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Microchip Technology 1N4747UR-1/TR
- Part No.:
- 1N4747UR-1/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AB, MELF (Glass)
- Datasheet:
-
1N4747UR-1/TR.pdf
- Description:
- DIODE ZENER 20V 1W DO213AB
- Quantity:
- Payment:
- Shipping:
Inventory:4,620
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Product details
Overview
1N4747UR-1/TR from Microsemi is a surface-mount 1.0 W glass Zener diode with nominal Zener voltage 20 V ±5%, 12.5 mA test current, 22 Ω dynamic impedance at IZT, and maximum reverse current 5 μA at 15.2 V. It operates from −65 °C to +175 °C and is used for precision voltage regulation in high-density power supply feedback loops.
For engineers reviewing the 1N4747UR-1/TR datasheet, 1N4747UR-1/TR pinout, 1N4747UR-1/TR application, or 1N4747UR-1/TR equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (130 °C/W on FR4), surge current rating (750 mA), hermetic DO-213AB package, and RoHS-compliant e3 plating.
Technical Context
This device functions as a two-terminal voltage reference diode operating in reverse breakdown. Its Zener voltage is specified at 20 V with ±5% tolerance (A-suffix), measured 90 s after DC current application, and exhibits 22 Ω dynamic impedance at 12.5 mA test current.
The DO-213AB glass MELF package provides hermetic sealing, inherent radiation hardness per MicroNote 050, and low parasitic capacitance. It supports steady-state dissipation of 1.0 W below 125 °C end-cap temperature or 45 °C ambient on FR4 with recommended pad layout.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 20 V ±5% - stable regulation point for feedback networks requiring tight voltage reference accuracy |
| Test Current (IZT) | 12.5 mA - defined operating point for specifying VZ and dynamic impedance |
| Dynamic Impedance (ZZT) | 22 Ω @ IZT - low AC impedance ensures minimal output voltage variation under load transients |
| Max Reverse Current (IR) | 5 μA @ 15.2 V - confirms sharp knee and low leakage below regulation threshold |
| Power Dissipation | 1.0 W @ TEC < 125 °C - defines safe continuous operation limit with thermal derating above that temperature |
| Operating Temperature | −65 °C to +175 °C - enables use in extended industrial, aerospace, and downhole environments |
| Thermal Resistance | 130 °C/W junction-to-ambient on FR4 - determines required PCB copper area and heatsinking for thermal management |
Pinout & Package
Package: DO-213AB glass MELF - hermetically sealed, leadless cylindrical surface-mount package with cathode band marking; dimensions A = 2.39–2.66 mm, B = 4.80–5.20 mm, C = 0.41–0.55 mm; weight 0.05 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Reverse-biased terminal | Connected to regulated voltage node; must be held positive relative to anode for Zener conduction |
| Anode (unbanded end) | Reference/ground terminal | Typically tied to system ground or lower-potential rail; completes reverse-bias path |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic glass MELF construction | Enables operation in harsh environments including high humidity, radiation exposure, and wide thermal cycling |
| JEDEC DO-213AB outline compliance | Ensures standardized SMT placement, reflow compatibility, and mechanical reliability in automated assembly |
| Nonsensitive to ESD | Eliminates need for external ESD protection circuitry in handling and board-level integration |
| Specified capacitance (see Figure 2) | Supports stable high-frequency regulation without unintended signal coupling or oscillation in feedback paths |
| Inherent radiation hardness | Validated per MicroNote 050 for use in space-grade and nuclear instrumentation applications without additional hardening |
Applications
| Switch-Mode Power Supply Feedback | Industrial Sensor Signal Conditioning |
|---|---|
Use Scenario: Regulating output voltage in isolated flyback or forward converter feedback loops using optocoupler-coupled error amplifiers. IC Role / Device Role / Timing Role: Precision voltage reference providing stable 20 V reference to TL431 or similar shunt regulator ICs. Use Value: Tight ±5% tolerance and low 22 Ω dynamic impedance minimize output voltage drift across line/load/temperature variations. | Use Scenario: Biasing and clamping analog front-end circuits in pressure, temperature, or strain gauge transmitters. IC Role / Device Role / Timing Role: Overvoltage protection and rail stabilization for op-amp input stages and ADC reference buffers. Use Value: Hermetic DO-213AB package ensures long-term stability and low leakage (<5 μA) in humid or corrosive industrial enclosures. |
| Aerospace Power Management | Downhole Oil & Gas Electronics |
Use Scenario: Providing reference voltage for DC-DC converters in satellite power distribution units exposed to total ionizing dose. IC Role / Device Role / Timing Role: Radiation-hardened Zener reference replacing less robust silicon alternatives in critical voltage monitoring paths. Use Value: Inherent radiation hardness per MicroNote 050 eliminates need for shielding or redundancy in space-qualified designs. | Use Scenario: Voltage clamping and regulation in high-temperature logging tools deployed at >150 °C wellbore environments. IC Role / Device Role / Timing Role: High-temperature-stable reference element maintaining regulation integrity across −65 °C to +175 °C range. Use Value: Extended operating temperature range and hermetic seal prevent parameter shift or failure during thermal shock cycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4747AUR-1/TR | Same Zener voltage (20 V), same ±5% tolerance, identical DO-213AB package, but lacks e3 RoHS suffix | No difference in function or mounting; non-RoHS version may be selected where legacy compliance or tin-lead soldering is required | Choose 1N4747AUR-1/TR only if RoHS exemption applies; otherwise prefer e3-compliant 1N4747UR-1/TR |
| SMAJ4747A | Same 20 V Zener voltage, ±5% tolerance, but uses SMA package (plastic, not glass); higher thermal resistance (~150 °C/W) | Lower cost and higher volume availability, but reduced reliability in high-radiation or high-humidity environments | Select SMAJ4747A for commercial-grade cost-sensitive designs; avoid where hermeticity or radiation hardness is mandatory |
Compared with 1N4747AUR-1/TR and SMAJ4747A, the 1N4747UR-1/TR delivers guaranteed RoHS compliance, hermetic glass sealing, and proven radiation hardness-making it the preferred choice for high-reliability, extended-temperature, and mission-critical regulation tasks.
Availability
1N4747UR-1/TR is available at Aetrix Electronics and suitable for switch-mode power supplies, industrial sensor interfaces, aerospace power management systems, and downhole electronics requiring stable component supply across extended temperature and reliability requirements.
Supply support for 1N4747UR-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 analog, RF, and radiation-hardened components for defense, aerospace, and industrial markets.
The 1N4747UR-1/TR belongs to Microsemi's surface-mount Zener diode family designed for precision voltage regulation in high-density, high-reliability applications where hermetic sealing, wide temperature operation, and radiation tolerance are essential.
FAQ
What is the Zener voltage tolerance of the 1N4747UR-1/TR?
The 1N4747UR-1/TR has a nominal Zener voltage of 20 V with a tolerance of ±5%, indicated by the "A" suffix in its designation. This tolerance is verified at 12.5 mA test current and 30 °C case temperature, and applies across the full operating temperature range of −65 °C to +175 °C. The 1N4747UR-1/TR maintains this specification due to its hermetic glass construction and process-controlled doping.
Does the 1N4747UR-1/TR require external ESD protection?
No, the 1N4747UR-1/TR is explicitly characterized as nonsensitive to ESD per manufacturer documentation, eliminating the need for external transient suppression or handling precautions beyond standard SMT practices. This property stems from its glass MELF structure and internal junction design, and is confirmed in the "Applications / Benefits" section of the official Microsemi datasheet for the 1N4747UR-1/TR.
What is the maximum surge current rating for the 1N4747UR-1/TR?
The 1N4747UR-1/TR has a maximum surge current rating of 750 mA, measured using a ½ sine-wave pulse of 1/120 second duration at 25 °C ambient. This rating reflects its ability to withstand short-duration overvoltage events in power supply clamp or transient protection roles without degradation, and is validated under JEDEC-standard test conditions referenced in the datasheet notes.
Is the 1N4747UR-1/TR compatible with lead-free reflow processes?
Yes, the 1N4747UR-1/TR carries the "e3" suffix, indicating RoHS-compliant annealed matte-tin plating that meets J-STD-020 moisture sensitivity level 1 and supports peak reflow temperatures up to 260 °C for 10 seconds. Its DO-213AB glass body is inherently compatible with standard lead-free reflow profiles, and no special prebake or handling is required prior to assembly.
How does the thermal resistance of the 1N4747UR-1/TR affect PCB layout?
The 1N4747UR-1/TR has a junction-to-ambient thermal resistance of 130 °C/W when mounted on FR4 with 1 oz copper and the recommended footprint. To maintain safe operation at full 1.0 W dissipation, the PCB must provide adequate copper area and thermal vias-especially near the cathode and anode terminations-to limit end-cap temperature below 125 °C. The datasheet specifies exact pad dimensions and layout guidance on Page 3 for optimal thermal performance of the 1N4747UR-1/TR.
1N4747UR-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):
- 20 V
- Tolerance:
- ±10%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 22 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 15.2 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)
1N4747UR-1/TR FAQ
1.How can I place an order for 1N4747UR-1/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4747UR-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 1N4747UR-1/TR reliable?
The price and inventory of 1N4747UR-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 1N4747UR-1/TR is usually 5 days.
3.What payment methods are accepted for 1N4747UR-1/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4747UR-1/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4747UR-1/TR?
1N4747UR-1/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4747UR-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 1N4747UR-1/TR?
For technical support, including 1N4747UR-1/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4747UR-1/TR requirements.
6.How does Aetrix verify that 1N4747UR-1/TR is sourced from the original manufacturer or authorized distributors?
All 1N4747UR-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 1N4747UR-1/TR meets industry standards.
7.What is the process for return or replacement of 1N4747UR-1/TR?
All 1N4747UR-1/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4747UR-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 1N4747UR-1/TR part is unused and in its original packaging.
Return procedure for 1N4747UR-1/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4747UR-1/TR Tags
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