Microchip Technology 1N4573A-1E3

Overview

1N4573A-1E3 from Microsemi is a 6.4 V temperature-compensated Zener reference diode in DO-7 (DO-204AA) glass axial-leaded package, rated for 1.0 mA Zener test current, 0.001%/°C temperature coefficient, and 100 Ω dynamic impedance at I_ZT. It delivers stable voltage reference performance across -55°C to +100°C operating range and is qualified to MIL-PRF-19500/452 with -1 suffix.

For engineers reviewing the 1N4573A-1E3 datasheet, 1N4573A-1E3 pinout, 1N4573A-1E3 application, or 1N4573A-1E3 equivalent, key selection criteria include its ultra-low TC (0.001%/°C), hermetic DO-7 packaging, military-grade reliability, and precise 6.4 V nominal output under 1 mA bias - critical for high-stability analog instrumentation and precision power supply feedback loops.

Technical Context

This device belongs to Microsemi's zero-temperature-coefficient Zener series, achieving thermal stability via internal metallurgical bonding of complementary junctions. Its 6.4 V nominal Zener voltage is optimized for minimal curvature in the V_Z vs. T curve over -55°C to +100°C.

It operates at 1.0 mA test current with 100 Ω dynamic impedance, ensuring low noise and predictable regulation under varying load conditions. The DO-7 package supports axial through-hole mounting and meets MIL-STD-750 solderability requirements with tin-lead plating.

Key Specifications

Pinout & Package

DO-7 (DO-204AA) is a hermetically sealed glass axial-leaded package with two terminals: anode and cathode. Cathode is identified by a painted band; device must be reverse-biased (cathode positive) for Zener operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4573A-1E3, the 1N4572A-1E3 offers 2× higher TC but identical form, fit, and function - useful for cost-sensitive industrial designs - while the base 1N4573A-1 differs only in packaging format, making it interchangeable in manual assembly contexts.

Availability

1N4573A-1E3 is available at Aetrix Electronics and suitable for high-reliability aerospace power systems, precision test equipment calibration, and industrial process controller reference circuits requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for 1N4573A-1E3 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 analog, RF, and radiation-hardened components for defense, aerospace, and industrial markets.

The 1N4573A-1E3 belongs to Microsemi's legacy Scottsdale Division temperature-compensated Zener reference diode family, engineered specifically for metrology-grade voltage stability in mission-critical systems where long-term drift and thermal hysteresis must be minimized.

FAQ

What is the Zener test current for 1N4573A-1E3?

The 1N4573A-1E3 is specified at a Zener test current (I_ZT) of 1.0 mA. This current level is required to achieve the published 6.4 V nominal voltage and 0.001%/°C temperature coefficient. Operating significantly above or below this value increases dynamic impedance and degrades TC performance. The 1N4573A-1E3 must be biased with a series resistor calculated to maintain ~1.0 mA under expected line and load conditions.

Is 1N4573A-1E3 suitable for military applications?

Yes, the 1N4573A-1E3 carries the "-1" suffix, indicating compliance with MIL-PRF-19500/452 Class JANTX requirements. It undergoes rigorous screening including temperature cycling, burn-in, and parametric testing per military standards. Its DO-7 hermetic glass package and internal metallurgical bonding ensure reliability in avionics, missile guidance, and space-qualified systems where failure is not an option.

How does the temperature coefficient of 1N4573A-1E3 compare to standard Zeners?

The 1N4573A-1E3 achieves a temperature coefficient of 0.001%/°C - over 100× better than typical 6.2 V Zeners (which often exceed 0.1%/°C). This ultra-low TC results from dual-junction compensation within the die, minimizing curvature in the V_Z vs. temperature curve. For example, over -55°C to +100°C, the 1N4573A-1E3 drifts less than ±0.15 mV, whereas a standard Zener may drift >15 mV.

What is the maximum power dissipation rating for 1N4573A-1E3?

The 1N4573A-1E3 has a maximum DC power dissipation of 500 mW at lead temperature (T_L) = 25°C. However, for optimal voltage-temperature stability, Microsemi recommends limiting power to <30 mW - achievable by biasing at 1.0 mA into a 6.4 V drop. Exceeding this derated power increases self-heating, which directly impacts TC accuracy and long-term parameter stability.

Can 1N4573A-1E3 be used in surface-mount designs?

No, the 1N4573A-1E3 uses a DO-7 (DO-204AA) axial-leaded glass package designed exclusively for through-hole mounting. Microsemi offers surface-mount equivalents such as the JANTX1N4569AUR-1 in DO-213AA, but those are distinct part numbers with different mechanical and thermal characteristics. Substituting 1N4573A-1E3 into an SMT footprint would require mechanical adaptation and invalidate qualification data.