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onsemi 1N4731A-T50A
- Part No.:
- 1N4731A-T50A
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4731A-T50A.pdf
- Description:
- DIODE ZENER 4.3V 1W DO41
- Quantity:
- Payment:
- Shipping:
Inventory:33,000
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Product details
Overview
1N4731A-T50A from onsemi is a 4.3 V ±5% Zener diode in DO-41 axial package, rated for 1.0 W power dissipation at TL ≤ 50°C, with 53 Ω maximum Zener impedance at 20 mA test current and 1 μA maximum leakage current at 3.4 V reverse voltage. It provides stable voltage reference in low-power linear regulators and overvoltage protection circuits.
For engineers reviewing the 1N4731A-T50A datasheet, pinout, applications, or equivalent options, key selection criteria include nominal Zener voltage tolerance, thermal derating behavior, surge current capability (IZSM = 970 mA), and DO-41 mechanical compatibility with through-hole PCB layouts.
Technical Context
This device operates as a silicon planar Zener diode optimized for voltage regulation and clamping in DC bias networks. Its breakdown mechanism is predominantly avalanche for voltages above ~5.6 V, but 1N4731A-T50A (4.3 V) relies on Zener tunneling, yielding lower dynamic impedance and tighter voltage stability at low currents.
The 1N4731A-T50A exhibits a temperature coefficient of approximately −2 mV/°C near its operating point, requiring thermal management in precision references. Its 3/8″ lead length specification defines the thermal resistance path to ambient, directly impacting safe continuous power handling above 50°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 4.3 V nominal, ±5% tolerance (4.085–4.515 V), defining precise clamping threshold in feedback loops. |
| Power Dissipation (PD) | 1.0 W at TL ≤ 50°C; derates 6.67 mW/°C above 50°C - sets max continuous current under thermal constraints. |
| Zener Impedance (ZZ) | 53 Ω max at IZ = 20 mA - determines output voltage variation under load transients. |
| Leakage Current (IR) | 1 μA max at VR = 3.4 V - ensures minimal error current in high-impedance reference nodes. |
| Peak Reverse Surge (IZSM) | 970 mA non-repetitive (8.3 ms pulse) - supports transient overvoltage suppression without failure. |
| Operating Temperature | −65°C to +200°C - enables use in automotive under-hood and industrial environments. |
Pinout & Package
DO-41 axial-leaded package (Case 017AH), Pb-free/halide-free, with cathode band marking. Leads are tinned copper-clad steel; body may be plastic or hermetically sealed glass.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference ground | Connected to circuit ground or lower-potential node; establishes reference polarity for clamping. |
| Cathode | Zener breakdown terminal / regulated output node | Connected to voltage source or feedback point; maintains stable 4.3 V relative to anode during reverse bias. |
Key Features
| Feature | Design Value |
|---|---|
| Stable Zener voltage tolerance | ±5% over manufacturing lot - reduces need for post-assembly trimming in cost-sensitive designs. |
| Controlled thermal derating | 6.67 mW/°C linear derating above 50°C - enables predictable power budgeting in thermally constrained enclosures. |
| Low leakage at sub-Zener voltage | ≤1 μA at 3.4 V (80% of VZ) - minimizes quiescent current error in battery-powered voltage monitors. |
| High surge current rating | 970 mA non-repetitive peak - absorbs ESD and line transients without degradation in protection circuits. |
Applications
| DC Power Supply Reference | Overvoltage Clamp |
|---|---|
Use Scenario: Stabilizing feedback voltage in 5 V linear regulator ICs (e.g., LM7805) where output accuracy depends on reference integrity. IC Role / Device Role / Timing Role: Zener diode acting as shunt voltage reference in regulator feedback divider network. Use Value: Maintains ±2% output regulation across line/load variations due to tight 4.3 V tolerance and low ZZ. |
Use Scenario: Protecting microcontroller I/O pins from 12 V supply rail transients in automotive body control modules. IC Role / Device Role / Timing Role: Passive clamping element limiting pin voltage to 4.3 V above ground during surge events. Use Value: Prevents latch-up by diverting >970 mA surge current away from sensitive CMOS inputs without replacement. |
| Temperature-Stable Bias Network | Low-Cost Voltage Monitor |
Use Scenario: Generating fixed bias for op-amp input stages in industrial sensor signal conditioning circuits operating from −40°C to +85°C. IC Role / Device Role / Timing Role: Zener diode providing temperature-compensated reference node for amplifier offset nulling. Use Value: Delivers <±10 mV drift over full range due to predictable negative TC and DO-41 thermal coupling to PCB copper. |
Use Scenario: Detecting brown-out conditions in 3.3 V embedded systems using comparator input referenced to 4.3 V Zener. IC Role / Device Role / Timing Role: Precision voltage threshold generator enabling system reset when supply drops below 3.0 V. Use Value: Enables reliable detection with 1 μA leakage ensuring <0.1% error contribution to comparator hysteresis design. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4731A-TAP | Same electrical specs; tape-and-reel packaging (3000 pcs/reel) vs. fan-fold (T50A). | No functional difference; suited for automated SMT placement only if axial leads are adapted via carrier tape. | Select T50A for manual/hand-soldered prototyping or low-volume through-hole assembly; TAP for high-volume pick-and-place with axial lead feeders. |
| BZX55C4V3 | 4.3 V ±5%, 500 mW rating, DO-35 package - 50% lower power, smaller footprint, higher ZZ (60 Ω). | Not suitable for 1 W continuous dissipation; limited to low-current references (<10 mA) or intermittent clamping. | Choose BZX55C4V3 only when board space is critical and thermal load remains below 0.5 W; retain 1N4731A-T50A for full-power operation. |
Compared with 1N4731A-T50A, the TAP variant offers identical performance with different packaging logistics, while BZX55C4V3 trades power handling and impedance for miniaturization - making 1N4731A-T50A the preferred choice for robust, thermally demanding Zener applications.
Availability
1N4731A-T50A is available at Aetrix Electronics and suitable for DC power supply reference, overvoltage clamp, and temperature-stable bias network applications requiring stable component supply, consistent parametric performance, and long-term obsolescence mitigation.
Supply support for 1N4731A-T50A 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
onsemi (formerly ON Semiconductor) is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The 1N47xxA series is part of onsemi's legacy Zener diode product line designed specifically for general-purpose voltage regulation and transient suppression in cost-sensitive, high-reliability through-hole applications.
FAQ
What is the Zener voltage tolerance of the 1N4731A-T50A?
The 1N4731A-T50A has a nominal Zener voltage of 4.3 V with a guaranteed tolerance of ±5%, meaning the actual measured VZ falls between 4.085 V and 4.515 V at 20 mA test current and 25°C. This tolerance is verified per onsemi's Electrical Characteristics table and applies across manufacturing lots without binning.
Can the 1N4731A-T50A be used in surface-mount designs?
No - the 1N4731A-T50A uses a DO-41 axial-leaded package intended for through-hole mounting. Its 3/8″ lead length and mechanical outline are incompatible with standard SMT reflow profiles or pick-and-place tooling. For surface-mount equivalents, consider SOD-123 or SOD-323 packaged Zeners with matching electrical specs.
What is the maximum allowable junction temperature for the 1N4731A-T50A?
The 1N4731A-T50A has a specified operating junction temperature range of −65°C to +200°C. However, sustained operation above 150°C requires careful thermal design, as power derating begins at 50°C lead temperature and cumulative thermal stress impacts long-term reliability beyond datasheet limits.
How does the 1N4731A-T50A compare to the 1N4733A in terms of Zener voltage?
The 1N4731A-T50A is rated for 4.3 V Zener voltage, while the 1N4733A is rated for 5.1 V. Both share identical package (DO-41), power rating (1.0 W), and test conditions, but their distinct VZ values make them non-interchangeable without circuit redesign - especially in feedback networks where voltage ratio accuracy is critical.
Is the 1N4731A-T50A RoHS compliant?
Yes - the 1N4731A-T50A is manufactured as Pb-free/halide-free per onsemi's ordering information, meeting RoHS Directive 2011/65/EU requirements. The "PbFree / Halide Free" designation appears in the package description on page 3 of the official datasheet.
1N4731A-T50A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Bulk
- Product Status:
- Active
- 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:
- -
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-41
1N4731A-T50A FAQ
1.How can I place an order for 1N4731A-T50A through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4731A-T50A 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-T50A reliable?
The price and inventory of 1N4731A-T50A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4731A-T50A is usually 5 days.
3.What payment methods are accepted for 1N4731A-T50A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4731A-T50A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4731A-T50A?
1N4731A-T50A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4731A-T50A 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-T50A?
For technical support, including 1N4731A-T50A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4731A-T50A requirements.
6.How does Aetrix verify that 1N4731A-T50A is sourced from the original manufacturer or authorized distributors?
All 1N4731A-T50A 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-T50A meets industry standards.
7.What is the process for return or replacement of 1N4731A-T50A?
All 1N4731A-T50A units undergo pre-shipment inspection (PSI). If there is an issue with 1N4731A-T50A, 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-T50A part is unused and in its original packaging.
Return procedure for 1N4731A-T50A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4731A-T50A Tags
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MMBZ5240B-7-F
Diodes Incorporated
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BZX84C3V3LT1G
onsemi
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