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Microchip Technology 1N5349B/TR8
- Part No.:
- 1N5349B/TR8
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- T-18, Axial
- Datasheet:
-
1N5349B/TR8.pdf
- Description:
- DIODE ZENER 12V 5W T18
- Quantity:
- Payment:
- Shipping:
Inventory:990
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Product details
Overview
1N5349B/TR8 from Microsemi is a 5 W axial-leaded silicon Zener diode with nominal regulation voltage of 12 V, ±5% tolerance (B suffix), 100 mA maximum Zener test current (IZT), 2.5 Ω maximum dynamic impedance (ZZ), and 7.5 A maximum surge current (IZSM). It operates across –65 °C to +150 °C and is used for precision voltage reference and overvoltage protection in DC power supplies.
For engineers reviewing the 1N5349B/TR8 datasheet, 1N5349B/TR8 pinout, 1N5349B/TR8 application, or 1N5349B/TR8 equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (25 °C/W junction-to-lead), steady-state power rating at lead temperature, reverse leakage current at 8.6 V (≤2 µA), and RoHS-compliant matte-tin plating per MIL-STD-750.
Technical Context
This Zener diode functions as a two-terminal voltage regulator in reverse-biased mode, maintaining stable output voltage across wide operating current (100 mA IZT) and temperature ranges. Its low dynamic impedance (2.5 Ω) ensures minimal voltage variation under load changes, and its 25 °C/W thermal resistance enables reliable 5 W dissipation with 3/8″ lead length heat sinking.
The device features cathode band polarity marking, UL94V-0 void-free epoxy encapsulation, and moisture sensitivity level 1 (no dry pack required). It supports tape-and-reel packaging (TR8 suffix) and meets MIL-PRF-19500 screening options when prefixed with MQ/MX/MV.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 12 V ±5% - precise regulation point for 12 V rail stabilization |
| Test Current (IZT) | 100 mA - defined operating point for VZ measurement and impedance characterization |
| Dynamic Impedance (ZZ) | 2.5 Ω max - low AC resistance ensures tight voltage regulation under varying load |
| Max Surge Current (IZSM) | 7.5 A (8.3 ms half-sine) - withstands transient overloads without degradation |
| Reverse Leakage (IR) | ≤2 µA at 8.6 V - negligible standby current in regulation mode |
| Thermal Resistance (RθJL) | 25 °C/W junction-to-lead - enables full 5 W power dissipation with minimal lead-length heatsinking |
| Operating Temperature | –65 °C to +150 °C - suitable for industrial and automotive under-hood environments |
Pinout & Package
Package: Axial-leaded T-18 plastic case (JEDEC DO-201AD), void-free UL94V-0 epoxy body, tin-lead or RoHS-compliant matte-tin plated leads, cathode indicated by color band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference | Connected to lower-potential node; reverse bias applied across anode–cathode for regulation |
| Cathode | Zener regulation terminal | Banded end; connected to higher-potential node; defines regulated output voltage referenced to anode |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered 5 W Zener | Industry-standard footprint and reliability for high-power voltage reference |
| ±5% voltage tolerance (B suffix) | Guaranteed regulation accuracy without post-manufacture trimming |
| Moisture Sensitivity Level 1 | No dry-pack requirement - simplifies handling and eliminates bake-out before assembly |
| Nonsensitive to ESD (MIL-STD-750 Method 1020) | Robust handling during manual and automated assembly without special precautions |
| RoHS-compliant (e3 suffix) | Meets global environmental compliance without performance trade-offs |
Applications
| DC Power Supply Regulation | Overvoltage Protection Circuit |
|---|---|
Use Scenario: Stabilizing unregulated 15 V input to deliver clean 12 V for analog sensor biasing in industrial PLC modules. IC Role / Device Role / Timing Role: Two-terminal shunt regulator providing fixed reference voltage independent of load current variations. Use Value: Maintains ≤0.44 V regulation error (ΔVZ) across 10–50% of IZM, ensuring sensor accuracy within datasheet limits. |
Use Scenario: Clamping transient spikes on 12 V CAN bus power rail during load dump events in automotive ECUs. IC Role / Device Role / Timing Role: Fast-acting voltage clamp absorbing surge energy up to 7.5 A peak (8.3 ms). Use Value: Prevents downstream IC damage by limiting rail voltage to ≤12.5 V during 100 V/100 ms transients. |
| Reference Voltage Source | Current-Limited Bias Generator |
Use Scenario: Providing stable 12 V reference for ADC voltage dividers in medical patient monitoring equipment. IC Role / Device Role / Timing Role: Precision voltage source with low dynamic impedance (2.5 Ω) minimizing reference drift under varying divider loading. Use Value: Enables <0.02% reference error contribution to overall system accuracy at 100 mA operating point. |
Use Scenario: Generating controlled 10 mA bias current for photodiode amplifiers in optical smoke detectors. IC Role / Device Role / Timing Role: Constant-current sink formed with series resistor, leveraging sharp Zener knee at 12 V. Use Value: Delivers stable bias despite ±15% supply variation due to 0.25 V voltage regulation (ΔVZ) specification. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5349B (bulk) | Identical electrical specs; differs only in packaging (bulk vs. TR8 tape-and-reel) | No difference in circuit function or layout; reel format enables automated pick-and-place | Select 1N5349B/TR8 for SMT production lines requiring tape-and-reel feed; choose bulk for hand-soldered prototypes or low-volume repair. |
| MMBZ5242B (SOT-23) | Same 12 V ±5%, but 0.5 W rating, 35 Ω ZZ, surface-mount package | Not suitable for 5 W continuous dissipation; limited to low-power bias/reference roles | Choose MMBZ5242B only where board space is constrained and power <0.3 W; retain 1N5349B/TR8 for full 5 W capability and thermal robustness. |
Compared with 1N5349B (bulk) and MMBZ5242B, the 1N5349B/TR8 delivers identical regulation performance with factory-verified tape-and-reel compatibility for high-throughput assembly, while offering 10× the power handling and 14× lower dynamic impedance versus the SOT-23 alternative.
Availability
1N5349B/TR8 is available at Aetrix Electronics and suitable for DC power supply regulation, overvoltage protection circuits, and precision reference voltage sources requiring stable component supply across industrial, automotive, and medical electronics programs.
Supply support for 1N5349B/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, RF, and timing solutions for aerospace, defense, and industrial markets.
The 1N53xxB series was designed as a JEDEC-standardized family of 5 W axial Zeners to replace legacy 1N47xx devices with improved thermal performance, tighter tolerances, and enhanced surge robustness for mission-critical power regulation.
FAQ
What is the Zener voltage tolerance of the 1N5349B/TR8?
The 1N5349B/TR8 has a nominal Zener voltage of 12 V with a tolerance of ±5%, as indicated by the "B" suffix per Microsemi's documentation. This tolerance is guaranteed over the full operating temperature range (–65 °C to +150 °C) and applies to all units in the 1N5349B/TR8 production lot without binning or sorting.
Does the 1N5349B/TR8 require dry packing before PCB assembly?
No, the 1N5349B/TR8 has IPC/JEDEC J-STD-020B moisture sensitivity level 1, meaning it does not absorb sufficient moisture during standard factory handling to require dry packing or baking prior to reflow soldering. This eliminates process steps and reduces risk of popcorn cracking during assembly.
What is the maximum continuous power dissipation for the 1N5349B/TR8 at 25 °C ambient?
The 1N5349B/TR8 is rated for 5.0 W continuous power dissipation at 25 °C lead temperature (TL), measured 3/8″ (10 mm) from the body. When mounted on a standard FR4 PCB (1 oz Cu, 4 mm² pads), its steady-state power drops to 1.47 W at 25 °C ambient due to higher junction-to-ambient thermal resistance (85 °C/W).
Can the 1N5349B/TR8 be used as a direct replacement for older 1N4742A Zeners?
The 1N5349B/TR8 provides the same 12 V ±5% regulation as the 1N4742A but with higher power (5 W vs. 1 W), lower dynamic impedance (2.5 Ω vs. ~9 Ω), and superior surge capability (7.5 A vs. ~1.5 A). It is not pin-compatible due to axial T-18 vs. DO-41 packaging, requiring PCB layout change, but offers significant performance upgrades in existing designs.
What is the reverse leakage current specification for the 1N5349B/TR8?
The 1N5349B/TR8 specifies a maximum reverse leakage current (IR) of 2 µA at 8.6 V (the rated VR for B-suffix parts), measured at 25 °C. This low leakage ensures minimal quiescent current draw in regulation mode and supports stable operation in battery-powered or low-power systems.
1N5349B/TR8 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:
- ±5%
- 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
1N5349B/TR8 FAQ
1.How can I place an order for 1N5349B/TR8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5349B/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 1N5349B/TR8 reliable?
The price and inventory of 1N5349B/TR8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5349B/TR8 is usually 5 days.
3.What payment methods are accepted for 1N5349B/TR8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5349B/TR8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5349B/TR8?
1N5349B/TR8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5349B/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 1N5349B/TR8?
For technical support, including 1N5349B/TR8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5349B/TR8 requirements.
6.How does Aetrix verify that 1N5349B/TR8 is sourced from the original manufacturer or authorized distributors?
All 1N5349B/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 1N5349B/TR8 meets industry standards.
7.What is the process for return or replacement of 1N5349B/TR8?
All 1N5349B/TR8 units undergo pre-shipment inspection (PSI). If there is an issue with 1N5349B/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 1N5349B/TR8 part is unused and in its original packaging.
Return procedure for 1N5349B/TR8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5349B/TR8 Tags
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