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Microchip Technology 1N4738APE3/TR8
- Part No.:
- 1N4738APE3/TR8
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4738APE3/TR8.pdf
- Description:
- DIODE ZENER 8.2V 1W DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:8,375
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Product details
Overview
1N4738APE3/TR8 from Microsemi is a 1.0 W, 8.2 V ±5% axial-lead silicon Zener diode in DO-41 (DO-204AL) plastic package, designed for precision voltage regulation in power supply feedback, overvoltage protection, and reference circuits across industrial and embedded systems.
For engineers reviewing the 1N4738APE3/TR8 datasheet, 1N4738APE3/TR8 pinout, 1N4738APE3/TR8 application, or 1N4738APE3/TR8 equivalent, key selection criteria include its 8.2 V nominal Zener voltage at 31 mA test current, 4.5 Ω dynamic impedance, 0.5 A maximum regulator current at 50°C, and RoHS-compliant matte-tin plating with tape-and-reel packaging (TR8).
Technical Context
This discrete Zener diode operates in reverse breakdown to maintain stable output voltage under varying load and temperature conditions. It exhibits a sharp knee at IZK = 6 mA with ZZK ≤ 400 Ω and supports steady-state dissipation of 1.0 W at lead temperature <105°C or ambient <45°C on FR4 board.
Its thermal resistance is 45°C/W junction-to-lead (3/8″ lead length) and 105°C/W junction-to-ambient under defined PCB layout (4 mm² copper pad, 1 mm trace width). Polarity is marked by cathode band; regulation requires cathode-positive bias.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 8.2 V ±5% at IZT = 31 mA - defines precise regulation point for feedback loops |
| Power Dissipation | 1.0 W at TL < 105°C - sets maximum continuous thermal load on lead-mounted design |
| Dynamic Impedance (ZZT) | 4.5 Ω at IZT = 31 mA - determines output voltage stability under load transients |
| Max Regulator Current (IZM) | 0.5 A at TA = 50°C - limits usable current range before thermal runaway |
| Reverse Leakage (IR) | 10 μA max at VR = 6 V - ensures low standby power loss in high-impedance bias networks |
| Forward Voltage | 1.2 V max at IF = 200 mA - relevant for polarity-check or clamp-on-forward paths |
| Thermal Resistance | 45°C/W junction-to-lead - enables thermal modeling for lead-length-dependent derating |
Pinout & Package
DO-41 (DO-204AL) plastic axial-lead package with cathode indicated by colored band; leads are tin-lead or RoHS-compliant matte-tin plated per MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Reverse-biased input terminal | Connected to lower-potential node; carries full Zener current during regulation |
| Cathode | Regulated output terminal | Banded end; held at stable 8.2 V above anode when reverse-biased ≥ VZ |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC 1N47xxAP registration | Guarantees mechanical and electrical interchangeability with legacy 1N4738A designs |
| RoHS-compliant "e3" suffix | Meets EU Directive 2011/65/EU without lead exemption; compatible with Pb-free reflow |
| Tape-and-reel "TR8" packaging | Standard EIA-296 format for automated SMT placement despite axial-lead form factor |
| Moisture Sensitivity Level 1 | No dry pack required per IPC/JEDEC J-STD-020B - simplifies handling and storage |
| Nonsensitive to ESD | Qualified per MIL-STD-750 Method 1020 - eliminates need for special ESD controls in assembly |
Applications
| Switching Power Supply Feedback | Overvoltage Protection Clamp |
|---|---|
Use Scenario: Stabilizing output voltage in flyback or forward converter feedback networks using optocoupler-coupled error amplifiers. IC Role / Device Role / Timing Role: Precision voltage reference providing 8.2 V threshold for TL431-type shunt regulators or discrete op-amp comparators. Use Value: Maintains ±5% regulation accuracy across -65°C to +150°C, enabling reliable closed-loop control without trimming. | Use Scenario: Clamping transient surges on 5–12 V DC rails caused by inductive switching or ESD events. IC Role / Device Role / Timing Role: Shunt protection device diverting excess energy to ground when rail exceeds 8.2 V + tolerance. Use Value: Withstands 0.5 A peak regulator current and 1.0 W continuous dissipation, preventing downstream IC damage. |
| Low-Power Voltage Reference | Industrial Sensor Excitation |
Use Scenario: Generating stable excitation voltage for resistive bridge sensors (e.g., strain gauges, RTDs) in battery-powered instrumentation. IC Role / Device Role / Timing Role: Low-drift, low-noise Zener source replacing higher-cost bandgap references where 5% tolerance suffices. Use Value: Delivers 8.2 V at 31 mA with 4.5 Ω dynamic impedance, minimizing load-induced error in ratiometric measurements. | Use Scenario: Biasing analog front-end circuitry in programmable logic controllers (PLCs) and distributed I/O modules operating in harsh environments. IC Role / Device Role / Timing Role: Regulation element maintaining clean 8.2 V supply for op-amps and ADC drivers amid wide ambient temperature swings. Use Value: Rated for -65°C to +150°C operation and qualified to MIL-PRF-19500 screening levels (with prefix), ensuring long-term reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4738A-T | Same 8.2 V/1 W specs but non-RoHS tin-lead plating; no "e3" or "TR8" suffix | Not suitable for Pb-free manufacturing; requires leaded solder process | Select when legacy assembly lines mandate Sn/Pb termination and tape-and-reel not needed |
| MMSZ4702T1G | Surface-mount SOD-123 package; same 8.2 V/1 W rating but higher ZZT = 7 Ω and lower IZM = 0.25 A | Requires PCB redesign; less robust for high-surge clamping due to smaller thermal mass | Choose for space-constrained layouts where automated pick-and-place justifies trade-offs in surge capability |
Compared with 1N4738APE3/TR8, 1N4738A-T lacks RoHS compliance and tape-and-reel packaging, while MMSZ4702T1G offers SMT compatibility at reduced surge current and higher dynamic impedance-making the original optimal for through-hole, high-reliability, Pb-free production.
Availability
1N4738APE3/TR8 is available at Aetrix Electronics and suitable for switching power supplies, overvoltage protection circuits, low-power voltage references, and industrial sensor excitation requiring stable component supply and full RoHS compliance.
Supply support for 1N4738APE3/TR8 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 analog and mixed-signal components for aerospace, defense, and industrial markets.
The 1N47xxAP series was engineered for ruggedized voltage regulation in mission-critical power systems, emphasizing thermal stability, ESD immunity, and long-term parametric consistency under extreme environmental stress.
FAQ
What is the Zener voltage tolerance of the 1N4738APE3/TR8?
The 1N4738APE3/TR8 has a nominal Zener voltage of 8.2 V with a tolerance of ±5%, as indicated by the "A" suffix in its JEDEC part number. This tolerance is specified at 31 mA test current and 25°C lead temperature, and remains valid across its full operating temperature range of -65°C to +150°C.
Does the 1N4738APE3/TR8 require dry packing before use?
No, the 1N4738APE3/TR8 does not require dry packing. It is moisture sensitivity level (MSL) 1 per IPC/JEDEC J-STD-020B, meaning it can be stored and assembled without baking or humidity-controlled handling-simplifying logistics and reducing manufacturing overhead.
What is the maximum surge current rating for the 1N4738APE3/TR8?
The 1N4738APE3/TR8 has a maximum surge current (ISM) rating of 500 mA, measured using a ½ sine-wave pulse of 1/120 second duration at 25°C ambient. This rating applies under short-duration transient conditions and assumes proper PCB thermal design to avoid junction overheating.
Can the 1N4738APE3/TR8 be used in surface-mount designs?
The 1N4738APE3/TR8 itself is an axial-lead DO-41 device and is not surface-mount compatible. However, Microsemi offers surface-mount equivalents such as SMAJ4738A and MLL4738A for SMT applications-these share identical electrical specs but differ in package and thermal performance.
How does the "TR8" suffix affect packaging and ordering of the 1N4738APE3/TR8?
"TR8" indicates standard EIA-296 tape-and-reel packaging containing 8,000 units per reel. This format enables automated placement in high-volume production and ensures consistent orientation and handling-critical for reliable insertion in through-hole assembly lines.
1N4738APE3/TR8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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:
- 1.2 V @ 200 mA
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AL (DO-41)
1N4738APE3/TR8 FAQ
1.How can I place an order for 1N4738APE3/TR8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4738APE3/TR8 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 1N4738APE3/TR8 reliable?
The price and inventory of 1N4738APE3/TR8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4738APE3/TR8 is usually 5 days.
3.What payment methods are accepted for 1N4738APE3/TR8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4738APE3/TR8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4738APE3/TR8?
1N4738APE3/TR8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4738APE3/TR8 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 1N4738APE3/TR8?
For technical support, including 1N4738APE3/TR8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4738APE3/TR8 requirements.
6.How does Aetrix verify that 1N4738APE3/TR8 is sourced from the original manufacturer or authorized distributors?
All 1N4738APE3/TR8 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 1N4738APE3/TR8 meets industry standards.
7.What is the process for return or replacement of 1N4738APE3/TR8?
All 1N4738APE3/TR8 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4738APE3/TR8, 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 1N4738APE3/TR8 part is unused and in its original packaging.
Return procedure for 1N4738APE3/TR8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4738APE3/TR8 Tags
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