Microchip Technology 1N2970D

Overview

1N2970D from Microsemi is a 10 W hermetically sealed, stud-mounted Zener diode with nominal Zener voltage 6.8 V at 1.2 mA test current, ±5% tolerance, and dynamic impedance of 370 Ω at I_ZT; it operates from −65 °C to +175 °C junction temperature and is qualified to MIL-PRF-19500/124 JANTX level for voltage regulation in high-reliability power supply and reference circuits.

For engineers reviewing the 1N2970D datasheet, 1N2970D pinout, 1N2970D application, or 1N2970D equivalent, this part serves as a rugged, thermally stable, reverse-polarity–capable voltage reference in military-grade power conditioning, radiation-hardened systems, and high-temperature industrial controls where hermetic sealing and solder-bond reliability are critical.

Technical Context

This device functions as a precision shunt regulator with breakdown behavior defined by its Zener voltage (V_Z = 6.8 V @ I_ZT = 1.2 mA), low dynamic impedance (Z_ZT = 370 Ω), and positive temperature coefficient (+0.057 %/°C) - enabling stable regulation across wide current and temperature ranges. Its DO-213AA (DO-4) metal-glass package features a 10-32 threaded stud for direct heatsinking and mechanical mounting.

It supports standard polarity (anode-to-stud) and reverse polarity (cathode-to-stud, suffix "RB") configurations, with maximum reverse leakage of 150 µA at 5.2 V and forward voltage ≤1.5 V at 2.0 A. Thermal resistance from junction to case is 12 °C/W, supporting full 10 W dissipation at T_C = +55 °C with linear derating above that temperature.

Key Specifications

Pinout & Package

Package: DO-213AA (DO-4), hermetically sealed metal-glass case with 7/16″ hex stud, 10-32 UNF–2A threads, tin-lead or matte-tin plating on nickel, weight ≈7.5 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N2970B and 1N5345B, the 1N2970D delivers higher reliability through JANTX-level screening, full 10 W power handling with stud thermal path, and guaranteed operation up to +175 °C - making it the sole option for mission-critical, high-temperature, or radiation-exposed regulation tasks.

Availability

1N2970D is available at Aetrix Electronics and suitable for avionics power regulation, military radar bias supply, and nuclear instrumentation requiring stable component supply with traceable sourcing and long-term lifecycle support.

Supply support for 1N2970D 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 1N2970D belongs to Microsemi's legacy MIL-qualified Zener diode family designed specifically for ruggedized voltage regulation in harsh-environment systems where hermeticity, thermal stability, and radiation tolerance are mandatory.

FAQ

What is the Zener voltage and test current for the 1N2970D?

The 1N2970D has a nominal Zener voltage of 6.8 V measured at a Zener test current (I_ZT) of 1.2 mA. This value is specified with ±5% tolerance and applies under stabilized thermal conditions per MIL-PRF-19500/124 test methodology. The 1N2970D maintains this regulation point across its full operating temperature range and is validated for use in JANTX-level applications.

Is the 1N2970D hermetically sealed and what package does it use?

Yes, the 1N2970D uses a hermetically sealed DO-213AA (DO-4) metal-glass package with a 10-32 threaded stud. The construction employs internal solder bonding and welded metal-to-glass seals to prevent moisture ingress and ensure long-term parameter stability. This packaging directly supports the 1N2970D's qualification to MIL-PRF-19500/124 and enables reliable operation in high-humidity, high-vibration, and high-radiation environments.

What is the maximum power dissipation and thermal derating behavior of the 1N2970D?

The 1N2970D is rated for 10 W steady-state power dissipation at case temperature (T_C) = +55 °C, with thermal resistance junction-to-case (R_θJC) of 12 °C/W. Above +55 °C, power must be linearly derated at 0.083 W/°C until reaching zero at +175 °C. This derating curve is documented in Figure 1 of the official datasheet and applies directly to the 1N2970D's thermal design in chassis-mounted applications.

Does the 1N2970D have radiation hardness and ESD immunity?

Yes, the 1N2970D exhibits inherent radiation hardness as described in Microsemi MicroNote 050 and is nonsensitive to ESD per MIL-STD-750 Method 1020. These characteristics are intrinsic to its material structure and hermetic packaging-not added coatings or external protection-making them fully applicable to the 1N2970D without qualification testing. No external TVS or shielding is required for standard handling or deployment.

What polarity configuration does the standard 1N2970D use and how is reverse polarity indicated?

The standard 1N2970D uses anode-to-stud polarity. Reverse polarity (cathode-to-stud) is indicated by the suffix "RB" in the full part number (e.g., 1N2970DRB). This polarity assignment is explicitly defined in the Mechanical and Packaging section of the datasheet and applies to all parts in the 1N2970B–1N3015B series, including the 1N2970D. Mounting orientation must match the specified polarity to avoid circuit malfunction.