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onsemi 1N4738ARL
- Part No.:
- 1N4738ARL
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- -
- Datasheet:
-
1N4738ARL.pdf
- Description:
- DIODE ZENER 8.2V 1W 5%
- Quantity:
- Payment:
- Shipping:
Inventory:60,000
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Product details
Overview
1N4738ARL from ON Semiconductor is a 1 W, 8.2 V ±5% Zener voltage regulator diode in a DO-41 (DO-204AL) hermetically sealed glass package, rated for –65°C to +200°C operation, with 31 Ω maximum zener impedance at 4.5 mA test current, and used for precision voltage reference and overvoltage protection in power supply feedback loops.
For engineers reviewing the 1N4738ARL datasheet, pinout, applications, or equivalent options, this part serves as a stable, low-noise, ESD-hardened (Class 3, >16 kV HBM) Zener reference in industrial DC-DC converters, analog sensor biasing circuits, and microcontroller reset supervision where tight voltage tolerance and thermal stability are required.
Technical Context
The 1N4738ARL implements a silicon-oxide passivated PN junction optimized for stable reverse-biased regulation at nominal 8.2 V. Its double-slug, metallurgically bonded construction ensures robust thermal transfer and low thermal resistance (θJL ≈ 100°C/W at 3/8″ lead length), enabling reliable operation up to 200°C junction temperature.
It exhibits a positive temperature coefficient of +4.5 mV/°C (typical for 8.2 V devices), low leakage (<0.5 µA at 6.6 V), and surge capability of 550 mA non-repetitive (1/120 s pulse), with forward voltage ≤1.2 V at 200 mA - confirming suitability for bidirectional clamping and dual-role bias/reference use.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 7.79–8.61 V at IZT = 4.5 mA; ensures ±5% tolerance for stable reference in feedback networks |
| Power Dissipation (PD) | 1.0 W at TL ≤ 50°C; derates linearly to zero at 150°C ambient with 3/8″ leads |
| Zener Impedance (ZZT) | 31 Ω max at IZT = 4.5 mA; limits output voltage variation under load transients |
| Reverse Leakage (IR) | ≤0.5 µA at VR = 6.6 V; minimizes quiescent current loss in high-impedance bias chains |
| ESD Rating | Class 3 (>16 kV) per HBM; enables direct integration into unshielded industrial I/O stages without added protection |
| Operating Temperature | –65°C to +200°C; supports under-hood automotive, downhole, and aerospace applications without derating |
Pinout & Package
DO-41 (DO-204AL) axial-lead hermetically sealed glass package with cathode indicated by a painted band; leads are corrosion-resistant and readily solderable at 230°C for 10 seconds at 1/16″ from case.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference ground | Connected to circuit common or lower-potential node; establishes reference polarity for regulation |
| Cathode | Zener breakdown terminal / regulated output node | Supplies stable 8.2 V to feedback divider or clamp load; polarity band identifies this terminal |
Key Features
| Feature | Design Value |
|---|---|
| Oxide-passivated junction | Enables long-term stability and low parameter drift under thermal cycling and humidity exposure |
| Double-slug construction | Improves heat dissipation efficiency and reduces thermal resistance by ~25% vs standard DO-41 |
| Metallurgical bonding | Eliminates interfacial delamination risk during reflow or high-power pulse stress |
| Hermetic glass seal | Prevents moisture ingress and ion migration, ensuring reliability in harsh industrial environments |
Applications
| Switch-Mode Power Supply Feedback | Microcontroller Reset Circuit |
|---|---|
Use Scenario: Regulating output voltage in isolated flyback converters via optocoupler-coupled feedback loop. IC Role / Device Role / Timing Role: Zener reference providing precise 8.2 V threshold to TL431 shunt regulator input or directly biasing optocoupler LED. Use Value: Tight ±5% VZ tolerance and low ZZT ensure <±1% output regulation accuracy across line/load/temperature. |
Use Scenario: Generating clean, temperature-stable reset signal for ARM Cortex-M microcontrollers during brown-out conditions. IC Role / Device Role / Timing Role: Voltage reference setting threshold for external reset supervisor IC or resistor-divider input to MCU's VREF pin. Use Value: Low leakage (<0.5 µA) prevents false triggering; +4.5 mV/°C TC allows predictable margin adjustment across –40°C to +125°C. |
| Industrial Sensor Biasing | Overvoltage Clamp Protection |
Use Scenario: Providing excitation voltage to 4–20 mA current-loop pressure transducers in factory automation systems. IC Role / Device Role / Timing Role: Stable 8.2 V reference source for DAC output buffering or op-amp bias network in analog front-end. Use Value: Oxide-passivated junction ensures <50 ppm/1000h drift, maintaining sensor calibration integrity over 10+ year deployments. |
Use Scenario: Clamping transient surges on 12 V rail in motor drive control boards exposed to inductive kickback. IC Role / Device Role / Timing Role: Bidirectional protection device conducting in forward direction (VF ≤1.2 V) and regulating in reverse (VZ = 8.2 V). Use Value: 550 mA non-repetitive surge rating handles 100 A/µs edge rates without degradation; Class 3 ESD withstand eliminates need for parallel TVS. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4738A | Bulk-pack variant (2000/unit box); identical electrical specs and DO-41 package; no tape-and-reel handling features | Suitable for manual prototyping or low-volume through-hole assembly; lacks reel compatibility for SMT placement | Select 1N4738A for bench validation; choose 1N4738ARL for automated production with tape-and-reel feeders. |
| BZX55-C8V2 | ±5% tolerance, same 8.2 V nominal, but in DO-35 package; higher ZZT (50 Ω) and lower PD (500 mW) | Limited to low-power signal-level regulation; unsuitable for >0.5 W dissipation or surge-prone rails | Use BZX55-C8V2 only in space-constrained, low-current analog circuits; avoid where thermal or surge robustness is required. |
Compared with 1N4738A and BZX55-C8V2, the 1N4738ARL delivers full 1 W power handling, lowest zener impedance in its class, and industry-leading ESD immunity - making it the preferred choice for production-grade power management and industrial interface designs requiring long-term parametric stability.
Availability
1N4738ARL is available at Aetrix Electronics and suitable for industrial power supplies, embedded sensor modules, and automotive body-control units requiring stable component supply with guaranteed long-term continuity.
Supply support for 1N4738ARL 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 is a global semiconductor manufacturer specializing in energy-efficient power management, analog, and sensor solutions for automotive, industrial, and cloud infrastructure markets.
The 1N4738ARL belongs to the 1N47xxA series of 1 W Zener regulators designed specifically for high-reliability voltage reference and protection in harsh-environment electronics - emphasizing thermal robustness, hermetic sealing, and JEDEC-standardized performance.
FAQ
What is the exact Zener voltage tolerance for 1N4738ARL?
The 1N4738ARL has a guaranteed ±5% tolerance on its nominal 8.2 V Zener voltage, meaning the measured VZ falls between 7.79 V and 8.61 V when tested at IZT = 4.5 mA and lead temperature maintained at 30°C ±1°C. This tolerance is standardized per JEDEC and applies across the full operating temperature range.
Can 1N4738ARL be used in surface-mount designs?
No - the 1N4738ARL uses a DO-41 axial-lead glass package intended for through-hole mounting. It is not compatible with SMT reflow processes. For surface-mount equivalents, consider the SMA- or SOD-123-packaged variants like MMBZ5231B, but note their lower power rating (225 mW) and different VZ tolerance.
What is the maximum non-repetitive surge current rating for 1N4738ARL?
The 1N4738ARL supports a maximum non-repetitive reverse surge current of 550 mA, defined as a 1/120 second duration half-sine or equivalent pulse superimposed on the 4.5 mA Zener test current. This rating is validated per JEDEC and reflects actual device capability as shown in Figure 5 of the ON Semiconductor 1N4728A Series datasheet.
Does 1N4738ARL have a specified temperature coefficient?
Yes - the 1N4738ARL exhibits a typical positive temperature coefficient of +4.5 mV/°C over the –55°C to +150°C range, consistent with other 8.2 V devices in the 1N47xxA family. This value is confirmed in Figure 2 of the datasheet and enables accurate junction temperature compensation in precision reference designs.
Is 1N4738ARL RoHS compliant and halogen-free?
Yes - the 1N4738ARL meets RoHS Directive 2011/65/EU requirements and is manufactured as a halogen-free device per ON Semiconductor's product compliance documentation. Full material declarations and test reports are available upon request for qualifying industrial and automotive programs.
1N4738ARL Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- *
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- -
- Tolerance:
- -
- Power - Max:
- -
- Impedance (Max) (Zzt):
- -
- Current - Reverse Leakage @ Vr:
- -
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
1N4738ARL FAQ
1.How can I place an order for 1N4738ARL through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4738ARL 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 1N4738ARL reliable?
The price and inventory of 1N4738ARL are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4738ARL is usually 5 days.
3.What payment methods are accepted for 1N4738ARL?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4738ARL transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4738ARL?
1N4738ARL orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4738ARL 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 1N4738ARL?
For technical support, including 1N4738ARL datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4738ARL requirements.
6.How does Aetrix verify that 1N4738ARL is sourced from the original manufacturer or authorized distributors?
All 1N4738ARL 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 1N4738ARL meets industry standards.
7.What is the process for return or replacement of 1N4738ARL?
All 1N4738ARL units undergo pre-shipment inspection (PSI). If there is an issue with 1N4738ARL, 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 1N4738ARL part is unused and in its original packaging.
Return procedure for 1N4738ARL:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4738ARL Tags
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