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Diodes Incorporated 1N4731A-T
- Part No.:
- 1N4731A-T
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4731A-T.pdf
- Description:
- DIODE ZENER 4.3V 1W DO41
- Quantity:
- Payment:
- Shipping:
Inventory:5,810
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Product details
Overview
1N4731A-T from Diodes Incorporated is a 1.0 W, 4.3 V ±5% Zener diode in DO-41 glass package, designed for precision voltage regulation and reference applications in power supply feedback loops, overvoltage protection circuits, and analog signal conditioning. It delivers 58 mA test current, 9.0 Ω dynamic impedance at 58 mA, and exhibits a temperature coefficient of –0.07 to –0.01 %/°C.
For engineers reviewing the 1N4731A-T datasheet, 1N4731A-T pinout, 1N4731A-T application, or 1N4731A-T equivalent, this device serves as a stable, RoHS-compliant 4.3 V shunt regulator with verified thermal resistance (175 °C/W), low reverse leakage (10 µA @ 1.0 V), and surge capability (1070 mA, 8.3 ms).
Technical Context
This discrete Zener diode operates in reverse breakdown mode to maintain a stable 4.3 V reference across varying load and line conditions. Its DO-41 glass package ensures hermetic sealing and reliable performance from –65 °C to +175 °C, with cathode band polarity marking and Sn96.5Ag3.5 solderable terminations.
It features a sharp knee in the breakdown curve validated by dual-point Zener impedance measurement (IZT = 58 mA, IZK = 1.0 mA), and its thermal derating begins above 50 °C at 6.67 mW/°C when leads are held at 50 °C with 9.5 mm length from case.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 4.3 V ±5% - precise DC reference voltage under 58 mA test current |
| Power Dissipation (Pd) | 1.0 W at 25 °C - supports continuous regulation in compact linear supplies |
| Zener Impedance (ZZT) | 9.0 Ω @ 58 mA - ensures minimal output voltage variation under load transients |
| Reverse Leakage (IR) | 10 µA @ 1.0 V - enables low-quiescent-current biasing in high-impedance circuits |
| Surge Current (IZS) | 1070 mA (8.3 ms) - withstands short-duration overvoltage events without failure |
| Temp. Coefficient (αVZ) | –0.07 to –0.01 %/°C - predictable, negative drift suitable for temperature-compensated references |
| Thermal Resistance (RθJA) | 175 °C/W - defines junction-to-ambient heat dissipation limit in free-air mounting |
Pinout & Package
DO-41 glass axial package with cathode band marking; body diameter 1.8–2.6 mm, overall length 26.0 mm max, lead diameter 0.86 mm max. Polarity is unambiguous: banded end is cathode.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Reference ground node | Connected to circuit common; establishes return path for Zener current |
| Cathode | Regulated output node | Provides stable 4.3 V relative to anode; marked with visible band |
Key Features
| Feature | Design Value |
|---|---|
| 1.0 W Power Rating | Enables use in mid-power voltage clamp and regulator circuits without heatsinking |
| ±5% VZ Tolerance | Reduces binning requirements while maintaining accuracy for non-critical references |
| DO-41 Glass Construction | Provides hermetic seal and UL 94V-0 flammability rating for safety-critical designs |
| RoHS-Compliant Finish | Sn96.5Ag3.5 termination meets lead-free assembly standards and MIL-STD-202 solderability |
| Low Temp. Coefficient Drift | Negative αVZ allows pairing with positive-drift components for compensated references |
Applications
| Switch-Mode Power Supply Feedback | Overvoltage Protection Clamp |
|---|---|
Use Scenario: Regulates output voltage in isolated flyback converters via optocoupler feedback loop. IC Role / Device Role / Timing Role: Shunt reference providing precise 4.3 V threshold for TL431-like control interface. Use Value: Maintains ±1% output regulation across line/load variations due to stable VZ and low ZZT. |
Use Scenario: Clamps transient surges on 5 V rail caused by ESD or inductive switching. IC Role / Device Role / Timing Role: Fast-acting shunt limiter diverting excess energy to ground before IC damage occurs. Use Value: Absorbs 1070 mA surge (8.3 ms) without degradation, protecting downstream logic and analog stages. |
| Industrial Sensor Biasing | Analog Signal Level Shifting |
Use Scenario: Supplies stable excitation voltage to resistive temperature detectors (RTDs) in PLC input modules. IC Role / Device Role / Timing Role: Low-drift voltage reference ensuring <0.1% measurement error over –40 °C to +85 °C ambient. Use Value: Negative temperature coefficient compensates for RTD self-heating drift in precision bridge circuits. |
Use Scenario: Shifts 0–3.3 V DAC output to 0–4.3 V range for legacy ADC input compatibility. IC Role / Device Role / Timing Role: Passive level translator using Zener forward drop and reverse breakdown characteristics. Use Value: Achieves accurate offset addition with <10 µA leakage, minimizing loading on high-impedance DAC outputs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DFLZ4.3-7 | Surface-mount SOD-123FL package; 4.3 V ±2%; 500 mW rating; lower ZZT (3 Ω) | Designed for automated PCB assembly and space-constrained layouts; not axial-replaceable | Select for new designs requiring higher precision, smaller footprint, and improved thermal performance. |
| 1N4731A-A | Identical electrical specs; DO-41 package; ammo-pack packaging instead of tape-and-reel | No functional difference; differs only in logistics format for manual vs. auto insertion | Choose based on assembly method-tape-and-reel (1N4731A-T) for pick-and-place, ammo pack for hand-soldering. |
Compared with DFLZ4.3-7, the 1N4731A-T offers higher power handling (1.0 W vs. 0.5 W) and axial through-hole mounting, while 1N4731A-A shares identical performance but differs only in packaging format-making the -T variant optimal for automated production.
Availability
1N4731A-T is available at Aetrix Electronics and suitable for industrial power supplies, sensor signal conditioning, overvoltage protection circuits, and analog reference design requiring stable component supply and long-term obsolescence management.
Supply support for 1N4731A-T 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.
The 1N47xxA series belongs to Diodes' standard Zener diode product line, engineered for cost-effective, reliable voltage regulation in general-purpose power and signal conditioning applications.
FAQ
Is the 1N4731A-T suitable for new designs?
No-it is explicitly marked "NOT RECOMMENDED FOR NEW DESIGN" in the official datasheet. Diodes Incorporated recommends migrating to the DFLZ4.3-7 surface-mount alternative for improved precision, thermal performance, and long-term supply assurance. The 1N4731A-T remains viable for legacy repair, maintenance, and existing production runs where DO-41 axial form factor is required.
What is the maximum allowable ambient temperature for full 1.0 W operation?
Full 1.0 W power dissipation is rated only at TA = 25 °C. Derating begins linearly above 50 °C at 6.67 mW/°C, assuming leads are held at 50 °C with 9.5 mm length from case. At 70 °C ambient, maximum dissipation drops to approximately 867 mW. Thermal resistance is 175 °C/W in free air.
How does the temperature coefficient affect circuit stability?
The 1N4731A-T has a negative temperature coefficient (–0.07 to –0.01 %/°C), meaning its Zener voltage decreases slightly as temperature rises. This behavior can be leveraged in temperature-compensated references-for example, pairing it with a positive-drift component like a forward-biased diode to achieve near-zero net drift over temperature.
Can the 1N4731A-T replace the 1N4730A or 1N4732A in existing circuits?
Yes-mechanically and electrically compatible within the 1N47xxA family. The 1N4731A-T (4.3 V) sits between 1N4730A (3.9 V) and 1N4732A (4.7 V); substitution requires verifying that the 0.4 V change does not violate system margin (e.g., feedback divider ratios, clamp thresholds). All share identical DO-41 package, 1.0 W rating, and ±5% tolerance.
1N4731A-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 4.3 V
- Tolerance:
- ±5%
- 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:
- Through Hole
- Supplier Device Package:
- DO-41
1N4731A-T FAQ
1.How can I place an order for 1N4731A-T through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4731A-T 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 1N4731A-T reliable?
The price and inventory of 1N4731A-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4731A-T is usually 5 days.
3.What payment methods are accepted for 1N4731A-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4731A-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4731A-T?
1N4731A-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4731A-T 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 1N4731A-T?
For technical support, including 1N4731A-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4731A-T requirements.
6.How does Aetrix verify that 1N4731A-T is sourced from the original manufacturer or authorized distributors?
All 1N4731A-T 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 1N4731A-T meets industry standards.
7.What is the process for return or replacement of 1N4731A-T?
All 1N4731A-T units undergo pre-shipment inspection (PSI). If there is an issue with 1N4731A-T, 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 1N4731A-T part is unused and in its original packaging.
Return procedure for 1N4731A-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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