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Microchip Technology 1N4487US/TR
- Part No.:
- 1N4487US/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- SQ-MELF, A
- Datasheet:
-
1N4487US/TR.pdf
- Description:
- DIODE ZENER 82V 1.5W D5A
- Quantity:
- Payment:
- Shipping:
Inventory:199
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Product details
Overview
1N4487US/TR from Microsemi is a hermetically sealed, voidless glass MELF (D-5A) surface-mount Zener diode rated for 1.5 W steady-state power dissipation, with nominal Zener voltage of 82.0 V at 3.0 mA test current, 160 Ω dynamic impedance, and maximum reverse leakage of 0.25 µA at 65.6 V. It is qualified to MIL-PRF-19500/406 at JANTXV level and used in high-reliability voltage regulation within aerospace power conditioning circuits.
For engineers reviewing the 1N4487US/TR datasheet, 1N4487US/TR pinout, 1N4487US/TR application, or 1N4487US/TR equivalent, key selection criteria include its military-grade hermeticity, 82 V Zener voltage tolerance (±5%), thermal resistance of 20 °C/W junction-to-end cap, and suitability for low-leakage, radiation-hardened biasing in avionics and defense electronics.
Technical Context
This device operates as a precision voltage reference in reverse-biased breakdown mode, delivering stable regulation across –65 °C to +175 °C junction temperature range. Its internal Category I metallurgical bond ensures mechanical robustness under thermal cycling and shock, while triple-layer passivation enhances long-term reliability in harsh environments.
The 1N4487US/TR exhibits a Zener knee current (IZK) of 0.05 mA and maximum Zener surge current of 0.17 A for 8.3 ms square wave, supporting transient overvoltage clamping in regulated DC supplies. Its forward voltage is 1.0 V at 200 mA, confirming standard silicon PN junction behavior.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 82.0 V at IZT = 3.0 mA - defines precise regulation point for feedback loops in high-voltage references |
| Power Dissipation (PD) | 1.5 W @ TA = 25 °C - sets maximum continuous thermal load without derating |
| Dynamic Impedance (ZZT) | 160 Ω @ IZT - determines output voltage stability under varying load current |
| Reverse Leakage (IR) | 0.25 µA @ VR = 65.6 V - enables ultra-low quiescent current operation in battery-backed systems |
| Junction Temp Range | –65 °C to +175 °C - supports deployment in extended-temperature military and space platforms |
| Thermal Resistance | 20 °C/W (Junction-to-End Cap) - informs heatsinking requirements for sustained 1.5 W operation |
| Package | D-5A MELF - surface-mount cylindrical glass package with cathode band marking and Sn/Pb terminations |
Pinout & Package
Hermetically sealed voidless glass D-5A MELF package with tungsten slugs and tin/lead (Sn/Pb) terminations. Cathode indicated by single black band. Weight: 193 mg. Dimensions: BD = 0.091–0.103 in (2.31–2.62 mm), BL = 0.168–0.200 in (4.28–5.08 mm).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential node in reverse-bias regulator configuration |
| Cathode | Zener breakdown terminal | Marked by black band; connected to higher-potential node to maintain reverse bias |
Key Features
| Feature | Design Value |
|---|---|
| Voidless hermetic glass seal | Prevents moisture ingress and internal corrosion, enabling >20-year field life in sealed modules |
| Triple-layer passivation | Reduces surface leakage paths and improves long-term parameter stability under humidity stress |
| MIL-PRF-19500/406 JANTXV qualification | Validates performance to screening, testing, and traceability standards required for flight-critical hardware |
| Category I metallurgical bond | Ensures mechanical integrity during thermal shock (–65 °C ↔ +175 °C) and vibration per MIL-STD-202 |
| Non-sensitive to ESD (MIL-STD-750 Method 1020) | Eliminates need for on-board ESD protection circuitry in handling and assembly |
Applications
| Aerospace Power Conditioning | Defense Radar Bias Supply |
|---|---|
Use Scenario: Regulating reference voltage for analog front-end amplifiers in satellite telemetry transmitters. IC Role / Device Role / Timing Role: Zener diode providing stable 82 V bias to op-amp input stages under wide temperature excursions. Use Value: Low 0.25 µA leakage preserves signal integrity in high-impedance sensor interfaces at –55 °C. | Use Scenario: Clamping transient spikes on high-voltage modulator rails in ground-based radar pulse generators. IC Role / Device Role / Timing Role: Surge-suppressing Zener operating in avalanche mode during 8.3 ms square-wave surges. Use Value: 0.17 A non-repetitive surge rating absorbs energy without parametric shift or failure. |
| Avionics Flight Control Reference | Nuclear Instrumentation Calibration |
Use Scenario: Generating precision 82 V reference for ADC calibration in inertial measurement units (IMUs). IC Role / Device Role / Timing Role: Voltage reference element in ratiometric measurement chains requiring <100 ppm/°C drift. Use Value: Hermetic seal and Category I bond ensure zero parameter drift over 10,000 thermal cycles. | Use Scenario: Stabilizing high-voltage bias for Geiger-Müller tube detectors in radiation monitoring equipment. IC Role / Device Role / Timing Role: Zener regulator maintaining constant detector bias despite supply ripple and aging effects. Use Value: Inherent radiation hardness per MicroNote 050 eliminates need for shielding or derating in gamma fields. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4487US (non-TR) | Same electrical specs and hermetic construction; differs only in packaging (bulk vs. tape-and-reel) | No functional difference; TR version optimized for automated SMT placement | Select 1N4487US/TR when using pick-and-place equipment with EIA-481-B compliant feeders |
| SMF82A (ON Semiconductor) | Surface-mount SMA package; 82 V, 1.0 W, ±5%, but not MIL-qualified or hermetically sealed | Limited to commercial-temperature industrial use; unsuitable for radiation or extended-temp missions | Choose SMF82A only for cost-sensitive, non-military designs where hermeticity is not required |
Compared with 1N4487US/TR, the bulk-packaged 1N4487US offers identical performance but requires manual handling, while SMF82A trades military reliability and hermetic sealing for lower cost and smaller footprint in benign environments.
Availability
1N4487US/TR is available at Aetrix Electronics and suitable for aerospace power conditioning, defense radar bias supply, and avionics flight control reference applications requiring stable component supply, full traceability, and long-term obsolescence management.
Supply support for 1N4487US/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 and mixed-signal components for aerospace, defense, and industrial markets.
The 1N44xxUS series belongs to Microsemi's military-qualified Zener diode product line, engineered specifically for voltage regulation in mission-critical systems where failure is not an option.
FAQ
What is the Zener voltage tolerance for 1N4487US/TR?
The 1N4487US/TR has a nominal Zener voltage of 82.0 V with a standard tolerance of ±5%, as specified in the Electrical Characteristics table on page 3 of the Microsemi datasheet T4-LDS-0183-1. No suffix indicates 5% tolerance; tighter tolerances (e.g., ±2% or ±1%) require different part number suffixes (C or D) and are not applicable to the 1N4487US/TR variant.
Is 1N4487US/TR RoHS compliant?
No, the 1N4487US/TR is not RoHS compliant. Per the datasheet, RoHS-compliant versions (marked with e3 suffix) are available only for commercial-grade parts; the 1N4487US/TR carries no e3 designation and uses traditional tin/lead (Sn/Pb) terminations, consistent with its MIL-PRF-19500/406 JANTXV qualification.
What is the maximum continuous Zener current for 1N4487US/TR?
The maximum continuous Zener current (IZM) for 1N4487US/TR is 17 mA, derived from its 1.5 W power rating and 82 V Zener voltage (IZM = PD/VZ ≈ 18.3 mA, rounded down to 17 mA per the datasheet's Electrical Characteristics table on page 3). This value assumes operation at 25 °C ambient with proper end-cap thermal path.
Does 1N4487US/TR have radiation hardness certification?
Yes, the 1N4487US/TR is inherently radiation hard as documented in Microsemi MicroNote 050. Its hermetic voidless glass construction and internal metallurgical bond provide immunity to total ionizing dose (TID) and displacement damage, making it suitable for space and nuclear instrumentation applications without additional shielding or derating.
What is the thermal resistance junction-to-end cap for 1N4487US/TR?
The thermal resistance junction-to-end cap (RθJEC) for 1N4487US/TR is 20 °C/W, as stated in the Maximum Ratings table on page 1 of the datasheet. This value applies under steady-state conditions at TA = 25 °C and is critical for calculating junction temperature rise when mounted to a thermally conductive end cap or heatsink.
1N4487US/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- SQ-MELF, A
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 82 V
- Tolerance:
- ±5%
- Power - Max:
- 1.5 W
- Impedance (Max) (Zzt):
- 160 Ohms
- Current - Reverse Leakage @ Vr:
- 250 nA @ 65.6 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:
- D-5A
1N4487US/TR FAQ
1.How can I place an order for 1N4487US/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4487US/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 1N4487US/TR reliable?
The price and inventory of 1N4487US/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4487US/TR is usually 5 days.
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Once your 1N4487US/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 1N4487US/TR?
For technical support, including 1N4487US/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4487US/TR requirements.
6.How does Aetrix verify that 1N4487US/TR is sourced from the original manufacturer or authorized distributors?
All 1N4487US/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 1N4487US/TR meets industry standards.
7.What is the process for return or replacement of 1N4487US/TR?
All 1N4487US/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4487US/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 1N4487US/TR part is unused and in its original packaging.
Return procedure for 1N4487US/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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