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Microchip Technology 1N2987RB
- Part No.:
- 1N2987RB
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-203AA, DO-4, Stud
- Datasheet:
-
1N2987RB.pdf
- Description:
- DIODE ZENER 25V 10W DO4
- Quantity:
- Payment:
- Shipping:
Inventory:2,444
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Product details
Overview
1N2987RB from Microsemi is a 10 W hermetically sealed, stud-mounted Zener diode with nominal Zener voltage 25 V at 6 mA test current, ±5% tolerance, +0.080 %/°C temperature coefficient, and reverse polarity (cathode-to-stud). It operates from –65 °C to +175 °C junction temperature and delivers stable voltage regulation in high-reliability power supply and reference circuits for aerospace and defense systems.
For engineers reviewing the 1N2987RB datasheet, 1N2987RB pinout, 1N2987RB application, or 1N2987RB equivalent, this part requires attention to stud-mounting torque (≤15 in-lb), thermal resistance (12 °C/W), reverse polarity configuration, and MIL-PRF-19500/124 JANTXV qualification status when designing for radiation-hardened, high-temperature, or mission-critical environments.
Technical Context
This device is a DO-213AA (DO-4) packaged, metal-glass hermetically sealed Zener diode with internal solder bond construction. Its regulation behavior is defined at IZT = 6 mA, with dynamic impedance ZZT = 100 Ω and maximum DC Zener current IZM = 250 mA at 25 °C stud temperature.
The 1N2987RB exhibits low reverse leakage (IR ≤ 10 µA at VR = 18.2 V), forward voltage VF = 1.5 V at 2.0 A, and linear power derating above +55 °C (0.083 W/°C). Its temperature coefficient (+0.080 %/°C) ensures predictable VZ drift across military-grade operating ranges.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 25 V ±5% at IZT = 6 mA - defines precise regulation point for feedback loops and reference rails |
| Power Dissipation (PD) | 10 W @ TC = +55 °C - supports high-current shunt regulation without external heatsink in constrained layouts |
| Junction Temperature Range | –65 °C to +175 °C - enables operation in extreme environmental conditions including engine bays and space electronics |
| Thermal Resistance (RθJC) | 12 °C/W - allows accurate thermal modeling of stud-to-heatsink interface for reliability prediction |
| Dynamic Impedance (ZZT) | 100 Ω @ IZT - determines AC ripple rejection capability in precision voltage references |
| Reverse Leakage (IR) | ≤10 µA @ VR = 18.2 V - ensures minimal standby current loss in battery-backed or low-power hold-up circuits |
| Temperature Coefficient (αVZ) | +0.080 %/°C - quantifies VZ drift per degree for system-level accuracy budgeting over temperature |
Pinout & Package
Package: DO-213AA (DO-4), hermetically sealed metal-glass stud package with 10-32 UNF–2A threaded stud (anode terminal), flat hex body (0.424–0.437 inch height), and tin-lead or matte-tin plating on nickel. Weight ≈ 7.5 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Stud (Threaded Body) | Cathode | Primary heat path and electrical connection; must be mounted to heatsink with ≤15 in-lb torque |
| Top Cap / Dome | Anode | Secondary terminal; requires mechanical retention or solder lug for PCB or chassis connection |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic metal-glass seal | Prevents moisture ingress and long-term parameter drift in humid or corrosive environments |
| MIL-PRF-19500/124 qualification | Validated reliability for JAN/JANTX/JANTXV levels - required for DoD and NASA procurement |
| Internal solder bond construction | Eliminates wire bonds susceptible to vibration fatigue - critical for avionics and launch systems |
| Radiation hardness | Inherently radiation-tolerant per Microsemi MicroNote 050 - suitable for space-grade applications without shielding |
| Nonsensitive to ESD | Qualified per MIL-STD-750 Method 1020 - simplifies handling and assembly in production |
Applications
| Avionics Power Reference | Missile Guidance Bias Supply |
|---|---|
Use Scenario: Provides stable 25 V reference for analog-to-digital converters and op-amp bias networks in flight control computers. IC Role / Device Role / Timing Role: Precision shunt voltage reference regulating output of unregulated DC-DC converter stage. Use Value: ±5% initial tolerance and +0.080 %/°C TC enable <±1.5% total error over –55 °C to +125 °C operational range. | Use Scenario: Supplies regulated bias voltage to gyroscopes and accelerometers in inertial measurement units (IMUs). IC Role / Device Role / Timing Role: High-reliability Zener clamp maintaining sensor excitation voltage under wide temperature and radiation exposure. Use Value: Hermetic seal and radiation hardness ensure uninterrupted operation during launch and orbital phases. |
| Ground Vehicle Engine Control | Satellite Power Bus Monitor |
Use Scenario: Regulates reference for fuel injector driver ICs in military diesel engines exposed to under-hood thermal cycling. IC Role / Device Role / Timing Role: Primary voltage reference in closed-loop feedback for high-side switch controllers. Use Value: 10 W power rating and –65 °C to +175 °C TJ range support continuous operation at 150 °C ambient with no derating penalty. | Use Scenario: Monitors 28 V bus voltage via resistive divider, feeding comparator inputs for undervoltage lockout in LEO satellite EPS. IC Role / Device Role / Timing Role: Stable Zener element in precision voltage divider network for telemetry accuracy. Use Value: Low IR (≤10 µA) prevents loading error in high-impedance sensing paths; DO-4 stud mount ensures mechanical robustness in vibration-prone payloads. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N2987B | Same 25 V rating but standard polarity (anode-to-stud); identical electrical specs and package | Requires reversed mounting orientation; incompatible with existing cathode-to-stud PCB layout | Select only if mechanical mounting permits anode connection to heatsink |
| 1N3006B | Higher 105 V Zener voltage; same DO-4 package, 10 W rating, and JANTXV qualification | Not interchangeable for 25 V regulation; used in higher-voltage transient suppression or HV reference designs | Consider only for redesigns requiring >100 V regulation with identical reliability and thermal performance |
Compared with 1N2987B and 1N3006B, the 1N2987RB uniquely combines 25 V regulation, reverse polarity (cathode-to-stud), and MIL-PRF-19500/124 JANTXV qualification - making it the sole option for legacy avionics systems requiring that specific mechanical and electrical interface.
Availability
1N2987RB is available at Aetrix Electronics and suitable for avionics power reference, missile guidance bias supply, and ground vehicle engine control applications requiring stable component supply, long-term obsolescence management, and traceable military-grade sourcing.
Supply support for 1N2987RB 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 aerospace-grade components.
The 1N2987RB belongs to Microsemi's legacy MIL-PRF-19500/124 qualified Zener diode family, designed specifically for voltage regulation in mission-critical defense, space, and industrial control systems where hermeticity, thermal stability, and qualification compliance are mandatory.
FAQ
What is the Zener voltage tolerance and test condition for the 1N2987RB?
The 1N2987RB has a nominal Zener voltage of 25 V with a tolerance of ±5%, measured at a Zener test current (IZT) of 6 mA. This tolerance is JEDEC-registered and applies across the full qualified temperature range. The 1N2987RB maintains this specification under steady-state conditions after thermal stabilization at 30 °C base temperature, per T4-LDS-0075 Rev. 3 test methodology.
Is the 1N2987RB RoHS compliant?
The 1N2987RB is not RoHS compliant by default. RoHS-compliant versions are available only for commercial-grade devices with the "e3" suffix (e.g., 1N2987RBe3); however, the 1N2987RB part number denotes a military-qualified variant without RoHS plating. Tin-lead plating is retained for solderability and reliability in high-reliability applications, consistent with MIL-PRF-19500/124 requirements.
What does the "RB" suffix mean in 1N2987RB?
The "RB" suffix in 1N2987RB indicates reverse polarity: cathode is connected to the threaded stud, while the anode is at the top cap. This is distinct from the standard polarity (1N2987B), where the anode connects to the stud. The "R" denotes reverse polarity, and "B" confirms compliance with the 1N2970B–1N3015B series revision level per Microsemi documentation.
What is the maximum stud temperature and power derating behavior for the 1N2987RB?
The 1N2987RB is rated for 10 W power dissipation at a stud temperature (TC) of +55 °C. Above +55 °C, power must be linearly derated at 0.083 W/°C until reaching zero watts at +175 °C. This derating curve is defined in Figure 1 of T4-LDS-0075 Rev. 3 and reflects the device's thermal resistance of 12 °C/W from junction to case (stud).
Which qualification levels are available for the 1N2987RB?
The 1N2987RB is qualified to MIL-PRF-19500/124 at JAN, JANTX, and JANTXV reliability levels. These denote progressively stricter screening: JAN (basic military), JANTX (extended environmental testing), and JANTXV (vibration and shock tested). All levels include burn-in, temperature cycling, and hermeticity verification - confirming suitability for flight-critical and strategic systems.
1N2987RB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-203AA, DO-4, Stud
- Packaging:
- Bulk
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 25 V
- Tolerance:
- ±5%
- Power - Max:
- 10 W
- Impedance (Max) (Zzt):
- 6 Ohms
- Current - Reverse Leakage @ Vr:
- 10 µA @ 18.2 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 2 A
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Stud Mount
- Supplier Device Package:
- DO-4 (DO-203AA)
1N2987RB FAQ
1.How can I place an order for 1N2987RB through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N2987RB 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 1N2987RB reliable?
The price and inventory of 1N2987RB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N2987RB is usually 5 days.
3.What payment methods are accepted for 1N2987RB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N2987RB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N2987RB?
1N2987RB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N2987RB 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 1N2987RB?
For technical support, including 1N2987RB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N2987RB requirements.
6.How does Aetrix verify that 1N2987RB is sourced from the original manufacturer or authorized distributors?
All 1N2987RB 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 1N2987RB meets industry standards.
7.What is the process for return or replacement of 1N2987RB?
All 1N2987RB units undergo pre-shipment inspection (PSI). If there is an issue with 1N2987RB, 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 1N2987RB part is unused and in its original packaging.
Return procedure for 1N2987RB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N2987RB Tags
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