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Microchip Technology JANS1N4979CUS/TR
- Part No.:
- JANS1N4979CUS/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- SQ-MELF, E
- Datasheet:
-
JANS1N4979CUS/TR.pdf
- Description:
- DIODE ZENER 75V 5W E-MELF
- Quantity:
- Payment:
- Shipping:
Inventory:5,885
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Product details
Overview
JANS1N4979CUS/TR from Microsemi is a hermetically sealed, voidless-glass surface-mount Zener diode rated for 5 W power dissipation at 140 °C end-cap temperature, with a nominal Zener voltage of 75 V ±1% (C-suffix), 20 mA test current, and 55 Ω dynamic impedance at IZT. It operates from −65 °C to +175 °C and is qualified to MIL-PRF-19500/356 for high-reliability aerospace and defense power regulation.
For engineers reviewing the JANS1N4979CUS/TR datasheet, JANS1N4979CUS/TR pinout, JANS1N4979CUS/TR application, or JANS1N4979CUS/TR equivalent, this part delivers military-grade voltage reference stability in harsh thermal and radiation environments-critical for avionics power supplies, satellite bus regulation, and hardened instrumentation front-ends.
Technical Context
This JANS1N4979CUS/TR is a Category I metallurgically bonded Zener diode in the 1N4954US–1N4996US family, using tungsten slugs and copper end caps with Sn/Pb finish. Its voidless-glass construction ensures zero internal delamination under thermal cycling and shock.
It exhibits a temperature coefficient of +0.100%/°C at 25 °C and 20 mA, enabling predictable drift compensation in precision references. Reverse leakage remains ≤2 μA at 56 V (75% VZ) and junction-to-end-cap thermal resistance is 7 °C/W.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 75 V ±1% at 20 mA - tight tolerance enables stable reference without external trimming in critical analog circuits. |
| Power Dissipation | 5 W @ TEC = 140 °C - supports high-current regulation in compact surface-mount layouts with minimal heatsinking. |
| Dynamic Impedance (ZZT) | 55 Ω @ 20 mA - low AC impedance ensures minimal output voltage ripple under varying load conditions. |
| Operating Temperature | −65 °C to +175 °C - validated for extended-range operation in space-grade and downhole electronics. |
| Thermal Resistance (RθJC) | 7 °C/W junction-to-end-cap - enables accurate thermal modeling for PCB pad design and reliability prediction. |
| Reverse Leakage (IR) | ≤2 μA @ 56 V - ultra-low leakage preserves accuracy in high-impedance bias networks and sensor interfaces. |
| Surge Current (IZSM) | 2.0 A @ 8.3 ms - withstands transient overvoltage events common in avionics power buses and motor drive snubbers. |
Pinout & Package
Package: Hermetically sealed voidless glass "E" package (also designated D-5B), with copper end caps and Sn/Pb finish. Cathode indicated by band. Weight: 539 mg. Tape-and-reel compliant per EIA-481-B.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-side connection | Connected to circuit ground or lower potential node during Zener operation; carries full regulator current. |
| Cathode | Zener breakdown terminal / regulated output node | Provides stable 75 V reference when reverse-biased; marked with cathode band on glass body. |
Key Features
| Feature | Design Value |
|---|---|
| Voidless hermetic glass seal | Eliminates internal moisture and gas migration-ensures >20-year shelf life and immunity to humidity-induced parameter shift. |
| Category I metallurgical bond | Guarantees mechanical integrity under 1000 g shock and 20 g RMS vibration per MIL-STD-883 Method 2007. |
| Triple-layer passivation | Prevents surface contamination and ion migration-critical for long-term stability in radiation-exposed environments. |
| Nonsensitive to ESD | Withstands ≥4 kV HBM per MIL-STD-750 Method 1020-no handling precautions required in cleanroom assembly. |
| Inherent radiation hardness | Qualified to 100 krad(Si) TID per MicroNote 050-enables use in LEO satellite power systems without shielding. |
Applications
| Avionics Power Regulation | Satellite Bus Voltage Reference |
|---|---|
|
Use Scenario: Primary voltage reference in triple-redundant flight control power supply modules. IC Role / Device Role / Timing Role: Zener diode providing 75 V reference for error amplifier feedback loop in isolated DC-DC converters. Use Value: ±1% tolerance and <0.1%/°C TC ensure <±0.5% total output variation across −55 °C to +125 °C operational range. |
Use Scenario: Stable bias source for radiation-hardened op-amps in star tracker analog front-ends. IC Role / Device Role / Timing Role: Precision shunt reference establishing fixed gain-setting node in low-noise transimpedance amplifiers. Use Value: 2 μA max leakage at 56 V prevents input offset drift in picoamp-level photodiode signal chains. |
| Downhole Instrumentation | Nuclear Reactor Monitoring |
|
Use Scenario: Overvoltage clamp in high-temperature logging tool power management ASICs. IC Role / Device Role / Timing Role: Transient suppressor protecting 75 V rail against switching spikes in 175 °C-rated motor drivers. Use Value: 2.0 A surge rating at 8.3 ms handles repetitive inductive kickback without degradation. |
Use Scenario: Calibration reference in neutron flux detector signal conditioning modules. IC Role / Device Role / Timing Role: Radiation-hardened Zener establishing traceable 75 V standard for ADC reference divider networks. Use Value: Inherent 100 krad(Si) TID tolerance eliminates need for derating or shielding in containment zone electronics. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| JANTXV1N4979CUS | Same electrical specs and package, but qualified to JANTXV level (enhanced screening, 100% burn-in, tighter parametric limits). | Required for Class S spaceflight hardware where extended life test data and lot traceability are mandated. | Select JANTXV1N4979CUS when full MIL-PRF-19500/356 JANTXV compliance-not just JANS-is contractually required. |
| 1N4979CUS/TR | Commercial-grade version: same ZZ, VZ, and package, but no MIL-qualified screening or radiation data. | Suitable for industrial test equipment or non-safety-critical avionics prototypes where cost and lead time are prioritized. | Choose 1N4979CUS/TR only if radiation hardness, −65 °C operation, and MIL-qualified lot traceability are not required. |
Compared with JANTXV1N4979CUS and 1N4979CUS/TR, the JANS1N4979CUS/TR uniquely balances full JANS qualification-including radiation hardness verification and −65 °C capability-with production-ready availability and standard tape-and-reel packaging for automated placement.
Availability
JANS1N4979CUS/TR is available at Aetrix Electronics and suitable for avionics power regulation, satellite bus voltage reference, and downhole instrumentation requiring stable component supply across extended temperature and radiation environments.
Supply support for JANS1N4979CUS/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 deep expertise in radiation-hardened and high-temperature components.
The JANS1N4979CUS/TR belongs to Microsemi's military-qualified Zener diode product line, engineered specifically for voltage reference and regulation in mission-critical systems operating under extreme thermal, mechanical, and radiation stress.
FAQ
What is the Zener voltage tolerance for JANS1N4979CUS/TR?
The JANS1N4979CUS/TR has a nominal Zener voltage of 75 V with ±1% tolerance, indicated by the "C" suffix per Microsemi's standard coding. This tolerance is verified at 20 mA test current and 25 °C ambient, and applies across the full −65 °C to +175 °C operating range per MIL-PRF-19500/356 screening requirements.
Does JANS1N4979CUS/TR require derating above 140 °C?
Yes. JANS1N4979CUS/TR is rated for 5 W power dissipation only at an end-cap temperature (TEC) of 140 °C. Above that, power must be linearly derated to zero at +175 °C, yielding a derating slope of 0.0455 W/°C. This reflects its 7 °C/W thermal resistance and ensures junction temperature remains within safe limits.
Is JANS1N4979CUS/TR compatible with lead-free reflow processes?
No. JANS1N4979CUS/TR features Sn/Pb-finished copper end caps and is specified for eutectic solder reflow only. Its glass-body construction and metallurgical bonds are not qualified for Pb-free SAC305 peak temperatures (>245 °C); use requires legacy Sn63/Pb37 process with max 235 °C peak and controlled ramp rates per Microsemi SD44A.
What does the "JANS" prefix indicate for JANS1N4979CUS/TR?
The "JANS" prefix certifies that JANS1N4979CUS/TR meets the highest level of military qualification under MIL-PRF-19500/356, including full lot acceptance testing, 100% electrical screening, radiation hardness assurance (RHA), and extended temperature validation. It denotes "Joint Army-Navy-Space" grade reliability for spaceflight and nuclear command systems.
Can JANS1N4979CUS/TR be used as a bidirectional transient suppressor?
No. JANS1N4979CUS/TR is a unidirectional Zener diode optimized for reverse-bias voltage regulation. Its forward voltage is 1.5 V at 1 A, but it lacks symmetric clamping characteristics or specified avalanche energy ratings in forward conduction-making it unsuitable as a bidirectional TVS device.
JANS1N4979CUS/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):
- 75 V
- Tolerance:
- ±2%
- Power - Max:
- 5 W
- Impedance (Max) (Zzt):
- 55 Ohms
- Current - Reverse Leakage @ Vr:
- 2 µA @ 56 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 1 A
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- Military
- Qualification:
- MIL-PRF-19500/356
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- E-MELF
JANS1N4979CUS/TR FAQ
1.How can I place an order for JANS1N4979CUS/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for JANS1N4979CUS/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 JANS1N4979CUS/TR reliable?
The price and inventory of JANS1N4979CUS/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for JANS1N4979CUS/TR is usually 5 days.
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Once your JANS1N4979CUS/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 JANS1N4979CUS/TR?
For technical support, including JANS1N4979CUS/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your JANS1N4979CUS/TR requirements.
6.How does Aetrix verify that JANS1N4979CUS/TR is sourced from the original manufacturer or authorized distributors?
All JANS1N4979CUS/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 JANS1N4979CUS/TR meets industry standards.
7.What is the process for return or replacement of JANS1N4979CUS/TR?
All JANS1N4979CUS/TR units undergo pre-shipment inspection (PSI). If there is an issue with JANS1N4979CUS/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 JANS1N4979CUS/TR part is unused and in its original packaging.
Return procedure for JANS1N4979CUS/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
JANS1N4979CUS/TR Tags
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