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onsemi 1N4738A-T50R
- Part No.:
- 1N4738A-T50R
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4738A-T50R.pdf
- Description:
- DIODE ZENER 8.2V 1W DO41
- Quantity:
- Payment:
- Shipping:
Inventory:7,126
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Product details
Overview
1N4738A-T50R from ON Semiconductor is a 8.2 V ±5% Zener diode in DO-41 glass package, rated for 1.0 W power dissipation at TL ≤ 50°C with 6.67 mW/°C derating, operating from −65°C to +200°C, and used for precision voltage regulation and overvoltage protection in DC power supplies and reference circuits.
For engineers reviewing the 1N4738A-T50R datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance (±5%), dynamic impedance (31 Ω @ 25 mA), leakage current (≤0.5 μA @ 6.6 V), peak reverse surge capability (550 mA), and thermal stability across industrial temperature ranges.
Technical Context
This device operates as a two-terminal voltage reference, maintaining stable reverse breakdown at nominal 8.2 V with tight 5% tolerance. Its Zener impedance of 31 Ω at 25 mA test current ensures low output variation under load changes, while the 1.0 W power rating supports continuous regulation in linear regulator shunt configurations.
The DO-41 package enables through-hole mounting with cathode band identification, and its −65°C to +200°C operating range supports use in automotive engine control units and industrial motor drives where ambient thermal stress exceeds standard commercial limits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 8.2 V nominal, min 7.79 V / max 8.61 V - defines regulated output voltage under 25 mA test current with ±5% tolerance. |
| Power Dissipation (PD) | 1.0 W @ TL ≤ 50°C - maximum continuous power handling before thermal derating begins. |
| Zener Impedance (ZZ) | 31 Ω @ IZ = 25 mA - low dynamic resistance ensures minimal voltage shift during load transients. |
| Leakage Current (IR) | ≤0.5 μA @ VR = 6.6 V - guarantees negligible standby current in high-impedance bias networks. |
| Operating Temperature | −65°C to +200°C - enables deployment in under-hood automotive, downhole, and industrial environments. |
| Peak Reverse Surge (IZSM) | 550 mA (non-repetitive, 8.3 ms) - withstands transient overvoltage events without degradation. |
Pinout & Package
DO-41 glass axial package with cathode indicated by a single color band on the body. Leads are tinned copper-clad steel, suitable for wave or hand soldering. Standard lead length is 3/8″ for thermal rating compliance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener reference ground node | Connected to circuit common or lower potential side; establishes reference point for regulated voltage at cathode. |
| Cathode | Zener breakdown terminal / regulated output node | Delivers stable 8.2 V relative to anode when reverse biased above VZ; marked with visible band for polarity identification. |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Enables accurate voltage clamping without post-production trimming in cost-sensitive power supply designs. |
| 1.0 W power rating with defined derating | Supports robust shunt regulation in 5–12 V DC rails without external heat sinking below 50°C ambient. |
| Low Zener impedance (31 Ω) | Minimizes output voltage deviation under varying load currents, critical for analog reference stability. |
| −65°C to +200°C operating range | Validates use in extended-temperature applications including automotive ECU modules and industrial PLC I/O stages. |
| Non-repetitive 550 mA surge rating | Provides inherent transient immunity against inductive kickback and ESD-induced reverse spikes. |
Applications
| DC Power Supply Regulation | Overvoltage Protection Circuit |
|---|---|
Use Scenario: Stabilizing unregulated 12 V input to generate a clean 8.2 V reference for op-amp biasing or ADC reference buffers. IC Role / Device Role / Timing Role: Shunt voltage regulator providing fixed reference potential independent of load current within 25 mA range. Use Value: Maintains <±1% output variation across 1–25 mA load due to 31 Ω Zener impedance and tight 5% VZ tolerance. |
Use Scenario: Clamping microcontroller I/O lines against 15 V transients induced by relay coil de-energization. IC Role / Device Role / Timing Role: Fast-acting voltage clamp limiting rail excursion to 8.61 V (VZ max) during surge events. Use Value: Absorbs 550 mA non-repetitive surges without failure, protecting downstream logic from latch-up or gate oxide damage. |
| Temperature-Stable Reference Source | Industrial Sensor Excitation |
Use Scenario: Providing excitation voltage for RTD or strain gauge bridges requiring low-drift, low-noise bias. IC Role / Device Role / Timing Role: Precision voltage source with minimal temperature coefficient across −40°C to +125°C operating envelope. Use Value: Delivers <0.01%/°C effective TC via matched Zener construction, reducing bridge offset drift in measurement front-ends. |
Use Scenario: Biasing 4–20 mA transmitter loop components in hazardous-area process instrumentation. IC Role / Device Role / Timing Role: Stable current-source reference enabling accurate loop calibration and fault detection thresholds. Use Value: Operates reliably at +150°C ambient (within full −65°C to +200°C spec), supporting SIL-2 compliant field device designs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4738A-TP (Micro Commercial Co.) | Same 8.2 V ±5% VZ, DO-41 package, but rated for 1.0 W at TL = 75°C (vs. 50°C for 1N4738A-T50R); ZZ = 33 Ω @ 25 mA. | Slightly higher thermal threshold allows marginally better power handling in compact layouts with limited airflow. | Select when board-level thermal management exceeds 50°C lead temperature and tighter ZZ matching is not required. |
| BZX55C8V2 (Vishay) | Same 8.2 V ±5%, DO-35 package (smaller than DO-41), 500 mW rating, ZZ = 35 Ω @ 20 mA, −65°C to +175°C range. | Lower power rating and smaller package limit use to low-current references; reduced thermal mass affects surge response. | Choose for space-constrained PCBs where 500 mW suffices and legacy DO-35 footprint compatibility is needed. |
Compared with 1N4738A-T50R, the 1N4738A-TP offers higher thermal derating headroom but slightly higher impedance, while BZX55C8V2 trades power and ruggedness for footprint reduction-making the original optimal for 1 W industrial regulation where DO-41 mechanical robustness matters.
Availability
1N4738A-T50R is available at Aetrix Electronics and suitable for DC power supply regulation, overvoltage protection circuits, and temperature-stable reference sources requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for 1N4738A-T50R 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
ON Semiconductor (now onsemi) is a global semiconductor supplier specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The 1N47xxA series was designed specifically for general-purpose Zener regulation in cost-sensitive, high-reliability applications-emphasizing wide temperature operation, repeatable breakdown characteristics, and robust surge immunity.
FAQ
What is the Zener voltage tolerance for 1N4738A-T50R?
The 1N4738A-T50R has a Zener voltage tolerance of ±5%, meaning its breakdown voltage falls between 7.79 V and 8.61 V at 25 mA test current and 25°C ambient. This tolerance is guaranteed per the ON Semiconductor datasheet Rev. 8 (October 2017) and applies to all units shipped under this part number, including the T50R tape-and-reel variant.
Does 1N4738A-T50R support operation above 125°C?
Yes, the 1N4738A-T50R is fully specified from −65°C to +200°C for both operating and storage conditions. Its DO-41 glass package and silicon die construction enable reliable function at junction temperatures up to 200°C, making it suitable for under-hood automotive and industrial motor drive applications where ambient exceeds 125°C.
What is the maximum non-repetitive peak reverse current for 1N4738A-T50R?
The 1N4738A-T50R supports a non-repetitive peak reverse current (IZSM) of 550 mA for an 8.3 ms pulse duration, as defined in the ON Semiconductor datasheet. This rating reflects its ability to absorb transient overvoltage events without permanent degradation, provided the device returns to thermal equilibrium between surges.
How does the 1N4738A-T50R differ from the standard 1N4738A?
The "T50R" suffix denotes a tape-and-reel packaging format per EIA-481-D standards, with 5000 units per reel. Electrically and thermally, the 1N4738A-T50R is identical to the bulk 1N4738A - same Zener voltage, impedance, power rating, and temperature range. The only difference is packaging configuration for automated SMT placement.
Can 1N4738A-T50R be used as a replacement for BZX55C8V2 in existing designs?
No direct substitution is recommended without layout and thermal review: the 1N4738A-T50R uses DO-41 (larger, 1.0 W), while BZX55C8V2 uses DO-35 (smaller, 0.5 W). Though both provide 8.2 V ±5%, the 1N4738A-T50R requires more PCB area and delivers higher surge capacity - redesign is needed to accommodate mechanical and thermal differences in the 1N4738A-T50R.
1N4738A-T50R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 8.2 V
- Tolerance:
- ±5%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 4.5 Ohms
- Current - Reverse Leakage @ Vr:
- 10 µA @ 6 V
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-41
1N4738A-T50R FAQ
1.How can I place an order for 1N4738A-T50R through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4738A-T50R 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 1N4738A-T50R reliable?
The price and inventory of 1N4738A-T50R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4738A-T50R is usually 5 days.
3.What payment methods are accepted for 1N4738A-T50R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4738A-T50R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4738A-T50R?
1N4738A-T50R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4738A-T50R 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 1N4738A-T50R?
For technical support, including 1N4738A-T50R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4738A-T50R requirements.
6.How does Aetrix verify that 1N4738A-T50R is sourced from the original manufacturer or authorized distributors?
All 1N4738A-T50R 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 1N4738A-T50R meets industry standards.
7.What is the process for return or replacement of 1N4738A-T50R?
All 1N4738A-T50R units undergo pre-shipment inspection (PSI). If there is an issue with 1N4738A-T50R, 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 1N4738A-T50R part is unused and in its original packaging.
Return procedure for 1N4738A-T50R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4738A-T50R Tags
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