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Microchip Technology 1N749DE3
- Part No.:
- 1N749DE3
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N749DE3.pdf
- Description:
- DIODE ZENER 4.3V 500MW DO204AH
- Quantity:
- Payment:
- Shipping:
Inventory:9,393
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Product details
Overview
1N749DE3 from Microsemi is a 500 mW, 4.3 V ±1% tolerance silicon Zener diode in DO-35 (DO-204AH) glass axial-leaded package, qualified to JANTXV level per MIL-PRF-19500/127, with dynamic impedance of 18 Ω at 20 mA and temperature coefficient of –0.055%/°C / +0.020%/°C, used for precision voltage regulation in military power supplies and reference circuits.
For engineers reviewing the 1N749DE3 datasheet, 1N749DE3 pinout, 1N749DE3 application, or 1N749DE3 equivalent, key selection criteria include its ±1% Zener voltage tolerance, hermetically sealed DO-35 package, JANTXV qualification, low 18 Ω dynamic impedance at IZT = 20 mA, and dual-signature temperature coefficient enabling stable regulation across –65°C to +175°C.
Technical Context
The 1N749DE3 operates as a reverse-biased voltage reference diode with nominal Zener voltage of 4.3 V at test current IZT = 20 mA, exhibiting a non-linear breakdown characteristic governed by avalanche and Zener mechanisms. Its dual-signature temperature coefficient (–0.055%/°C below 25°C, +0.020%/°C above) reflects mixed conduction physics near the 4.3 V threshold.
It features an internal metallurgical bond for enhanced reliability and thermal stability, with junction-to-lead thermal resistance of 250 °C/W at 0.375″ lead length. The device is rated for 500 mW average power dissipation at TL = 50°C, derating linearly to zero at 175°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 4.3 V at IZT = 20 mA - defines precise regulation point for low-voltage reference design |
| Zener Tolerance | ±1% - enables tight voltage control in critical analog and power supply feedback loops |
| Dynamic Impedance | 18 Ω at IZT = 20 mA - ensures minimal output voltage variation under load current changes |
| Max Reverse Current | 2 µA at VR = 1.0 V - guarantees low leakage in high-impedance bias networks |
| Temp Coefficient | –0.055%/°C / +0.020%/°C - supports stable regulation across wide ambient ranges |
| Power Dissipation | 500 mW at TL = 50°C - sets maximum continuous thermal load on PCB-mounted leads |
| Junction Temp Range | –65°C to +175°C - validated for extended operation in aerospace and defense environments |
Pinout & Package
Hermetically sealed axial-leaded DO-35 (DO-204AH) glass package with cathode indicated by color band; leads are tin-lead or RoHS-compliant matte-tin plated, solderable per MIL-STD-750 method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Non-banded end | Connected to lower-potential node; forward conduction path when biased positive relative to cathode |
| Cathode | Banded end | Connected to higher-potential node during Zener regulation; defines polarity for reverse-bias operation |
Key Features
| Feature | Design Value |
|---|---|
| JANTXV qualification | MIL-PRF-19500/127 certified for high-reliability military systems with full screening and traceability |
| Metallurgical bond construction | Eliminates wire bonds to improve thermal cycling endurance and long-term parameter stability |
| RoHS-compliant plating | e3 suffix indicates annealed matte-tin termination compatible with lead-free reflow processes |
| Low capacitance | Minimizes signal coupling in high-frequency bias and reference applications |
| Radiation hardness | Inherently radiation-tolerant per Microsemi MicroNote 050 - suitable for space-qualified designs |
Applications
| Avionics Power Reference | Military Sensor Biasing |
|---|---|
Use Scenario: Providing stable 4.3 V reference for ADC front-end and op-amp offset trimming in airborne navigation units. IC Role / Device Role / Timing Role: Precision voltage reference source for analog signal conditioning circuitry. Use Value: ±1% tolerance and low 18 Ω dynamic impedance ensure <±2.5 mV regulation error over 1–50 mA load range. | Use Scenario: Biasing photodiode amplifiers and MEMS transducer interfaces in ruggedized battlefield sensors. IC Role / Device Role / Timing Role: Low-noise, low-leakage voltage clamp and bias generator. Use Value: 2 µA max reverse current at 1.0 V and –65°C to +175°C operating range enable reliable operation in extreme environments. |
| Spacecraft Telemetry Regulator | Tactical Radio RF Stage Bias |
Use Scenario: Regulating supply to telemetry interface ICs in CubeSat payloads where radiation tolerance is mandatory. IC Role / Device Role / Timing Role: Radiation-hardened Zener shunt regulator for secondary voltage rail stabilization. Use Value: Inherent radiation hardness per MicroNote 050 and JANTXV qualification support mission-critical uptime without shielding overhead. | Use Scenario: Setting gate bias for GaAs FETs in S-band transmitter driver stages subject to thermal cycling. IC Role / Device Role / Timing Role: Temperature-compensated voltage reference for RF amplifier DC bias networks. Use Value: Dual-signature temperature coefficient (–0.055%/°C / +0.020%/°C) minimizes drift-induced gain variation across –40°C to +85°C operational envelope. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N749A-1 | Same 4.3 V nominal, but ±5% tolerance (vs. ±1% for 1N749DE3); no e3 RoHS marking | Acceptable where tighter regulation not required; lacks JANTXV screening and RoHS compliance | Select only if cost sensitivity outweighs precision and compliance requirements |
| SMF4.3A | Surface-mount SOD-123 package; 4.3 V ±5%; 1 W PPM; 200 mW PM(AV); no military qualification | Designed for automated assembly and higher power pulse handling, not hermetic reliability | Choose for commercial high-volume production where DO-35 axial mounting is impractical |
Compared with 1N749A-1 and SMF4.3A, the 1N749DE3 uniquely combines ±1% tolerance, JANTXV qualification, hermetic DO-35 packaging, and RoHS-compliant termination-making it the sole option for precision, high-reliability, through-hole military avionics references.
Availability
1N749DE3 is available at Aetrix Electronics and suitable for avionics power references, military sensor biasing, spacecraft telemetry regulators, and tactical radio RF stage bias requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for 1N749DE3 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 Corporation (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability, radiation-hardened, and military-qualified analog and mixed-signal components.
The 1N749DE3 belongs to Microsemi's legacy MIL-PRF-19500/127-qualified Zener diode family, designed specifically for precision voltage regulation in defense, aerospace, and industrial systems demanding guaranteed performance under extreme thermal, mechanical, and radiation stress.
FAQ
What is the Zener voltage tolerance of the 1N749DE3?
The 1N749DE3 has a Zener voltage tolerance of ±1%, specified at 4.3 V nominal with test current IZT = 20 mA. This tight tolerance is enabled by the "D" suffix in the part nomenclature and distinguishes it from the ±5% 1N749A-1 variant. The 1N749DE3 maintains this accuracy across its qualified operating temperature range of –65°C to +175°C.
Is the 1N749DE3 RoHS compliant?
Yes, the 1N749DE3 is RoHS compliant, indicated by the "e3" suffix in its full designation. It features annealed matte-tin plating on its axial leads and meets JEDEC/IPC standards for lead-free solderability per MIL-STD-750 method 2026. This compliance applies exclusively to the commercial-grade version; military-grade variants (JAN/JANTX/JANTXV) retain tin-lead plating unless otherwise specified.
What does the "DE3" suffix mean in 1N749DE3?
The "DE3" suffix in 1N749DE3 decodes as follows: "D" denotes ±1% Zener voltage tolerance, "E" indicates metallurgically bonded construction, and "e3" specifies RoHS-compliant matte-tin plating. Per Microsemi's nomenclature guide, this full suffix confirms the device meets all three attributes-precision tolerance, enhanced reliability bonding, and environmental compliance-in a single commercial-grade part.
What is the maximum power dissipation rating for the 1N749DE3?
The 1N749DE3 is rated for 500 mW average power dissipation at a lead temperature (TL) of +50°C with 0.375″ (9.53 mm) lead length from the body. Power derates linearly to zero at +175°C. When mounted on a PCB, its rated power drops to 400 mW at TA = +55°C, with derating beginning at that ambient temperature per Figure 2 in the datasheet.
Does the 1N749DE3 have JANTXV qualification?
No, the 1N749DE3 does not carry JANTXV qualification. Its "e3" suffix confirms RoHS compliance and commercial-grade status. JANTXV-qualified versions use different suffixes (e.g., 1N749AUSV for JANTXV with ±5% tolerance) and require separate ordering. The 1N749DE3 is intended for commercial applications needing precision and RoHS compliance-not for programs mandating MIL-PRF-19500/127 screening.
1N749DE3 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):
- 4.3 V
- Tolerance:
- ±1%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 22 Ohms
- Current - Reverse Leakage @ Vr:
- 2 µA @ 1 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.1 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AH (DO-35)
1N749DE3 FAQ
1.How can I place an order for 1N749DE3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N749DE3 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 1N749DE3 reliable?
The price and inventory of 1N749DE3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N749DE3 is usually 5 days.
3.What payment methods are accepted for 1N749DE3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N749DE3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N749DE3?
1N749DE3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N749DE3 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 1N749DE3?
For technical support, including 1N749DE3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N749DE3 requirements.
6.How does Aetrix verify that 1N749DE3 is sourced from the original manufacturer or authorized distributors?
All 1N749DE3 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 1N749DE3 meets industry standards.
7.What is the process for return or replacement of 1N749DE3?
All 1N749DE3 units undergo pre-shipment inspection (PSI). If there is an issue with 1N749DE3, 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 1N749DE3 part is unused and in its original packaging.
Return procedure for 1N749DE3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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