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Microchip Technology 1N4746CP/TR12
- Part No.:
- 1N4746CP/TR12
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4746CP/TR12.pdf
- Description:
- DIODE ZENER 18V 1W DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:4,383
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Product details
Overview
1N4746CP/TR12 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 mA maximum reverse leakage at 13.7 V. It regulates voltage in power supply reference and overvoltage protection circuits across -65°C to +150°C.
For engineers reviewing the 1N4746CP/TR12 datasheet, 1N4746CP/TR12 pinout, 1N4746CP/TR12 application, or 1N4746CP/TR12 equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (45°C/W junction-to-lead), surge current rating (250 mA), RoHS-compliant "e3" plating, and tape-and-reel packaging (TR12).
Technical Context
This axial-leaded silicon Zener diode operates in reverse breakdown to maintain stable voltage under varying load and temperature. Its 18 V nominal Zener voltage exhibits a positive temperature coefficient above ~5.6 V, with typical TC of +3.5 mV/°C per Figure 3.
The device delivers regulation across 0.25 mA to 250 mA operating current range, with knee impedance of 50 Ω at 0.25 mA and low forward voltage (≤1.2 V @ 200 mA) enabling bidirectional circuit use where needed.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18 V ±5% at 14 mA - defines precise regulation point for feedback loops and reference rails |
| Power Dissipation | 1.0 W at 25°C lead temperature - sets maximum continuous DC power before thermal derating |
| Dynamic Impedance (ZZT) | 20 Ω at 14 mA - determines output voltage stability under load transients |
| Reverse Leakage (IR) | 0.25 μA max at 13.7 V - ensures minimal quiescent current in high-impedance bias networks |
| Surge Current (ISM) | 250 mA (½-sine, 1/120 s) - supports transient overvoltage clamping without failure |
| Thermal Resistance | 45°C/W junction-to-lead (3/8″ lead length) - enables accurate junction temp estimation in lead-mounted designs |
| Operating Temperature | -65°C to +150°C - validated for industrial, automotive under-hood, and aerospace environments |
Pinout & Package
DO-41 (JEDEC DO-204AL) plastic axial-leaded package with cathode band marking. Leads are tin-lead or RoHS-compliant matte tin, solderable per MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference | Connected to lower-potential node; reverse-biased during regulation |
| Cathode | Zener breakdown terminal / voltage reference output | Banded end; connected to regulated rail; must be held >18 V relative to anode |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC 1N47xxA registration | Industry-standard footprint and electrical behavior for drop-in compatibility with legacy designs |
| Moisture Sensitivity Level 1 | No dry pack required - simplifies SMT handling and eliminates bake-out prior to assembly |
| RoHS-compliant "e3" suffix | Matte tin plating meets EU Directive 2011/65/EU and J-STD-609A Class 1 requirements |
| Tape-and-reel packaging (TR12) | Standard EIA-296 format - supports automated pick-and-place for high-volume PCB assembly |
| Nonsensitive to ESD | Qualified per MIL-STD-750 Method 1020 - no special handling required during board assembly |
Applications
| Power Supply Reference | Overvoltage Clamp |
|---|---|
Use Scenario: Stabilizing feedback voltage in linear regulator ICs or discrete transistor-based regulators. IC Role / Device Role / Timing Role: Voltage reference element providing fixed 18 V setpoint for error amplifier comparison. Use Value: Maintains ±5% output accuracy over temperature and line/load variations due to low ZZT and stable VZ. |
Use Scenario: Protecting downstream logic inputs from 24 V bus transients in industrial PLC I/O modules. IC Role / Device Role / Timing Role: Shunt clamping device diverting excess energy when bus exceeds 18 V. Use Value: Absorbs 250 mA surge pulses without degradation, preventing latch-up or damage to 3.3 V/5 V receivers. |
| Signal Level Translation | Temperature-Stable Bias Network |
Use Scenario: Generating a fixed 18 V bias for op-amp input stages in precision analog front-ends. IC Role / Device Role / Timing Role: Stable DC reference source for offset calibration and common-mode setting. Use Value: Delivers <0.25 μA leakage at 13.7 V, minimizing input bias error in high-Z sensor interfaces. |
Use Scenario: Providing temperature-compensated bias current in RF power amplifier bias circuits. IC Role / Device Role / Timing Role: Zener-based current source with predictable TC (+3.5 mV/°C) for thermal tracking. Use Value: Enables matched thermal drift with GaAs FETs or SiC MOSFETs across -65°C to +150°C range. |
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 "P" suffix → glass-body DO-35 package; higher thermal resistance (105°C/W on FR4 vs. 45°C/W for DO-41) | Limited to lower-power PCB layouts without thermal relief; unsuitable for high ambient or lead-mounted heatsinking | Select 1N4746CP/TR12 when lead-mount thermal performance or moisture-insensitive handling is required. |
| MMSZ4708T1G | Surface-mount SOD-123 package; 18 V ±5%, 500 mW rating; 30 Ω ZZT; RoHS-compliant | Designed for space-constrained, high-density boards; not suitable for through-hole or high-surge-current roles | Choose MMSZ4708T1G only when board area is constrained and peak surge current remains below 150 mA. |
Compared with 1N4746A and MMSZ4708T1G, the 1N4746CP/TR12 uniquely balances 1 W power handling, DO-41 thermal performance, tape-and-reel automation support, and MIL-STD-750 qualified ESD robustness - making it optimal for industrial power supplies and ruggedized control systems.
Availability
1N4746CP/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, PLC I/O protection, analog signal conditioning, and temperature-stable bias networks requiring stable component supply and long-term obsolescence management.
Supply support for 1N4746CP/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, mixed-signal, and RF solutions for aerospace, defense, and industrial markets.
The 1N4746CP/TR12 belongs to Microsemi's legacy 1N47xxAP Zener series, engineered for stable voltage regulation in harsh-environment power systems where thermal resilience, moisture immunity, and long-term parametric consistency are critical.
FAQ
What is the Zener voltage tolerance of the 1N4746CP/TR12?
The 1N4746CP/TR12 has a nominal Zener voltage of 18 V with a ±5% tolerance, as indicated by the "A" suffix in its JEDEC designation. This tolerance is verified at 14 mA test current and 25°C lead temperature, ensuring predictable regulation in feedback and reference circuits.
Does the 1N4746CP/TR12 require dry packing before PCB assembly?
No, the 1N4746CP/TR12 is moisture sensitivity level (MSL) 1 per IPC/JEDEC J-STD-020B, meaning it may be stored and assembled without dry pack or baking. Its void-free epoxy body and RoHS-compliant plating eliminate moisture-related popcorning risks during reflow.
What is the maximum surge current rating for the 1N4746CP/TR12?
The 1N4746CP/TR12 is rated for 250 mA maximum non-repetitive reverse surge current (ISM) using a ½-sine wave pulse of 1/120 second duration at 25°C ambient, per Microsemi's datasheet. This enables reliable transient suppression in 24 V industrial bus protection.
How does the thermal resistance of the 1N4746CP/TR12 compare to glass-body variants?
The 1N4746CP/TR12 has a junction-to-lead thermal resistance of 45°C/W at 3/8″ lead length, significantly lower than the 105°C/W junction-to-ambient rating of glass-body 1N4746A on FR4. This allows higher sustained power dissipation in lead-mounted configurations.
Is the 1N4746CP/TR12 compatible with lead-free reflow processes?
Yes, the 1N4746CP/TR12 features RoHS-compliant annealed matte-tin plating and is rated for solder temperatures up to 260°C for 10 seconds, fully supporting standard lead-free reflow profiles including JEDEC J-STD-020D Level 1 requirements.
1N4746CP/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)
1N4746CP/TR12 FAQ
1.How can I place an order for 1N4746CP/TR12 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4746CP/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 1N4746CP/TR12 reliable?
The price and inventory of 1N4746CP/TR12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4746CP/TR12 is usually 5 days.
3.What payment methods are accepted for 1N4746CP/TR12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4746CP/TR12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4746CP/TR12?
1N4746CP/TR12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4746CP/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 1N4746CP/TR12?
For technical support, including 1N4746CP/TR12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4746CP/TR12 requirements.
6.How does Aetrix verify that 1N4746CP/TR12 is sourced from the original manufacturer or authorized distributors?
All 1N4746CP/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 1N4746CP/TR12 meets industry standards.
7.What is the process for return or replacement of 1N4746CP/TR12?
All 1N4746CP/TR12 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4746CP/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 1N4746CP/TR12 part is unused and in its original packaging.
Return procedure for 1N4746CP/TR12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4746CP/TR12 Tags
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MMBZ5240B-7-F
Diodes Incorporated
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