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Microchip Technology 1N4678UR-1/TR
- Part No.:
- 1N4678UR-1/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AA
- Datasheet:
-
1N4678UR-1/TR.pdf
- Description:
- DIODE ZENER 1.8V 500MW DO213AA
- Quantity:
- Payment:
- Shipping:
Inventory:2,924
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Product details
Overview
1N4678UR-1/TR from Microsemi is a 500 mW surface-mount Zener diode in DO-213AA (SOD-80/MLL34) MELF package, rated for 1.8 V nominal Zener voltage at 50 µA test current, ±5% tolerance, with 0.70 V regulation change over 10–100 µA and 7.5 µA reverse leakage at 1.0 V. It serves precision low-current voltage reference and regulation in space-constrained analog sensor interfaces.
For engineers reviewing the 1N4678UR-1/TR datasheet, 1N4678UR-1/TR pinout, 1N4678UR-1/TR application, or 1N4678UR-1/TR equivalent, key selection criteria include ultra-low test current (50 µA), hermetic glass MELF construction, MIL-PRF-19500 up-screening capability, minimal capacitance (<1.5 pF), and radiation-hardened performance per MicroNote 050.
Technical Context
This Zener operates in reverse breakdown with a sharp knee at IZT = 50 µA, enabling stable regulation even in micro-power circuits where supply current is limited to tens of microamps. Its metallurgically bonded silicon die and hermetically sealed glass package ensure long-term stability under thermal cycling and high-reliability environmental stress.
The device exhibits low dynamic impedance (ΔVZ = 0.70 V between 10 µA and 100 µA), tight voltage consistency across temperature (–65 °C to +175 °C junction range), and negligible capacitance-critical for noise-sensitive reference paths in instrumentation and aerospace signal conditioning.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 1.8 V at 50 µA - sets precise low-voltage reference point for biasing or clamping in sub-2 V systems. |
| Power Dissipation | 0.5 W - supports continuous operation at ambient ≤50 °C on FR4 with 1 oz Cu, derating linearly above. |
| Regulation Change (ΔVZ) | 0.70 V from 10 µA to 100 µA - indicates low dynamic impedance for stable regulation across wide current range. |
| Reverse Leakage (IR) | 7.5 µA at 1.0 V - ensures minimal error contribution in high-impedance reference nodes. |
| Junction Temp Range | –65 °C to +175 °C - enables deployment in extended industrial, avionics, and downhole environments. |
| Package Type | DO-213AA (SOD-80 / MLL34) MELF - hermetic glass surface-mount form factor with axial symmetry and no PCB pad voids. |
| Thermal Resistance (RθJA) | 250 °C/W - defines maximum allowable ambient rise before reaching 125 °C junction limit at full power. |
Pinout & Package
DO-213AA (SOD-80/MLL34) is a cylindrical, hermetically sealed glass MELF package with two metallized end caps. Cathode is marked by a single dark band; polarity must be observed for proper Zener operation (banded end positive in regulation mode).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unbanded end) | Reference Ground Node | Connected to circuit ground or lowest potential node; forms return path for Zener current. |
| Cathode (banded end) | Regulated Output Node | Provides stable 1.8 V relative to anode when reverse-biased; used as voltage reference or clamp point. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low test current | 50 µA Zener test current enables use in nano-power sensor bias networks without loading source. |
| Hermetic glass MELF | DO-213AA package prevents moisture ingress and parametric drift over 20+ year field life. |
| MIL-PRF-19500 up-screening | Available with MQ/MX/MV/MSP reliability levels for defense, space, and critical infrastructure applications. |
| Radiation hardness | Inherently radiation-tolerant per MicroNote 050 - suitable for low-dose TID environments without shielding. |
| Low capacitance | <1.5 pF typical - preserves high-frequency signal integrity in RF detector and timing reference circuits. |
Applications
| Medical Sensor Biasing | Aerospace Power Monitor Reference |
|---|---|
Use Scenario: Providing stable 1.8 V bias to MEMS pressure transducer bridge in portable ultrasound probe. IC Role / Device Role / Timing Role: Low-current Zener reference establishing excitation voltage for Wheatstone bridge. Use Value: 50 µA test current avoids depleting coin-cell battery; ±5% tolerance meets ISO 13485 calibration traceability. |
Use Scenario: Voltage reference for ADC monitoring 28 V aircraft bus in flight control electronics. IC Role / Device Role / Timing Role: Precision shunt regulator feeding ratiometric reference input of isolated sigma-delta ADC. Use Value: Hermetic DO-213AA withstands thermal shock during altitude cycling; –65 °C to +175 °C rating covers full operational envelope. |
| Downhole Instrumentation | Industrial IoT Edge Node |
Use Scenario: Regulating bias for piezoelectric acoustic sensor in oil/gas well logging tool operating at 150 °C. IC Role / Device Role / Timing Role: High-temperature-stable shunt reference maintaining ADC reference accuracy under thermal stress. Use Value: Junction temperature rating up to +175 °C eliminates need for external thermal derating; metallurgical bond prevents delamination. |
Use Scenario: Clamping ESD transients on 1.8 V I²C lines in smart meter communication module. IC Role / Device Role / Timing Role: Low-capacitance Zener acting as bidirectional transient suppressor at interface pins. Use Value: <1.5 pF capacitance prevents signal integrity loss on 400 kHz bus; non-sensitive to ESD per MIL-STD-750 Method 1020. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX55C1V8 | 500 mW, DO-35 package, 5% tolerance, IZT = 5 mA - 100× higher test current than 1N4678UR-1/TR. | Not suitable for micro-power designs; requires larger PCB footprint and lacks MIL-PRF-19500 screening. | Select only if legacy DO-35 layout exists and system current budget exceeds 5 mA. |
| MMBZ5221BS | SOT-23 package, 225 mW, 5% tolerance, IZT = 20 µA - lower power rating and plastic encapsulation. | Lacks hermeticity and radiation hardness; unsuitable for aerospace or high-reliability industrial use. | Choose for cost-sensitive consumer applications where DO-213AA form factor and reliability are not required. |
Compared with BZX55C1V8 and MMBZ5221BS, the 1N4678UR-1/TR uniquely delivers ultra-low-current regulation (50 µA), hermetic MELF packaging, and MIL-qualified reliability options - making it the only choice for space-constrained, high-stability, and mission-critical 1.8 V reference needs.
Availability
1N4678UR-1/TR is available at Aetrix Electronics and suitable for medical sensor biasing, aerospace power monitor reference, and downhole instrumentation requiring stable component supply with guaranteed long-term availability and traceable sourcing.
Supply support for 1N4678UR-1/TR 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) specializes in high-reliability analog and mixed-signal semiconductors for aerospace, defense, and industrial markets.
The 1N4678UR-1/TR belongs to Microsemi's legacy MIL-PRF-19500-qualified Zener family, engineered for extreme environment voltage reference and regulation where stability, hermeticity, and radiation tolerance are mandatory.
FAQ
What is the Zener voltage tolerance for 1N4678UR-1/TR?
The standard 1N4678UR-1/TR has a ±5% Zener voltage tolerance at 50 µA test current. Tighter tolerances of ±2% (suffix "C") and ±1% (suffix "D") are available upon request, but the base part number 1N4678UR-1/TR specifies ±5%. This tolerance is verified across the full operating temperature range of –65 °C to +175 °C.
Can 1N4678UR-1/TR be used in place of through-hole 1N4678-1?
Yes - the 1N4678UR-1/TR is the surface-mount DO-213AA equivalent of the through-hole DO-35 1N4678-1, sharing identical electrical characteristics including 1.8 V nominal Zener voltage, 50 µA test current, and ±5% tolerance. However, the UR-1 variant adds hermetic sealing and metallurgical bonding not present in the standard version.
What is the maximum steady-state power dissipation for 1N4678UR-1/TR?
The 1N4678UR-1/TR is rated for 0.5 W steady-state power dissipation when mounted on an FR4 PCB with 1 oz copper and ambient temperature below 50 °C. Above 50 °C, power must be linearly derated using the 250 °C/W junction-to-ambient thermal resistance, reaching zero dissipation at 175 °C ambient.
Is 1N4678UR-1/TR RoHS compliant?
Yes - the 1N4678UR-1/TR is available in RoHS-compliant matte-tin plating (designated by "e3" suffix in full nomenclature), but only for commercial-grade versions. MIL-qualified variants (MQ, MX, MV, MSP) retain tin-lead plating to meet legacy reliability requirements and are not RoHS compliant.
Does 1N4678UR-1/TR require special handling for soldering?
No special handling beyond standard MELF component practices is required. The 1N4678UR-1/TR supports reflow soldering up to 260 °C for 10 seconds per JEDEC J-STD-020. Its glass body and metallurgically bonded structure tolerate thermal shock better than plastic-packaged Zeners, and its end-cap plating complies with MIL-STD-750 Method 2026 for solderability.
1N4678UR-1/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-213AA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 1.8 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- -
- Current - Reverse Leakage @ Vr:
- 7.5 µA @ 1 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 100 mA
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-213AA
1N4678UR-1/TR FAQ
1.How can I place an order for 1N4678UR-1/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4678UR-1/TR 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 1N4678UR-1/TR reliable?
The price and inventory of 1N4678UR-1/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4678UR-1/TR is usually 5 days.
3.What payment methods are accepted for 1N4678UR-1/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4678UR-1/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4678UR-1/TR?
1N4678UR-1/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4678UR-1/TR 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 1N4678UR-1/TR?
For technical support, including 1N4678UR-1/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4678UR-1/TR requirements.
6.How does Aetrix verify that 1N4678UR-1/TR is sourced from the original manufacturer or authorized distributors?
All 1N4678UR-1/TR 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 1N4678UR-1/TR meets industry standards.
7.What is the process for return or replacement of 1N4678UR-1/TR?
All 1N4678UR-1/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4678UR-1/TR, 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 1N4678UR-1/TR part is unused and in its original packaging.
Return procedure for 1N4678UR-1/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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