Schottky Barrier Diodes Extremely Fast Switching Speed Low Forward Voltage # BAS70LT1G Schottky Barrier Diode Technical Documentation
Manufacturer : ON Semiconductor
## 1. Application Scenarios
### Typical Use Cases
The BAS70LT1G is a dual series-connected Schottky barrier diode array commonly employed in:
High-Frequency Rectification
- Switching power supply output rectification (up to 200 kHz)
- DC-DC converter circuits
- Freewheeling diode applications in buck/boost converters
- RF detection circuits in communication systems
Signal Processing
- Signal clamping and limiting circuits
- High-speed switching applications
- Logic gate protection
- Sample-and-hold circuits
Protection Circuits
- ESD protection for sensitive IC inputs
- Reverse polarity protection
- Voltage spike suppression
- Input/output port protection
### Industry Applications
Consumer Electronics
- Smartphones and tablets (power management, USB protection)
- Portable devices (battery charging circuits)
- LCD/LED displays (backlight driver circuits)
- Audio/video equipment (signal conditioning)
Automotive Systems
- Infotainment systems
- Body control modules
- Sensor interface protection
- Low-power DC motor control
Industrial Control
- PLC I/O protection
- Sensor signal conditioning
- Low-power relay drivers
- Industrial communication interfaces
Telecommunications
- Network equipment port protection
- Base station power supplies
- Fiber optic transceivers
### Practical Advantages and Limitations
Advantages:
- Low Forward Voltage : Typically 0.35V at 1mA, reducing power losses
- Fast Switching Speed : <4ns recovery time, suitable for high-frequency applications
- Low Capacitance : 2pF typical, minimizing signal distortion
- Compact Package : SOT-23-3 saves board space
- High Temperature Operation : -65°C to +150°C junction temperature range
- Series Connection : Two diodes in series simplify bi-directional protection circuits
Limitations:
- Limited Current Handling : 70mA continuous forward current per diode
- Voltage Constraints : 70V reverse voltage maximum
- Thermal Considerations : Small package limits power dissipation
- Not Suitable for High Power : Limited to low-current applications
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Thermal Management Issues
- Problem : Overheating in continuous high-current applications
- Solution : Limit continuous current to 50mA maximum, provide adequate copper pour for heat dissipation
Reverse Recovery Concerns
- Problem : Assumed zero reverse recovery current (not entirely true for Schottky diodes)
- Solution : Account for small reverse current during fast switching transitions
ESD Protection Limitations
- Problem : Inadequate protection against high-energy ESD events
- Solution : Implement additional TVS diodes for robust ESD protection in harsh environments
Voltage Drop Miscalculations
- Problem : Underestimating forward voltage at higher currents
- Solution : Use Vf vs If curves from datasheet for accurate voltage drop calculations
### Compatibility Issues with Other Components
Microcontroller Interfaces
- Compatible with 3.3V and 5V logic families
- Ensure diode forward voltage doesn't interfere with logic thresholds
- Watch for leakage current affecting high-impedance inputs
Power Supply Integration
- Works well with switching regulators up to 200 kHz
- Compatible with LDO regulators for reverse protection
- May require current limiting with high-capacitance loads
Analog Circuit Considerations
- Low capacitance minimizes impact on high-frequency signals
- Temperature coefficient of Vf (-1.8mV/°C) affects precision circuits
- Matching considerations for differential pairs
### PCB Layout Recommendations
Power and Ground Routing
- Use wide traces for anode/cathode connections
- Place decoupling capacitors close
