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Microchip Technology 1N4731UR/TR
- Part No.:
- 1N4731UR/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AB, MELF (Glass)
- Datasheet:
-
1N4731UR/TR.pdf
- Description:
- DIODE ZENER 4.3V 1W DO213AB
- Quantity:
- Payment:
- Shipping:
Inventory:3,843
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Product details
Overview
1N4731UR/TR from Microsemi is a surface-mount 1.0 W glass-encapsulated Zener diode with nominal Zener voltage 4.3 V ±5%, 58 mA test current, 9 Ω dynamic impedance at IZT, and 10 μA maximum reverse leakage at 1 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 1N4731UR/TR datasheet, 1N4731UR/TR pinout, 1N4731UR/TR application, or 1N4731UR/TR equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (130 °C/W on FR4), surge current rating (217 mA), hermetic glass MELF packaging, and RoHS-compliant e3 suffix availability.
Technical Context
This device implements a single-junction silicon Zener structure optimized for stable breakdown regulation under DC and low-frequency AC conditions. Its DO-213AB glass MELF package provides hermetic sealing, low parasitic capacitance, and inherent radiation hardness per MicroNote 050.
It delivers regulated output across 1–217 mA operating current range with sharp knee characteristics verified by dual-point Zener impedance measurement (IZK and IZT). Forward voltage is ≤1.2 V at 200 mA, and it supports reflow soldering up to 260 °C for 10 s.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 4.3 V ±5% - defines precise reference point for feedback networks in switching regulators |
| Power Dissipation | 1.0 W at TEC < 125 °C - sets thermal design limit for PCB copper area and heatsinking |
| Dynamic Impedance ZZT | 9 Ω at IZT = 58 mA - ensures minimal output voltage variation under load transients |
| Reverse Leakage IR | 10 μA max at VR = 1 V - guarantees low quiescent current in standby-mode circuits |
| Operating Temperature | –65 °C to +175 °C - enables use in automotive engine control and downhole industrial systems |
| Thermal Resistance | 130 °C/W junction-to-ambient on FR4 - informs minimum pad size and copper pour requirements |
| Surge Current IS | 217 mA (½-sine, 1/120 s) - determines transient overvoltage clamping capability |
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, weight = 0.05 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Zener anode connection | Must be biased positive relative to anode to achieve Zener breakdown; polarity critical for regulation |
| Anode (unbanded end) | Zener cathode connection | Connected to circuit ground or lower potential node; forms reference return path |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic glass MELF construction | Eliminates moisture ingress and long-term parameter drift in harsh environments |
| JEDEC DO-213AB outline compliance | Ensures compatibility with standard SMT pick-and-place and reflow processes |
| Inherent radiation hardness | Validated per MicroNote 050 - suitable for aerospace and defense electronics |
| Nonsensitive to ESD | No special handling required during assembly; simplifies manufacturing flow |
| RoHS-compliant e3 option | Meets EU Directive 2011/65/EU without lead or hazardous substances |
Applications
| Switching Power Supply Feedback | Industrial Sensor Reference |
|---|---|
Use Scenario: Regulates output voltage in flyback and forward converter feedback paths using optocoupler-coupled error amplifiers. IC Role / Device Role / Timing Role: Provides stable 4.3 V reference for TL431 or similar shunt regulator ICs in secondary-side control. Use Value: Tight ±5% tolerance and low 9 Ω dynamic impedance minimize output voltage deviation across line/load/temperature. | Use Scenario: Supplies excitation voltage to bridge-based pressure or temperature sensors in factory automation modules. IC Role / Device Role / Timing Role: Acts as precision bias source replacing active references where ultra-low noise is not required. Use Value: Hermetic glass package ensures long-term stability of reference voltage in humid or chemically aggressive enclosures. |
| Automotive Engine Control Unit | Downhole Oilfield Instrumentation |
Use Scenario: Clamps microcontroller I/O rail against load dump transients in 12 V vehicle subsystems. IC Role / Device Role / Timing Role: Functions as overvoltage protection element on analog input lines feeding ADCs. Use Value: 217 mA surge rating and –65 °C to +175 °C operation support ASIL-B functional safety requirements. | Use Scenario: Stabilizes bias voltage for piezoelectric sensor front-ends in high-temperature well logging tools. IC Role / Device Role / Timing Role: Serves as primary voltage reference in sealed, oil-filled probe housings. Use Value: Radiation hardness and hermetic seal prevent parameter shift under neutron/gamma exposure and extreme pressure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4731AUR | Same Zener voltage and tolerance, but axial DO-41 through-hole package | Requires PCB through-hole mounting; unsuitable for high-density SMT designs | Select when legacy board reuse or manual prototyping is prioritized over automated assembly |
| SMAJ4731A | Same electrical specs, but SMA package with higher thermal resistance (150 °C/W) | Lower power derating margin on FR4; requires larger copper area for 1 W operation | Select when existing SMA footprint exists and thermal budget allows reduced power headroom |
Compared with 1N4731UR/TR, 1N4731AUR offers identical regulation performance but mandates through-hole assembly, while SMAJ4731A trades package compatibility for slightly degraded thermal performance-both require layout adjustments and do not provide drop-in replacement capability.
Availability
1N4731UR/TR is available at Aetrix Electronics and suitable for switching power supplies, industrial sensor interfaces, automotive engine control units, and downhole instrumentation requiring stable component supply across extended temperature and reliability lifecycles.
Supply support for 1N4731UR/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 high-voltage analog components.
The 1N47xxUR/TR series belongs to Microsemi's surface-mount Zener diode product line, engineered for voltage regulation in mission-critical systems where hermeticity, temperature resilience, and long-term parametric stability are mandatory.
FAQ
What is the Zener voltage tolerance for 1N4731UR/TR?
The 1N4731UR/TR has a nominal Zener voltage of 4.3 V with a standard tolerance of ±5%, as indicated by the "A" suffix in its full designation. This tolerance is verified at 30 °C with 58 mA test current and ensures predictable regulation in feedback and reference circuits across industrial temperature ranges.
Does 1N4731UR/TR support RoHS compliance?
Yes, the 1N4731UR/TR is available in RoHS-compliant form with the "e3" suffix, indicating lead-free matte-tin plating per JEDEC J-STD-609. The base part number without "e3" uses traditional tin-lead termination, so designers must specify "1N4731UR/TR e3" explicitly for compliant builds.
What is the maximum steady-state power dissipation for 1N4731UR/TR?
The 1N4731UR/TR is rated for 1.00 W steady-state power dissipation at end-cap temperature < 125 °C or ambient temperature < 45 °C when mounted on FR4 with the recommended footprint. Derating follows the curve in Figure 1, reaching zero power at 175 °C ambient.
How is polarity marked on 1N4731UR/TR?
The 1N4731UR/TR uses a single cathode band on the glass MELF body to indicate polarity. During operation, the banded end must be held positive relative to the unbanded end to achieve Zener breakdown regulation; reversing polarity subjects the device to forward conduction only, with VF ≤ 1.2 V at 200 mA.
What is the thermal resistance of 1N4731UR/TR on FR4 PCB?
The 1N4731UR/TR exhibits 130 °C/W junction-to-ambient thermal resistance when mounted on standard FR4 with 1 oz copper and Microsemi's recommended pad layout. This value assumes proper solder wetting and no additional thermal vias; adding thermal relief or copper pours reduces effective θJA.
1N4731UR/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):
- 4.3 V
- Tolerance:
- ±10%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 9 Ohms
- Current - Reverse Leakage @ Vr:
- 10 µA @ 1 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)
1N4731UR/TR FAQ
1.How can I place an order for 1N4731UR/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4731UR/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 1N4731UR/TR reliable?
The price and inventory of 1N4731UR/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4731UR/TR is usually 5 days.
3.What payment methods are accepted for 1N4731UR/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4731UR/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4731UR/TR?
1N4731UR/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4731UR/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 1N4731UR/TR?
For technical support, including 1N4731UR/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4731UR/TR requirements.
6.How does Aetrix verify that 1N4731UR/TR is sourced from the original manufacturer or authorized distributors?
All 1N4731UR/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 1N4731UR/TR meets industry standards.
7.What is the process for return or replacement of 1N4731UR/TR?
All 1N4731UR/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4731UR/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 1N4731UR/TR part is unused and in its original packaging.
Return procedure for 1N4731UR/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4731UR/TR Tags
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MMBZ5240B-7-F
Diodes Incorporated
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BZT52C5V6T-7
Diodes Incorporated
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MMSZ5231B-7-F
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BZX84C3V3LT1G
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MMSZ4682T1G
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Diodes Incorporated
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MM5Z5V1ST1G
onsemi
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