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Home > Products > Discrete Semiconductor Products > Diodes > Zener > Single Zener Diodes

Microchip Technology JANTX1N4991CUS/TR

Name: JANTX1N4991CUS/TR
Brand: Microchip Technology
SKU: JANTX1N4991CUS/TR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: JANTX1N4991CUS/TR

Manufacturer:: Microchip Technology

Category:: Single Zener Diodes

Package:: SQ-MELF, E

Datasheet:: JANTX1N4991CUS/TR.pdf

Description:: DIODE ZENER 240V 5W E-MELF

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Product details

Overview

JANTX1N4991US/TR from Microsemi is a military-grade, hermetically sealed surface-mount Zener diode rated for 5 W power dissipation, with a nominal Zener voltage of 240 V at 5 mA test current, ±5% tolerance, and maximum reverse leakage of 2 μA at 182 V. It operates across –65 °C to +175 °C and is used in high-reliability voltage regulation for avionics power conditioning and radiation-hardened instrumentation.

For engineers reviewing the JANTX1N4991US/TR datasheet, JANTX1N4991US/TR pinout, JANTX1N4991US/TR application, or JANTX1N4991US/TR equivalent, this part serves as a voidless-glass, Category I metallurgically bonded Zener regulator requiring no derating below 140 °C end-cap temperature and offering 0.115 %/°C temperature coefficient for precision reference stability in harsh environments.

Technical Context

This device belongs to the MIL-PRF-19500/356 qualified 1N4954US–1N4996US series, featuring triple-layer passivation and internal tungsten-slug construction for enhanced thermal and mechanical robustness. Its Zener breakdown mechanism delivers stable regulation over wide current (10%–50% IZM) and temperature ranges, with dynamic impedance of 650 Ω at 5 mA and 2000 Ω near the knee (IZK = 5 mA).

The "JANTX" prefix confirms JAN-level screening per MIL-PRF-19500, including extended temperature cycling, hermeticity testing, and radiation hardness per MicroNote 050. The "TR" suffix indicates tape-and-reel packaging per EIA-481-B, while the "US" denotes surface-mount "E" package (D-5B), distinct from axial-leaded equivalents.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	240 V ±5% at I_ZT = 5 mA - sets precise regulation point for high-voltage biasing and clamping circuits
Power Dissipation	5 W @ T_EC = 140 °C - defines maximum continuous thermal load before linear derating to zero at 175 °C
Dynamic Impedance	650 Ω @ I_ZT = 5 mA - determines output voltage variation under load transients; lower values improve regulation fidelity
Reverse Leakage (I_R)	2 μA max at V_R = 182 V - ensures minimal parasitic current in high-impedance reference paths
Temp. Coefficient (αV_Z)	+0.115 %/°C - quantifies voltage drift with ambient change; critical for systems operating across –65 °C to +175 °C
Max. Surge Current	19.8 A @ 8.3 ms - supports transient overvoltage suppression without failure in aerospace surge events
Forward Voltage	1.5 V @ 1.0 A - defines conduction loss during forward-bias fault conditions or polarity protection use

Pinout & Package

Package: Hermetically sealed voidless glass "E" package (also designated D-5B), with copper end caps finished in Sn/Pb, cathode indicated by band, weight 539 mg, and EIA-481-B tape-and-reel compatible.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward conduction terminal	Connected to lower-potential node in reverse-biased Zener operation; carries full surge current during clamping
Cathode	Zener breakdown terminal	Marked with band; connected to regulated voltage rail; must be held at higher potential than anode for regulation

Key Features

Feature	Design Value
Voidless hermetic glass seal	Prevents moisture ingress and internal corrosion, enabling >20-year field life in sealed avionics enclosures
Category I metallurgical bond	Ensures mechanical integrity under shock/vibration up to 100 g and thermal cycling from –65 °C to +175 °C
Nonsensitive to ESD	Withstands >4 kV HBM per MIL-STD-750 Method 1020 without parameter shift or failure
Radiation hardness	Qualified to 100 krad(Si) TID per MicroNote 050 - suitable for low-earth orbit satellite power subsystems
Triple-layer passivation	Reduces surface leakage and enhances long-term stability of Zener voltage in humid or contaminated environments

Applications

Aerospace Power Bus Clamping	High-Voltage Instrumentation Reference
Use Scenario: Protection of 200–280 V DC aircraft power distribution bus against lightning-induced transients. IC Role / Device Role / Timing Role: Zener diode operating in reverse breakdown to clamp surges above 240 V while sinking up to 19.8 A peak. Use Value: Prevents downstream converter damage by limiting bus overvoltage to ≤274 V (1.15 × V_Z) with <2 μA leakage at nominal bus voltage.	Use Scenario: Stable voltage reference for 16-bit ADC front-end in radiation-tolerant telemetry modules. IC Role / Device Role / Timing Role: Precision shunt reference providing 240 V bias with <±0.115 %/°C drift across mission temperature range. Use Value: Enables <±0.02% full-scale accuracy over –55 °C to +125 °C without active compensation circuitry.
Avionics Sensor Bias Supply	Military Radar HV Bias Regulation
Use Scenario: Biasing of piezoelectric accelerometers and MEMS gyros requiring stable high-voltage excitation. IC Role / Device Role / Timing Role: Shunt regulator maintaining 240 V supply despite input ripple and load variations up to 1.4 mA. Use Value: Delivers <10 ppm/°C effective stability via low dynamic impedance (650 Ω) and tight 5% initial tolerance.	Use Scenario: Regulation of 200–250 V modulator supply in ground-based radar transmitter stages. IC Role / Device Role / Timing Role: High-reliability Zener regulating HV gate drive rails where failure would disable entire transmit chain. Use Value: Guarantees uninterrupted operation with MIL-qualified screening, 175 °C junction rating, and 100 krad(Si) TID tolerance.

Aerospace Power Bus Clamping

High-Voltage Instrumentation Reference

Use Scenario: Protection of 200–280 V DC aircraft power distribution bus against lightning-induced transients.

IC Role / Device Role / Timing Role: Zener diode operating in reverse breakdown to clamp surges above 240 V while sinking up to 19.8 A peak.

Use Value: Prevents downstream converter damage by limiting bus overvoltage to ≤274 V (1.15 × V_Z) with <2 μA leakage at nominal bus voltage.

Use Scenario: Stable voltage reference for 16-bit ADC front-end in radiation-tolerant telemetry modules.

IC Role / Device Role / Timing Role: Precision shunt reference providing 240 V bias with <±0.115 %/°C drift across mission temperature range.

Use Value: Enables <±0.02% full-scale accuracy over –55 °C to +125 °C without active compensation circuitry.

Avionics Sensor Bias Supply

Military Radar HV Bias Regulation

Use Scenario: Biasing of piezoelectric accelerometers and MEMS gyros requiring stable high-voltage excitation.

IC Role / Device Role / Timing Role: Shunt regulator maintaining 240 V supply despite input ripple and load variations up to 1.4 mA.

Use Value: Delivers <10 ppm/°C effective stability via low dynamic impedance (650 Ω) and tight 5% initial tolerance.

Use Scenario: Regulation of 200–250 V modulator supply in ground-based radar transmitter stages.

IC Role / Device Role / Timing Role: High-reliability Zener regulating HV gate drive rails where failure would disable entire transmit chain.

Use Value: Guarantees uninterrupted operation with MIL-qualified screening, 175 °C junction rating, and 100 krad(Si) TID tolerance.

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener voltage regulation applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
JANTXV1N4991US	Higher screening level (JANTXV per MIL-PRF-19500/356); tighter lot acceptance testing and 100% burn-in	Required for Class H (spaceflight) and Class K (nuclear survivability) programs where zero defect risk is mandated	Select JANTXV1N4991US when mission-critical redundancy or single-fault tolerance justifies premium cost and longer lead time
1N4991US	Commercial-grade version; no MIL screening, wider parametric spread, and no radiation hardness validation	Suitable only for non-mission-critical industrial test equipment or lab prototypes not subject to environmental stress screening	Choose 1N4991US for cost-sensitive development builds where full JAN qualification is unnecessary

Compared with JANTX1N4991US/TR, JANTXV1N4991US adds burn-in and tighter lot controls for space-grade reliability, while 1N4991US omits all military screening-making the JANTX variant the optimal balance of assured performance and procurement availability for defense electronics production.

Availability

JANTX1N4991US/TR is available at Aetrix Electronics and suitable for aerospace power conditioning, radiation-hardened instrumentation, and avionics sensor biasing requiring stable component supply across extended temperature and radiation environments.

Supply support for JANTX1N4991US/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 defense, aerospace, and industrial markets.

The JANTX1N4991US/TR belongs to Microsemi's legacy MIL-PRF-19500/356 Zener diode family, engineered specifically for voltage regulation in mission-critical systems where hermetic sealing, radiation tolerance, and extreme temperature operation are mandatory.

FAQ

What is the Zener voltage tolerance for JANTX1N4991US/TR?

JANTX1N4991US/TR has a nominal Zener voltage of 240 V with a standard tolerance of ±5%, as specified in the Microsemi SD44A datasheet. This tolerance applies at 25 °C and I_ZT = 5 mA, and is maintained across the full military temperature range due to the device's Category I metallurgical bond and triple-layer passivation.

Does JANTX1N4991US/TR require heatsinking in 5 W operation?

JANTX1N4991US/TR is rated for 5 W at T_EC = 140 °C, meaning its end-cap temperature must be held at or below 140 °C for full power operation. With a junction-to-end-cap thermal resistance of 7 °C/W, it can dissipate 5 W without external heatsinking only if PCB copper area and ambient conditions maintain T_EC ≤140 °C; forced air or thermal vias are recommended for sustained loads.

Is JANTX1N4991US/TR radiation-hardened?

Yes, JANTX1N4991US/TR is inherently radiation-hardened to 100 krad(Si) total ionizing dose (TID), as documented in Microsemi MicroNote 050. This qualification stems from its voidless hermetic glass construction and tungsten-slug design, making it suitable for low-earth orbit satellite power systems and nuclear instrumentation.

What does the "TR" suffix indicate in JANTX1N4991US/TR?

The "TR" suffix in JANTX1N4991US/TR specifies tape-and-reel packaging per EIA-481-B standards, enabling automated SMT placement. This format includes orientation control, carrier tape specifications, and reel quantity compliance-distinct from bulk or ammo-pack options-and is required for high-volume defense electronics assembly lines.

How does JANTX1N4991US/TR differ from commercial 1N4991US?

JANTX1N4991US/TR undergoes full MIL-PRF-19500/356 screening-including temperature cycling, hermeticity testing, and lot acceptance tests-while 1N4991US is commercial-grade with no military qualification. JANTX1N4991US/TR also guarantees radiation hardness and tighter parametric limits, making it suitable for flight-critical avionics where 1N4991US is not authorized.

JANTX1N4991CUS/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

JANTX1N4991CUS/TR FAQ

1.How can I place an order for JANTX1N4991CUS/TR through Aetrix?

Please submit a Request for Quotation (RFQ) for JANTX1N4991CUS/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 JANTX1N4991CUS/TR reliable?

The price and inventory of JANTX1N4991CUS/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for JANTX1N4991CUS/TR is usually 5 days.

3.What payment methods are accepted for JANTX1N4991CUS/TR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for JANTX1N4991CUS/TR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for JANTX1N4991CUS/TR?

JANTX1N4991CUS/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your JANTX1N4991CUS/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 JANTX1N4991CUS/TR?

For technical support, including JANTX1N4991CUS/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your JANTX1N4991CUS/TR requirements.

6.How does Aetrix verify that JANTX1N4991CUS/TR is sourced from the original manufacturer or authorized distributors?

All JANTX1N4991CUS/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 JANTX1N4991CUS/TR meets industry standards.

7.What is the process for return or replacement of JANTX1N4991CUS/TR?

All JANTX1N4991CUS/TR units undergo pre-shipment inspection (PSI). If there is an issue with JANTX1N4991CUS/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 JANTX1N4991CUS/TR part is unused and in its original packaging.

Return procedure for JANTX1N4991CUS/TR:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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