Microchip Technology JANTXV1N4959US/TR

Overview

JANTXV1N4959US/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 11 V at 125 mA test current, ±5% tolerance, and operates from −65 °C to +175 °C - used in high-reliability voltage regulation for aerospace power conditioning circuits.

For engineers reviewing the JANTXV1N4959US/TR datasheet, JANTXV1N4959US/TR pinout, JANTXV1N4959US/TR application, or JANTXV1N4959US/TR equivalent, key selection criteria include its voidless-glass package, Category I metallurgical bond, 2.5 Ω dynamic impedance at I_ZT, and compliance with MIL-PRF-19500/356 Class V screening.

Technical Context

This device functions as a precision shunt voltage regulator in high-stress environments where thermal stability and radiation hardness are critical. It exhibits a temperature coefficient of ±0.07 %/°C at I_ZT, reverse leakage ≤10 μA at 8.4 V, and maintains regulation across 10–50% of I_ZM (430 mA) with ΔV_Z ≤0.8 V.

The "E" package (D-5B) uses tungsten slugs and copper end caps with Sn/Pb finish, enabling direct solder attachment without adhesive. Its 7 °C/W junction-to-end-cap thermal resistance supports stable operation at T_EC = 140 °C under full 5 W load.

Key Specifications

Pinout & Package

The JANTXV1N4959US/TR uses the "E" package (also designated D-5B), a voidless hermetically sealed glass surface-mount case with tungsten slugs and copper end caps finished in Sn/Pb. Cathode is marked by a band on the glass body. No internal leads - terminals are the two metallized end caps.

Key Features

Applications

Equivalent & Alternatives

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

Compared with JANTXV1N4959US/TR, JANTXV1N4959US offers identical regulation performance but no military screening or radiation assurance, while 1N4959US omits high-temperature capability and hermetic reliability validation - making JANTXV1N4959US/TR the sole choice for flight-critical or nuclear-grade use.

Availability

JANTXV1N4959US/TR is available at Aetrix Electronics and suitable for aerospace power conditioning, downhole sensor biasing, and military avionics requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for JANTXV1N4959US/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 JANTXV1N4959US/TR belongs to Microsemi's legacy MIL-PRF-19500/356-qualified Zener series, engineered specifically for mission-critical voltage regulation where failure is not an option - emphasizing hermeticity, radiation tolerance, and extreme-temperature operation.

FAQ

What is the Zener voltage tolerance for JANTXV1N4959US/TR?

The JANTXV1N4959US/TR has a nominal Zener voltage of 11 V with a standard tolerance of ±5%, as specified in the Microsemi SD44A datasheet. This tolerance applies at 25 °C and I_ZT = 125 mA. Tighter tolerances (e.g., ±2% or ±1%) require different suffixes (C or D), which are not present in this part number.

Does JANTXV1N4959US/TR require heatsinking in a 5 W application?

JANTXV1N4959US/TR is rated for 5 W at T_EC = 140 °C, meaning it relies on end-cap conduction to a thermally managed PCB pad - no discrete heatsink is needed if the board layout provides adequate copper area and thermal vias. Its 7 °C/W junction-to-end-cap resistance enables full-power operation within its −65 °C to +175 °C range when properly mounted.

Is JANTXV1N4959US/TR compatible with lead-free reflow processes?

JANTXV1N4959US/TR features Sn/Pb-finished copper end caps and is qualified for traditional eutectic solder reflow. While it can survive lead-free peak temperatures (≤260 °C), Microsemi's documentation does not certify it for Pb-free process compliance. For RoHS-compliant designs, consult Microchip's updated guidance or consider alternative qualified parts.

What is the surge current rating of JANTXV1N4959US/TR?

JANTXV1N4959US/TR is rated for a nonrepetitive peak Zener surge current (I_ZSM) of 19 A at an 8.3 ms half-sine waveform, as confirmed in the SD44A datasheet. This rating reflects its ability to absorb transient energy without parametric shift or catastrophic failure - critical for load-dump and ESD protection roles.

How is polarity identified on JANTXV1N4959US/TR?

JANTXV1N4959US/TR uses a cathode band - a visible opaque ring near one end of the glass body - to indicate the cathode terminal. The unmarked end is the anode. This marking aligns with JEDEC-standard orientation for surface-mount Zeners and must be observed during PCB layout to ensure correct reverse-bias connection.