1N5349BRLG Zener Diode: Premium 12V, 5W Voltage Regulator by onsemi

The 1N5349BRLG from onsemi is a high-reliability, industrial-grade Zener diode designed for precision voltage regulation. With its 12V nominal voltage, 5W power dissipation, and rugged axial package, this diode is engineered to deliver stable performance in demanding applications across automotive, industrial, and consumer electronics.

In-Depth Technical Specifications

Precision Voltage Regulation

• Nominal Zener Voltage (Vz): 12V 5% tolerance ensures consistent regulation even under load variations
• Dynamic Impedance: Just 2.5 (max) at test current minimizes output fluctuations
• Reverse Leakage: Ultra-low 2 A @ 9.1V reduces power loss

Robust Power Handling

• 5W Power Rating: Handles higher currents than standard Zeners (typical 1.3W)
• Thermal Performance: T-18 axial package optimizes heat dissipation
• Forward Characteristics: 1.2V drop @ 1A minimizes conduction losses

Extreme Environment Operation

• Wide Temperature Range: -65 C to +200 C ensures reliability in harsh conditions
• Mechanical Durability: Axial leaded package withstands vibration and thermal cycling

Comparative Advantages

When benchmarked against generic 12V Zeners, the 1N5349BRLG offers:

• 3.8 Higher Power Rating than standard 1.3W parts
• 50% Lower Impedance for better regulation
• Military-Grade Temperature Range (-65 C vs typical -55 C)

Application Circuits

1. Overvoltage Protection

Implement as a clamp diode across sensitive IC power inputs. The 5W rating handles substantial surge currents during transient events.

2. Voltage Reference

Use with current-limiting resistor to create stable 12V references for:

• ADC/DAC reference circuits
• Sensor calibration points
• Comparator threshold setting

3. Automotive Load Dump Protection

Its extended temperature range makes it ideal for protecting ECUs against vehicle electrical system transients.

Design Considerations

1. Heat Sinking: Derate power above 25 C ambient - use 3.5W max @ 100 C
2. Current Limiting: Always series resistor (R = (Vin - 12V)/Iload)
3. Board Layout: Keep leads short to minimize parasitic inductance

Why Engineers Choose 1N5349BRLG

This diode delivers three critical advantages:

1. Reliability: onsemi's automotive-grade manufacturing
2. Performance: Tight 5% tolerance with low impedance
3. Versatility: Suitable for both precision references and power protection

Purchasing Information

Available through authorized distributors with full traceability. Bulk packaging options for production quantities. Onsemi provides:

• Detailed SPICE models
• Application notes (AND9129/D)
• Reliability reports (AEC-Q101 qualified)

Upgrade your designs today with the 1N5349BRLG - the professional's choice for robust 12V regulation.