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Microchip Technology 1N4744UR-1/TR
- Part No.:
- 1N4744UR-1/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AB, MELF (Glass)
- Datasheet:
-
1N4744UR-1/TR.pdf
- Description:
- DIODE ZENER 15V 1W DO213AB
- Quantity:
- Payment:
- Shipping:
Inventory:59
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Product details
Overview
1N4744UR-1/TR from Microsemi is a surface-mount 15 V, ±5% tolerance glass-encapsulated Zener diode in DO-213AB (MELF) package, rated for 1.0 W steady-state power dissipation at 25°C, with 14 Ω dynamic impedance at 17 mA test current and 5 μA maximum reverse leakage at 11.4 V. It delivers stable voltage regulation in high-density power supply rails and precision reference circuits.
For engineers reviewing the 1N4744UR-1/TR datasheet, 1N4744UR-1/TR pinout, 1N4744UR-1/TR application, or 1N4744UR-1/TR equivalent, key selection criteria include Zener voltage accuracy, thermal resistance (130°C/W on FR4), surge current capability (304 mA), hermetic glass construction, and RoHS-compliant e3 termination.
Technical Context
This device operates as a two-terminal voltage reference diode, conducting in reverse breakdown to clamp voltage across its terminals. Its DO-213AB MELF package provides low parasitic inductance and capacitance-critical for noise-sensitive analog references and fast transient response in DC-DC feedback loops.
It is electrically equivalent to through-hole 1N4744A but optimized for surface mounting with hermetic glass sealing, -65°C to +175°C operating temperature range, and specified knee impedance (61 Ω at 1 mA) ensuring stable regulation down to low currents.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 15 V ±5% at 17 mA - defines precise clamping threshold for overvoltage protection and reference generation |
| Power Dissipation | 1.0 W at TEC < 125°C - supports continuous regulation in compact layouts with adequate end-cap heatsinking |
| Dynamic Impedance (ZZT) | 14 Ω at IZT = 17 mA - ensures minimal output voltage variation under load current changes |
| Reverse Leakage Current | 5 μA max at VR = 11.4 V - guarantees low quiescent error in high-impedance bias networks |
| Surge Current (IS) | 304 mA (½-sine, 1/120 s) - withstands brief transients without degradation in power rail protection |
| Thermal Resistance | 130°C/W junction-to-ambient on FR4 (1 oz Cu) - informs PCB pad design and derating above 45°C ambient |
| Operating Temperature | -65°C to +175°C - enables use in aerospace, downhole, and industrial environments without derating |
Pinout & Package
DO-213AB (Glass MELF) package: cylindrical hermetically sealed glass body with axial tin-lead or RoHS-compliant matte-tin terminations; cathode indicated by single black band; polarity-critical - banded end must be biased positive for Zener operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference ground | Connected to circuit ground or lower-potential node; reverse-biased relative to cathode during regulation |
| Cathode | Zener breakdown terminal / regulated output node | Banded end; connected to voltage rail requiring stabilization; carries full Zener current during regulation |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic glass MELF construction | Eliminates moisture ingress and long-term parameter drift; qualified for high-reliability applications per source control drawing |
| Low dynamic impedance (14 Ω) | Minimizes output voltage deviation under varying load conditions in feedback and reference paths |
| Specified knee impedance (61 Ω @ 1 mA) | Ensures predictable turn-on behavior and stable regulation even at microampere bias currents |
| ESD-insensitive design | Withstands handling without special precautions-reduces manufacturing yield loss in automated SMT lines |
| RoHS-compliant e3 termination | Matte-tin plating meets JEDEC J-STD-020 reflow requirements and eliminates lead-based solder compatibility issues |
Applications
| Industrial Power Supply Reference | Automotive ECU Voltage Clamp |
|---|---|
Use Scenario: Stabilizing feedback voltage in isolated DC-DC converters for PLC I/O modules. IC Role / Device Role / Timing Role: Two-terminal shunt regulator providing precise 15 V reference for optocoupler-driven error amplifiers. Use Value: Maintains ±0.75 V regulation accuracy across -40°C to +105°C ambient, enabling consistent loop gain and transient response. |
Use Scenario: Protecting microcontroller ADC inputs from battery voltage spikes in engine control units. IC Role / Device Role / Timing Role: Reverse-biased clamping diode limiting input to 15.8 V (15 V + 5%) during load dump events. Use Value: Survives 304 mA surge pulses without parametric shift, preserving signal integrity and preventing ADC saturation. |
| Aerospace Sensor Bias Network | Medical Instrument Precision Reference |
Use Scenario: Generating stable bias for radiation-hardened op-amps in satellite telemetry front-ends. IC Role / Device Role / Timing Role: Low-noise Zener reference supplying 15 V to instrumentation amplifier stages. Use Value: Hermetic glass package and inherent radiation hardness (per MicroNote 050) prevent performance degradation in LEO orbits. |
Use Scenario: Setting reference voltage for calibrated blood glucose meter analog front-end. IC Role / Device Role / Timing Role: Primary voltage reference in ratiometric measurement chain with 16-bit SAR ADC. Use Value: ±5% initial tolerance and <100 ppm/°C TC enable sub-0.5% total measurement uncertainty over clinical temperature range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4744A | Same 15 V ±5% Zener voltage and 1 W rating, but in axial DO-41 package with higher thermal resistance (70°C/W junction-to-lead) | Requires through-hole assembly and larger board area; unsuitable for ultra-high-density layouts | Select when legacy through-hole compatibility or manual prototyping is prioritized over miniaturization |
| SMAJ4744A | Surface-mount SMA package (JEDEC DO-214AC), 15 V ±5%, 1 W, but plastic-bodied with higher capacitance (~20 pF vs. ~5 pF) and lower max temp (+150°C) | Higher parasitic capacitance limits use in RF-coupled or high-speed transient suppression | Select for cost-sensitive consumer designs where hermeticity and extended temperature range are non-critical |
Compared with 1N4744A and SMAJ4744A, the 1N4744UR-1/TR uniquely combines MELF's low-inductance geometry, hermetic reliability, and full -65°C to +175°C operation-making it optimal for space-constrained, high-stability, and mission-critical regulation where long-term parameter stability is mandatory.
Availability
1N4744UR-1/TR is available at Aetrix Electronics and suitable for industrial power supplies, automotive ECUs, aerospace sensor interfaces, and medical instrument references requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for 1N4744UR-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 (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 1N4744UR-1/TR belongs to Microsemi's surface-mount glass Zener diode family designed specifically for high-density, low-parasitic, and high-reliability voltage regulation-targeting applications where hermetic sealing, wide temperature operation, and stable long-term performance are essential.
FAQ
What is the Zener voltage tolerance of the 1N4744UR-1/TR?
The 1N4744UR-1/TR has a nominal Zener voltage of 15 V with a tolerance of ±5%, as indicated by the "A" suffix in its full designation. This tolerance is guaranteed at 17 mA test current and 30°C case temperature, and applies across its full operating temperature range of -65°C to +175°C.
Can the 1N4744UR-1/TR replace the through-hole 1N4744A in existing designs?
The 1N4744UR-1/TR is electrically equivalent to the 1N4744A but uses a DO-213AB MELF surface-mount package instead of DO-41. While electrical parameters match, PCB layout must be updated for MELF footprint and reflow profile. Thermal performance differs: 1N4744UR-1/TR has 130°C/W junction-to-ambient vs. 1N4744A's 70°C/W junction-to-lead-requiring careful thermal validation.
What is the maximum surge current rating for the 1N4744UR-1/TR?
The 1N4744UR-1/TR is rated for a maximum non-repetitive reverse surge current (IS) of 304 mA, measured using a ½-sine wave pulse of 1/120 second duration at 25°C ambient. This rating supports transient overvoltage protection in automotive load-dump and industrial switching scenarios without permanent parameter shift.
Is the 1N4744UR-1/TR RoHS compliant?
Yes-the "e3" suffix in the full part number confirms RoHS compliance. The 1N4744UR-1/TR features annealed matte-tin plating per MIL-STD-750 Method 2026, compatible with lead-free reflow profiles up to 260°C for 10 seconds, and meets all substance restrictions under Directive 2011/65/EU.
How does the DO-213AB package affect PCB layout for the 1N4744UR-1/TR?
The DO-213AB (MELF) package requires a specific circular pad layout per Microsemi's recommended footprint: 2.8 mm pad diameter with 4.8–5.2 mm center-to-center spacing. Unlike rectangular SMD diodes, MELF devices roll during placement-so stencil aperture design and pick-and-place vacuum nozzle selection must accommodate cylindrical geometry to ensure alignment and solder joint integrity.
1N4744UR-1/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-213AB, MELF (Glass)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 15 V
- Tolerance:
- ±10%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 14 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 11.4 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-213AB (MELF, LL41)
1N4744UR-1/TR FAQ
1.How can I place an order for 1N4744UR-1/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4744UR-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 1N4744UR-1/TR reliable?
The price and inventory of 1N4744UR-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 1N4744UR-1/TR is usually 5 days.
3.What payment methods are accepted for 1N4744UR-1/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4744UR-1/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4744UR-1/TR?
1N4744UR-1/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4744UR-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 1N4744UR-1/TR?
For technical support, including 1N4744UR-1/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4744UR-1/TR requirements.
6.How does Aetrix verify that 1N4744UR-1/TR is sourced from the original manufacturer or authorized distributors?
All 1N4744UR-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 1N4744UR-1/TR meets industry standards.
7.What is the process for return or replacement of 1N4744UR-1/TR?
All 1N4744UR-1/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4744UR-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 1N4744UR-1/TR part is unused and in its original packaging.
Return procedure for 1N4744UR-1/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4744UR-1/TR Tags
-
MMBZ5240B-7-F
Diodes Incorporated
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BZT52C5V6T-7
Diodes Incorporated
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MMSZ5231B-7-F
Diodes Incorporated
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BZT52C15-7-F
Diodes Incorporated
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BZX84C3V3LT1G
onsemi
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MMSZ5245BS-7-F
Diodes Incorporated
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MMSZ4682T1G
onsemi
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BZT52C15S-7-F
Diodes Incorporated
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MM5Z5V1ST1G
onsemi
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SMAJ4744A-TP
Micro Commercial Co
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BZT52C3V6LP-7
Diodes Incorporated
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SMAZ12-13-F
Diodes Incorporated
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