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Microchip Technology 1N4746CPE3/TR12
- Part No.:
- 1N4746CPE3/TR12
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4746CPE3/TR12.pdf
- Description:
- DIODE ZENER 18V 1W DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:9,501
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Product details
Overview
1N4746CPE3/TR12 from Microsemi is a 1 W, 18 V ±2% tolerance silicon 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 50°C. It provides precision voltage regulation in power supply reference and overvoltage protection circuits.
For engineers reviewing the 1N4746CPE3/TR12 datasheet, 1N4746CPE3/TR12 pinout, 1N4746CPE3/TR12 application, or 1N4746CPE3/TR12 equivalent, key selection criteria include its tight ±2% VZ tolerance (C suffix), RoHS-compliant matte-tin plating (e3), tape-and-reel packaging (TR12), and DO-41 thermal performance with 45°C/W junction-to-lead resistance.
Technical Context
This Zener operates in reverse breakdown to maintain stable 18 V output across a wide current range (1–250 mA) and temperature span (−65°C to +150°C). Its 20 Ω dynamic impedance at 14 mA ensures low regulation error under varying load conditions.
The device uses axial-leaded DO-41 construction with cathode band marking, tin-lead or RoHS-compliant matte-tin terminations, and UL94V-0 epoxy encapsulation. It meets MIL-STD-750 ESD immunity (Method 1020) and IPC/JEDEC J-STD-020B moisture sensitivity Level 1.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18 V ±2% at 14 mA - enables precise reference generation with minimal calibration drift |
| Power Dissipation | 1.0 W at 25°C - supports continuous regulation in compact linear supplies without forced cooling |
| Dynamic Impedance (ZZT) | 20 Ω at IZT = 14 mA - limits output voltage variation to <±280 mV over ±5 mA load change |
| Max Regulator Current (IZM) | 0.25 A at TL = 50°C - defines safe DC operating limit before thermal runaway |
| Reverse Leakage (IR) | 5 μA max at VR = 13.7 V - ensures low standby power loss in high-impedance bias networks |
| Thermal Resistance (RθJL) | 45°C/W junction-to-lead at 10 mm lead length - allows accurate junction temperature estimation from measured lead temp |
Pinout & Package
DO-41 (DO-204AL) plastic axial-leaded 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 | Forward conduction terminal / Zener cathode reference node | Connected to circuit ground or lower-potential rail during regulation; must be held ≤13.7 V to avoid leakage |
| Cathode | Zener breakdown terminal / regulated output node | Banded end; connected to unregulated input; maintains 18 V relative to anode when reverse-biased above knee voltage |
Key Features
| Feature | Design Value |
|---|---|
| ±2% Zener voltage tolerance (C suffix) | Reduces need for post-assembly trimming in precision 18 V references |
| RoHS-compliant "e3" termination | Enables compliance with EU RoHS Directive 2011/65/EU without process requalification |
| Tape-and-reel packaging (TR12) | Supports automated SMT placement via standard 12 mm carrier tape per EIA-296 |
| Moisture sensitivity Level 1 | Eliminates dry-pack requirement and bake-out prior to assembly |
| Nonsensitive to ESD (MIL-STD-750 Method 1020) | Permits handling in standard workstations without special static controls |
Applications
| Power Supply Reference | Overvoltage Clamp |
|---|---|
Use Scenario: Stable 18 V reference for op-amp feedback networks or ADC voltage references in industrial PLC analog I/O modules. IC Role / Device Role / Timing Role: Zener diode providing fixed reference voltage independent of input ripple or load variation. Use Value: ±2% tolerance and 20 Ω dynamic impedance ensure reference stability within ±360 mV over full operating current range. | Use Scenario: Protection of 15 V logic rails against transient surges in automotive body control modules. IC Role / Device Role / Timing Role: Shunt clamp limiting voltage to 18 V during load-dump events. Use Value: 1 W power rating and 0.25 A IZM sustain 100 ms transients up to 2.5 W peak without degradation. |
| Voltage Monitor Threshold | Field-Programmable Bias Network |
Use Scenario: Undervoltage lockout (UVLO) trigger point in battery-powered medical sensor nodes. IC Role / Device Role / Timing Role: Zener-based comparator threshold set to 18 V to disable system below safe operating voltage. Use Value: Tight 2% tolerance ensures consistent trip point across temperature and unit-to-unit variation. | Use Scenario: Adjustable biasing of RF amplifier stages using series Zener + resistor networks in base station front-end designs. IC Role / Device Role / Timing Role: Fixed-voltage node establishing DC operating point for GaAs FET gate bias. Use Value: Low 20 Ω ZZT minimizes bias shift under RF current modulation, preserving gain flatness. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4746A | Same 18 V nominal, but ±5% tolerance (A suffix) vs. ±2% (C suffix) | Less suitable for precision references; acceptable for general-purpose clamping | Select 1N4746CPE3/TR12 when ±2% VZ accuracy is required; choose 1N4746A for cost-sensitive non-critical use |
| BZX85C18 | Same 18 V ±2%, but 1.3 W power rating and DO-41 package; different thermal resistance (50°C/W) | Higher surge capability but slightly degraded regulation stability at high currents | Prefer 1N4746CPE3/TR12 for legacy compatibility and tighter thermal spec; consider BZX85C18 only if >1 W surge margin is critical |
Compared with 1N4746A and BZX85C18, the 1N4746CPE3/TR12 delivers superior voltage accuracy (±2%) and optimized thermal resistance (45°C/W), making it ideal for space-constrained industrial references where long-term stability and predictable derating are essential.
Availability
1N4746CPE3/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, medical sensor biasing, and telecom voltage monitoring requiring stable component supply and RoHS-compliant sourcing.
Supply support for 1N4746CPE3/TR12 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 designed specifically for robust, low-cost voltage regulation in harsh-environment power systems where long-term parametric stability and MIL-grade screening options are critical.
FAQ
What is the Zener voltage tolerance of 1N4746CPE3/TR12?
The 1N4746CPE3/TR12 has a Zener voltage tolerance of ±2%, denoted by the "C" suffix in the part number. This means its nominal 18 V breakdown voltage falls between 17.64 V and 18.36 V when measured at 14 mA and 25°C lead temperature. This tighter tolerance supports precision reference applications where post-calibration is impractical.
Does 1N4746CPE3/TR12 meet RoHS requirements?
Yes, the "e3" suffix confirms that 1N4746CPE3/TR12 uses RoHS-compliant matte-tin plating on its axial leads and complies with Directive 2011/65/EU. The device contains no lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE above threshold limits, and is suitable for environmentally regulated production environments.
What is the maximum continuous current for 1N4746CPE3/TR12?
The maximum continuous Zener current (IZM) for 1N4746CPE3/TR12 is 0.25 A at a lead temperature of 50°C. This value decreases with rising temperature per the derating curve in Figure 1 of the datasheet; at 105°C lead temperature, the safe DC current drops to zero. Proper heatsinking or PCB copper area is required to maintain TL ≤ 50°C under full load.
How is polarity marked on 1N4746CPE3/TR12?
The cathode of 1N4746CPE3/TR12 is marked by a visible color band on the DO-41 plastic body. During Zener operation, the banded end must be held at a higher potential than the anode (unbanded end) to achieve reverse-bias breakdown. Forward voltage is ≤1.2 V at 200 mA, confirming standard silicon diode behavior in forward conduction.
What packaging format does 1N4746CPE3/TR12 use?
1N4746CPE3/TR12 is supplied in tape-and-reel format per EIA-296 standard, indicated by the "TR12" suffix. It uses a 12 mm carrier tape with standard pocket dimensions and orientation, enabling direct integration into automated pick-and-place equipment for high-volume PCB assembly without manual handling or repackaging.
1N4746CPE3/TR12 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:
- ±2%
- 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)
1N4746CPE3/TR12 FAQ
1.How can I place an order for 1N4746CPE3/TR12 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4746CPE3/TR12 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 1N4746CPE3/TR12 reliable?
The price and inventory of 1N4746CPE3/TR12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4746CPE3/TR12 is usually 5 days.
3.What payment methods are accepted for 1N4746CPE3/TR12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4746CPE3/TR12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4746CPE3/TR12?
1N4746CPE3/TR12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4746CPE3/TR12 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 1N4746CPE3/TR12?
For technical support, including 1N4746CPE3/TR12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4746CPE3/TR12 requirements.
6.How does Aetrix verify that 1N4746CPE3/TR12 is sourced from the original manufacturer or authorized distributors?
All 1N4746CPE3/TR12 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 1N4746CPE3/TR12 meets industry standards.
7.What is the process for return or replacement of 1N4746CPE3/TR12?
All 1N4746CPE3/TR12 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4746CPE3/TR12, 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 1N4746CPE3/TR12 part is unused and in its original packaging.
Return procedure for 1N4746CPE3/TR12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4746CPE3/TR12 Tags
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MMBZ5240B-7-F
Diodes Incorporated
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BZT52C5V6T-7
Diodes Incorporated
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MMSZ5231B-7-F
Diodes Incorporated
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BZT52C15-7-F
Diodes Incorporated
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BZX84C3V3LT1G
onsemi
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MMSZ5245BS-7-F
Diodes Incorporated
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MMSZ4682T1G
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BZT52C15S-7-F
Diodes Incorporated
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MM5Z5V1ST1G
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SMAJ4744A-TP
Micro Commercial Co
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BZT52C3V6LP-7
Diodes Incorporated
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SMAZ12-13-F
Diodes Incorporated
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