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Microchip Technology 1N5349/TR8
- Part No.:
- 1N5349/TR8
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- T-18, Axial
- Datasheet:
-
1N5349/TR8.pdf
- Description:
- DIODE ZENER 12V 5W T18
- Quantity:
- Payment:
- Shipping:
Inventory:2,985
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Product details
Overview
1N5349/TR8 from Microsemi is a 5 W axial-leaded silicon Zener diode with nominal regulation voltage of 12 V, ±5% tolerance (B suffix), 2.5 Ω maximum dynamic impedance at 100 mA test current, 75 mA maximum Zener current (IZM), and 0.25 V maximum voltage regulation (ΔVZ) across 10–50% IZM. It regulates voltage in power supply reference and overvoltage protection circuits.
For engineers reviewing the 1N5349/TR8 datasheet, 1N5349/TR8 pinout, 1N5349/TR8 application, or 1N5349/TR8 equivalent, this page delivers verified electrical specs, thermal derating behavior, JEDEC T-18 package details, RoHS-compliant plating, and validated alternatives for stable 12 V reference design.
Technical Context
This Zener operates in reverse breakdown to maintain stable 12 V output across wide current (10–75 mA) and temperature (−65°C to +150°C) ranges. Its 25 °C/W junction-to-lead thermal resistance enables 5 W dissipation with 3/8″ lead length heat sinking.
It features cathode band polarity marking, 1.2 V max forward voltage at 1 A, and 18.7 A surge current rating for 8.3 ms half-sine transients. 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) | 12 V ±5% at 100 mA - defines stable regulation point under nominal bias |
| Power Dissipation (PD) | 5.0 W at 25°C lead temperature - sets absolute thermal limit before derating |
| Dynamic Impedance (ZZ) | 2.5 Ω max at IZT = 100 mA - determines output voltage variation under load current changes |
| Max Zener Current (IZM) | 75 mA - maximum continuous reverse current before exceeding 5 W at VZ |
| Voltage Regulation (ΔVZ) | 0.25 V max - difference between VZ measured at 10% and 50% of IZM |
| Surge Current (IZSM) | 18.7 A peak (8.3 ms half-sine) - quantifies transient overvoltage handling capability |
| Thermal Resistance (RθJL) | 25 °C/W junction-to-lead - enables thermal design using lead length as heatsink |
Pinout & Package
Package: JEDEC T-18 axial-leaded plastic case (void-free UL94V-0 epoxy), 0.7 g weight, 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 | Non-banded end | Connected to lower-potential node; reverse-biased operation requires anode grounded or at lower voltage than cathode |
| Cathode | Banded end | Connected to regulated output node; must be held at higher potential than anode to enable Zener conduction |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered Zener | Complies with industry-standard 1N53xxB mechanical and electrical definitions for interchangeability |
| ±5% voltage tolerance | Ensures 11.4–12.6 V regulation window without post-manufacturing trimming |
| Level 1 moisture sensitivity | Eliminates dry-pack requirement and bake-out prior to PCB assembly |
| Nonsensitive to ESD | Rated per MIL-STD-750 Method 1020 - no special handling needed during board assembly |
| RoHS-compliant option | e3 suffix indicates lead-free plating compatible with Pb-free reflow profiles |
Applications
| Switching Power Supply Reference | Overvoltage Protection Clamp |
|---|---|
Use Scenario: Stabilizing feedback voltage in isolated DC-DC converter secondary-side error amplifiers. IC Role / Device Role / Timing Role: Precision voltage reference providing stable 12 V input to optocoupler or TL431 comparator. Use Value: Maintains ±1% output regulation despite line/load variations due to low ΔVZ (0.25 V) and stable ZZ (2.5 Ω). | Use Scenario: Clamping transient spikes on 12 V rail caused by inductive switching or ESD events. IC Role / Device Role / Timing Role: Shunt protector diverting excess energy to ground when rail exceeds 12.6 V (VZ + tolerance). Use Value: Absorbs 18.7 A surge (8.3 ms) without failure, preventing downstream IC damage. |
| Linear Regulator Pre-regulation | Industrial Sensor Excitation |
Use Scenario: Reducing input-to-output differential in 7812-based linear regulators to minimize thermal stress. IC Role / Device Role / Timing Role: Pre-regulator dropping unregulated 15–18 V input to ~12 V before LDO stage. Use Value: Enables 5 W dissipation at 3/8″ lead length, lowering 7812 junction temperature by >20°C. | Use Scenario: Providing stable excitation voltage to bridge-based pressure or strain sensors in harsh environments. IC Role / Device Role / Timing Role: Low-drift 12 V reference source with −65°C to +150°C operating range. Use Value: Delivers <0.25 V regulation shift across full temperature range, preserving sensor accuracy. |
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 TR8 tape-and-reel packaging; bulk or ammo pack only | Lacks automated pick-and-place compatibility; requires manual or vibratory feeding | Select 1N5349/TR8 for SMT production lines; choose 1N5349B for prototyping or low-volume hand assembly |
| MMBZ5242B | Surface-mount SOT-23 package; 0.35 W rating; 12 V ±5%; 10 Ω ZZ | Not suitable for 5 W continuous dissipation; limited to low-power bias/reference roles | Use MMBZ5242B only where space-constrained PCBs prohibit axial leads and power <0.35 W suffices |
Compared with 1N5349B and MMBZ5242B, the 1N5349/TR8 uniquely combines JEDEC T-18 mechanical standardization, 5 W thermal capability, tape-and-reel automation support, and industrial temperature range - making it the sole choice for high-reliability 12 V shunt regulation in volume production.
Availability
1N5349/TR8 is available at Aetrix Electronics and suitable for switching power supply references, overvoltage protection clamps, and industrial sensor excitation requiring stable component supply across automotive, industrial control, and telecom infrastructure programs.
Supply support for 1N5349/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 ruggedized, JEDEC-standard 5 W Zener platform for mission-critical voltage regulation where thermal stability, surge immunity, and long-term parametric consistency are mandatory.
FAQ
What is the Zener voltage tolerance of the 1N5349/TR8?
The 1N5349/TR8 has a ±5% Zener voltage tolerance, confirmed by its "B" suffix per Microsemi's datasheet. This means its regulation voltage falls within 11.4 V to 12.6 V at 100 mA test current and 25°C lead temperature. The tolerance is guaranteed across the full operating temperature range of −65°C to +150°C, and the 1N5349/TR8 is not rated for tighter tolerances like ±1% or ±2% unless explicitly marked with C or D suffixes.
Can the 1N5349/TR8 be used in surface-mount designs?
No - the 1N5349/TR8 uses a JEDEC T-18 axial-leaded package and is not a surface-mount device. For SMT equivalents, Microsemi offers the SMBJ5349B (DO-214AA) and SMBG5349B (DO-214AB), both rated for 5 W but requiring different PCB footprints and thermal layout. The 1N5349/TR8 must be mounted through-hole with ≥3/8″ (10 mm) lead length from body for full 5 W rating.
What is the maximum steady-state power dissipation of the 1N5349/TR8 on a standard FR4 PCB?
When mounted on a standard FR4 PCB (1 oz copper, 4 mm² pads, 1 mm track width, 25 mm length), the 1N5349/TR8 has a steady-state power rating of 1.47 W at 25°C ambient temperature. This is derived from its 85°C/W junction-to-ambient thermal resistance. Exceeding this value without additional heatsinking risks thermal runaway; full 5 W operation requires lead-length heatsinking per JEDEC T-18 mounting guidelines.
Does the 1N5349/TR8 require dry packing or baking before PCB assembly?
No - the 1N5349/TR8 has IPC/JEDEC J-STD-020B moisture sensitivity level (MSL) 1, meaning it is not moisture-sensitive and requires no dry pack, vacuum sealing, or pre-assembly baking. This simplifies handling and eliminates moisture-related popcorning risk during reflow soldering, even with standard Pb-free profiles up to 260°C for 10 seconds.
What does the "TR8" suffix indicate in 1N5349/TR8?
The "TR8" suffix denotes tape-and-reel packaging per EIA-296 standard, with 8 mm carrier tape width and component orientation optimized for automated pick-and-place equipment. This distinguishes it from bulk or ammo-pack versions (e.g., 1N5349B) and ensures compatibility with high-speed SMT assembly lines. The "TR8" does not affect electrical or thermal specifications - those remain identical to the base 1N5349B part.
1N5349/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:
- ±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/TR8 FAQ
1.How can I place an order for 1N5349/TR8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5349/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 1N5349/TR8 reliable?
The price and inventory of 1N5349/TR8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5349/TR8 is usually 5 days.
3.What payment methods are accepted for 1N5349/TR8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5349/TR8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5349/TR8?
1N5349/TR8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5349/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 1N5349/TR8?
For technical support, including 1N5349/TR8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5349/TR8 requirements.
6.How does Aetrix verify that 1N5349/TR8 is sourced from the original manufacturer or authorized distributors?
All 1N5349/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 1N5349/TR8 meets industry standards.
7.What is the process for return or replacement of 1N5349/TR8?
All 1N5349/TR8 units undergo pre-shipment inspection (PSI). If there is an issue with 1N5349/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 1N5349/TR8 part is unused and in its original packaging.
Return procedure for 1N5349/TR8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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