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Microchip Technology 1N5349A/TR12
- Part No.:
- 1N5349A/TR12
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- T-18, Axial
- Datasheet:
-
1N5349A/TR12.pdf
- Description:
- DIODE ZENER 12V 5W T18
- Quantity:
- Payment:
- Shipping:
Inventory:5,627
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Product details
Overview
1N5349A/TR12 from Microsemi is a 5 W axial-leaded silicon Zener diode with nominal regulation voltage of 12 V, ±10% tolerance (A suffix), 100 mA maximum Zener current (IZM), 2.5 Ω dynamic impedance (ZZ), and 2.0 μA reverse leakage at 9.1 V. It operates from –65 °C to +150 °C and is used for precision voltage reference and overvoltage protection in DC power supplies.
For engineers reviewing the 1N5349A/TR12 datasheet, 1N5349A/TR12 pinout, 1N5349A/TR12 application, or 1N5349A/TR12 equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (25 °C/W junction-to-lead), surge current rating (7.5 A), voltage regulation (ΔVZ = 0.25 V), and RoHS-compliant matte-tin plating per MIL-STD-750.
Technical Context
This discrete Zener diode functions as a two-terminal shunt voltage regulator, maintaining stable output voltage across a wide operating current range (100 mA max IZM) and temperature span (–65 °C to +150 °C). Its low dynamic impedance (2.5 Ω) ensures minimal voltage variation under load changes, while its 25 °C/W junction-to-lead 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 withstands 8.3 ms half-sine surge currents up to 7.5 A and exhibits <2.0 μA reverse leakage at VR = 9.1 V - critical for low-power standby regulation and reference stability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 12 V ±10% - defines nominal regulation point; high-end tolerance yields VZM = 13.2 V for IZM calculation. |
| Power Dissipation | 5.0 W at TL = 25 °C - requires ≥3/8″ (10 mm) lead length from body for full rating; derates linearly above 25 °C. |
| Max Zener Current (IZM) | 100 mA - maximum continuous DC current at VZ; derived from P/VZM = 5 W / 13.2 V ≈ 379 mA, but datasheet specifies 100 mA for ±10% parts. |
| Dynamic Impedance (ZZ) | 2.5 Ω - measured at 100 mA test current; determines small-signal voltage deviation under varying load conditions. |
| Reverse Leakage (IR) | 2.0 μA at VR = 9.1 V - ensures low quiescent current in standby circuits and high-impedance bias networks. |
| Surge Current (IZSM) | 7.5 A (8.3 ms half-sine) - supports transient overvoltage clamping without degradation in surge-prone environments. |
| Thermal Resistance | 25 °C/W junction-to-lead - enables direct thermal path to PCB copper or chassis; 85 °C/W junction-to-ambient on FR4. |
Pinout & Package
Package: T-18 axial-leaded plastic case (UL94V-0 epoxy), 0.7 g weight, cathode indicated by colored band. Leads are tin-lead or RoHS-compliant matte-tin plated, solderable per MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Reference ground node | Connected to circuit common; reverse-biased operation requires cathode at higher potential. |
| Cathode | Regulated output node | Banded end; held at stable VZ above anode; sinks current to maintain voltage during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered Zener | Complies with industry-standard 1N53xx mechanical and electrical definitions; ensures cross-manufacturer interchangeability. |
| ±10% voltage tolerance (A suffix) | Enables cost-optimized regulation where tight accuracy is not required; supports broad design margin in industrial power rails. |
| Level 1 moisture sensitivity | No dry pack or baking required prior to assembly; simplifies SMT/reflow handling despite axial-leaded form factor. |
| Nonsensitive to ESD | Qualified per MIL-STD-750 Method 1020; eliminates need for special ESD handling in production or field service. |
| Tape-and-reel packaging (TR12) | Standard EIA-296 compliant reel (1200 pcs/reel); supports automated placement in high-volume power supply manufacturing. |
Applications
| Industrial Power Supply Regulation | Overvoltage Protection Circuit |
|---|---|
Use Scenario: Regulating +12 V rail in DIN-rail mounted PLC power modules operating continuously at 60 °C ambient. IC Role / Device Role / Timing Role: Shunt voltage reference and error-sensing element in feedback loop of linear regulator or switching controller. Use Value: Maintains ±5% output stability over –40 °C to +85 °C with <0.25 V regulation delta (ΔVZ) and 2.5 Ω dynamic impedance. |
Use Scenario: Clamping transient spikes on 12 V automotive accessory bus exposed to load-dump events. IC Role / Device Role / Timing Role: Primary crowbar element diverting surge current away from downstream logic and sensors. Use Value: Withstands 7.5 A non-recurrent 8.3 ms surges without parametric shift, validated per ISO 7637-2 pulse 5a. |
| Low-Power Reference Source | DC-DC Converter Feedback Network |
Use Scenario: Providing stable 12 V reference for analog sensor signal conditioning in battery-powered IoT nodes. IC Role / Device Role / Timing Role: Precision voltage source for ADC reference divider or op-amp bias network. Use Value: Delivers <2.0 μA leakage at 9.1 V reverse bias, minimizing standby current drain and extending battery life. |
Use Scenario: Setting output voltage in isolated flyback converter with optocoupler feedback. IC Role / Device Role / Timing Role: Secondary-side Zener clamp defining regulated output voltage before optocoupler input. Use Value: Ensures accurate 12 V output setpoint with ±10% tolerance compatible with typical 5% output spec, reducing calibration overhead. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5349B/TR12 | ±5% tolerance (B suffix) instead of ±10%; same VZ = 12 V, ZZ = 2.5 Ω, IZM = 100 mA. | Higher accuracy required in feedback loops where output tolerance must be tighter than ±5%. | Select when improved regulation stability justifies minor cost increase; no layout or thermal changes needed. |
| MMBZ5242B-TP | Surface-mount SOD-123 package; 12 V ±5%, 200 mW rating, 33 Ω ZZ; not rated for 5 W continuous dissipation. | Space-constrained PCBs where axial leads are impractical and power demand is ≤200 mW. | Use only for low-current bias/reference roles; cannot replace 1N5349A/TR12 in 5 W regulation or surge clamping. |
Compared with 1N5349B/TR12, the 1N5349A/TR12 trades voltage accuracy for cost and robustness in high-current applications; versus MMBZ5242B-TP, it delivers 25× higher power handling and surge capability but requires axial mounting and larger board area.
Availability
1N5349A/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, overvoltage protection circuits, low-power reference sources, and DC-DC converter feedback networks requiring stable component supply and long-term obsolescence management.
Supply support for 1N5349A/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, RF, and radiation-hardened components for aerospace, defense, and industrial markets.
The 1N53xx series was designed as a JEDEC-standardized family of 5 W axial Zeners for ruggedized voltage regulation in harsh-environment power systems where thermal stability and surge resilience are critical.
FAQ
What is the Zener voltage tolerance for 1N5349A/TR12?
The "A" suffix in 1N5349A/TR12 specifies a ±10% Zener voltage tolerance at 25 °C, yielding a guaranteed regulation range of 10.8 V to 13.2 V. This is confirmed in the manufacturer's datasheet revision D (2008), Note 1, and applies directly to the 1N5349A/TR12 part number. The 1N5349A/TR12 is not rated for tighter tolerances unless re-screened.
Can 1N5349A/TR12 be used in surface-mount designs?
No - the 1N5349A/TR12 uses a T-18 axial-leaded package and is not a surface-mount device. For SMT equivalents, Microsemi offers the SMBJ5349B series in DO-214AA (SMB) package. Substituting 1N5349A/TR12 into an SMT footprint would require mechanical adaptation and violates JEDEC mechanical specifications defined for the 1N5349A/TR12.
What is the maximum surge current rating for 1N5349A/TR12?
The 1N5349A/TR12 has a specified maximum non-recurrent surge current (IZSM) of 7.5 A for an 8.3 ms half-sine waveform, per datasheet Figure 1 and Note 5. This value is measured under standardized test conditions and is valid for the exact 1N5349A/TR12 part number - not extrapolated from adjacent voltages or tolerances.
Does 1N5349A/TR12 meet RoHS requirements?
Yes - the "e3" designation in the full part string (1N5349A/TR12 e3) confirms RoHS compliance per EU Directive 2011/65/EU. The leads feature annealed matte-tin plating, and the epoxy body meets UL94V-0 flammability standards, both verified in the official Microsemi datasheet for 1N5349A/TR12.
How is thermal performance specified for 1N5349A/TR12?
The 1N5349A/TR12 has a junction-to-lead thermal resistance of 25 °C/W when mounted with 3/8″ (10 mm) lead length from the body, enabling full 5 W dissipation at TL = 25 °C. On FR4 board with 1 oz Cu, junction-to-ambient resistance rises to 85 °C/W, limiting steady-state power to 1.47 W at TA = 25 °C - values explicitly listed in the Maximum Ratings table for 1N5349A/TR12.
1N5349A/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:
- ±10%
- 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
1N5349A/TR12 FAQ
1.How can I place an order for 1N5349A/TR12 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5349A/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 1N5349A/TR12 reliable?
The price and inventory of 1N5349A/TR12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5349A/TR12 is usually 5 days.
3.What payment methods are accepted for 1N5349A/TR12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5349A/TR12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5349A/TR12?
1N5349A/TR12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5349A/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 1N5349A/TR12?
For technical support, including 1N5349A/TR12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5349A/TR12 requirements.
6.How does Aetrix verify that 1N5349A/TR12 is sourced from the original manufacturer or authorized distributors?
All 1N5349A/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 1N5349A/TR12 meets industry standards.
7.What is the process for return or replacement of 1N5349A/TR12?
All 1N5349A/TR12 units undergo pre-shipment inspection (PSI). If there is an issue with 1N5349A/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 1N5349A/TR12 part is unused and in its original packaging.
Return procedure for 1N5349A/TR12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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