Dual N-Channel Logic Level PowerTrench MOSFET# FDS6990A_NL Technical Documentation
## 1. Application Scenarios
### Typical Use Cases
The FDS6990A_NL is a dual N-channel PowerTrench® MOSFET commonly employed in:
Power Management Circuits
- DC-DC buck/boost converters (1-5A output range)
- Voltage regulator modules (VRMs) for processor power delivery
- Load switch applications with soft-start capabilities
- Power OR-ing circuits for redundant power supplies
Motor Control Applications
- Brushed DC motor H-bridge configurations
- Stepper motor driver circuits
- Small motor drives (<100W) in automotive and industrial systems
Switching Power Supplies
- Synchronous rectification in SMPS (up to 200kHz)
- Primary-side switching in low-power flyback converters
- Secondary-side synchronous rectification
### Industry Applications
Consumer Electronics
- Laptop computers (CPU/GPU power delivery)
- Gaming consoles (power distribution systems)
- LCD/LED TV power management
- Portable device battery management systems
Automotive Systems
- Electronic control units (ECUs)
- Power window/lock controllers
- LED lighting drivers
- Infotainment system power management
Industrial Equipment
- PLC I/O modules
- Small motor drives
- Power distribution boards
- Test and measurement equipment
### Practical Advantages and Limitations
Advantages:
- Low RDS(ON) : 9.5mΩ typical at VGS = 10V enables high efficiency
- Fast Switching : 15ns typical rise time supports high-frequency operation
- Dual Configuration : Two independent MOSFETs in single package saves board space
- Low Gate Charge : 25nC typical reduces gate drive requirements
- AEC-Q101 Qualified : Suitable for automotive applications
Limitations:
- Voltage Constraint : 30V maximum VDS limits high-voltage applications
- Thermal Performance : SO-8 package thermal resistance (40°C/W) requires careful thermal management
- Current Handling : 6.7A continuous current per MOSFET may require paralleling for high-current applications
- Gate Sensitivity : Maximum VGS of ±20V requires proper gate drive protection
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Gate Drive Issues
- Pitfall : Insufficient gate drive current causing slow switching and increased losses
- Solution : Use dedicated gate driver ICs capable of 2-3A peak current
- Pitfall : Gate oscillation due to layout parasitics
- Solution : Implement series gate resistors (2.2-10Ω) close to MOSFET gate
Thermal Management
- Pitfall : Inadequate heatsinking leading to thermal runaway
- Solution : Use thermal vias, adequate copper area (≥100mm² per MOSFET), and consider external heatsinks for high-power applications
- Pitfall : Poor thermal coupling between dual MOSFETs
- Solution : Distribute power evenly between both channels when possible
Protection Circuits
- Pitfall : Missing overcurrent protection
- Solution : Implement current sensing with appropriate shutdown mechanisms
- Pitfall : Absence of undervoltage lockout (UVLO)
- Solution : Add UVLO circuitry to prevent operation below recommended VGS
### Compatibility Issues with Other Components
Gate Driver Compatibility
- Compatible with most logic-level gate drivers (3.3V/5V capable)
- Ensure driver output voltage does not exceed maximum VGS rating
- Watch for shoot-through with half-bridge configurations
Controller IC Considerations
- Works well with PWM controllers up to 500kHz
- Compatible with most synchronous buck controllers
- May require external bootstrap circuits for high-side operation
Passive Component Selection
- Bootstrap capacitors: 0
