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Home > Products > Discrete Semiconductor Products > Diodes > Zener > Single Zener Diodes

Microchip Technology 1N4574A

Name: 1N4574A
Brand: Microchip Technology
SKU: 1N4574A
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 1N4574A

Manufacturer:: Microchip Technology

Category:: Single Zener Diodes

Package:: DO-204AH, DO-35, Axial

Datasheet:: 1N4574A.pdf

Description:: DIODE ZENER 6.4V 500MW DO204AH

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Product details

Overview

1N4574A 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, 0.0005 %/°C temperature coefficient, 100 Ω dynamic impedance, and operation from –65 °C to +175 °C. It delivers high-stability voltage referencing in precision analog instrumentation and military-grade power supply feedback loops.

For engineers reviewing the 1N4574A datasheet, 1N4574A pinout, 1N4574A application, or 1N4574A equivalent, key selection criteria include its ultra-low TC (0.0005 %/°C), tight 6.4 V ±5% nominal tolerance, hermetic DO-7 packaging, MIL-PRF-19500/452 qualification readiness via JANTXV prefix, and 1.0 mA optimal bias point for minimal thermal drift.

Technical Context

This device belongs to Microsemi's zero-temperature-coefficient Zener family, using internal metallurgical bonding to achieve ultra-low TC through complementary Zener and forward-biased junction compensation. Its 6.4 V nominal voltage aligns with silicon bandgap reference fundamentals, enabling intrinsic cancellation of first-order thermal effects.

The 1N4574A operates at 1.0 mA I_ZT, delivering 100 Ω dynamic impedance and <2.0 µA reverse leakage at 3 V. It is specified over –55 °C to +100 °C for TC measurement and supports full military temperature range (–65 °C to +175 °C) for storage and operation.

Key Specifications

Parameter	Value and Actual Design Meaning
Nominal Zener Voltage	6.4 V ±5% - stable reference point aligned with silicon bandgap, minimizing curvature error across temperature.
Zener Test Current (I_ZT)	1.0 mA - optimal bias point where TC is minimized and dynamic impedance is 100 Ω.
Temperature Coefficient (αV_Z)	0.0005 %/°C - enables sub-0.1 mV/°C drift over –55 °C to +100 °C, critical for metrology-grade references.
Dynamic Impedance (Z_ZT)	100 Ω @ I_ZT - low AC impedance ensures minimal AC ripple coupling into reference node.
Max Reverse Current (I_R)	2.0 µA @ 3 V - confirms low leakage, supporting high-impedance bias networks without loading error.
Operating Temperature Range	–65 °C to +175 °C - fully qualified for aerospace, downhole, and extended-temperature industrial environments.
Package	DO-7 (DO-204AA) - hermetically sealed glass axial package with tin-lead leads, MIL-STD-750 compliant.

Pinout & Package

DO-7 (DO-204AA) hermetically sealed glass axial package with cathode band marking; leads are tin-lead plated per MIL-STD-750 Method 2026. Polarity: banded end is anode (positive) when used as reference diode (reverse-biased configuration).

Pin/Terminal	Circuit Role	Design Meaning
Anode (banded end)	Reference output node	Connected to regulated positive rail; reverse-bias voltage develops across cathode-to-anode.
Cathode (unbanded end)	Ground/reference return	Typically tied to system ground or error amplifier inverter input; defines reference polarity.

Key Features

Feature	Design Value
Ultra-low temperature coefficient	0.0005 %/°C enables <0.03 mV/°C drift over –55 °C to +100 °C, meeting Class A instrumentation requirements.
Hermetic DO-7 glass package	Ensures long-term stability and moisture resistance; qualified to MIL-PRF-19500/452 with JANTXV prefix.
Internal metallurgical bonding	Eliminates interfacial stress and thermal hysteresis, preserving TC accuracy over thermal cycling.
Nonsensitive to ESD	Qualified per MIL-STD-750 Method 1020 - no special handling required during board assembly or test.

Applications

High-Accuracy ADC Reference	Military Power Supply Feedback
Use Scenario: Precision 16-bit+ analog-to-digital conversion in avionics data acquisition systems requiring <±1 LSB total unadjusted error. IC Role / Device Role / Timing Role: Primary voltage reference for SAR or sigma-delta ADC reference input (REF+), replacing buried-zener ICs where size and radiation tolerance matter. Use Value: 0.0005 %/°C TC and 6.4 V nominal enable <0.01% full-scale drift over –55 °C to +100 °C, eliminating recalibration cycles.	Use Scenario: Feedback sensing in MIL-STD-704-compliant 28 V DC-DC converters for airborne radar transceivers. IC Role / Device Role / Timing Role: Stable reference for TL431-like shunt regulator error amplifier, setting output voltage with <±0.5% tolerance over life. Use Value: Hermetic DO-7 package and –65 °C to +175 °C rating ensure reliability under shock, vibration, and thermal shock per MIL-STD-810.
Downhole Oilfield Sensor Biasing	Atomic Clock Local Oscillator Trim
Use Scenario: Biasing front-end amplifiers and RTD bridges in logging-while-drilling (LWD) tools operating at 175 °C ambient. IC Role / Device Role / Timing Role: Low-drift reference for Wheatstone bridge excitation and PGA gain-setting resistors. Use Value: Validated operation at +175 °C with <2 µA leakage ensures stable offset and gain over full borehole temperature profile.	Use Scenario: Fine-tuning voltage-controlled crystal oscillator (VCXO) control voltage in rubidium frequency standards. IC Role / Device Role / Timing Role: Ultra-stable DC reference for DAC output buffering and loop filter biasing in phase-lock circuitry. Use Value: Sub-0.1 ppm/°C TC contribution minimizes Allan deviation degradation in short-term stability (<1 s tau).

High-Accuracy ADC Reference

Military Power Supply Feedback

Use Scenario: Precision 16-bit+ analog-to-digital conversion in avionics data acquisition systems requiring <±1 LSB total unadjusted error.

IC Role / Device Role / Timing Role: Primary voltage reference for SAR or sigma-delta ADC reference input (REF+), replacing buried-zener ICs where size and radiation tolerance matter.

Use Value: 0.0005 %/°C TC and 6.4 V nominal enable <0.01% full-scale drift over –55 °C to +100 °C, eliminating recalibration cycles.

Use Scenario: Feedback sensing in MIL-STD-704-compliant 28 V DC-DC converters for airborne radar transceivers.

IC Role / Device Role / Timing Role: Stable reference for TL431-like shunt regulator error amplifier, setting output voltage with <±0.5% tolerance over life.

Use Value: Hermetic DO-7 package and –65 °C to +175 °C rating ensure reliability under shock, vibration, and thermal shock per MIL-STD-810.

Downhole Oilfield Sensor Biasing

Atomic Clock Local Oscillator Trim

Use Scenario: Biasing front-end amplifiers and RTD bridges in logging-while-drilling (LWD) tools operating at 175 °C ambient.

IC Role / Device Role / Timing Role: Low-drift reference for Wheatstone bridge excitation and PGA gain-setting resistors.

Use Value: Validated operation at +175 °C with <2 µA leakage ensures stable offset and gain over full borehole temperature profile.

Use Scenario: Fine-tuning voltage-controlled crystal oscillator (VCXO) control voltage in rubidium frequency standards.

IC Role / Device Role / Timing Role: Ultra-stable DC reference for DAC output buffering and loop filter biasing in phase-lock circuitry.

Use Value: Sub-0.1 ppm/°C TC contribution minimizes Allan deviation degradation in short-term stability (<1 s tau).

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
1N4574	No "A" suffix; ±10% V_Z tolerance vs. ±5% for 1N4574A; identical TC (0.0005 %/°C), I_ZT (1.0 mA), and Z_ZT (100 Ω).	Acceptable where tighter voltage tolerance is not required; lower cost for non-critical biasing.	Select 1N4574A when ±5% initial accuracy is mandated by system calibration budget.
LM399H	Monolithic buried-Zener IC with 6.95 V output, 0.3 ppm/°C TC, on-chip heater; requires 10 mA supply and thermal stabilization time.	Used where ultra-low TC (<0.5 ppm/°C) justifies complexity, power, and footprint; not drop-in replaceable.	Choose LM399H only when sub-ppm/°C stability is required and board space/power allow heater control circuitry.

Compared with 1N4574 and LM399H, the 1N4574A uniquely balances ultra-low TC (0.0005 %/°C), hermetic ruggedness, zero external components, and ±5% V_Z tolerance-making it optimal for high-reliability analog signal chains where simplicity and extended temperature operation are mandatory.

Availability

1N4574A is available at Aetrix Electronics and suitable for high-reliability analog instrumentation, military power supply feedback, and downhole sensor biasing requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for 1N4574A 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 aerospace, defense, and industrial markets.

The 1N4574A belongs to Microsemi's legacy 1N45xxA series of temperature-compensated Zener references, designed specifically for applications demanding ultra-low TC, hermetic packaging, and MIL-PRF-19500 qualification readiness.

FAQ

What is the Zener test current for the 1N4574A and why is it important?

The 1N4574A has a specified Zener test current (I_ZT) of 1.0 mA. This current is critical because it defines the operating point at which the device achieves its guaranteed 0.0005 %/°C temperature coefficient and 100 Ω dynamic impedance. Operating significantly above or below 1.0 mA increases TC and impedance, degrading reference stability. The 1N4574A must be biased at or near this value for optimal performance in precision circuits.

Does the 1N4574A require external qualification for military use?

No-the 1N4574A itself is not pre-qualified, but it is designed to meet MIL-PRF-19500/452 requirements when ordered with appropriate prefixes and suffixes (e.g., JANTXV1N4574A-1). The base 1N4574A shares the same die, DO-7 package, and electrical specs; qualification is achieved through process control and screening added during ordering-not by modifying the core 1N4574A design.

How does the 1N4574A achieve its ultra-low temperature coefficient?

The 1N4574A achieves 0.0005 %/°C TC through internal metallurgical bonding of complementary Zener and forward-biased junctions within a single DO-7 package. This structure cancels first-order thermal voltage drift by balancing positive and negative TC components. Its 6.4 V nominal voltage is intentionally selected to coincide with the silicon bandgap voltage (~1.22 eV), enabling intrinsic cancellation without external compensation networks.

Can the 1N4574A be used in surface-mount designs?

No-the 1N4574A is exclusively offered in the axial-leaded DO-7 (DO-204AA) package. For surface-mount equivalents, Microsemi offers the UR-1 series (e.g., JANTX1N4574AUR-1) in DO-213AA, which shares identical electrical specs but requires different PCB layout and reflow profiles. The 1N4574A itself is not SMT-compatible due to its axial lead form factor.

What is the maximum power dissipation rating for the 1N4574A and how does it affect design?

The 1N4574A has a maximum DC power dissipation of 500 mW at 25 °C lead temperature (T_L), but its datasheet specifies that optimum voltage-temperature stability occurs at <30 mW-achieved at 1.0 mA × 6.4 V = 6.4 mW. Exceeding ~30 mW raises junction temperature, increasing TC deviation and accelerating long-term drift. Designers must limit bias current and ensure adequate thermal relief to maintain the 1N4574A within its low-power stability envelope.

1N4574A Specifications

Product attributes: Attribute value

Manufacturer:: Microchip Technology

Series:: -

Package/Case:: DO-204AH, DO-35, Axial

Packaging:: Bulk

Product Status:: Active

Voltage - Zener (Nom) (Vz):: 6.4 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 100 Ohms

Current - Reverse Leakage @ Vr:: 2 µA @ 3 V

Voltage - Forward (Vf) (Max) @ If:: -

Operating Temperature:: -65°C ~ 175°C

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: DO-204AH (DO-35)

1N4574A FAQ

1.How can I place an order for 1N4574A through Aetrix?

Please submit a Request for Quotation (RFQ) for 1N4574A on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 1N4574A reliable?

The price and inventory of 1N4574A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4574A is usually 5 days.

3.What payment methods are accepted for 1N4574A?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4574A transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 1N4574A?

1N4574A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 1N4574A order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 1N4574A?

For technical support, including 1N4574A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4574A requirements.

6.How does Aetrix verify that 1N4574A is sourced from the original manufacturer or authorized distributors?

All 1N4574A products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 1N4574A meets industry standards.

7.What is the process for return or replacement of 1N4574A?

All 1N4574A units undergo pre-shipment inspection (PSI). If there is an issue with 1N4574A, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 1N4574A part is unused and in its original packaging.

Return procedure for 1N4574A:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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