UNI-DIRECTIONAL GLASS PASSIVATED JUNCTION TRANSIENT VOLTAGE SUPPRESSOR 1500 WATTS, 6.8 THRU 200 VOLTS# 15SMC150A Technical Documentation
Manufacturer : VISHAY
Component Type : 15kV Transient Voltage Suppressor (TVS) Diode
Series : SMC (Surface Mount Case)
Configuration : Unidirectional
## 1. Application Scenarios
### Typical Use Cases
The 15SMC150A is primarily employed for robust transient voltage protection in high-voltage circuits. Typical applications include:
- Surge Protection : Safeguarding sensitive electronic components from voltage spikes up to 15kV
- Lightning Strike Mitigation : Protecting telecommunications and power line equipment from induced surges
- ESD Protection : Shielding high-impedance circuits from electrostatic discharge events
- Inductive Load Switching : Suppressing voltage transients from relay coils, motor windings, and solenoid valves
### Industry Applications
- Telecommunications : Base station equipment, DSL modems, and network interface cards
- Industrial Automation : PLC I/O modules, motor drives, and control systems
- Power Systems : Smart meters, power supplies, and grid monitoring equipment
- Automotive Electronics : EV charging systems, battery management, and onboard electronics
- Medical Equipment : Patient monitoring systems and diagnostic instruments
### Practical Advantages and Limitations
Advantages:
- High Surge Capacity : Capable of handling 1.5kW peak pulse power (10/1000μs waveform)
- Fast Response Time : Typically <1.0ps reaction to transient events
- Low Clamping Ratio : Provides effective voltage limiting during surge events
- Surface Mount Design : Enables automated assembly and compact PCB layouts
- Wide Temperature Range : Operational from -65°C to +150°C
Limitations:
- Voltage Specificity : Fixed 150V breakdown voltage limits design flexibility
- Power Dissipation : Continuous power handling limited to 5W
- Physical Size : SMC package (10.3mm × 9.1mm) may be large for space-constrained designs
- Unidirectional Operation : Only protects against positive voltage transients
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Pitfall 1: Improper Voltage Selection
- Issue : Selecting TVS with incorrect working voltage
- Solution : Ensure maximum continuous operating voltage (130V) exceeds normal circuit voltage by 10-15%
Pitfall 2: Inadequate Thermal Management
- Issue : Overheating during repeated surge events
- Solution : Implement proper PCB copper pours and consider heatsinking for high-surge environments
Pitfall 3: Incorrect Placement
- Issue : TVS located too far from protected components
- Solution : Place 15SMC150A as close as possible to the protected circuit or connector
### Compatibility Issues with Other Components
Power Supply Compatibility:
- Compatible with switching power supplies up to 130V DC
- May require series resistors with linear regulators to limit current
Microcontroller/MCU Interfaces:
- Excellent protection for high-voltage analog inputs
- Ensure clamping voltage (208V max) doesn't exceed protected component ratings
Communication Lines:
- Suitable for RS-485, CAN bus, and industrial Ethernet protection
- Consider bidirectional TVS for bidirectional communication lines
### PCB Layout Recommendations
Placement Strategy:
- Position immediately after connectors or entry points
- Minimize trace length between TVS and protected circuit (<25mm ideal)
Routing Guidelines:
- Use wide traces (≥1.5mm) for high-current surge paths
- Implement ground planes for optimal heat dissipation
- Avoid vias in the high-current surge path
Thermal Management:
- Utilize 2oz copper for power and ground planes
- Include thermal relief patterns for soldering while maintaining
