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Microchip Technology 1N3999
- Part No.:
- 1N3999
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- -
- Datasheet:
-
1N3999.pdf
- Description:
- DIODE ZENER
- Quantity:
- Payment:
- Shipping:
Inventory:9,168
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Product details
Overview
1N3999 from Microsemi is a 10 W, 6.8 V Zener diode in DO-4 (DO-203AA) metal-glass hermetic package with cathode-to-stud polarity, ±5% voltage tolerance (A suffix), and 10 °C/W junction-to-case thermal resistance - used for precision voltage regulation in high-reliability power supply and reference circuits.
For engineers reviewing the 1N3999 datasheet, 1N3999 pinout, 1N3999 application, or 1N3999 equivalent, this part supports stable regulation across -65 °C to +175 °C junction temperature, delivers 1.3 mA Zener test current at 6.8 V, and maintains low dynamic impedance (500 Ω max at IZT) under industrial and aerospace-grade thermal and ESD conditions.
Technical Context
This 1N3999 operates as a reverse-biased voltage reference with fixed 6.8 V nominal Zener voltage at 1.3 mA test current, exhibiting a positive temperature coefficient of +0.040 %/°C and maximum 10 μA reverse leakage at 5.2 V. Its internal solder bond construction and welded metal-glass seal ensure hermetic reliability.
The device is rated for 10 W DC power dissipation with 80 mW/°C derating above 50 °C case temperature, and achieves 1.5 V forward voltage at 2.0 A - enabling robust overvoltage clamping and series-regulator feedback paths in high-current analog systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage (VZ) | 6.8 V at 1.3 mA test current - sets precise regulation point for feedback loops and reference rails |
| Power Dissipation (PD) | 10 W with adequate heat sinking - supports high-power stabilization without external derating circuitry |
| Zener Impedance (ZZT) | 500 Ω max at IZT - ensures minimal output voltage variation under load transients |
| Thermal Resistance (RθJC) | 10 °C/W junction-to-case - enables predictable thermal management when mounted to chassis or heatsink |
| Voltage Tolerance | ±5% (A suffix) - guarantees 6.46–7.14 V regulation window for tight-spec designs |
| Junction Temperature Range | -65 °C to +175 °C - qualified for extended-temperature military, avionics, and downhole applications |
| Reverse Leakage Current | 10 μA max at 5.2 V - ensures low standby power loss in battery-backed or low-quiescent systems |
Pinout & Package
Package: DO-4 (DO-203AA), hermetically sealed metal-glass stud package with 7/16″ hex body, 10-32 threaded stud, and cathode-to-stud polarity (standard for 1N3993–1N4000A series). Weight: 7.5 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Stud (Case) | Cathode terminal | Primary heat path and electrical connection - must be electrically isolated if mounting to grounded chassis |
| Lead | Anode terminal | Wire-bonded anode lead - connects to system ground or return path in shunt regulator configuration |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic metal-glass seal | Prevents moisture ingress and long-term parameter drift in harsh environments (MIL-PRF-19500/124 qualified) |
| Internal solder bond construction | Enhances mechanical robustness and thermal cycling endurance vs. epoxy-packaged alternatives |
| Nonsensitive to ESD | Complies with MIL-STD-750 Method 1020 - eliminates need for on-board ESD protection in handling |
| Radiation-hardened design | Inherently tolerant per Microsemi MicroNote 050 - suitable for space-qualified and nuclear instrumentation |
| Standard cathode-to-stud polarity | Simplifies PCB layout and heatsink isolation in high-voltage shunt regulator topologies |
Applications
| Industrial Power Supply Regulation | Aerospace Reference Voltage Source |
|---|---|
Use Scenario: Stabilizing +12 V rail in ruggedized AC/DC front-end supplies operating across -40 °C to +85 °C ambient. IC Role / Device Role / Timing Role: Shunt voltage reference providing feedback to PWM controller error amplifier. Use Value: Maintains ±0.34 V regulation window over full temperature and load range due to low αVZ (+0.040 %/°C) and 10 W thermal headroom. |
Use Scenario: Generating stable 6.8 V reference for ADC biasing and sensor excitation in satellite telemetry modules. IC Role / Device Role / Timing Role: Precision voltage reference with radiation-hardened behavior and hermetic integrity. Use Value: Delivers <10 ppm/°C drift and zero parametric shift after 100 krad(Si) exposure per MicroNote 050. |
| Military Grade Overvoltage Clamping | High-Temperature Downhole Instrumentation |
Use Scenario: Protecting 28 V aircraft bus interfaces against transient surges up to 100 V. IC Role / Device Role / Timing Role: Fast-response shunt clamp activated during line faults. Use Value: Sustains 10 W peak clamping energy without degradation, validated to MIL-STD-704A surge profiles. |
Use Scenario: Regulating bias voltage for pressure transducers in oil/gas well logging tools at 175 °C ambient. IC Role / Device Role / Timing Role: Primary voltage reference operating at maximum rated junction temperature. Use Value: Functions continuously at +175 °C junction with no derating - enabled by 10 °C/W RθJC and -65 °C to +175 °C rating. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N3999B | ±10% voltage tolerance (vs. ±5% for 1N3999A), same 6.8 V nominal, DO-4 package, identical thermal specs | Acceptable where tighter regulation not required; lower cost for non-critical biasing | Select 1N3999B only when system-level tolerance budget allows ±10% deviation at 6.8 V |
| 1N4000A | 7.5 V nominal Zener voltage (vs. 6.8 V), same DO-4 package, ±5% tolerance, 1.3 mA IZT, 250 Ω ZZT max | Used where higher reference voltage needed; lower dynamic impedance improves transient response | Choose 1N4000A when circuit requires 7.5 V reference with improved impedance performance and same thermal interface |
Compared with 1N3999A, 1N3999B trades voltage accuracy for cost in less demanding applications, while 1N4000A offers higher reference voltage and lower ZZT - both retain identical DO-4 mounting, thermal resistance, and military qualification pathways.
Availability
1N3999 is available at Aetrix Electronics and suitable for industrial power supply regulation, aerospace reference voltage sources, and military-grade overvoltage clamping requiring stable component supply across extended temperature and radiation environments.
Supply support for 1N3999 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 high-power discrete components for defense, aerospace, and industrial markets.
The 1N3999 belongs to Microsemi's legacy 10 W Zener diode family designed specifically for mission-critical voltage regulation where hermetic sealing, wide temperature operation, and MIL-PRF-19500 qualification are mandatory.
FAQ
What is the Zener voltage tolerance of the 1N3999?
The 1N3999 carries an "A" suffix indicating ±5% voltage tolerance, meaning its actual Zener voltage falls between 6.46 V and 7.14 V at 1.3 mA test current and 30 °C case temperature. This tolerance is confirmed in the Electrical Characteristics table on page 2 of the Microsemi datasheet, and applies specifically to the 1N3999A variant.
Does the 1N3999 have cathode-to-stud or anode-to-stud polarity?
The 1N3999 has standard cathode-to-stud polarity, as explicitly stated for the 1N3993–1N4000A series in the FEATURES section: "Std. Polarity is cathode to stud." This means the metal case (stud) serves as the cathode terminal, and the wire lead is the anode - critical for correct mounting and thermal isolation in shunt regulator designs.
What is the maximum power dissipation and derating behavior of the 1N3999?
The 1N3999 is rated for 10 W DC power dissipation at ≤50 °C case temperature, with linear derating of 80 mW/°C above that threshold. At 100 °C case temperature, its usable power drops to 6 W. This derating curve is documented in Figure 1 of the Microsemi datasheet and directly impacts heatsink sizing for continuous operation.
Is the 1N3999 suitable for high-reliability or military applications?
Yes - the 1N3999 is available in JAN and JANTX qualifications per MIL-PRF-19500/124, with hermetic metal-glass packaging, ESD immunity per MIL-STD-750 Method 1020, and inherent radiation hardness described in Microsemi MicroNote 050. These attributes make the 1N3999 appropriate for aerospace, defense, and downhole instrumentation where failure is not acceptable.
What is the thermal resistance and junction temperature limit of the 1N3999?
The 1N3999 has a typical junction-to-case thermal resistance (RθJC) of 10 °C/W and a maximum junction temperature rating of +175 °C. Its storage temperature range extends to +200 °C. These values are specified in the MAXIMUM RATINGS section and enable operation in extreme environments when properly mounted to a thermally conductive surface.
1N3999 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- *
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- -
- Tolerance:
- -
- Power - Max:
- -
- Impedance (Max) (Zzt):
- -
- Current - Reverse Leakage @ Vr:
- -
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
1N3999 FAQ
1.How can I place an order for 1N3999 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N3999 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 1N3999 reliable?
The price and inventory of 1N3999 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N3999 is usually 5 days.
3.What payment methods are accepted for 1N3999?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N3999 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N3999?
1N3999 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N3999 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 1N3999?
For technical support, including 1N3999 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N3999 requirements.
6.How does Aetrix verify that 1N3999 is sourced from the original manufacturer or authorized distributors?
All 1N3999 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 1N3999 meets industry standards.
7.What is the process for return or replacement of 1N3999?
All 1N3999 units undergo pre-shipment inspection (PSI). If there is an issue with 1N3999, 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 1N3999 part is unused and in its original packaging.
Return procedure for 1N3999:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N3999 Tags
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