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Microchip Technology JANS1N4991CUS/TR
- Part No.:
- JANS1N4991CUS/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- SQ-MELF, E
- Datasheet:
-
JANS1N4991CUS/TR.pdf
- Description:
- DIODE ZENER 240V 5W E-MELF
- Quantity:
- Payment:
- Shipping:
Inventory:4,686
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Product details
Overview
JANS1N4991CUS/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 nominal Zener voltage of 240 V ±1% (C-suffix), dynamic impedance of 650 Ω at 5 mA test current, and maximum reverse leakage of 2 μA at 182 V. It serves as a precision voltage reference and overvoltage clamp in radiation-hardened, high-reliability military power conditioning circuits.
For engineers reviewing the JANS1N4991CUS/TR datasheet, JANS1N4991CUS/TR pinout, JANS1N4991CUS/TR application, or JANS1N4991CUS/TR equivalent, key selection criteria include its MIL-PRF-19500/356 qualification, Category I metallurgical bond, -65 °C to +175 °C operating range, and 0.115 %/°C temperature coefficient - critical for stable regulation in aerospace avionics and satellite power subsystems.
Technical Context
This device operates in reverse breakdown mode with tightly controlled Zener voltage regulation across 10–50% of IZM (22 mA), exhibiting ΔVZ ≤ 22 V per Note 1. Its voidless glass package with tungsten slugs and copper end caps enables robust thermal conduction (7 °C/W junction-to-end-cap) and ESD immunity per MIL-STD-750 Method 1020.
The JANS1N4991CUS/TR belongs to the 1N4954US–1N4996US family, distinguished by Category I internal metallurgical bonds and triple-layer passivation. It delivers inherent radiation hardness per MicroNote 050 and supports surge currents up to 1.6 A (8.3 ms square wave) without degradation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 240 V ±1% at 5 mA - enables precise 240 V rail clamping with minimal tolerance drift under load. |
| Power Dissipation | 5 W @ TEC = 140 °C - supports continuous operation in high-temperature military enclosures without forced cooling. |
| Dynamic Impedance (ZZ) | 650 Ω @ IZT = 5 mA - ensures stable regulation against line/load transients in low-current reference paths. |
| Reverse Leakage (IR) | 2 μA @ VR = 182 V - guarantees negligible standby current in high-impedance sensing circuits. |
| Temp. Coefficient (αVZ) | +0.115 %/°C - allows predictable voltage shift compensation in wide-temperature-range systems. |
| Surge Current (IZSM) | 1.6 A (8.3 ms) - withstands lightning-induced transients in vehicle-mounted power interfaces. |
| Operating Temperature | -65 °C to +175 °C - certified for use in space-grade thermal cycling environments without derating. |
Pinout & Package
Package: Hermetically sealed voidless hard glass case with tungsten slugs and copper end caps (E package / D-5B outline); polarity indicated by cathode band; weight 539 mg; RoHS-compliant Sn/Pb termination.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential node; conducts <1.5 V @ 1 A during forward bias. |
| Cathode | Zener breakdown terminal | Marked with band; referenced to system ground or return path for regulated voltage output. |
Key Features
| Feature | Design Value |
|---|---|
| Voidless hermetic glass seal | Eliminates moisture ingress and internal voids, ensuring >20-year reliability in vacuum and humid environments. |
| Category I metallurgical bond | Provides mechanical integrity under shock/vibration per MIL-STD-883, critical for launch-phase survivability. |
| Triple-layer passivation | Prevents surface contamination and leakage path formation on glass surface in high-humidity storage. |
| Nonsensitive to ESD | Withstands ≥8 kV HBM per MIL-STD-750 Method 1020 without parameter shift or failure. |
| Inherent radiation hardness | Qualified to 100 krad(Si) TID per MicroNote 050 - no shielding required in LEO satellite power rails. |
Applications
| Avionics Power Conditioning | Satellite Bus Voltage Regulation |
|---|---|
|
Use Scenario: Stabilizing 240 V primary bus in airborne radar transmitters subject to wide ambient swings (-55 °C to +125 °C). IC Role / Device Role / Timing Role: Zener voltage reference and overvoltage clamp protecting downstream DC-DC converters. Use Value: Maintains regulation within ±1.2 V over full temperature range due to tight 1% tolerance and low αVZ. |
Use Scenario: Providing reference voltage for telemetry ADCs in geostationary communication satellites exposed to total ionizing dose. IC Role / Device Role / Timing Role: Radiation-hardened voltage reference enabling accurate sensor readout over mission lifetime. Use Value: Delivers stable 240 V output after 100 krad(Si) exposure, eliminating need for redundant calibration circuitry. |
| Tactical Vehicle Power Protection | Nuclear Instrumentation Systems |
|
Use Scenario: Clamping 240 V battery-fed control systems in armored vehicles subjected to load-dump transients. IC Role / Device Role / Timing Role: Transient voltage suppressor absorbing 1.6 A surge pulses without degradation. Use Value: Survives repeated 8.3 ms surges per ISO 7637-2 Pulse 5a, reducing field failure rates by >90% vs. commercial Zeners. |
Use Scenario: Biasing high-voltage photomultiplier tubes in reactor monitoring equipment requiring ultra-low leakage. IC Role / Device Role / Timing Role: Low-leakage (2 μA) voltage reference ensuring signal fidelity in neutron detection circuits. Use Value: Prevents false trip events caused by leakage-induced offset drift in analog front-end amplifiers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| JANTXV1N4991CUS/TR | Same electrical specs but qualified to JANTXV level (enhanced screening, 100% lot testing). | Required for Class S spaceflight hardware where burn-in and radiation lot acceptance testing are mandated. | Select JANTXV1N4991CUS/TR when full MIL-PRF-19500/356 Class S compliance is contractually required. |
| 1N4991CUS/TR | Commercial-grade version; identical Zener voltage, impedance, and thermal specs but no MIL-PRF-19500 qualification. | Suitable for industrial test equipment or non-mission-critical avionics where radiation hardness is not needed. | Choose 1N4991CUS/TR for cost-sensitive prototyping or ground-support equipment with relaxed reliability requirements. |
Compared with JANS1N4991CUS/TR, JANTXV1N4991CUS/TR adds screening rigor for flight-critical use, while 1N4991CUS/TR removes military qualification overhead for terrestrial R&D - both share identical Zener characteristics and D-5B packaging.
Availability
JANS1N4991CUS/TR is available at Aetrix Electronics and suitable for avionics power conditioning, satellite bus voltage regulation, and nuclear instrumentation systems requiring stable component supply with guaranteed traceability and long-term obsolescence management.
Supply support for JANS1N4991CUS/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 semiconductor components for aerospace, defense, and industrial markets, with deep expertise in radiation-hardened and hermetic packaging technologies.
The JANS1N4991CUS/TR belongs to Microsemi's MIL-PRF-19500/356-qualified Zener regulator family, engineered specifically for voltage reference and transient suppression in mission-critical power systems where failure is not an option.
FAQ
What is the Zener voltage tolerance and test current for JANS1N4991CUS/TR?
JANS1N4991CUS/TR has a nominal Zener voltage of 240 V with ±1% tolerance (C-suffix), measured at a test current IZT of 5 mA. This tight tolerance ensures predictable clamping behavior in precision reference circuits where voltage accuracy directly impacts system-level calibration stability.
Does JANS1N4991CUS/TR meet MIL-PRF-19500/356 requirements?
Yes, JANS1N4991CUS/TR is fully qualified to MIL-PRF-19500/356 as a JAN-class device, including Category I metallurgical bonds, voidless hermetic glass construction, and screening per Method 5005. It carries full traceability documentation required for DoD procurement and space program acceptance.
What is the maximum operating temperature and thermal resistance of JANS1N4991CUS/TR?
JANS1N4991CUS/TR operates from -65 °C to +175 °C and exhibits a junction-to-end-cap thermal resistance of 7 °C/W. This allows full 5 W power dissipation at end-cap temperatures up to 140 °C, making it suitable for conduction-cooled chassis in high-temperature military platforms.
How does the radiation hardness of JANS1N4991CUS/TR compare to commercial Zeners?
JANS1N4991CUS/TR provides inherent radiation hardness to 100 krad(Si) total ionizing dose per MicroNote 050, unlike commercial Zeners which typically degrade above 10 krad. This eliminates need for shielding or derating in low-earth-orbit satellite power supplies where cumulative radiation exposure is unavoidable.
Is JANS1N4991CUS/TR compatible with standard surface-mount reflow profiles?
Yes, JANS1N4991CUS/TR uses Sn/Pb terminations and is qualified for standard Pb-based reflow profiles (peak 220 °C, 60-second dwell). Its voidless glass body withstands thermal shock without cracking, supporting automated assembly in high-reliability production lines compliant with J-STD-020.
JANS1N4991CUS/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):
- 240 V
- Tolerance:
- ±2%
- Power - Max:
- 5 W
- Impedance (Max) (Zzt):
- 650 Ohms
- Current - Reverse Leakage @ Vr:
- 2 µA @ 182 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
JANS1N4991CUS/TR FAQ
1.How can I place an order for JANS1N4991CUS/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for JANS1N4991CUS/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 JANS1N4991CUS/TR reliable?
The price and inventory of JANS1N4991CUS/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for JANS1N4991CUS/TR is usually 5 days.
3.What payment methods are accepted for JANS1N4991CUS/TR?
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4.How is shipping managed for JANS1N4991CUS/TR?
JANS1N4991CUS/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your JANS1N4991CUS/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 JANS1N4991CUS/TR?
For technical support, including JANS1N4991CUS/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your JANS1N4991CUS/TR requirements.
6.How does Aetrix verify that JANS1N4991CUS/TR is sourced from the original manufacturer or authorized distributors?
All JANS1N4991CUS/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 JANS1N4991CUS/TR meets industry standards.
7.What is the process for return or replacement of JANS1N4991CUS/TR?
All JANS1N4991CUS/TR units undergo pre-shipment inspection (PSI). If there is an issue with JANS1N4991CUS/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 JANS1N4991CUS/TR part is unused and in its original packaging.
Return procedure for JANS1N4991CUS/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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