Microchip Technology JANTX1N4964CUS/TR

Overview

JANTX1N4964CUS/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 18 V at 65 mA test current, ±2% tolerance (C suffix), and operating junction temperature range of –65 °C to +175 °C. It serves as a precision voltage reference or overvoltage clamp in high-reliability aerospace power conditioning circuits.

For engineers reviewing the JANTX1N4964CUS/TR datasheet, JANTX1N4964CUS/TR pinout, JANTX1N4964CUS/TR application, or JANTX1N4964CUS/TR equivalent, key selection criteria include its voidless-glass package, Category III metallurgical bond, radiation-hardened construction per MicroNote 050, and compliance with MIL-PRF-19500/356 Class JANTX.

Technical Context

This device belongs to the 1N4954US–1N4996US family, fabricated using triple-layer passivated, voidless hermetic glass construction with internal tungsten slugs and copper end caps finished with Sn/Pb. Its Category III metallurgical bond ensures mechanical robustness under thermal shock and vibration.

It operates across –65 °C to +175 °C with 7 °C/W junction-to-end-cap thermal resistance and delivers stable regulation with dynamic impedance of 4.0 Ω at 65 mA, reverse leakage ≤5 μA at 13.7 V, and temperature coefficient of +0.085 %/°C - enabling use in unregulated DC rails where drift must remain bounded.

Key Specifications

Pinout & Package

Package: Hermetically sealed voidless glass "E" package (also designated D-5B), surface-mount, cathode indicated by band, weight 539 mg, tape-and-reel compliant per EIA-481-B.

Key Features

Applications

Equivalent & Alternatives

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

Compared with JANTX1N4964CUS/TR, JANTXV1N4964CUS/TR adds burn-in and parametric screening for mission-critical use, while 1N4964US omits military qualification entirely - making JANTX1N4964CUS/TR the optimal balance of reliability, documentation, and procurement availability for flight-qualified hardware.

Availability

JANTX1N4964CUS/TR is available at Aetrix Electronics and suitable for aerospace power conditioning, avionics sensor referencing, and satellite payload supervision requiring stable component supply across extended temperature and radiation environments.

Supply support for JANTX1N4964CUS/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 emphasis on radiation-hardened, high-temperature, and MIL-spec components.

The JANTX1N4964CUS/TR belongs to Microsemi's legacy military Zener diode product line, engineered specifically for voltage regulation in mission-critical systems where failure is not an option - including launch vehicle power distribution and spacecraft telemetry subsystems.

FAQ

What is the Zener voltage tolerance for JANTX1N4964CUS/TR?

JANTX1N4964CUS/TR has a nominal Zener voltage of 18 V with ±2% tolerance, indicated by the "C" suffix per Microsemi's ordering nomenclature. This tolerance is verified at 25 °C and maintained across the full –65 °C to +175 °C operating range per MIL-PRF-19500/356 screening requirements. The JANTX1N4964CUS/TR datasheet specifies ΔV_Z ≤0.1 V between 10% and 50% of I_ZM, confirming tight regulation stability.

Is JANTX1N4964CUS/TR compatible with lead-free solder reflow profiles?

JANTX1N4964CUS/TR features Sn/Pb-finished copper end caps and is qualified for traditional eutectic soldering. While it can survive peak temperatures up to 260 °C for ≤10 seconds, Microsemi does not certify it for Pb-free reflow due to potential intermetallic growth at sustained >220 °C. For JANTX1N4964CUS/TR assembly, use Sn63/Pb37 paste and profile per IPC-J-STD-020 Class 3, avoiding dwell above 235 °C.

Does JANTX1N4964CUS/TR require derating above 140 °C case temperature?

Yes - JANTX1N4964CUS/TR is rated for 5 W at T_EC = 140 °C and derates linearly to zero at 175 °C, yielding a derating slope of 143 mW/°C. At 155 °C case temperature, maximum allowable power drops to 2.86 W. This derating applies regardless of airflow or heatsinking, as thermal resistance is defined junction-to-end-cap (7 °C/W), not junction-to-ambient.

What is the surge current rating for JANTX1N4964CUS/TR?

JANTX1N4964CUS/TR is rated for 9.0 A nonrepetitive surge current at an 8.3 ms half-sine waveform, per Figure 1 in the SD44A datasheet. This rating reflects capability to absorb transient energy from induced surges in aircraft electrical systems. The device sustains this surge without parameter shift when mounted per recommended pad layout with thermal relief and minimum 0.080″ adhesive spot centering.

How is polarity identified on JANTX1N4964CUS/TR?

JANTX1N4964CUS/TR uses a cathode band - a single opaque circumferential stripe near one end of the glass body - to identify the cathode terminal. The banded end connects to the regulated node or higher-potential rail during Zener operation. Anode is the unmarked end. Polarity must be verified optically before placement, as marking is absent per datasheet specification.