Microchip Technology 1N4000A

Overview

1N4000A from Microsemi is a 10 W, 7.5 V ±5% tolerance Zener diode in DO-4 (DO-203AA) metal-glass hermetic package with cathode-to-stud polarity, designed for high-reliability voltage regulation in power supply feedback loops, overvoltage protection circuits, and precision reference applications requiring stable operation from –65°C to +175°C junction temperature.

For engineers reviewing the 1N4000A datasheet, 1N4000A pinout, 1N4000A application, or 1N4000A equivalent, this part delivers verified 7.5 V regulation at 335 mA test current, 250 Ω dynamic impedance at I_ZT, and 10 W DC power dissipation with 10°C/W junction-to-case thermal resistance - critical for thermal-aware industrial and aerospace designs.

Technical Context

The 1N4000A operates as a two-terminal voltage reference device with sharp Zener breakdown at nominal 7.5 V, characterized at 30°C case temperature using 335 mA Zener test current (I_ZT). Its low 250 Ω dynamic impedance (Z_ZT) ensures minimal output voltage variation under load transients.

It features hermetically sealed DO-4 construction with welded metal-glass enclosure, internal solder bond assembly, and cathode-connected stud polarity - enabling direct mounting to heatsinks with electrical isolation options. Thermal resistance of 10°C/W supports sustained 10 W operation when stud temperature remains ≤50°C.

Key Specifications

Pinout & Package

Package: DO-4 (DO-203AA), hermetically sealed metal-glass case with 7/16″ hex stud, 10-32 threaded mounting interface, weight 7.5 g. Standard polarity: cathode connected to stud (case). Reverse polarity available with "R" suffix (e.g., 1N4000RA).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4000 and 1N4000B, the 1N4000A provides identical performance and packaging but guarantees ±5% Zener voltage tolerance - essential for closed-loop control accuracy where 1% output regulation is mandated.

Availability

1N4000A is available at Aetrix Electronics and suitable for switch-mode power supplies, overvoltage protection circuits, industrial sensor references, and aerospace voltage monitors requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for 1N4000A 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 aerospace, defense, and industrial markets.

The 1N4000A belongs to Microsemi's legacy 10 W Zener diode family (1N3993–1N4000A), engineered for ruggedized voltage regulation in mission-critical systems where hermetic sealing, wide temperature range, and MIL-spec qualification matter.

FAQ

What is the Zener voltage tolerance of the 1N4000A?

The 1N4000A has a nominal Zener voltage of 7.5 V with a guaranteed tolerance of ±5%, indicated by the "A" suffix per Microsemi's datasheet revision A. This tolerance is tighter than the base 1N4000 (±10%) and aligns with JEDEC-standardized grading for precision regulation applications where feedback loop accuracy is critical.

What is the maximum power dissipation rating for the 1N4000A?

The 1N4000A is rated for 10 W DC power dissipation at stud temperatures ≤50°C. Above 50°C, power must be derated at 80 mW/°C, reaching zero at 175°C. This rating assumes proper mounting to a heatsink or chassis with thermal interface management - the 10°C/W junction-to-case resistance enables predictable thermal design for the 1N4000A.

Does the 1N4000A have a hermetically sealed package?

Yes, the 1N4000A uses a DO-4 (DO-203AA) hermetically sealed metal-glass package with welded construction, confirmed in Microsemi's datasheet Page 1. This sealing provides immunity to moisture, contaminants, and outgassing - making the 1N4000A suitable for vacuum, high-humidity, and space-grade applications per MicroNote 050.

What is the polarity configuration of the 1N4000A?

The 1N4000A has standard polarity: cathode connected to the metal stud (case), with the axial lead serving as the anode. This is explicitly stated in the "POLARITY" section of the datasheet for the 1N3993–1N4000A series. Reverse polarity versions (anode-to-stud) exist but require the "R" suffix, e.g., 1N4000RA - not applicable to the base 1N4000A.

Is the 1N4000A qualified for military applications?

The 1N4000A itself is not pre-qualified, but JAN, JANTX, and JANTXV versions are available per MIL-PRF-19500/124 by adding the appropriate prefix (e.g., JANTX1N4000A). These variants undergo enhanced screening for temperature cycling, vibration, and burn-in - enabling use in defense and aerospace programs where the base 1N4000A would not meet qualification requirements.