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Microchip Technology 1N5349/TR12
- Part No.:
- 1N5349/TR12
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- T-18, Axial
- Datasheet:
-
1N5349/TR12.pdf
- Description:
- DIODE ZENER 12V 5W T18
- Quantity:
- Payment:
- Shipping:
Inventory:9,524
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Product details
Overview
1N5349/TR12 from Microsemi is a 5 W axial-leaded silicon Zener diode with a nominal regulation voltage of 12 V, ±5% tolerance (B suffix), 2.5 Ω maximum dynamic impedance at 100 mA test current, and 7.5 A maximum surge current (8.3 ms half-sine). It operates from –65 °C to +150 °C and is used for precision voltage reference and overvoltage protection in power supply feedback loops.
For engineers reviewing the 1N5349/TR12 datasheet, 1N5349/TR12 pinout, 1N5349/TR12 application, or 1N5349/TR12 equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (25 °C/W junction-to-lead), steady-state power rating (5 W at TL < 25 °C), reverse leakage current (≤2.0 µA at 9.1 V), and RoHS-compliant plating options.
Technical Context
This device functions as a two-terminal voltage regulator in reverse-biased mode, maintaining stable output voltage across wide current (100 mA to 750 mA max IZM) and temperature ranges. Its low dynamic impedance (2.5 Ω) ensures minimal voltage deviation under load transients.
The 1N5349/TR12 uses a void-free thermosetting epoxy T-18 package with cathode band polarity marking, tin-lead or matte-tin plating per MIL-STD-750, and meets IPC/JEDEC J-STD-020B Level 1 moisture sensitivity-no dry pack required.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 12 V ±5% at 100 mA - defines regulated output level with tight tolerance for stable reference design |
| Power Dissipation | 5.0 W at 25 °C lead temperature - requires minimum 10 mm lead length from body for full rating |
| Dynamic Impedance (ZZ) | 2.5 Ω max at IZT = 100 mA - ensures low voltage variation under changing load current |
| Max Reverse Leakage (IR) | 2.0 µA at VR = 9.1 V - guarantees low standby power loss in high-impedance bias networks |
| Surge Current (IZSM) | 7.5 A peak (8.3 ms half-sine) - supports transient overvoltage clamping without failure |
| Thermal Resistance | 25 °C/W junction-to-lead - enables predictable thermal design when mounted with 3/8″ lead length |
| Operating Temp Range | –65 °C to +150 °C - suitable for industrial and automotive under-hood environments |
Pinout & Package
T-18 axial-leaded plastic package with cathode indicated by color 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 / low-voltage side in Zener mode | Connected to circuit ground or lower potential node during regulation |
| Cathode | Zener breakdown terminal / high-voltage side in Zener mode | Marked with band; connected to unregulated input or voltage rail requiring stabilization |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered Zener | Complies with industry-standard 1N53xxB mechanical and electrical definitions for interchangeability |
| ±5% voltage tolerance | Reduces calibration overhead in mid-precision reference circuits versus ±10% or ±20% variants |
| Level 1 moisture sensitivity | Eliminates baking requirement before PCB assembly, lowering manufacturing cost and cycle time |
| RoHS-compliant option (e3) | Enables compliance with EU environmental directives without performance trade-offs |
| Nonsensitive to ESD | Withstands handling per MIL-STD-750 Method 1020 - no special ESD controls needed in production |
Applications
| Switch-Mode Power Supply Feedback | Industrial Sensor Reference |
|---|---|
Use Scenario: Provides stable 12 V reference for optocoupler-based feedback in isolated DC-DC converters. IC Role / Device Role / Timing Role: Voltage regulation element in secondary-side error amplifier loop. Use Value: Maintains ±1% output regulation over line/load/temperature with 2.5 Ω ZZ limiting error signal drift. | Use Scenario: Supplies excitation voltage to bridge-based pressure transducers in factory automation systems. IC Role / Device Role / Timing Role: Precision bias source replacing higher-cost IC references where 5% tolerance suffices. Use Value: Delivers stable 12 V at <100 µA quiescent current, minimizing self-heating error in millivolt-level sensor outputs. |
| Overvoltage Clamp Protection | Programmable Logic Controller Input Conditioning |
Use Scenario: Clamps induced surges on 12 V control bus lines in motor drive cabinets. IC Role / Device Role / Timing Role: Transient voltage suppression element shunting excess energy to ground. Use Value: Withstands 7.5 A 8.3 ms surges without degradation, protecting downstream logic from >15 V transients. | Use Scenario: Regulates and conditions 24 V field input to PLC digital input modules. IC Role / Device Role / Timing Role: Pre-regulator stage reducing voltage to safe logic levels before opto-isolator input. Use Value: Enables robust operation across –65 °C to +150 °C ambient, meeting industrial PLC environmental specs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5349B | No TR12 tape-and-reel packaging; bulk or ammo pack only | Lacks automated SMT placement support; suited for through-hole prototyping or low-volume hand assembly | Select 1N5349B when reel packaging is unnecessary and manual assembly is preferred |
| MMBZ5242B | SOT-23 surface-mount package; 500 mW rating; same 12 V ±5% VZ | Not interchangeable due to 10× lower power rating and different thermal path; limited to low-current biasing | Choose MMBZ5242B only for space-constrained, low-power signal conditioning-not for 5 W regulation |
Compared with 1N5349B and MMBZ5242B, the 1N5349/TR12 uniquely combines JEDEC-standard axial packaging, 5 W dissipation capability, and tape-and-reel delivery for high-reliability through-hole production-making it optimal for industrial power supply and protection designs requiring proven thermal performance and automated assembly compatibility.
Availability
1N5349/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, sensor excitation circuits, overvoltage protection systems, and programmable logic controller input conditioning requiring stable component supply and long-term manufacturability.
Supply support for 1N5349/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 1N53xxB series was designed specifically for ruggedized voltage regulation in harsh-environment power systems, emphasizing thermal robustness, surge resilience, and long-term parametric stability under extended temperature cycling.
FAQ
What is the Zener voltage tolerance for 1N5349/TR12?
The 1N5349/TR12 has a ±5% Zener voltage tolerance, confirmed by its "B" suffix per Microsemi's datasheet. This means its measured VZ falls between 11.4 V and 12.6 V at 100 mA test current and 25 °C lead temperature. The tolerance is tighter than standard ±10% (A suffix) or ±20% (no suffix) variants, supporting more accurate regulation in feedback and reference applications.
Does 1N5349/TR12 require dry packing before PCB assembly?
No, the 1N5349/TR12 has IPC/JEDEC J-STD-020B Level 1 moisture sensitivity, meaning it may be stored and assembled without dry pack or baking. Its void-free epoxy T-18 package inherently limits moisture ingress, eliminating pre-reflow baking steps and reducing manufacturing risk and cost in high-volume production.
What is the maximum steady-state current for 1N5349/TR12 at room temperature?
The 1N5349/TR12 supports a maximum steady-state Zener current (IZM) of 750 mA at 25 °C lead temperature, calculated from P = 5 W and VZ = 12 V. This value assumes adequate heat sinking via 3/8″ (10 mm) lead length from the body; derating applies above 25 °C per Figure 1 in the Microsemi datasheet.
Can 1N5349/TR12 be used as a direct replacement for 1N5349B?
Yes, the 1N5349/TR12 is electrically and mechanically identical to 1N5349B except for packaging: TR12 denotes EIA-296 tape-and-reel format (12-inch reel), while 1N5349B is supplied in bulk or ammo pack. All electrical parameters-including 12 V ±5% VZ, 2.5 Ω ZZ, and 5 W rating-are identical per Microsemi documentation.
What is the forward voltage specification for 1N5349/TR12?
The forward voltage of 1N5349/TR12 is specified as ≤1.2 V at 1.0 A forward current, per Microsemi's Maximum Ratings table. This parameter is relevant only during forward conduction (e.g., accidental polarity reversal or transient crowbar scenarios); in normal Zener operation, the device is reverse-biased and conducts only leakage current until breakdown.
1N5349/TR12 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- T-18, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 12 V
- Tolerance:
- ±20%
- Power - Max:
- 5 W
- Impedance (Max) (Zzt):
- 2.5 Ohms
- Current - Reverse Leakage @ Vr:
- 2 µA @ 8.6 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 1 A
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- T-18
1N5349/TR12 FAQ
1.How can I place an order for 1N5349/TR12 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5349/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 1N5349/TR12 reliable?
The price and inventory of 1N5349/TR12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5349/TR12 is usually 5 days.
3.What payment methods are accepted for 1N5349/TR12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5349/TR12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5349/TR12?
1N5349/TR12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5349/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 1N5349/TR12?
For technical support, including 1N5349/TR12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5349/TR12 requirements.
6.How does Aetrix verify that 1N5349/TR12 is sourced from the original manufacturer or authorized distributors?
All 1N5349/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 1N5349/TR12 meets industry standards.
7.What is the process for return or replacement of 1N5349/TR12?
All 1N5349/TR12 units undergo pre-shipment inspection (PSI). If there is an issue with 1N5349/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 1N5349/TR12 part is unused and in its original packaging.
Return procedure for 1N5349/TR12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5349/TR12 Tags
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