unused and in its original packaging.
Return procedure for 1N4981US/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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