Microchip Technology 1N2979C

Overview

1N2979C from Microsemi is a 10 W hermetically sealed, stud-mounted Zener diode with nominal Zener voltage of 15 V at 3 mA test current, ±5% tolerance, and positive temperature coefficient (+0.082 %/°C). It operates from −65 °C to +175 °C junction temperature and delivers stable voltage regulation in high-reliability power supply and reference circuits for aerospace and defense systems.

For engineers reviewing the 1N2979C datasheet, 1N2979C pinout, 1N2979C application, or 1N2979C equivalent, this part requires attention to stud polarity (anode-to-stud standard), thermal derating above +55 °C, MIL-PRF-19500/124 qualification level, and DO-213AA (DO-4) metal-glass package mounting constraints.

Technical Context

This device functions as a precision voltage reference in high-stability analog and power conditioning circuits, leveraging its low dynamic impedance (170 Ω at I_ZT = 3 mA) and tightly controlled Zener knee behavior. Its hermetic metal-glass construction ensures immunity to moisture ingress and long-term parameter drift under thermal cycling.

The 1N2979C exhibits a defined anode-to-stud polarity per JEDEC nomenclature, requiring mechanical grounding through the threaded stud while maintaining electrical isolation via optional insulator hardware. Its 12 °C/W junction-to-case thermal resistance enables direct heat sinking to chassis or cold plates without supplemental heatsinks up to full 10 W dissipation at T_C = +55 °C.

Key Specifications

Pinout & Package

Package: DO-213AA (DO-4), hermetically sealed metal-glass stud package with 10-32 UNF–2A threaded stud (anode), flat hex body (0.424″ max diameter), and tin-lead or matte-tin plating on nickel terminals. Weight ≈ 7.5 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N2979B and 1N2979RB, the 1N2979C offers the highest reliability assurance (JANTXV) and standard anode-to-stud polarity, making it optimal for flight-critical voltage references where parameter stability under radiation and thermal stress is non-negotiable.

Availability

1N2979C is available at Aetrix Electronics and suitable for aerospace power supplies, defense radar bias networks, and industrial high-temperature control systems requiring stable component supply across extended product lifecycles.

Supply support for 1N2979C 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 Corporation (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 1N2979C belongs to Microsemi's legacy MIL-PRF-19500/124 qualified Zener diode family, engineered for voltage regulation in mission-critical systems where hermeticity, radiation tolerance, and thermal robustness are mandatory.

FAQ

What is the Zener voltage tolerance for the 1N2979C?

The 1N2979C has a nominal Zener voltage of 15 V with a guaranteed tolerance of ±5%, meaning the actual V_Z falls between 14.25 V and 15.75 V when measured at I_ZT = 3 mA and T_J = 25 °C. This tolerance is standardized across all 1N2970B–1N3015B series parts and is verified during MIL-PRF-19500/124 qualification testing.

Does the 1N2979C require a heatsink for 10 W operation?

No external heatsink is required for the 1N2979C to dissipate its full 10 W rating - provided the stud is mounted directly to a thermally conductive chassis or cold plate with adequate surface area. Its 12 °C/W junction-to-case thermal resistance allows full power operation at T_C = +55 °C; derating begins linearly above that temperature.

What does the "C" suffix indicate in 1N2979C?

The "C" suffix in 1N2979C denotes JANTXV reliability level per MIL-PRF-19500/124, the highest qualification tier in this series. It signifies full military screening including extended burn-in, radiation testing, and lot traceability - distinct from "B" (JANTX) and blank (commercial) variants of the same 1N2979 base number.

Can the 1N2979C be used in surface-mount designs?

No - the 1N2979C uses a through-hole DO-213AA (DO-4) stud-mount package with 10-32 threaded metal stud and cannot be surface-mounted. The datasheet explicitly states surface-mount equivalents require factory consultation, and no SMT variant of 1N2979C exists in Microsemi's qualified product list.

What is the maximum reverse leakage current for the 1N2979C?

The 1N2979C specifies a maximum reverse leakage current (I_R) of 10 µA at V_R = 11.4 V and T_J = 25 °C. This value is confirmed in the Electrical Characteristics table on page 4 of T4-LDS-0075 Rev. 3 and applies to all 1N2979x variants regardless of qualification level.