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Microchip Technology JANTX1N4991DUS/TR
- Part No.:
- JANTX1N4991DUS/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- SQ-MELF, E
- Datasheet:
-
JANTX1N4991DUS/TR.pdf
- Description:
- DIODE ZENER 240V 5W E-MELF
- Quantity:
- Payment:
- Shipping:
Inventory:5,233
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Product details
Overview
JANTX1N4991DUS/TR from Microsemi is a military-qualified, hermetically sealed surface-mount Zener diode rated for 5 W power dissipation at 140 °C end-cap temperature, with nominal Zener voltage of 240 V ±5%, dynamic impedance of 650 Ω at 5 mA test current, and operating junction temperature range of −65 °C to +175 °C. It serves as a precision voltage reference and overvoltage clamp in high-reliability aerospace power conditioning circuits.
For engineers reviewing the JANTX1N4991DUS/TR datasheet, JANTX1N4991DUS/TR pinout, JANTX1N4991DUS/TR application, or JANTX1N4991DUS/TR equivalent, this part is selected for mission-critical voltage regulation where radiation hardness, ESD immunity per MIL-STD-750 Method 1020, and long-term parametric stability under thermal cycling are mandatory design requirements.
Technical Context
This device belongs to the MIL-PRF-19500/356 qualified 1N4954US–1N4996US family and uses voidless hard-glass hermetic construction with internal Category I metallurgical bonds. Its Zener breakdown mechanism delivers stable regulation across 10%–50% of maximum Zener current (IZM), with voltage change ΔVZ ≤22 V under that load range.
Thermal resistance is 7 °C/W junction-to-end-cap, enabling reliable 5 W operation up to 140 °C end-cap temperature before linear derating to zero at 175 °C. The cathode band marking and Sn/Pb-finished copper end caps support manual and automated SMT assembly per EIA-481-B tape-and-reel packaging.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 240 V ±5% at IZT = 5 mA - defines precise clamping threshold for overvoltage protection in 200–280 V DC bus systems. |
| Power Dissipation | 5 W @ TEC = 140 °C - supports continuous regulation in compact, conduction-cooled enclosures without forced air. |
| Dynamic Impedance (ZZ) | 650 Ω @ IZT = 5 mA - ensures minimal output voltage shift under varying load currents in feedback-sensing applications. |
| Max Reverse Leakage (IR) | 2 μA @ VR = 192 V - guarantees low standby power loss and signal integrity in high-impedance bias networks. |
| Operating Temperature | −65 °C to +175 °C - enables deployment in satellite power subsystems and downhole drilling electronics. |
| Surge Current (IZSM) | 19.8 A @ 8.3 ms - withstands lightning-induced transients and capacitor discharge events without degradation. |
| Temp Coefficient (αVZ) | +0.115 %/°C - allows predictable drift compensation in wide-temperature-range analog references. |
Pinout & Package
Package: Hermetically sealed voidless hard-glass "E" package (also designated D-5B), with copper end caps finished in Sn/Pb, cathode identified by band marking, weight 539 mg.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential node; carries full forward current up to 1.0 A at ≤1.5 V drop. |
| Cathode | Zener breakdown terminal | Marked with band; connected to higher-potential node; regulates voltage when reverse-biased above 240 V. |
Key Features
| Feature | Design Value |
|---|---|
| Voidless hermetic glass seal | Eliminates moisture ingress and internal delamination, ensuring >20-year parametric stability in vacuum or humid environments. |
| Category I metallurgical bond | Provides mechanical robustness against thermal shock and vibration, validated per MIL-PRF-19500/356 screening. |
| Nonsensitive to ESD | Withstands ≥8 kV HBM per MIL-STD-750 Method 1020 without parameter shift or failure-critical for handling in cleanrooms. |
| Radiation-hardened | Inherently tolerant to total ionizing dose (TID) per MicroNote 050-enables use in LEO and GEO satellite power supplies. |
| Tape-and-reel packaging | EIA-481-B compliant reels support high-yield pick-and-place assembly with zero tombstoning risk due to symmetric mass distribution. |
Applications
| Avionics Power Bus Protection | Satellite DC-DC Converter Reference |
|---|---|
|
Use Scenario: Clamping transient overvoltages on 230 V DC primary bus in UAV flight control power distribution units. IC Role / Device Role / Timing Role: Zener diode acting as shunt regulator and crowbar element during load dump or switching surge events. Use Value: Withstands 19.8 A surge for 8.3 ms and maintains 240 V regulation tolerance within ±5%, preventing downstream converter latch-up. |
Use Scenario: Providing stable voltage reference for error amplifiers in radiation-tolerant 28 V → 240 V isolated DC-DC converters. IC Role / Device Role / Timing Role: Precision Zener reference source with +0.115 %/°C tempco, used in feedback divider network. Use Value: Enables <1% output voltage drift over −55 °C to +125 °C ambient, meeting MIL-STD-704F line regulation requirements. |
| Downhole Instrumentation Biasing | Nuclear Reactor Control Monitoring |
|
Use Scenario: Biasing high-voltage op-amps and isolation amplifiers in borehole logging tools operating at 175 °C ambient. IC Role / Device Role / Timing Role: High-temperature-stable Zener voltage source for sensor excitation and signal conditioning front-ends. Use Value: Guaranteed operation from −65 °C to +175 °C with no parameter screening waiver required per MIL-PRF-19500/356 Class B. |
Use Scenario: Overvoltage detection in safety-critical reactor coolant pump motor drive control circuits. IC Role / Device Role / Timing Role: Fail-safe voltage clamp protecting FPGA-based monitoring logic from 240 V rail faults. Use Value: Hermetic voidless glass construction prevents outgassing and leakage path formation in inert gas-filled enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| JANTXV1N4991DUS/TR | Higher screening level: JANTXV per MIL-PRF-19500/356 includes extended burn-in and 100% lot testing for αVZ and ZZ. | Required for Class K spaceflight avionics where single-event burnout (SEB) immunity must be demonstrated. | Select JANTXV1N4991DUS/TR when radiation environment exceeds 100 krad(Si) TID or SEB testing is mandated. |
| 1N4991US | Commercial-grade version: No MIL-qualified screening; same electrical specs but no temperature cycling or life test data. | Suitable only for non-mission-critical industrial controls with ambient ≤125 °C and no radiation exposure. | Choose 1N4991US only for cost-sensitive prototyping or ground-test fixtures where qualification traceability is not required. |
Compared with JANTX1N4991DUS/TR, JANTXV1N4991DUS/TR adds process controls for extreme radiation environments, while 1N4991US omits military screening-making the JANTX grade the optimal balance of reliability, documentation, and procurement availability for defense and space programs.
Availability
JANTX1N4991DUS/TR is available at Aetrix Electronics and suitable for avionics power bus protection, satellite DC-DC converter reference, and downhole instrumentation biasing requiring stable component supply across extended temperature and radiation environments.
Supply support for JANTX1N4991DUS/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) is a U.S.-based semiconductor company specializing in high-reliability analog and mixed-signal components for aerospace, defense, and industrial markets.
The JANTX1N4991DUS/TR belongs to Microsemi's MIL-PRF-19500/356 qualified Zener diode product line, engineered specifically for voltage regulation and overvoltage protection in mission-critical systems where long-term parametric stability and environmental survivability are non-negotiable.
FAQ
What is the Zener voltage tolerance for JANTX1N4991DUS/TR?
JANTX1N4991DUS/TR has a nominal Zener voltage of 240 V with a standard tolerance of ±5%, consistent with MIL-PRF-19500/356 requirements for the 1N4954US–1N4996US series. Tighter tolerances (e.g., ±2% or ±1%) require different suffixes (C or D), which are not applied to this specific JANTX-grade part.
Does JANTX1N4991DUS/TR require derating above 140 °C?
Yes, JANTX1N4991DUS/TR must be derated linearly above an end-cap temperature (TEC) of 140 °C, reaching zero power dissipation at 175 °C. This derating curve is defined in the absolute maximum ratings table and applies regardless of ambient or board-level cooling method.
Is JANTX1N4991DUS/TR compatible with lead-free reflow processes?
No-JANTX1N4991DUS/TR features Sn/Pb-finished copper end caps and is not qualified for lead-free reflow. Its maximum peak reflow temperature is limited to 235 °C per MIL-STD-202 Method 210, and exposure to lead-free profiles (>260 °C) risks solder joint fracture and hermetic seal compromise.
What is the surge current rating for JANTX1N4991DUS/TR?
JANTX1N4991DUS/TR is rated for a nonrepetitive peak Zener surge current (IZSM) of 19.8 A at an 8.3 ms half-sine waveform, as specified in the Electrical Characteristics table. This value is measured under standardized conditions and must not be exceeded even once without verification of post-surge parameter stability.
How is polarity marked on JANTX1N4991DUS/TR?
JANTX1N4991DUS/TR uses a cathode band marking on the glass body to indicate the cathode terminal. The anode is the unmarked end cap. This polarity identification is consistent across all 1N4954US–1N4996US devices and is critical for correct orientation during PCB placement and functional testing.
JANTX1N4991DUS/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:
- ±1%
- 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
JANTX1N4991DUS/TR FAQ
1.How can I place an order for JANTX1N4991DUS/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for JANTX1N4991DUS/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 JANTX1N4991DUS/TR reliable?
The price and inventory of JANTX1N4991DUS/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for JANTX1N4991DUS/TR is usually 5 days.
3.What payment methods are accepted for JANTX1N4991DUS/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for JANTX1N4991DUS/TR transactions.
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4.How is shipping managed for JANTX1N4991DUS/TR?
JANTX1N4991DUS/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your JANTX1N4991DUS/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 JANTX1N4991DUS/TR?
For technical support, including JANTX1N4991DUS/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your JANTX1N4991DUS/TR requirements.
6.How does Aetrix verify that JANTX1N4991DUS/TR is sourced from the original manufacturer or authorized distributors?
All JANTX1N4991DUS/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 JANTX1N4991DUS/TR meets industry standards.
7.What is the process for return or replacement of JANTX1N4991DUS/TR?
All JANTX1N4991DUS/TR units undergo pre-shipment inspection (PSI). If there is an issue with JANTX1N4991DUS/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 JANTX1N4991DUS/TR part is unused and in its original packaging.
Return procedure for JANTX1N4991DUS/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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