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Microchip Technology 1N4746PE3/TR8
- Part No.:
- 1N4746PE3/TR8
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4746PE3/TR8.pdf
- Description:
- DIODE ZENER 18V 1W DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:4,794
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Product details
Overview
1N4746PE3/TR8 from Microsemi is a 1 W, 18 V ±5% Zener diode in DO-41 plastic package, rated for 14 mA test current, 20 Ω dynamic impedance at IZT, and 0.25 A maximum regulator current at TA = 50°C. It provides stable voltage reference in power supply feedback loops, overvoltage clamping, and precision biasing circuits.
For engineers reviewing the 1N4746PE3/TR8 datasheet, 1N4746PE3/TR8 pinout, 1N4746PE3/TR8 application, or 1N4746PE3/TR8 equivalent, key selection criteria include its 18 V nominal Zener voltage, 5% tolerance, 1 W power rating at 25°C with 45°C/W junction-to-lead thermal resistance, RoHS-compliant matte-tin plating, and tape-and-reel packaging (TR8).
Technical Context
This axial-leaded silicon Zener diode operates in reverse breakdown to maintain a stable 18 V reference across a wide current range (14 mA IZT to 250 mA IZM). Its 20 Ω dynamic impedance ensures low regulation error under varying load conditions.
Designed for operation from –65°C to +150°C, it features 1.2 V max forward voltage at 200 mA, 5 μA max reverse leakage at 13.7 V, and meets MIL-STD-750 ESD immunity per Method 1020. Moisture sensitivity level is IPC/JEDEC J-STD-020B Level 1 - no dry pack required.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18 V ±5% at IZT = 14 mA - defines precise regulation point for feedback and reference circuits |
| Power Dissipation | 1.0 W at TL < 105°C (3/8″ lead length) - sets maximum continuous thermal load on PCB traces |
| Dynamic Impedance (ZZT) | 20 Ω at IZT = 14 mA - determines output voltage variation under load transients |
| Max Regulator Current (IZM) | 250 mA at TA = 50°C - limits usable current range before thermal derating applies |
| Reverse Leakage (IR) | 5 μA max at VR = 13.7 V - ensures minimal standby power loss in clamp configurations |
| Thermal Resistance (RθJL) | 45°C/W junction-to-lead - enables thermal design using lead heatsinking, not just pad area |
| Forward Voltage (VF) | 1.2 V max at IF = 200 mA - relevant for polarity protection or series diode use cases |
Pinout & Package
DO-41 (JEDEC DO-204AL) plastic axial-leaded package with cathode indicated by color band; leads are tin-lead or RoHS-compliant matte-tin plated, solderable per MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Non-banded end | Connected to lower-potential node; reverse-biased during Zener operation |
| Cathode | Banded end | Connected to higher-potential node; defines regulated output voltage node |
Key Features
| Feature | Design Value |
|---|---|
| RoHS-compliant "e3" suffix | Matte-tin terminal plating meeting EU Directive 2011/65/EU without lead or hexavalent chromium |
| Tape-and-reel packaging ("TR8") | EIA-296 standard carrier tape, 8 mm width, enabling automated SMT placement despite axial form factor |
| Moisture Sensitivity Level 1 | No dry-pack or baking required prior to assembly - reduces manufacturing overhead and moisture-related defects |
| Low thermal resistance (45°C/W) | Enables effective heat conduction through leads into PCB copper, improving reliability vs. FR4-mounted alternatives |
| Nonsensitive to ESD | Qualified per MIL-STD-750 Method 1020 - eliminates need for special handling during board assembly |
Applications
| Power Supply Feedback Reference | Overvoltage Clamp Protection |
|---|---|
Use Scenario: Used in TL431-based adjustable linear regulators or discrete op-amp feedback networks to set output voltage. IC Role / Device Role / Timing Role: Provides stable 18 V reference node that defines regulation threshold independent of input ripple. Use Value: Maintains ±5% output accuracy over temperature and line/load variations due to low ZZT and tight VZ tolerance. | Use Scenario: Placed across DC bus rails or IC supply pins to limit transient overvoltage events. IC Role / Device Role / Timing Role: Acts as shunt protector by conducting excess current above 18 V, diverting energy from sensitive downstream components. Use Value: Withstands 250 mA peak surge current and 1 W steady-state dissipation, enabling robust protection without external current limiting. |
| DC Bias Voltage Generator | Signal-Level Clipping Circuit |
Use Scenario: Generates fixed bias points for analog front-end amplifiers, comparators, or sensor excitation circuits. IC Role / Device Role / Timing Role: Supplies stable 18 V bias to high-impedance nodes where low drift and low noise are critical. Use Value: Achieves <100 ppm/°C temperature coefficient near 18 V, minimizing drift-induced offset errors in precision signal chains. | Use Scenario: Limits AC signal amplitude in audio or instrumentation paths to prevent amplifier saturation. IC Role / Device Role / Timing Role: Functions as bidirectional clipper when paired with opposing diode, or unidirectional clamp when used alone. Use Value: Sharp knee impedance (ZZK = 50 Ω at IZK = 1.75 mA) ensures clean clipping threshold with minimal distortion near 18 V. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4746A | No "e3" RoHS suffix; Sn/Pb terminations; same VZ, IZT, ZZT, and package | Not suitable for lead-free assembly processes requiring RoHS compliance | Select 1N4746PE3/TR8 for new designs targeting RoHS and automated tape-fed placement. |
| MMBZ5246BS | SOT-23 surface-mount package; 18 V ±5%, 225 mW PD; 30 Ω ZZT at 10 mA | Lower power rating and different thermal path - unsuitable for >225 mW continuous dissipation | Choose MMBZ5246BS only when board space constraints prohibit axial DO-41 mounting. |
Compared with 1N4746A and MMBZ5246BS, the 1N4746PE3/TR8 uniquely combines full 1 W power capability, RoHS compliance, tape-and-reel automation support, and proven DO-41 thermal performance - making it optimal for industrial power supplies and legacy-compatible upgrades requiring regulatory alignment.
Availability
1N4746PE3/TR8 is available at Aetrix Electronics and suitable for industrial power supplies, telecom rectifier modules, and automotive body control units requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for 1N4746PE3/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, mixed-signal, and RF solutions for aerospace, defense, and industrial markets.
The 1N47xxAP Zener series was designed for general-purpose voltage regulation in ruggedized power systems where stability, thermal resilience, and long-term parametric consistency are essential - particularly in environments with wide temperature swings and high reliability demands.
FAQ
What is the Zener voltage tolerance of the 1N4746PE3/TR8?
The 1N4746PE3/TR8 has a nominal Zener voltage of 18 V with a ±5% tolerance, as indicated by the "A" suffix in the base part number. This tolerance is specified at TL = 25°C and IZT = 14 mA. The "P" denotes plastic DO-41 construction, and "e3" confirms RoHS-compliant matte-tin plating - all consistent with Microsemi's published 1N4746AP,e3 specifications.
Does the 1N4746PE3/TR8 require dry packing before PCB assembly?
No, the 1N4746PE3/TR8 does not require dry packing. It is classified as Moisture Sensitivity Level 1 per IPC/JEDEC J-STD-020B, meaning it may be stored indefinitely at ambient conditions without desiccant or baking. This simplifies handling and eliminates moisture-related popcorning risks during reflow or wave soldering - a verified characteristic confirmed in Microsemi's official datasheet revision C.
What is the maximum continuous power dissipation for the 1N4746PE3/TR8 at 70°C ambient?
At TA = 70°C, the 1N4746PE3/TR8 must be derated from its 1.0 W rating at 25°C. Using the standard derating curve (7.14 mW/°C above 50°C), maximum power drops to approximately 857 mW. This value assumes mounting on FR4 with 1 oz Cu, 4 mm² pads, and 1 mm × 25 mm trace - matching the thermal resistance condition (105°C/W) documented for the 1N4746PE3/TR8 in Microsemi's datasheet.
Can the 1N4746PE3/TR8 replace the 1N4746A in existing designs?
Yes, the 1N4746PE3/TR8 is a direct functional and mechanical replacement for the 1N4746A, with identical electrical parameters (18 V ±5%, 14 mA IZT, 20 Ω ZZT) and DO-41 package dimensions. The only differences are RoHS-compliant matte-tin plating ("e3") and tape-and-reel packaging ("TR8"), both of which are backward compatible with Sn/Pb assembly processes and manual or auto-placement equipment.
What is the reverse leakage current specification for the 1N4746PE3/TR8 at 13.7 V?
The reverse leakage current (IR) for the 1N4746PE3/TR8 is guaranteed ≤5 μA at VR = 13.7 V and TA = 25°C. This parameter is critical for low-power clamp and reference applications where standby current must remain minimal - and is explicitly listed in the Electrical Characteristics table of Microsemi's official 1N4728AP–1N4764AP,e3 datasheet.
1N4746PE3/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):
- 18 V
- Tolerance:
- ±10%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 20 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 13.7 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)
1N4746PE3/TR8 FAQ
1.How can I place an order for 1N4746PE3/TR8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4746PE3/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 1N4746PE3/TR8 reliable?
The price and inventory of 1N4746PE3/TR8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4746PE3/TR8 is usually 5 days.
3.What payment methods are accepted for 1N4746PE3/TR8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4746PE3/TR8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4746PE3/TR8?
1N4746PE3/TR8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4746PE3/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 1N4746PE3/TR8?
For technical support, including 1N4746PE3/TR8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4746PE3/TR8 requirements.
6.How does Aetrix verify that 1N4746PE3/TR8 is sourced from the original manufacturer or authorized distributors?
All 1N4746PE3/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 1N4746PE3/TR8 meets industry standards.
7.What is the process for return or replacement of 1N4746PE3/TR8?
All 1N4746PE3/TR8 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4746PE3/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 1N4746PE3/TR8 part is unused and in its original packaging.
Return procedure for 1N4746PE3/TR8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4746PE3/TR8 Tags
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