Microchip Technology 1N4000

Overview

1N4000 from Microsemi is a 10 W hermetically sealed, stud-mounted Zener diode with nominal Zener voltage 7.5 V, ±5% tolerance (A suffix), 335 Ω dynamic impedance at 335 mA test current, and cathode-to-stud polarity in standard configuration. It operates from –65 °C to +175 °C junction temperature and delivers stable voltage regulation in high-reliability power supply feedback loops.

For engineers reviewing the 1N4000 datasheet, 1N4000 pinout, 1N4000 application, or 1N4000 equivalent, this part requires attention to stud-mount thermal management, polarity designation (R suffix for anode-to-stud), voltage tolerance suffix (A = ±5%), and DO-4 package mechanical integration into chassis-grounded heat sinks.

Technical Context

The 1N4000 belongs to Microsemi's high-power JEDEC-registered 1N3993–1N4000A series, designed for precision DC voltage regulation under sustained 10 W dissipation when mounted on thermally conductive metal surfaces. Its low 10 °C/W junction-to-case thermal resistance enables operation up to +175 °C junction temperature with proper stud cooling.

Electrical behavior is defined at 30 °C case temperature: Zener voltage is specified at 335 mA test current (IZT), with dynamic impedance measured at 10% AC ripple superimposed on IZT. Temperature coefficient is +0.045 %/°C, indicating positive drift with rising temperature - critical for closed-loop stability analysis in regulated supplies.

Key Specifications

Pinout & Package

Package: DO-4 (DO-203AA), 7/16″ hex stud with 10-32 threaded interface, hermetically sealed metal-glass construction, weight 7.5 g. Mounting requires conductive thermal interface to chassis ground or heatsink.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4000, the 1N4000A offers identical electrical specs but lacks 10 W thermal capability, while 1N5341B trades power and ruggedness for compact PCB fit - making 1N4000 uniquely suited for high-reliability, high-power, chassis-grounded regulation.

Availability

1N4000 is available at Aetrix Electronics and suitable for high-reliability power supply regulation, aerospace DC-DC converter references, and industrial motor drive gate bias clamping requiring stable component supply across extended temperature and radiation environments.

Supply support for 1N4000 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, radiation-hardened, and high-power discrete components for defense, aerospace, and industrial markets.

The 1N4000 belongs to Microsemi's legacy 10 W Zener diode family, engineered for voltage regulation in mission-critical systems where thermal robustness, hermetic sealing, and MIL-spec qualification are mandatory.

FAQ

What is the Zener voltage tolerance of the 1N4000?

Standard 1N4000 has ±5% Zener voltage tolerance, indicated by the "A" suffix in its full ordering designation (1N4000A). This means the actual V_Z falls between 7.125 V and 7.875 V at 335 mA test current and 30 °C case temperature. Tighter tolerances (±2%, ±1%) require factory consultation and C/D suffixes.

Does the 1N4000 require a heatsink?

Yes - the 1N4000 must be mounted to a thermally conductive surface via its threaded stud to dissipate up to 10 W. Its 10 °C/W junction-to-case thermal resistance means even at 5 W dissipation, junction temperature rises 50 °C above stud temperature. Without metal-mount thermal path, it will exceed +175 °C junction limit and fail.

What does the "R" suffix mean for the 1N4000?

The "R" suffix (e.g., 1N4000RA) denotes reverse polarity: anode-to-stud instead of the standard cathode-to-stud configuration. This changes grounding topology - the stud becomes the anode node, requiring electrical isolation from chassis ground and re-routing of the cathode lead to the regulated rail.

Is the 1N4000 suitable for surface-mount designs?

No - the 1N4000 uses a DO-4 (DO-203AA) stud-mount package incompatible with SMT assembly. Microsemi explicitly states surface-mount equivalents require factory consultation. For SMT Zener regulation, consider alternatives like SMAJ7.5A or SMBJ7.5A, though none match its 10 W power or hermetic reliability.

What is the maximum reverse current for the 1N4000 at rated Zener voltage?

At V_R = 3.0 V, the 1N4000 exhibits maximum reverse current (I_R) of 10 µA. This leakage value is measured well below breakdown and confirms low off-state conduction - critical for minimizing quiescent current in battery-backed or low-power standby circuits using the 1N4000 as a reference.