Microchip Technology 1N4566E3

Overview

1N4566E3 from Microsemi is a 6.4 V temperature-compensated Zener reference diode in DO-7 (DO-204AA) glass axial-leaded package, rated for 0.5 mA test current, ±0.005 %/°C temperature coefficient (±0.32 mV/°C), 200 Ω dynamic impedance, and operation from –65 °C to +175 °C - used in precision voltage references for aerospace instrumentation and military-grade power supply regulation.

For engineers reviewing the 1N4566E3 datasheet, 1N4566E3 pinout, 1N4566E3 application, or 1N4566E3 equivalent, key selection criteria include its ultra-low TC, hermetic DO-7 packaging, MIL-PRF-19500/452 qualification path, and stable 6.4 V reference under wide-temperature and low-current conditions.

Technical Context

The 1N4566E3 implements a metallurgically bonded Zener junction optimized for minimal voltage drift across temperature via dual-junction compensation. Its 0.5 mA Zener test current and 200 Ω dynamic impedance reflect design for low-power, high-stability reference nodes where thermal self-heating must be minimized.

Rated for –65 °C to +175 °C operating range and hermetically sealed in glass, the device supports mission-critical applications requiring long-term parametric stability without polymer encapsulation degradation. Reverse leakage remains ≤2.0 µA at 3 V, ensuring negligible error contribution in high-impedance bias networks.

Key Specifications

Pinout & Package

DO-7 (DO-204AA) hermetically sealed glass axial-leaded package with cathode band marking; leads are tin-lead plated and solderable per MIL-STD-750 Method 2026. Polarity: banded end is cathode (anode is unmarked lead).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4566A, the 1N4566E3 trades tighter initial tolerance for broader commercial availability and lower cost; versus LM399H, it delivers wider temperature range and simpler biasing at the expense of absolute TC performance - making 1N4566E3 optimal for ruggedized embedded references.

Availability

1N4566E3 is available at Aetrix Electronics and suitable for aerospace instrumentation, military power supply regulation, and downhole oilfield electronics requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for 1N4566E3 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 precision analog components for defense, aerospace, and industrial markets.

The 1N4565–1N4584A series was engineered specifically for mission-critical voltage reference applications demanding hermetic reliability, ultra-low temperature coefficients, and MIL-spec qualification paths - not general-purpose Zener use.

FAQ

What is the Zener test current for 1N4566E3?

The 1N4566E3 is specified at a Zener test current (I_ZT) of 0.5 mA. This value is used to measure its 6.4 V nominal Zener voltage and ±0.005 %/°C temperature coefficient. Operating significantly above or below this current increases dynamic impedance and degrades TC performance - so bias networks should target 0.5 mA for optimal stability.

Does 1N4566E3 have military qualification options?

Yes - the 1N4566E3 base part can be ordered with JAN, JANTX, or JANTXV prefixes plus a "-1" suffix (e.g., JANTX1N4566E3-1) to meet MIL-PRF-19500/452 requirements. These versions undergo additional screening for vibration, thermal shock, and lot acceptance testing, making them suitable for defense avionics and spaceflight hardware where 1N4566E3's base reliability is insufficient.

What is the maximum operating temperature of 1N4566E3?

The 1N4566E3 is rated for continuous operation from –65 °C to +175 °C. This full range is validated per JEDEC and MIL-STD-202 environmental tests. At +175 °C, its Zener voltage drift remains within specification due to internal temperature compensation - enabling use in engine-mounted sensors and geothermal probe electronics where 1N4566E3 replaces less robust plastic-packaged alternatives.

How does the temperature coefficient of 1N4566E3 compare to standard Zeners?

The 1N4566E3 achieves ±0.005 %/°C (±0.32 mV/°C), which is 10–20× lower than typical 5–10 %/°C TCs of non-compensated Zeners. This is accomplished via dual-junction compensation in its metallurgically bonded structure - allowing 1N4566E3 to maintain <±1.5 mV error over 0–75 °C, whereas a standard 6.2 V Zener would drift >±50 mV in the same range.

Is 1N4566E3 compatible with automated PCB assembly processes?

Yes - the 1N4566E3's DO-7 package features tin-lead plated axial leads compliant with MIL-STD-750 Method 2026, supporting wave and selective soldering at 260 °C for 10 seconds max. Its glass body withstands thermal shock better than epoxy packages, and the absence of moisture sensitivity means no baking is required before reflow - simplifying manufacturing for 1N4566E3 integration into high-reliability assemblies.